mirror of
https://github.com/intel/llvm.git
synced 2026-01-14 03:14:06 +08:00
8d5854ef09
Summary: Add option `-check-encoding` to verify if the input to LLVM disassembler matches the output of the assembler. When set, the verification runs on every instruction in processed functions. I'm not enabling the option by default as it could be quite noisy on x86 where instruction encoding is ambiguous and can include redundant prefixes. (cherry picked from FBD16595415)
4401 lines
150 KiB
C++
4401 lines
150 KiB
C++
//===--- BinaryFunction.cpp - Interface for machine-level function --------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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//===----------------------------------------------------------------------===//
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#include "BinaryBasicBlock.h"
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#include "BinaryFunction.h"
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#include "DataReader.h"
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#include "DynoStats.h"
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#include "MCPlusBuilder.h"
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#include "llvm/ADT/edit_distance.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/DebugInfo/DWARF/DWARFContext.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCInst.h"
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#include "llvm/MC/MCInstPrinter.h"
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#include "llvm/MC/MCSection.h"
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#include "llvm/MC/MCSectionELF.h"
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/Object/ObjectFile.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/GraphWriter.h"
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#include "llvm/Support/Timer.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Support/Regex.h"
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#include <cxxabi.h>
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#include <functional>
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#include <limits>
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#include <numeric>
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#include <queue>
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#include <string>
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#undef DEBUG_TYPE
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#define DEBUG_TYPE "bolt"
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using namespace llvm;
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using namespace bolt;
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namespace opts {
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extern cl::OptionCategory BoltCategory;
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extern cl::OptionCategory BoltOptCategory;
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extern cl::OptionCategory BoltRelocCategory;
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extern bool shouldProcess(const BinaryFunction &);
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extern cl::opt<bool> EnableBAT;
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extern cl::opt<bool> Instrument;
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extern cl::opt<bool> StrictMode;
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extern cl::opt<bool> UpdateDebugSections;
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extern cl::opt<unsigned> Verbosity;
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cl::opt<bool>
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AlignBlocks("align-blocks",
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cl::desc("align basic blocks"),
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cl::init(false),
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cl::ZeroOrMore,
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cl::cat(BoltOptCategory));
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cl::opt<MacroFusionType>
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AlignMacroOpFusion("align-macro-fusion",
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cl::desc("fix instruction alignment for macro-fusion (x86 relocation mode)"),
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cl::init(MFT_HOT),
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cl::values(clEnumValN(MFT_NONE, "none",
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"do not insert alignment no-ops for macro-fusion"),
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clEnumValN(MFT_HOT, "hot",
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"only insert alignment no-ops on hot execution paths (default)"),
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clEnumValN(MFT_ALL, "all",
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"always align instructions to allow macro-fusion")),
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cl::ZeroOrMore,
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cl::cat(BoltRelocCategory));
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cl::opt<bool>
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CheckEncoding("check-encoding",
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cl::desc("perform verification of LLVM instruction encoding/decoding. "
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"Every instruction in the input is decoded and re-encoded. "
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"If the resulting bytes do not match the input, a warning message "
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"is printed."),
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cl::init(false),
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cl::ZeroOrMore,
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cl::Hidden,
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cl::cat(BoltCategory));
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static cl::opt<bool>
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DotToolTipCode("dot-tooltip-code",
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cl::desc("add basic block instructions as tool tips on nodes"),
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cl::ZeroOrMore,
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cl::Hidden,
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cl::cat(BoltCategory));
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cl::opt<JumpTableSupportLevel>
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JumpTables("jump-tables",
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cl::desc("jump tables support (default=basic)"),
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cl::init(JTS_BASIC),
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cl::values(
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clEnumValN(JTS_NONE, "none",
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"do not optimize functions with jump tables"),
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clEnumValN(JTS_BASIC, "basic",
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"optimize functions with jump tables"),
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clEnumValN(JTS_MOVE, "move",
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"move jump tables to a separate section"),
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clEnumValN(JTS_SPLIT, "split",
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"split jump tables section into hot and cold based on "
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"function execution frequency"),
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clEnumValN(JTS_AGGRESSIVE, "aggressive",
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"aggressively split jump tables section based on usage "
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"of the tables")),
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cl::ZeroOrMore,
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cl::cat(BoltOptCategory));
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cl::opt<bool>
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PreserveBlocksAlignment("preserve-blocks-alignment",
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cl::desc("try to preserve basic block alignment"),
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cl::init(false),
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cl::ZeroOrMore,
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cl::cat(BoltOptCategory));
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cl::opt<bool>
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PrintDynoStats("dyno-stats",
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cl::desc("print execution info based on profile"),
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cl::cat(BoltCategory));
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static cl::opt<bool>
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PrintDynoStatsOnly("print-dyno-stats-only",
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cl::desc("while printing functions output dyno-stats and skip instructions"),
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cl::init(false),
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cl::Hidden,
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cl::cat(BoltCategory));
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static cl::opt<bool>
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PrintJumpTables("print-jump-tables",
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cl::desc("print jump tables"),
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cl::ZeroOrMore,
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cl::Hidden,
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cl::cat(BoltCategory));
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static cl::list<std::string>
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PrintOnly("print-only",
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cl::CommaSeparated,
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cl::desc("list of functions to print"),
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cl::value_desc("func1,func2,func3,..."),
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cl::Hidden,
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cl::cat(BoltCategory));
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cl::opt<bool>
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TimeBuild("time-build",
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cl::desc("print time spent constructing binary functions"),
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cl::ZeroOrMore,
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cl::Hidden,
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cl::cat(BoltCategory));
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cl::opt<bool>
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TrapOnAVX512("trap-avx512",
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cl::desc("in relocation mode trap upon entry to any function that uses "
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"AVX-512 instructions (on by default)"),
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cl::init(true),
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cl::ZeroOrMore,
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cl::Hidden,
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cl::cat(BoltCategory));
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bool shouldPrint(const BinaryFunction &Function) {
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if (PrintOnly.empty())
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return true;
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for (auto &Name : opts::PrintOnly) {
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if (Function.hasNameRegex(Name)) {
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return true;
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}
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}
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return false;
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}
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} // namespace opts
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namespace llvm {
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namespace bolt {
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constexpr unsigned BinaryFunction::MinAlign;
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namespace {
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template <typename R>
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bool emptyRange(const R &Range) {
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return Range.begin() == Range.end();
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}
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/// Gets debug line information for the instruction located at the given
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/// address in the original binary. The SMLoc's pointer is used
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/// to point to this information, which is represented by a
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/// DebugLineTableRowRef. The returned pointer is null if no debug line
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/// information for this instruction was found.
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SMLoc findDebugLineInformationForInstructionAt(
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uint64_t Address,
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DWARFUnitLineTable &ULT) {
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// We use the pointer in SMLoc to store an instance of DebugLineTableRowRef,
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// which occupies 64 bits. Thus, we can only proceed if the struct fits into
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// the pointer itself.
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assert(
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sizeof(decltype(SMLoc().getPointer())) >= sizeof(DebugLineTableRowRef) &&
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"Cannot fit instruction debug line information into SMLoc's pointer");
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SMLoc NullResult = DebugLineTableRowRef::NULL_ROW.toSMLoc();
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auto &LineTable = ULT.second;
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if (!LineTable)
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return NullResult;
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uint32_t RowIndex = LineTable->lookupAddress(Address);
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if (RowIndex == LineTable->UnknownRowIndex)
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return NullResult;
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assert(RowIndex < LineTable->Rows.size() &&
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"Line Table lookup returned invalid index.");
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decltype(SMLoc().getPointer()) Ptr;
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DebugLineTableRowRef *InstructionLocation =
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reinterpret_cast<DebugLineTableRowRef *>(&Ptr);
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InstructionLocation->DwCompileUnitIndex = ULT.first->getOffset();
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InstructionLocation->RowIndex = RowIndex + 1;
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return SMLoc::getFromPointer(Ptr);
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}
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} // namespace
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uint64_t BinaryFunction::Count = 0;
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const std::string *
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BinaryFunction::hasNameRegex(const StringRef Name) const {
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const auto RegexName = (Twine("^") + StringRef(Name) + "$").str();
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Regex MatchName(RegexName);
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for (auto &Name : Names)
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if (MatchName.match(Name))
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return &Name;
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return nullptr;
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}
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std::string BinaryFunction::getDemangledName() const {
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StringRef MangledName = Names.back();
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MangledName = MangledName.substr(0, MangledName.find_first_of('/'));
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int Status = 0;
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char *const Name =
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abi::__cxa_demangle(MangledName.str().c_str(), 0, 0, &Status);
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const std::string NameStr(Status == 0 ? Name : MangledName);
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free(Name);
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return NameStr;
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}
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BinaryBasicBlock *
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BinaryFunction::getBasicBlockContainingOffset(uint64_t Offset) {
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if (Offset > Size)
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return nullptr;
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if (BasicBlockOffsets.empty())
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return nullptr;
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/*
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* This is commented out because it makes BOLT too slow.
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* assert(std::is_sorted(BasicBlockOffsets.begin(),
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* BasicBlockOffsets.end(),
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* CompareBasicBlockOffsets())));
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*/
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auto I = std::upper_bound(BasicBlockOffsets.begin(),
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BasicBlockOffsets.end(),
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BasicBlockOffset(Offset, nullptr),
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CompareBasicBlockOffsets());
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assert(I != BasicBlockOffsets.begin() && "first basic block not at offset 0");
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--I;
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auto *BB = I->second;
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return (Offset < BB->getOffset() + BB->getOriginalSize()) ? BB : nullptr;
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}
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void BinaryFunction::markUnreachableBlocks() {
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std::stack<BinaryBasicBlock *> Stack;
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for (auto *BB : layout()) {
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BB->markValid(false);
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}
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// Add all entries and landing pads as roots.
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for (auto *BB : BasicBlocks) {
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if (BB->isEntryPoint() || BB->isLandingPad()) {
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Stack.push(BB);
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BB->markValid(true);
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continue;
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}
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// FIXME:
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// Also mark BBs with indirect jumps as reachable, since we do not
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// support removing unused jump tables yet (T29418024 / GH-issue20)
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for (const auto &Inst : *BB) {
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if (BC.MIB->getJumpTable(Inst)) {
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Stack.push(BB);
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BB->markValid(true);
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break;
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}
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}
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}
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// Determine reachable BBs from the entry point
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while (!Stack.empty()) {
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auto BB = Stack.top();
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Stack.pop();
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for (auto Succ : BB->successors()) {
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if (Succ->isValid())
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continue;
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Succ->markValid(true);
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Stack.push(Succ);
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}
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}
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}
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// Any unnecessary fallthrough jumps revealed after calling eraseInvalidBBs
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// will be cleaned up by fixBranches().
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std::pair<unsigned, uint64_t> BinaryFunction::eraseInvalidBBs() {
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BasicBlockOrderType NewLayout;
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unsigned Count = 0;
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uint64_t Bytes = 0;
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for (auto *BB : layout()) {
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if (BB->isValid()) {
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NewLayout.push_back(BB);
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} else {
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assert(!BB->isEntryPoint() && "all entry blocks must be valid");
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++Count;
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Bytes += BC.computeCodeSize(BB->begin(), BB->end());
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}
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}
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BasicBlocksLayout = std::move(NewLayout);
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BasicBlockListType NewBasicBlocks;
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for (auto I = BasicBlocks.begin(), E = BasicBlocks.end(); I != E; ++I) {
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auto *BB = *I;
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if (BB->isValid()) {
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NewBasicBlocks.push_back(BB);
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} else {
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// Make sure the block is removed from the list of predecessors.
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BB->removeAllSuccessors();
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DeletedBasicBlocks.push_back(BB);
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}
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}
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BasicBlocks = std::move(NewBasicBlocks);
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assert(BasicBlocks.size() == BasicBlocksLayout.size());
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// Update CFG state if needed
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if (Count > 0)
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recomputeLandingPads();
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return std::make_pair(Count, Bytes);
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}
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bool BinaryFunction::isForwardCall(const MCSymbol *CalleeSymbol) const {
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// This function should work properly before and after function reordering.
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// In order to accomplish this, we use the function index (if it is valid).
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// If the function indices are not valid, we fall back to the original
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// addresses. This should be ok because the functions without valid indices
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// should have been ordered with a stable sort.
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const auto *CalleeBF = BC.getFunctionForSymbol(CalleeSymbol);
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if (CalleeBF) {
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if(CalleeBF->isInjected())
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return true;
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if (hasValidIndex() && CalleeBF->hasValidIndex()) {
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return getIndex() < CalleeBF->getIndex();
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} else if (hasValidIndex() && !CalleeBF->hasValidIndex()) {
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return true;
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} else if (!hasValidIndex() && CalleeBF->hasValidIndex()) {
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return false;
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} else {
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return getAddress() < CalleeBF->getAddress();
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}
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} else {
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// Absolute symbol.
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auto CalleeAddressOrError = BC.getSymbolValue(*CalleeSymbol);
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assert(CalleeAddressOrError && "unregistered symbol found");
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return *CalleeAddressOrError > getAddress();
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}
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}
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void BinaryFunction::dump(bool PrintInstructions) const {
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print(dbgs(), "", PrintInstructions);
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}
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void BinaryFunction::print(raw_ostream &OS, std::string Annotation,
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bool PrintInstructions) const {
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// FIXME: remove after #15075512 is done.
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if (!opts::shouldProcess(*this) || !opts::shouldPrint(*this))
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return;
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StringRef SectionName =
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IsInjected ? "<no input section>" : InputSection->getName();
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OS << "Binary Function \"" << *this << "\" " << Annotation << " {";
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if (Names.size() > 1) {
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OS << "\n Other names : ";
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auto Sep = "";
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for (unsigned i = 0; i < Names.size() - 1; ++i) {
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OS << Sep << Names[i];
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Sep = "\n ";
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}
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}
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OS << "\n Number : " << FunctionNumber
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<< "\n State : " << CurrentState
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<< "\n Address : 0x" << Twine::utohexstr(Address)
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<< "\n Size : 0x" << Twine::utohexstr(Size)
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<< "\n MaxSize : 0x" << Twine::utohexstr(MaxSize)
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<< "\n Offset : 0x" << Twine::utohexstr(FileOffset)
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<< "\n Section : " << SectionName
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<< "\n Orc Section : " << getCodeSectionName()
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<< "\n LSDA : 0x" << Twine::utohexstr(getLSDAAddress())
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<< "\n IsSimple : " << IsSimple
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<< "\n IsSplit : " << isSplit()
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<< "\n BB Count : " << size();
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if (HasFixedIndirectBranch) {
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OS << "\n HasFixedIndirectBranch : true";
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}
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if (HasUnknownControlFlow) {
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OS << "\n Unknown CF : true";
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}
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if (IsFragment) {
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OS << "\n IsFragment : true";
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}
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if (ParentFunction) {
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OS << "\n Parent : " << *ParentFunction;
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}
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if (!Fragments.empty()) {
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OS << "\n Fragments : ";
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auto Sep = "";
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for (auto *Frag : Fragments) {
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OS << Sep << *Frag;
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Sep = ", ";
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}
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}
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if (hasCFG()) {
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OS << "\n Hash : " << Twine::utohexstr(hash());
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}
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if (FrameInstructions.size()) {
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OS << "\n CFI Instrs : " << FrameInstructions.size();
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}
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if (BasicBlocksLayout.size()) {
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OS << "\n BB Layout : ";
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auto Sep = "";
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for (auto BB : BasicBlocksLayout) {
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OS << Sep << BB->getName();
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Sep = ", ";
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}
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}
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if (ImageAddress)
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OS << "\n Image : 0x" << Twine::utohexstr(ImageAddress);
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if (ExecutionCount != COUNT_NO_PROFILE) {
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OS << "\n Exec Count : " << ExecutionCount;
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OS << "\n Profile Acc : " << format("%.1f%%", ProfileMatchRatio * 100.0f);
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}
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if (opts::PrintDynoStats && !BasicBlocksLayout.empty()) {
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OS << '\n';
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DynoStats dynoStats = getDynoStats(*this);
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OS << dynoStats;
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}
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OS << "\n}\n";
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if (opts::PrintDynoStatsOnly || !PrintInstructions || !BC.InstPrinter)
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return;
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// Offset of the instruction in function.
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uint64_t Offset{0};
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if (BasicBlocks.empty() && !Instructions.empty()) {
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// Print before CFG was built.
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for (const auto &II : Instructions) {
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Offset = II.first;
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// Print label if exists at this offset.
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auto LI = Labels.find(Offset);
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if (LI != Labels.end())
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OS << LI->second->getName() << ":\n";
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BC.printInstruction(OS, II.second, Offset, this);
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}
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}
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for (uint32_t I = 0, E = BasicBlocksLayout.size(); I != E; ++I) {
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auto BB = BasicBlocksLayout[I];
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if (I != 0 &&
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BB->isCold() != BasicBlocksLayout[I - 1]->isCold())
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OS << "------- HOT-COLD SPLIT POINT -------\n\n";
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OS << BB->getName() << " ("
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<< BB->size() << " instructions, align : " << BB->getAlignment()
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<< ")\n";
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if (BB->isEntryPoint())
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OS << " Entry Point\n";
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if (BB->isLandingPad())
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OS << " Landing Pad\n";
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uint64_t BBExecCount = BB->getExecutionCount();
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if (hasValidProfile()) {
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OS << " Exec Count : ";
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if (BB->getExecutionCount() != BinaryBasicBlock::COUNT_NO_PROFILE)
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OS << BBExecCount << '\n';
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else
|
|
OS << "<unknown>\n";
|
|
}
|
|
if (BB->getCFIState() >= 0) {
|
|
OS << " CFI State : " << BB->getCFIState() << '\n';
|
|
}
|
|
if (opts::EnableBAT) {
|
|
OS << " Input offset: " << Twine::utohexstr(BB->getInputOffset())
|
|
<< "\n";
|
|
}
|
|
if (!BB->pred_empty()) {
|
|
OS << " Predecessors: ";
|
|
auto Sep = "";
|
|
for (auto Pred : BB->predecessors()) {
|
|
OS << Sep << Pred->getName();
|
|
Sep = ", ";
|
|
}
|
|
OS << '\n';
|
|
}
|
|
if (!BB->throw_empty()) {
|
|
OS << " Throwers: ";
|
|
auto Sep = "";
|
|
for (auto Throw : BB->throwers()) {
|
|
OS << Sep << Throw->getName();
|
|
Sep = ", ";
|
|
}
|
|
OS << '\n';
|
|
}
|
|
|
|
Offset = alignTo(Offset, BB->getAlignment());
|
|
|
|
// Note: offsets are imprecise since this is happening prior to relaxation.
|
|
Offset = BC.printInstructions(OS, BB->begin(), BB->end(), Offset, this);
|
|
|
|
if (!BB->succ_empty()) {
|
|
OS << " Successors: ";
|
|
// For more than 2 successors, sort them based on frequency.
|
|
std::vector<uint64_t> Indices(BB->succ_size());
|
|
std::iota(Indices.begin(), Indices.end(), 0);
|
|
if (BB->succ_size() > 2 && BB->getKnownExecutionCount()) {
|
|
std::stable_sort(Indices.begin(), Indices.end(),
|
|
[&](const uint64_t A, const uint64_t B) {
|
|
return BB->BranchInfo[B] < BB->BranchInfo[A];
|
|
});
|
|
}
|
|
auto Sep = "";
|
|
for (unsigned I = 0; I < Indices.size(); ++I) {
|
|
auto *Succ = BB->Successors[Indices[I]];
|
|
auto &BI = BB->BranchInfo[Indices[I]];
|
|
OS << Sep << Succ->getName();
|
|
if (ExecutionCount != COUNT_NO_PROFILE &&
|
|
BI.MispredictedCount != BinaryBasicBlock::COUNT_INFERRED) {
|
|
OS << " (mispreds: " << BI.MispredictedCount
|
|
<< ", count: " << BI.Count << ")";
|
|
} else if (ExecutionCount != COUNT_NO_PROFILE &&
|
|
BI.Count != BinaryBasicBlock::COUNT_NO_PROFILE) {
|
|
OS << " (inferred count: " << BI.Count << ")";
|
|
}
|
|
Sep = ", ";
|
|
}
|
|
OS << '\n';
|
|
}
|
|
|
|
if (!BB->lp_empty()) {
|
|
OS << " Landing Pads: ";
|
|
auto Sep = "";
|
|
for (auto LP : BB->landing_pads()) {
|
|
OS << Sep << LP->getName();
|
|
if (ExecutionCount != COUNT_NO_PROFILE) {
|
|
OS << " (count: " << LP->getExecutionCount() << ")";
|
|
}
|
|
Sep = ", ";
|
|
}
|
|
OS << '\n';
|
|
}
|
|
|
|
// In CFG_Finalized state we can miscalculate CFI state at exit.
|
|
if (CurrentState == State::CFG) {
|
|
const auto CFIStateAtExit = BB->getCFIStateAtExit();
|
|
if (CFIStateAtExit >= 0)
|
|
OS << " CFI State: " << CFIStateAtExit << '\n';
|
|
}
|
|
|
|
OS << '\n';
|
|
}
|
|
|
|
// Dump new exception ranges for the function.
|
|
if (!CallSites.empty()) {
|
|
OS << "EH table:\n";
|
|
for (auto &CSI : CallSites) {
|
|
OS << " [" << *CSI.Start << ", " << *CSI.End << ") landing pad : ";
|
|
if (CSI.LP)
|
|
OS << *CSI.LP;
|
|
else
|
|
OS << "0";
|
|
OS << ", action : " << CSI.Action << '\n';
|
|
}
|
|
OS << '\n';
|
|
}
|
|
|
|
// Print all jump tables.
|
|
for (auto &JTI : JumpTables) {
|
|
JTI.second->print(OS);
|
|
}
|
|
|
|
OS << "DWARF CFI Instructions:\n";
|
|
if (OffsetToCFI.size()) {
|
|
// Pre-buildCFG information
|
|
for (auto &Elmt : OffsetToCFI) {
|
|
OS << format(" %08x:\t", Elmt.first);
|
|
assert(Elmt.second < FrameInstructions.size() && "Incorrect CFI offset");
|
|
BinaryContext::printCFI(OS, FrameInstructions[Elmt.second]);
|
|
OS << "\n";
|
|
}
|
|
} else {
|
|
// Post-buildCFG information
|
|
for (uint32_t I = 0, E = FrameInstructions.size(); I != E; ++I) {
|
|
const MCCFIInstruction &CFI = FrameInstructions[I];
|
|
OS << format(" %d:\t", I);
|
|
BinaryContext::printCFI(OS, CFI);
|
|
OS << "\n";
|
|
}
|
|
}
|
|
if (FrameInstructions.empty())
|
|
OS << " <empty>\n";
|
|
|
|
OS << "End of Function \"" << *this << "\"\n\n";
|
|
}
|
|
|
|
void BinaryFunction::printRelocations(raw_ostream &OS,
|
|
uint64_t Offset,
|
|
uint64_t Size) const {
|
|
const char *Sep = " # Relocs: ";
|
|
|
|
auto RI = Relocations.lower_bound(Offset);
|
|
while (RI != Relocations.end() && RI->first < Offset + Size) {
|
|
OS << Sep << "(R: " << RI->second << ")";
|
|
Sep = ", ";
|
|
++RI;
|
|
}
|
|
|
|
RI = MoveRelocations.lower_bound(Offset);
|
|
while (RI != MoveRelocations.end() && RI->first < Offset + Size) {
|
|
OS << Sep << "(M: " << RI->second << ")";
|
|
Sep = ", ";
|
|
++RI;
|
|
}
|
|
|
|
auto PI = PCRelativeRelocationOffsets.lower_bound(Offset);
|
|
if (PI != PCRelativeRelocationOffsets.end() && *PI < Offset + Size) {
|
|
OS << Sep << "(pcrel)";
|
|
}
|
|
}
|
|
|
|
IndirectBranchType
|
|
BinaryFunction::processIndirectBranch(MCInst &Instruction,
|
|
unsigned Size,
|
|
uint64_t Offset,
|
|
uint64_t &TargetAddress) {
|
|
const auto PtrSize = BC.AsmInfo->getCodePointerSize();
|
|
|
|
// An instruction referencing memory used by jump instruction (directly or
|
|
// via register). This location could be an array of function pointers
|
|
// in case of indirect tail call, or a jump table.
|
|
MCInst *MemLocInstr;
|
|
|
|
// Address of the table referenced by MemLocInstr. Could be either an
|
|
// array of function pointers, or a jump table.
|
|
uint64_t ArrayStart = 0;
|
|
|
|
unsigned BaseRegNum, IndexRegNum;
|
|
int64_t DispValue;
|
|
const MCExpr *DispExpr;
|
|
|
|
// In AArch, identify the instruction adding the PC-relative offset to
|
|
// jump table entries to correctly decode it.
|
|
MCInst *PCRelBaseInstr;
|
|
uint64_t PCRelAddr = 0;
|
|
|
|
auto Begin = Instructions.begin();
|
|
if (BC.isAArch64()) {
|
|
PreserveNops = BC.HasRelocations;
|
|
// Start at the last label as an approximation of the current basic block.
|
|
// This is a heuristic, since the full set of labels have yet to be
|
|
// determined
|
|
for (auto LI = Labels.rbegin(); LI != Labels.rend(); ++LI) {
|
|
auto II = Instructions.find(LI->first);
|
|
if (II != Instructions.end()) {
|
|
Begin = II;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
auto Type = BC.MIB->analyzeIndirectBranch(Instruction,
|
|
Begin,
|
|
Instructions.end(),
|
|
PtrSize,
|
|
MemLocInstr,
|
|
BaseRegNum,
|
|
IndexRegNum,
|
|
DispValue,
|
|
DispExpr,
|
|
PCRelBaseInstr);
|
|
|
|
if (Type == IndirectBranchType::UNKNOWN && !MemLocInstr)
|
|
return Type;
|
|
|
|
if (MemLocInstr != &Instruction)
|
|
IndexRegNum = BC.MIB->getNoRegister();
|
|
|
|
if (BC.isAArch64()) {
|
|
const auto *Sym = BC.MIB->getTargetSymbol(*PCRelBaseInstr, 1);
|
|
assert (Sym && "Symbol extraction failed");
|
|
auto SymValueOrError = BC.getSymbolValue(*Sym);
|
|
if (SymValueOrError) {
|
|
PCRelAddr = *SymValueOrError;
|
|
} else {
|
|
for (auto &Elmt : Labels) {
|
|
if (Elmt.second == Sym) {
|
|
PCRelAddr = Elmt.first + getAddress();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
uint64_t InstrAddr = 0;
|
|
for (auto II = Instructions.rbegin(); II != Instructions.rend(); ++II) {
|
|
if (&II->second == PCRelBaseInstr) {
|
|
InstrAddr = II->first + getAddress();
|
|
break;
|
|
}
|
|
}
|
|
assert(InstrAddr != 0 && "instruction not found");
|
|
// We do this to avoid spurious references to code locations outside this
|
|
// function (for example, if the indirect jump lives in the last basic
|
|
// block of the function, it will create a reference to the next function).
|
|
// This replaces a symbol reference with an immediate.
|
|
BC.MIB->replaceMemOperandDisp(*PCRelBaseInstr,
|
|
MCOperand::createImm(PCRelAddr - InstrAddr));
|
|
// FIXME: Disable full jump table processing for AArch64 until we have a
|
|
// proper way of determining the jump table limits.
|
|
return IndirectBranchType::UNKNOWN;
|
|
}
|
|
|
|
// RIP-relative addressing should be converted to symbol form by now
|
|
// in processed instructions (but not in jump).
|
|
if (DispExpr) {
|
|
const MCSymbol *TargetSym;
|
|
uint64_t TargetOffset;
|
|
std::tie(TargetSym, TargetOffset) = BC.MIB->getTargetSymbolInfo(DispExpr);
|
|
auto SymValueOrError = BC.getSymbolValue(*TargetSym);
|
|
assert(SymValueOrError && "global symbol needs a value");
|
|
ArrayStart = *SymValueOrError + TargetOffset;
|
|
BaseRegNum = BC.MIB->getNoRegister();
|
|
if (BC.isAArch64()) {
|
|
ArrayStart &= ~0xFFFULL;
|
|
ArrayStart += DispValue & 0xFFFULL;
|
|
}
|
|
} else {
|
|
ArrayStart = static_cast<uint64_t>(DispValue);
|
|
}
|
|
|
|
if (BaseRegNum == BC.MRI->getProgramCounter())
|
|
ArrayStart += getAddress() + Offset + Size;
|
|
|
|
DEBUG(dbgs() << "BOLT-DEBUG: addressed memory is 0x"
|
|
<< Twine::utohexstr(ArrayStart) << '\n');
|
|
|
|
auto Section = BC.getSectionForAddress(ArrayStart);
|
|
if (!Section) {
|
|
// No section - possibly an absolute address. Since we don't allow
|
|
// internal function addresses to escape the function scope - we
|
|
// consider it a tail call.
|
|
if (opts::Verbosity >= 1) {
|
|
errs() << "BOLT-WARNING: no section for address 0x"
|
|
<< Twine::utohexstr(ArrayStart) << " referenced from function "
|
|
<< *this << '\n';
|
|
}
|
|
return IndirectBranchType::POSSIBLE_TAIL_CALL;
|
|
}
|
|
if (Section->isVirtual()) {
|
|
// The contents are filled at runtime.
|
|
return IndirectBranchType::POSSIBLE_TAIL_CALL;
|
|
}
|
|
|
|
if (Type == IndirectBranchType::POSSIBLE_FIXED_BRANCH) {
|
|
auto Value = BC.getPointerAtAddress(ArrayStart);
|
|
if (!Value)
|
|
return IndirectBranchType::UNKNOWN;
|
|
|
|
if (!BC.getSectionForAddress(ArrayStart)->isReadOnly())
|
|
return IndirectBranchType::UNKNOWN;
|
|
|
|
outs() << "BOLT-INFO: fixed indirect branch detected in " << *this
|
|
<< " at 0x" << Twine::utohexstr(getAddress() + Offset)
|
|
<< " referencing data at 0x" << Twine::utohexstr(ArrayStart)
|
|
<< " the destination value is 0x" << Twine::utohexstr(*Value)
|
|
<< '\n';
|
|
|
|
TargetAddress = *Value;
|
|
return Type;
|
|
}
|
|
|
|
auto useJumpTableForInstruction = [&](JumpTable::JumpTableType JTType) {
|
|
const MCSymbol *JTLabel =
|
|
BC.getOrCreateJumpTable(*this, ArrayStart, JTType);
|
|
|
|
BC.MIB->replaceMemOperandDisp(const_cast<MCInst &>(*MemLocInstr),
|
|
JTLabel, BC.Ctx.get());
|
|
BC.MIB->setJumpTable(Instruction, ArrayStart, IndexRegNum);
|
|
|
|
JTSites.emplace_back(Offset, ArrayStart);
|
|
};
|
|
|
|
// Check if there's already a jump table registered at this address.
|
|
// At this point, all jump tables are empty.
|
|
if (auto *JT = BC.getJumpTableContainingAddress(ArrayStart)) {
|
|
// Make sure the type of the table matches the code.
|
|
if (Type == IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE) {
|
|
assert(JT->Type == JumpTable::JTT_PIC && "PIC jump table expected");
|
|
} else {
|
|
assert(JT->Type == JumpTable::JTT_NORMAL && "normal jump table expected");
|
|
Type = IndirectBranchType::POSSIBLE_JUMP_TABLE;
|
|
}
|
|
|
|
useJumpTableForInstruction(JT->Type);
|
|
|
|
return Type;
|
|
}
|
|
|
|
const auto MemType = BC.analyzeMemoryAt(ArrayStart, *this);
|
|
if (Type == IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE) {
|
|
assert(MemType == MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE &&
|
|
"PIC jump table heuristic failure");
|
|
useJumpTableForInstruction(JumpTable::JTT_PIC);
|
|
return Type;
|
|
}
|
|
|
|
if (MemType == MemoryContentsType::POSSIBLE_JUMP_TABLE) {
|
|
assert(Type == IndirectBranchType::UNKNOWN &&
|
|
"non-PIC jump table heuristic failure");
|
|
useJumpTableForInstruction(JumpTable::JTT_NORMAL);
|
|
return IndirectBranchType::POSSIBLE_JUMP_TABLE;
|
|
}
|
|
|
|
// We have a possible tail call, so let's add the value read from the possible
|
|
// memory location as a reference. Only do that if the address we read is sane
|
|
// enough (is inside an allocatable section). It is possible that we read
|
|
// garbage if the load instruction we analyzed is in a basic block different
|
|
// than the one where the indirect jump is. However, later,
|
|
// postProcessIndirectBranches() is going to mark the function as non-simple
|
|
// in this case.
|
|
auto Value = BC.getPointerAtAddress(ArrayStart);
|
|
if (Value && BC.getSectionForAddress(*Value))
|
|
BC.InterproceduralReferences.insert(std::make_pair(this, *Value));
|
|
|
|
return IndirectBranchType::POSSIBLE_TAIL_CALL;
|
|
}
|
|
|
|
MCSymbol *BinaryFunction::getOrCreateLocalLabel(uint64_t Address,
|
|
bool CreatePastEnd) {
|
|
// Check if there's already a registered label.
|
|
auto Offset = Address - getAddress();
|
|
|
|
if ((Offset == getSize()) && CreatePastEnd)
|
|
return getFunctionEndLabel();
|
|
|
|
// Check if there's a global symbol registered at given address.
|
|
// If so - reuse it since we want to keep the symbol value updated.
|
|
if (Offset != 0) {
|
|
if (auto *BD = BC.getBinaryDataAtAddress(Address)) {
|
|
Labels[Offset] = BD->getSymbol();
|
|
return BD->getSymbol();
|
|
}
|
|
}
|
|
|
|
auto LI = Labels.find(Offset);
|
|
if (LI != Labels.end())
|
|
return LI->second;
|
|
|
|
// For AArch64, check if this address is part of a constant island.
|
|
if (MCSymbol *IslandSym = getOrCreateIslandAccess(Address)) {
|
|
return IslandSym;
|
|
}
|
|
MCSymbol *Result;
|
|
{
|
|
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
|
|
Result = BC.Ctx->createTempSymbol();
|
|
}
|
|
Labels[Offset] = Result;
|
|
return Result;
|
|
}
|
|
|
|
void BinaryFunction::disassemble(ArrayRef<uint8_t> FunctionData) {
|
|
NamedRegionTimer T("disassemble", "Disassemble function", "buildfuncs",
|
|
"Build Binary Functions", opts::TimeBuild);
|
|
|
|
assert(FunctionData.size() == getMaxSize() &&
|
|
"function size does not match raw data size");
|
|
|
|
auto &Ctx = BC.Ctx;
|
|
auto &MIB = BC.MIB;
|
|
|
|
DWARFUnitLineTable ULT = getDWARFUnitLineTable();
|
|
|
|
matchProfileMemData();
|
|
|
|
// Insert a label at the beginning of the function. This will be our first
|
|
// basic block.
|
|
Labels[0] = Ctx->createTempSymbol("BB0", false);
|
|
addEntryPointAtOffset(0);
|
|
|
|
auto handlePCRelOperand =
|
|
[&](MCInst &Instruction, uint64_t Address, uint64_t Size) {
|
|
uint64_t TargetAddress{0};
|
|
if (!MIB->evaluateMemOperandTarget(Instruction, TargetAddress, Address,
|
|
Size)) {
|
|
errs() << "BOLT-ERROR: PC-relative operand can't be evaluated:\n";
|
|
BC.InstPrinter->printInst(&Instruction, errs(), "", *BC.STI);
|
|
errs() << '\n';
|
|
Instruction.dump_pretty(errs(), BC.InstPrinter.get());
|
|
errs() << '\n';
|
|
return false;
|
|
}
|
|
if (TargetAddress == 0 && opts::Verbosity >= 1) {
|
|
outs() << "BOLT-INFO: PC-relative operand is zero in function " << *this
|
|
<< '\n';
|
|
}
|
|
|
|
const MCSymbol *TargetSymbol;
|
|
uint64_t TargetOffset;
|
|
std::tie(TargetSymbol, TargetOffset) =
|
|
BC.handleAddressRef(TargetAddress, *this, /*IsPCRel*/ true);
|
|
const MCExpr *Expr = MCSymbolRefExpr::create(TargetSymbol,
|
|
MCSymbolRefExpr::VK_None,
|
|
*BC.Ctx);
|
|
if (TargetOffset) {
|
|
auto *Offset = MCConstantExpr::create(TargetOffset, *BC.Ctx);
|
|
Expr = MCBinaryExpr::createAdd(Expr, Offset, *BC.Ctx);
|
|
}
|
|
MIB->replaceMemOperandDisp(
|
|
Instruction, MCOperand::createExpr(BC.MIB->getTargetExprFor(
|
|
Instruction,
|
|
Expr,
|
|
*BC.Ctx, 0)));
|
|
return true;
|
|
};
|
|
|
|
// Used to fix the target of linker-generated AArch64 stubs with no relocation
|
|
// info
|
|
auto fixStubTarget = [&](MCInst &LoadLowBits, MCInst &LoadHiBits,
|
|
uint64_t Target) {
|
|
const MCSymbol *TargetSymbol;
|
|
uint64_t Addend{0};
|
|
std::tie(TargetSymbol, Addend) = BC.handleAddressRef(Target, *this, true);
|
|
|
|
int64_t Val;
|
|
MIB->replaceImmWithSymbolRef(LoadHiBits, TargetSymbol, Addend, Ctx.get(),
|
|
Val, ELF::R_AARCH64_ADR_PREL_PG_HI21);
|
|
MIB->replaceImmWithSymbolRef(LoadLowBits, TargetSymbol, Addend, Ctx.get(),
|
|
Val, ELF::R_AARCH64_ADD_ABS_LO12_NC);
|
|
};
|
|
|
|
uint64_t Size = 0; // instruction size
|
|
for (uint64_t Offset = 0; Offset < getSize(); Offset += Size) {
|
|
MCInst Instruction;
|
|
const uint64_t AbsoluteInstrAddr = getAddress() + Offset;
|
|
|
|
// Check for data inside code and ignore it
|
|
if (DataOffsets.find(Offset) != DataOffsets.end()) {
|
|
auto Iter = CodeOffsets.upper_bound(Offset);
|
|
if (Iter != CodeOffsets.end()) {
|
|
Size = *Iter - Offset;
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (!BC.DisAsm->getInstruction(Instruction,
|
|
Size,
|
|
FunctionData.slice(Offset),
|
|
AbsoluteInstrAddr,
|
|
nulls(),
|
|
nulls())) {
|
|
// Functions with "soft" boundaries, e.g. coming from assembly source,
|
|
// can have 0-byte padding at the end.
|
|
bool IsZeroPadding = true;
|
|
uint64_t EndOfCode = getSize();
|
|
auto Iter = DataOffsets.upper_bound(Offset);
|
|
if (Iter != DataOffsets.end())
|
|
EndOfCode = *Iter;
|
|
for (auto I = Offset; I < EndOfCode; ++I) {
|
|
if (FunctionData[I] != 0) {
|
|
IsZeroPadding = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!IsZeroPadding) {
|
|
// Ignore this function. Skip to the next one in non-relocs mode.
|
|
errs() << "BOLT-WARNING: unable to disassemble instruction at offset 0x"
|
|
<< Twine::utohexstr(Offset) << " (address 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr) << ") in function "
|
|
<< *this << '\n';
|
|
// Some AVX-512 instructions could not be disassembled at all.
|
|
if (BC.HasRelocations && opts::TrapOnAVX512 && BC.isX86()) {
|
|
setTrapOnEntry();
|
|
BC.TrappedFunctions.push_back(this);
|
|
} else {
|
|
IsSimple = false;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Check integrity of LLVM assembler/disassembler.
|
|
if (opts::CheckEncoding && !BC.MIB->isBranch(Instruction) &&
|
|
!BC.MIB->isCall(Instruction) && !BC.MIB->isNoop(Instruction)) {
|
|
SmallString<256> Code;
|
|
SmallVector<MCFixup, 4> Fixups;
|
|
raw_svector_ostream VecOS(Code);
|
|
BC.MCE->encodeInstruction(Instruction, VecOS, Fixups, *BC.STI);
|
|
auto EncodedData = ArrayRef<uint8_t>((uint8_t *)Code.data(), Code.size());
|
|
if (FunctionData.slice(Offset, Size) != EncodedData) {
|
|
errs() << "BOLT-WARNING: mismatching LLVM encoding detected in "
|
|
<< "function " << *this << ":\n";
|
|
BC.printInstruction(errs(), Instruction, AbsoluteInstrAddr);
|
|
errs() << " input: " << FunctionData.slice(Offset, Size)
|
|
<< "\n output: " << EncodedData << "\n\n";
|
|
}
|
|
}
|
|
|
|
// Cannot process functions with AVX-512 instructions.
|
|
if (MIB->hasEVEXEncoding(Instruction)) {
|
|
if (opts::Verbosity >= 1) {
|
|
errs() << "BOLT-WARNING: function " << *this << " uses instruction"
|
|
" encoded with EVEX (AVX-512) at offset 0x"
|
|
<< Twine::utohexstr(Offset) << ". Disassembly could be wrong."
|
|
" Skipping further processing.\n";
|
|
}
|
|
|
|
if (BC.HasRelocations && opts::TrapOnAVX512) {
|
|
setTrapOnEntry();
|
|
BC.TrappedFunctions.push_back(this);
|
|
} else {
|
|
IsSimple = false;
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Check if there's a relocation associated with this instruction.
|
|
bool UsedReloc{false};
|
|
for (auto Itr = Relocations.lower_bound(Offset);
|
|
Itr != Relocations.upper_bound(Offset + Size);
|
|
++Itr) {
|
|
const auto &Relocation = Itr->second;
|
|
if (Relocation.Offset >= Offset + Size)
|
|
continue;
|
|
|
|
const MCSymbol *TargetSymbol = Relocation.Symbol;
|
|
auto Addend = Relocation.Addend;
|
|
|
|
DEBUG(dbgs() << "BOLT-DEBUG: replacing immediate 0x"
|
|
<< Twine::utohexstr(Relocation.Value) << " with relocation"
|
|
" against " << TargetSymbol->getName()
|
|
<< "+" << Addend << " in function " << *this
|
|
<< " for instruction at offset 0x"
|
|
<< Twine::utohexstr(Offset) << '\n');
|
|
int64_t Value = Relocation.Value;
|
|
|
|
// Process reference to the primary symbol.
|
|
if (!Relocation.isPCRelative())
|
|
BC.handleAddressRef(Relocation.Value - Relocation.Addend,
|
|
*this,
|
|
/*IsPCRel*/ false);
|
|
|
|
const auto Result = BC.MIB->replaceImmWithSymbolRef(Instruction,
|
|
Relocation.Symbol,
|
|
Relocation.Addend,
|
|
Ctx.get(),
|
|
Value,
|
|
Relocation.Type);
|
|
(void)Result;
|
|
assert(Result && "cannot replace immediate with relocation");
|
|
|
|
// For aarch, if we replaced an immediate with a symbol from a
|
|
// relocation, we mark it so we do not try to further process a
|
|
// pc-relative operand. All we need is the symbol.
|
|
if (BC.isAArch64())
|
|
UsedReloc = true;
|
|
|
|
// Make sure we replaced the correct immediate (instruction
|
|
// can have multiple immediate operands).
|
|
if (BC.isX86()) {
|
|
assert(truncateToSize(static_cast<uint64_t>(Value),
|
|
Relocation::getSizeForType(Relocation.Type)) ==
|
|
truncateToSize(Relocation.Value,
|
|
Relocation::getSizeForType(Relocation.Type)) &&
|
|
"immediate value mismatch in function");
|
|
}
|
|
}
|
|
|
|
// Convert instruction to a shorter version that could be relaxed if
|
|
// needed.
|
|
MIB->shortenInstruction(Instruction);
|
|
|
|
if (MIB->isBranch(Instruction) || MIB->isCall(Instruction)) {
|
|
uint64_t TargetAddress = 0;
|
|
if (MIB->evaluateBranch(Instruction, AbsoluteInstrAddr, Size,
|
|
TargetAddress)) {
|
|
// Check if the target is within the same function. Otherwise it's
|
|
// a call, possibly a tail call.
|
|
//
|
|
// If the target *is* the function address it could be either a branch
|
|
// or a recursive call.
|
|
bool IsCall = MIB->isCall(Instruction);
|
|
const bool IsCondBranch = MIB->isConditionalBranch(Instruction);
|
|
MCSymbol *TargetSymbol = nullptr;
|
|
|
|
if (IsCall && containsAddress(TargetAddress)) {
|
|
if (TargetAddress == getAddress()) {
|
|
// Recursive call.
|
|
TargetSymbol = getSymbol();
|
|
} else {
|
|
if (BC.isX86()) {
|
|
// Dangerous old-style x86 PIC code. We may need to freeze this
|
|
// function, so preserve the function as is for now.
|
|
PreserveNops = true;
|
|
} else {
|
|
errs() << "BOLT-WARNING: internal call detected at 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr) << " in function "
|
|
<< *this << ". Skipping.\n";
|
|
IsSimple = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!TargetSymbol) {
|
|
// Create either local label or external symbol.
|
|
if (containsAddress(TargetAddress)) {
|
|
TargetSymbol = getOrCreateLocalLabel(TargetAddress);
|
|
} else {
|
|
if (TargetAddress == getAddress() + getSize() &&
|
|
TargetAddress < getAddress() + getMaxSize()) {
|
|
// Result of __builtin_unreachable().
|
|
DEBUG(dbgs() << "BOLT-DEBUG: jump past end detected at 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr)
|
|
<< " in function " << *this
|
|
<< " : replacing with nop.\n");
|
|
BC.MIB->createNoop(Instruction);
|
|
if (IsCondBranch) {
|
|
// Register branch offset for profile validation.
|
|
IgnoredBranches.emplace_back(Offset, Offset + Size);
|
|
}
|
|
goto add_instruction;
|
|
}
|
|
BC.InterproceduralReferences.insert(
|
|
std::make_pair(this, TargetAddress));
|
|
if (opts::Verbosity >= 2 && !IsCall && Size == 2 &&
|
|
!BC.HasRelocations) {
|
|
errs() << "BOLT-WARNING: relaxed tail call detected at 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr) << " in function "
|
|
<< *this << ". Code size will be increased.\n";
|
|
}
|
|
|
|
assert(!MIB->isTailCall(Instruction) &&
|
|
"synthetic tail call instruction found");
|
|
|
|
// This is a call regardless of the opcode.
|
|
// Assign proper opcode for tail calls, so that they could be
|
|
// treated as calls.
|
|
if (!IsCall) {
|
|
if (!MIB->convertJmpToTailCall(Instruction)) {
|
|
assert(IsCondBranch && "unknown tail call instruction");
|
|
if (opts::Verbosity >= 2) {
|
|
errs() << "BOLT-WARNING: conditional tail call detected in "
|
|
<< "function " << *this << " at 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr) << ".\n";
|
|
}
|
|
}
|
|
IsCall = true;
|
|
}
|
|
|
|
TargetSymbol =
|
|
BC.getOrCreateGlobalSymbol(TargetAddress, "FUNCat");
|
|
if (TargetAddress == 0) {
|
|
// We actually see calls to address 0 in presence of weak
|
|
// symbols originating from libraries. This code is never meant
|
|
// to be executed.
|
|
if (opts::Verbosity >= 2) {
|
|
outs() << "BOLT-INFO: Function " << *this
|
|
<< " has a call to address zero.\n";
|
|
}
|
|
}
|
|
|
|
if (BC.HasRelocations) {
|
|
// Check if we need to create relocation to move this function's
|
|
// code without re-assembly.
|
|
size_t RelSize = (Size < 5) ? 1 : 4;
|
|
auto RelOffset = Offset + Size - RelSize;
|
|
if (BC.isAArch64()) {
|
|
RelSize = 0;
|
|
RelOffset = Offset;
|
|
}
|
|
auto RI = MoveRelocations.find(RelOffset);
|
|
if (RI == MoveRelocations.end()) {
|
|
uint64_t RelType =
|
|
(RelSize == 1) ? ELF::R_X86_64_PC8 : ELF::R_X86_64_PC32;
|
|
if (BC.isAArch64())
|
|
RelType = ELF::R_AARCH64_CALL26;
|
|
DEBUG(dbgs() << "BOLT-DEBUG: creating relocation for static"
|
|
<< " function call to " << TargetSymbol->getName()
|
|
<< " at offset 0x" << Twine::utohexstr(RelOffset)
|
|
<< " with size " << RelSize << " for function "
|
|
<< *this << '\n');
|
|
addRelocation(getAddress() + RelOffset, TargetSymbol, RelType,
|
|
-RelSize, 0);
|
|
}
|
|
auto OI = PCRelativeRelocationOffsets.find(RelOffset);
|
|
if (OI != PCRelativeRelocationOffsets.end()) {
|
|
PCRelativeRelocationOffsets.erase(OI);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!IsCall) {
|
|
// Add taken branch info.
|
|
TakenBranches.emplace_back(Offset, TargetAddress - getAddress());
|
|
}
|
|
BC.MIB->replaceBranchTarget(Instruction, TargetSymbol, &*Ctx);
|
|
|
|
// Mark CTC.
|
|
if (IsCondBranch && IsCall) {
|
|
MIB->setConditionalTailCall(Instruction, TargetAddress);
|
|
}
|
|
} else {
|
|
// Could not evaluate branch. Should be an indirect call or an
|
|
// indirect branch. Bail out on the latter case.
|
|
if (MIB->isIndirectBranch(Instruction)) {
|
|
uint64_t IndirectTarget{0};
|
|
auto Result =
|
|
processIndirectBranch(Instruction, Size, Offset, IndirectTarget);
|
|
switch (Result) {
|
|
default:
|
|
llvm_unreachable("unexpected result");
|
|
case IndirectBranchType::POSSIBLE_TAIL_CALL: {
|
|
auto Result = MIB->convertJmpToTailCall(Instruction);
|
|
(void)Result;
|
|
assert(Result);
|
|
break;
|
|
}
|
|
case IndirectBranchType::POSSIBLE_JUMP_TABLE:
|
|
case IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE:
|
|
if (opts::JumpTables == JTS_NONE)
|
|
IsSimple = false;
|
|
break;
|
|
case IndirectBranchType::POSSIBLE_FIXED_BRANCH: {
|
|
if (containsAddress(IndirectTarget)) {
|
|
const auto *TargetSymbol = getOrCreateLocalLabel(IndirectTarget);
|
|
Instruction.clear();
|
|
MIB->createUncondBranch(Instruction, TargetSymbol, BC.Ctx.get());
|
|
TakenBranches.emplace_back(Offset, IndirectTarget - getAddress());
|
|
HasFixedIndirectBranch = true;
|
|
} else {
|
|
MIB->convertJmpToTailCall(Instruction);
|
|
BC.InterproceduralReferences.insert(
|
|
std::make_pair(this, IndirectTarget));
|
|
}
|
|
break;
|
|
}
|
|
case IndirectBranchType::UNKNOWN:
|
|
// Keep processing. We'll do more checks and fixes in
|
|
// postProcessIndirectBranches().
|
|
UnknownIndirectBranchOffsets.emplace(Offset);
|
|
break;
|
|
};
|
|
}
|
|
// Indirect call. We only need to fix it if the operand is RIP-relative.
|
|
if (IsSimple && MIB->hasPCRelOperand(Instruction)) {
|
|
if (!handlePCRelOperand(Instruction, AbsoluteInstrAddr, Size)) {
|
|
errs() << "BOLT-ERROR: cannot handle PC-relative operand at 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr)
|
|
<< ". Skipping function " << *this << ".\n";
|
|
if (BC.HasRelocations)
|
|
exit(1);
|
|
IsSimple = false;
|
|
}
|
|
}
|
|
// AArch64 indirect call - check for linker veneers, which lack
|
|
// relocations and need manual adjustments
|
|
MCInst *TargetHiBits, *TargetLowBits;
|
|
uint64_t TargetAddress;
|
|
if (BC.isAArch64() &&
|
|
MIB->matchLinkerVeneer(Instructions.begin(), Instructions.end(),
|
|
AbsoluteInstrAddr, Instruction, TargetHiBits,
|
|
TargetLowBits, TargetAddress)) {
|
|
MIB->addAnnotation(Instruction, "AArch64Veneer", true);
|
|
|
|
uint8_t Counter = 0;
|
|
for (auto It = std::prev(Instructions.end()); Counter != 2;
|
|
--It, ++Counter) {
|
|
MIB->addAnnotation(It->second, "AArch64Veneer", true);
|
|
}
|
|
|
|
fixStubTarget(*TargetLowBits, *TargetHiBits, TargetAddress);
|
|
}
|
|
}
|
|
} else {
|
|
if (MIB->hasPCRelOperand(Instruction) && !UsedReloc) {
|
|
if (!handlePCRelOperand(Instruction, AbsoluteInstrAddr, Size)) {
|
|
errs() << "BOLT-ERROR: cannot handle PC-relative operand at 0x"
|
|
<< Twine::utohexstr(AbsoluteInstrAddr)
|
|
<< ". Skipping function " << *this << ".\n";
|
|
if (BC.HasRelocations)
|
|
exit(1);
|
|
IsSimple = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
add_instruction:
|
|
if (ULT.first && ULT.second) {
|
|
Instruction.setLoc(
|
|
findDebugLineInformationForInstructionAt(AbsoluteInstrAddr, ULT));
|
|
}
|
|
|
|
// Record offset of the instruction for profile matching.
|
|
if (BC.keepOffsetForInstruction(Instruction)) {
|
|
MIB->addAnnotation(Instruction, "Offset", static_cast<uint32_t>(Offset));
|
|
}
|
|
|
|
if (MemData && !emptyRange(MemData->getMemInfoRange(Offset))) {
|
|
MIB->addAnnotation(Instruction, "MemDataOffset", Offset);
|
|
}
|
|
|
|
addInstruction(Offset, std::move(Instruction));
|
|
}
|
|
|
|
updateState(State::Disassembled);
|
|
|
|
postProcessEntryPoints();
|
|
}
|
|
|
|
void BinaryFunction::postProcessEntryPoints() {
|
|
if (!isSimple())
|
|
return;
|
|
|
|
for (auto Offset : EntryOffsets) {
|
|
if (!getInstructionAtOffset(Offset)) {
|
|
// On AArch64 there are legitimate reasons to have references past the
|
|
// end of the function, e.g. jump tables.
|
|
if (BC.isAArch64() && Offset == getSize()) {
|
|
continue;
|
|
}
|
|
|
|
// If we are at Offset 0 and there is no instruction associated with it,
|
|
// this means this is an empty function. Just ignore.
|
|
if (Offset == 0) {
|
|
continue;
|
|
}
|
|
|
|
errs() << "BOLT-WARNING: reference in the middle of instruction "
|
|
"detected in function " << *this
|
|
<< " at offset 0x" << Twine::utohexstr(Offset) << '\n';
|
|
if (BC.HasRelocations) {
|
|
errs() << "BOLT-ERROR: unable to keep processing in relocation mode\n";
|
|
exit(1);
|
|
}
|
|
setSimple(false);
|
|
}
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::postProcessJumpTables() {
|
|
// Create labels for all entries.
|
|
for (auto &JTI : JumpTables) {
|
|
auto &JT = *JTI.second;
|
|
if (JT.Type == JumpTable::JTT_PIC && opts::JumpTables == JTS_BASIC) {
|
|
opts::JumpTables = JTS_MOVE;
|
|
outs() << "BOLT-INFO: forcing -jump-tables=move as PIC jump table was "
|
|
"detected in function " << *this << '\n';
|
|
}
|
|
for (unsigned I = 0; I < JT.OffsetEntries.size(); ++I) {
|
|
auto *Label = getOrCreateLocalLabel(getAddress() + JT.OffsetEntries[I],
|
|
/*CreatePastEnd*/ true);
|
|
JT.Entries.push_back(Label);
|
|
}
|
|
|
|
const auto BDSize = BC.getBinaryDataAtAddress(JT.getAddress())->getSize();
|
|
if (!BDSize) {
|
|
BC.setBinaryDataSize(JT.getAddress(), JT.getSize());
|
|
} else {
|
|
assert(BDSize >= JT.getSize() &&
|
|
"jump table cannot be larger than the containing object");
|
|
}
|
|
}
|
|
|
|
// Add TakenBranches from JumpTables.
|
|
//
|
|
// We want to do it after initial processing since we don't know jump tables'
|
|
// boundaries until we process them all.
|
|
for (auto &JTSite : JTSites) {
|
|
const auto JTSiteOffset = JTSite.first;
|
|
const auto JTAddress = JTSite.second;
|
|
const auto *JT = getJumpTableContainingAddress(JTAddress);
|
|
if (!JT)
|
|
continue;
|
|
assert(JT && "cannot find jump table for address");
|
|
auto EntryOffset = JTAddress - JT->getAddress();
|
|
while (EntryOffset < JT->getSize()) {
|
|
auto TargetOffset = JT->OffsetEntries[EntryOffset / JT->EntrySize];
|
|
if (TargetOffset < getSize()) {
|
|
TakenBranches.emplace_back(JTSiteOffset, TargetOffset);
|
|
|
|
if (opts::StrictMode)
|
|
registerReferencedOffset(TargetOffset);
|
|
}
|
|
|
|
// Take ownership of jump table relocations.
|
|
if (BC.HasRelocations) {
|
|
auto EntryAddress = JT->getAddress() + EntryOffset;
|
|
auto Res = BC.removeRelocationAt(EntryAddress);
|
|
(void)Res;
|
|
DEBUG(
|
|
auto Section = BC.getSectionForAddress(EntryAddress);
|
|
auto Offset = EntryAddress - Section->getAddress();
|
|
dbgs() << "BOLT-DEBUG: removing relocation from section "
|
|
<< Section->getName() << " at offset 0x"
|
|
<< Twine::utohexstr(Offset) << " = "
|
|
<< Res << '\n');
|
|
}
|
|
|
|
EntryOffset += JT->EntrySize;
|
|
|
|
// A label at the next entry means the end of this jump table.
|
|
if (JT->Labels.count(EntryOffset))
|
|
break;
|
|
}
|
|
}
|
|
clearList(JTSites);
|
|
|
|
// Free memory used by jump table offsets.
|
|
for (auto &JTI : JumpTables) {
|
|
auto &JT = *JTI.second;
|
|
clearList(JT.OffsetEntries);
|
|
}
|
|
|
|
// Conservatively populate all possible destinations for unknown indirect
|
|
// branches.
|
|
if (opts::StrictMode && hasInternalReference()) {
|
|
for (auto Offset : UnknownIndirectBranchOffsets) {
|
|
for (auto PossibleDestination : ExternallyReferencedOffsets) {
|
|
TakenBranches.emplace_back(Offset, PossibleDestination);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Remove duplicates branches. We can get a bunch of them from jump tables.
|
|
// Without doing jump table value profiling we don't have use for extra
|
|
// (duplicate) branches.
|
|
std::sort(TakenBranches.begin(), TakenBranches.end());
|
|
auto NewEnd = std::unique(TakenBranches.begin(), TakenBranches.end());
|
|
TakenBranches.erase(NewEnd, TakenBranches.end());
|
|
}
|
|
|
|
bool BinaryFunction::postProcessIndirectBranches(
|
|
MCPlusBuilder::AllocatorIdTy AllocId) {
|
|
auto addUnknownControlFlow = [&](BinaryBasicBlock &BB) {
|
|
HasUnknownControlFlow = true;
|
|
BB.removeAllSuccessors();
|
|
for (auto PossibleDestination : ExternallyReferencedOffsets) {
|
|
if (auto *SuccBB = getBasicBlockAtOffset(PossibleDestination))
|
|
BB.addSuccessor(SuccBB);
|
|
}
|
|
};
|
|
|
|
uint64_t NumIndirectJumps{0};
|
|
MCInst *LastIndirectJump = nullptr;
|
|
BinaryBasicBlock *LastIndirectJumpBB{nullptr};
|
|
uint64_t LastJT{0};
|
|
uint16_t LastJTIndexReg = BC.MIB->getNoRegister();
|
|
for (auto *BB : layout()) {
|
|
for (auto &Instr : *BB) {
|
|
if (!BC.MIB->isIndirectBranch(Instr))
|
|
continue;
|
|
|
|
// If there's an indirect branch in a single-block function -
|
|
// it must be a tail call.
|
|
if (layout_size() == 1) {
|
|
BC.MIB->convertJmpToTailCall(Instr);
|
|
return true;
|
|
}
|
|
|
|
++NumIndirectJumps;
|
|
|
|
if (opts::StrictMode && !hasInternalReference()) {
|
|
BC.MIB->convertJmpToTailCall(Instr);
|
|
break;
|
|
}
|
|
|
|
// Validate the tail call or jump table assumptions now that we know
|
|
// basic block boundaries.
|
|
if (BC.MIB->isTailCall(Instr) || BC.MIB->getJumpTable(Instr)) {
|
|
const auto PtrSize = BC.AsmInfo->getCodePointerSize();
|
|
MCInst *MemLocInstr;
|
|
unsigned BaseRegNum, IndexRegNum;
|
|
int64_t DispValue;
|
|
const MCExpr *DispExpr;
|
|
MCInst *PCRelBaseInstr;
|
|
auto Type = BC.MIB->analyzeIndirectBranch(Instr,
|
|
BB->begin(),
|
|
BB->end(),
|
|
PtrSize,
|
|
MemLocInstr,
|
|
BaseRegNum,
|
|
IndexRegNum,
|
|
DispValue,
|
|
DispExpr,
|
|
PCRelBaseInstr);
|
|
if (Type != IndirectBranchType::UNKNOWN || MemLocInstr != nullptr)
|
|
continue;
|
|
|
|
if (!opts::StrictMode)
|
|
return false;
|
|
|
|
if (BC.MIB->isTailCall(Instr)) {
|
|
BC.MIB->convertTailCallToJmp(Instr);
|
|
} else {
|
|
LastIndirectJump = &Instr;
|
|
LastIndirectJumpBB = BB;
|
|
LastJT = BC.MIB->getJumpTable(Instr);
|
|
LastJTIndexReg = BC.MIB->getJumpTableIndexReg(Instr);
|
|
BC.MIB->unsetJumpTable(Instr);
|
|
|
|
auto *JT = BC.getJumpTableContainingAddress(LastJT);
|
|
if (JT->Type == JumpTable::JTT_NORMAL) {
|
|
// Invalidating the jump table may also invalidate other jump table
|
|
// boundaries. Until we have/need a support for this, mark the
|
|
// function as non-simple.
|
|
DEBUG(dbgs() << "BOLT-DEBUG: rejected jump table reference"
|
|
<< JT->getName() << " in " << *this << '\n');
|
|
return false;
|
|
}
|
|
}
|
|
|
|
addUnknownControlFlow(*BB);
|
|
continue;
|
|
}
|
|
|
|
// If this block contains an epilogue code and has an indirect branch,
|
|
// then most likely it's a tail call. Otherwise, we cannot tell for sure
|
|
// what it is and conservatively reject the function's CFG.
|
|
bool IsEpilogue = false;
|
|
for (const auto &Instr : *BB) {
|
|
if (BC.MIB->isLeave(Instr) || BC.MIB->isPop(Instr)) {
|
|
IsEpilogue = true;
|
|
break;
|
|
}
|
|
}
|
|
if (IsEpilogue) {
|
|
BC.MIB->convertJmpToTailCall(Instr);
|
|
BB->removeAllSuccessors();
|
|
continue;
|
|
}
|
|
|
|
if (opts::Verbosity >= 2) {
|
|
outs() << "BOLT-INFO: rejected potential indirect tail call in "
|
|
<< "function " << *this << " in basic block "
|
|
<< BB->getName() << ".\n";
|
|
DEBUG(BC.printInstructions(dbgs(), BB->begin(), BB->end(),
|
|
BB->getOffset(), this, true));
|
|
}
|
|
|
|
if (!opts::StrictMode)
|
|
return false;
|
|
|
|
addUnknownControlFlow(*BB);
|
|
}
|
|
}
|
|
|
|
if (HasInternalLabelReference)
|
|
return false;
|
|
|
|
// If there's only one jump table, and one indirect jump, and no other
|
|
// references, then we should be able to derive the jump table even if we
|
|
// fail to match the pattern.
|
|
if (HasUnknownControlFlow && NumIndirectJumps == 1 &&
|
|
JumpTables.size() == 1 && LastIndirectJump) {
|
|
BC.MIB->setJumpTable(*LastIndirectJump, LastJT, LastJTIndexReg, AllocId);
|
|
HasUnknownControlFlow = false;
|
|
|
|
// re-populate successors based on the jump table.
|
|
std::set<const MCSymbol *> JTLabels;
|
|
LastIndirectJumpBB->removeAllSuccessors();
|
|
const auto *JT = getJumpTableContainingAddress(LastJT);
|
|
for (const auto *Label : JT->Entries) {
|
|
JTLabels.emplace(Label);
|
|
}
|
|
for (const auto *Label : JTLabels) {
|
|
LastIndirectJumpBB->addSuccessor(getBasicBlockForLabel(Label));
|
|
}
|
|
}
|
|
|
|
if (HasFixedIndirectBranch)
|
|
return false;
|
|
|
|
if (HasUnknownControlFlow && !BC.HasRelocations)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
void BinaryFunction::recomputeLandingPads() {
|
|
updateBBIndices(0);
|
|
|
|
for (auto *BB : BasicBlocks) {
|
|
BB->LandingPads.clear();
|
|
BB->Throwers.clear();
|
|
}
|
|
|
|
for (auto *BB : BasicBlocks) {
|
|
std::unordered_set<const BinaryBasicBlock *> BBLandingPads;
|
|
for (auto &Instr : *BB) {
|
|
if (!BC.MIB->isInvoke(Instr))
|
|
continue;
|
|
|
|
const auto EHInfo = BC.MIB->getEHInfo(Instr);
|
|
if (!EHInfo || !EHInfo->first)
|
|
continue;
|
|
|
|
auto *LPBlock = getBasicBlockForLabel(EHInfo->first);
|
|
if (!BBLandingPads.count(LPBlock)) {
|
|
BBLandingPads.insert(LPBlock);
|
|
BB->LandingPads.emplace_back(LPBlock);
|
|
LPBlock->Throwers.emplace_back(BB);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
bool BinaryFunction::buildCFG(MCPlusBuilder::AllocatorIdTy AllocatorId) {
|
|
auto &MIB = BC.MIB;
|
|
|
|
if (!isSimple()) {
|
|
assert(!BC.HasRelocations &&
|
|
"cannot process file with non-simple function in relocs mode");
|
|
return false;
|
|
}
|
|
|
|
if (CurrentState != State::Disassembled)
|
|
return false;
|
|
|
|
assert(BasicBlocks.empty() && "basic block list should be empty");
|
|
assert((Labels.find(0) != Labels.end()) &&
|
|
"first instruction should always have a label");
|
|
|
|
// Create basic blocks in the original layout order:
|
|
//
|
|
// * Every instruction with associated label marks
|
|
// the beginning of a basic block.
|
|
// * Conditional instruction marks the end of a basic block,
|
|
// except when the following instruction is an
|
|
// unconditional branch, and the unconditional branch is not
|
|
// a destination of another branch. In the latter case, the
|
|
// basic block will consist of a single unconditional branch
|
|
// (missed "double-jump" optimization).
|
|
//
|
|
// Created basic blocks are sorted in layout order since they are
|
|
// created in the same order as instructions, and instructions are
|
|
// sorted by offsets.
|
|
BinaryBasicBlock *InsertBB{nullptr};
|
|
BinaryBasicBlock *PrevBB{nullptr};
|
|
bool IsLastInstrNop{false};
|
|
uint64_t LastInstrOffset{0};
|
|
|
|
auto addCFIPlaceholders =
|
|
[this](uint64_t CFIOffset, BinaryBasicBlock *InsertBB) {
|
|
for (auto FI = OffsetToCFI.lower_bound(CFIOffset),
|
|
FE = OffsetToCFI.upper_bound(CFIOffset);
|
|
FI != FE; ++FI) {
|
|
addCFIPseudo(InsertBB, InsertBB->end(), FI->second);
|
|
}
|
|
};
|
|
|
|
// For profiling purposes we need to save the offset of the last instruction
|
|
// in the basic block. But in certain cases we don't if the instruction was
|
|
// the last one, and we have to go back and update its offset.
|
|
auto updateOffset = [&](uint64_t Offset) {
|
|
assert(PrevBB && PrevBB != InsertBB && "invalid previous block");
|
|
auto *PrevInstr = PrevBB->getLastNonPseudoInstr();
|
|
if (PrevInstr && !MIB->hasAnnotation(*PrevInstr, "Offset"))
|
|
MIB->addAnnotation(*PrevInstr, "Offset", static_cast<uint32_t>(Offset),
|
|
AllocatorId);
|
|
};
|
|
|
|
for (auto I = Instructions.begin(), E = Instructions.end(); I != E; ++I) {
|
|
const auto Offset = I->first;
|
|
auto &Instr = I->second;
|
|
|
|
auto LI = Labels.find(Offset);
|
|
if (LI != Labels.end()) {
|
|
// Always create new BB at branch destination.
|
|
PrevBB = InsertBB;
|
|
InsertBB = addBasicBlock(LI->first, LI->second,
|
|
opts::PreserveBlocksAlignment && IsLastInstrNop);
|
|
if (hasEntryPointAtOffset(Offset))
|
|
InsertBB->setEntryPoint();
|
|
if (PrevBB)
|
|
updateOffset(LastInstrOffset);
|
|
}
|
|
|
|
const auto InstrInputAddr = I->first + Address;
|
|
bool IsSDTMarker =
|
|
MIB->isNoop(Instr) && BC.SDTMarkers.count(InstrInputAddr);
|
|
|
|
if (IsSDTMarker) {
|
|
HasSDTMarker = true;
|
|
DEBUG(dbgs() << "SDTMarker detected in the input at : "
|
|
<< utohexstr(InstrInputAddr) << "\n");
|
|
|
|
MIB->addAnnotation<uint64_t>(Instr, "SDTMarker", InstrInputAddr,
|
|
AllocatorId);
|
|
|
|
// This mutex is used to lock concurrent writes to GlobalSymbols and
|
|
// BinaryDataMap that happens in registerNameAtAddress
|
|
{
|
|
static std::shared_timed_mutex GlobalSymbolCreationMtx;
|
|
std::unique_lock<std::shared_timed_mutex> Lock(GlobalSymbolCreationMtx);
|
|
BC.SDTMarkers[InstrInputAddr].Label =
|
|
getOrCreateLocalLabel(InstrInputAddr);
|
|
}
|
|
}
|
|
|
|
// Ignore nops except SDT markers. We use nops to derive alignment of the
|
|
// next basic block. It will not always work, as some blocks are naturally
|
|
// aligned, but it's just part of heuristic for block alignment.
|
|
if (MIB->isNoop(Instr) && !PreserveNops && !IsSDTMarker) {
|
|
IsLastInstrNop = true;
|
|
continue;
|
|
}
|
|
if (!InsertBB) {
|
|
// It must be a fallthrough or unreachable code. Create a new block unless
|
|
// we see an unconditional branch following a conditional one. The latter
|
|
// should not be a conditional tail call.
|
|
assert(PrevBB && "no previous basic block for a fall through");
|
|
auto *PrevInstr = PrevBB->getLastNonPseudoInstr();
|
|
assert(PrevInstr && "no previous instruction for a fall through");
|
|
if (MIB->isUnconditionalBranch(Instr) &&
|
|
!MIB->isUnconditionalBranch(*PrevInstr) &&
|
|
!MIB->getConditionalTailCall(*PrevInstr)) {
|
|
// Temporarily restore inserter basic block.
|
|
InsertBB = PrevBB;
|
|
} else {
|
|
MCSymbol *Label;
|
|
{
|
|
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
|
|
Label = BC.Ctx->createTempSymbol("FT", true);
|
|
}
|
|
InsertBB = addBasicBlock(
|
|
Offset, Label, opts::PreserveBlocksAlignment && IsLastInstrNop);
|
|
updateOffset(LastInstrOffset);
|
|
}
|
|
}
|
|
if (Offset == 0) {
|
|
// Add associated CFI pseudos in the first offset (0)
|
|
addCFIPlaceholders(0, InsertBB);
|
|
}
|
|
|
|
const auto IsBlockEnd = MIB->isTerminator(Instr);
|
|
IsLastInstrNop = MIB->isNoop(Instr);
|
|
LastInstrOffset = Offset;
|
|
InsertBB->addInstruction(std::move(Instr));
|
|
|
|
// Add associated CFI instrs. We always add the CFI instruction that is
|
|
// located immediately after this instruction, since the next CFI
|
|
// instruction reflects the change in state caused by this instruction.
|
|
auto NextInstr = std::next(I);
|
|
uint64_t CFIOffset;
|
|
if (NextInstr != E)
|
|
CFIOffset = NextInstr->first;
|
|
else
|
|
CFIOffset = getSize();
|
|
|
|
// Note: this potentially invalidates instruction pointers/iterators.
|
|
addCFIPlaceholders(CFIOffset, InsertBB);
|
|
|
|
if (IsBlockEnd) {
|
|
PrevBB = InsertBB;
|
|
InsertBB = nullptr;
|
|
}
|
|
}
|
|
|
|
if (BasicBlocks.empty()) {
|
|
setSimple(false);
|
|
return false;
|
|
}
|
|
|
|
// Intermediate dump.
|
|
DEBUG(print(dbgs(), "after creating basic blocks"));
|
|
|
|
// TODO: handle properly calls to no-return functions,
|
|
// e.g. exit(3), etc. Otherwise we'll see a false fall-through
|
|
// blocks.
|
|
|
|
for (auto &Branch : TakenBranches) {
|
|
DEBUG(dbgs() << "registering branch [0x" << Twine::utohexstr(Branch.first)
|
|
<< "] -> [0x" << Twine::utohexstr(Branch.second) << "]\n");
|
|
auto *FromBB = getBasicBlockContainingOffset(Branch.first);
|
|
auto *ToBB = getBasicBlockAtOffset(Branch.second);
|
|
if (!FromBB || !ToBB) {
|
|
if (!FromBB)
|
|
errs() << "BOLT-ERROR: cannot find BB containing the branch.\n";
|
|
if (!ToBB)
|
|
errs() << "BOLT-ERROR: cannot find BB containing branch destination.\n";
|
|
BC.exitWithBugReport("disassembly failed - inconsistent branch found.",
|
|
*this);
|
|
}
|
|
|
|
FromBB->addSuccessor(ToBB);
|
|
}
|
|
|
|
// Add fall-through branches.
|
|
PrevBB = nullptr;
|
|
bool IsPrevFT = false; // Is previous block a fall-through.
|
|
for (auto BB : BasicBlocks) {
|
|
if (IsPrevFT) {
|
|
PrevBB->addSuccessor(BB);
|
|
}
|
|
if (BB->empty()) {
|
|
IsPrevFT = true;
|
|
PrevBB = BB;
|
|
continue;
|
|
}
|
|
|
|
auto LastInstr = BB->getLastNonPseudoInstr();
|
|
assert(LastInstr &&
|
|
"should have non-pseudo instruction in non-empty block");
|
|
|
|
if (BB->succ_size() == 0) {
|
|
// Since there's no existing successors, we know the last instruction is
|
|
// not a conditional branch. Thus if it's a terminator, it shouldn't be a
|
|
// fall-through.
|
|
//
|
|
// Conditional tail call is a special case since we don't add a taken
|
|
// branch successor for it.
|
|
IsPrevFT = !MIB->isTerminator(*LastInstr) ||
|
|
MIB->getConditionalTailCall(*LastInstr);
|
|
} else if (BB->succ_size() == 1) {
|
|
IsPrevFT = MIB->isConditionalBranch(*LastInstr);
|
|
} else {
|
|
IsPrevFT = false;
|
|
}
|
|
|
|
PrevBB = BB;
|
|
}
|
|
|
|
if (!IsPrevFT) {
|
|
// Possibly a call that does not return.
|
|
DEBUG(dbgs() << "last block was marked as a fall-through in " << *this
|
|
<< '\n');
|
|
}
|
|
|
|
// Assign landing pads and throwers info.
|
|
recomputeLandingPads();
|
|
|
|
// Assign CFI information to each BB entry.
|
|
annotateCFIState();
|
|
|
|
// Annotate invoke instructions with GNU_args_size data.
|
|
propagateGnuArgsSizeInfo(AllocatorId);
|
|
|
|
// Set the basic block layout to the original order and set end offsets.
|
|
PrevBB = nullptr;
|
|
for (auto BB : BasicBlocks) {
|
|
BasicBlocksLayout.emplace_back(BB);
|
|
if (PrevBB)
|
|
PrevBB->setEndOffset(BB->getOffset());
|
|
PrevBB = BB;
|
|
}
|
|
PrevBB->setEndOffset(getSize());
|
|
|
|
updateLayoutIndices();
|
|
|
|
normalizeCFIState();
|
|
|
|
// Clean-up memory taken by intermediate structures.
|
|
//
|
|
// NB: don't clear Labels list as we may need them if we mark the function
|
|
// as non-simple later in the process of discovering extra entry points.
|
|
clearList(Instructions);
|
|
clearList(OffsetToCFI);
|
|
clearList(TakenBranches);
|
|
|
|
// Update the state.
|
|
CurrentState = State::CFG;
|
|
|
|
// Make any necessary adjustments for indirect branches.
|
|
if (!postProcessIndirectBranches(AllocatorId)) {
|
|
if (opts::Verbosity) {
|
|
errs() << "BOLT-WARNING: failed to post-process indirect branches for "
|
|
<< *this << '\n';
|
|
}
|
|
// In relocation mode we want to keep processing the function but avoid
|
|
// optimizing it.
|
|
setSimple(false);
|
|
}
|
|
|
|
clearList(ExternallyReferencedOffsets);
|
|
clearList(UnknownIndirectBranchOffsets);
|
|
|
|
return true;
|
|
}
|
|
|
|
void BinaryFunction::postProcessCFG() {
|
|
if (isSimple() && !BasicBlocks.empty()) {
|
|
// Convert conditional tail call branches to conditional branches that jump
|
|
// to a tail call.
|
|
removeConditionalTailCalls();
|
|
|
|
postProcessProfile();
|
|
|
|
// Eliminate inconsistencies between branch instructions and CFG.
|
|
postProcessBranches();
|
|
}
|
|
|
|
calculateMacroOpFusionStats();
|
|
|
|
// The final cleanup of intermediate structures.
|
|
clearList(IgnoredBranches);
|
|
clearList(EntryOffsets);
|
|
|
|
// Remove "Offset" annotations, unless we need to write a BOLT address
|
|
// translation table later. This has no cost, since annotations are allocated
|
|
// by a bumpptr allocator and won't be released anyway until late in the
|
|
// pipeline.
|
|
if (!opts::EnableBAT && !opts::Instrument)
|
|
for (auto *BB : layout())
|
|
for (auto &Inst : *BB)
|
|
BC.MIB->removeAnnotation(Inst, "Offset");
|
|
|
|
assert((!isSimple() || validateCFG()) &&
|
|
"invalid CFG detected after post-processing");
|
|
}
|
|
|
|
void BinaryFunction::calculateMacroOpFusionStats() {
|
|
if (!getBinaryContext().isX86())
|
|
return;
|
|
for (auto *BB : layout()) {
|
|
auto II = BB->getMacroOpFusionPair();
|
|
if (II == BB->end())
|
|
continue;
|
|
|
|
// Check offset of the second instruction.
|
|
// FIXME: arch-specific.
|
|
const auto Offset =
|
|
BC.MIB->getAnnotationWithDefault<uint32_t>(*std::next(II), "Offset", 0);
|
|
if (!Offset || (getAddress() + Offset) % 64)
|
|
continue;
|
|
|
|
DEBUG(dbgs() << "\nmissed macro-op fusion at address 0x"
|
|
<< Twine::utohexstr(getAddress() + Offset) << " in function "
|
|
<< *this << "; executed " << BB->getKnownExecutionCount()
|
|
<< " times.\n");
|
|
++BC.MissedMacroFusionPairs;
|
|
BC.MissedMacroFusionExecCount += BB->getKnownExecutionCount();
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::removeTagsFromProfile() {
|
|
for (auto *BB : BasicBlocks) {
|
|
if (BB->ExecutionCount == BinaryBasicBlock::COUNT_NO_PROFILE)
|
|
BB->ExecutionCount = 0;
|
|
for (auto &BI : BB->branch_info()) {
|
|
if (BI.Count != BinaryBasicBlock::COUNT_NO_PROFILE &&
|
|
BI.MispredictedCount != BinaryBasicBlock::COUNT_NO_PROFILE)
|
|
continue;
|
|
BI.Count = 0;
|
|
BI.MispredictedCount = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::updateReferences(const MCSymbol *From, const MCSymbol *To) {
|
|
assert(CurrentState == State::Empty || CurrentState == State::Disassembled);
|
|
assert(From && To && "invalid symbols");
|
|
|
|
for (auto I = Instructions.begin(), E = Instructions.end(); I != E; ++I) {
|
|
auto &Inst = I->second;
|
|
for (int I = 0, E = MCPlus::getNumPrimeOperands(Inst); I != E; ++I) {
|
|
const MCSymbol *S = BC.MIB->getTargetSymbol(Inst, I);
|
|
if (S == From)
|
|
BC.MIB->setOperandToSymbolRef(Inst, I, To, 0, &*BC.Ctx, 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::addEntryPoint(uint64_t Address) {
|
|
assert(containsAddress(Address) && "address does not belong to the function");
|
|
|
|
auto Offset = Address - getAddress();
|
|
|
|
DEBUG(dbgs() << "BOLT-INFO: adding external entry point to function " << *this
|
|
<< " at offset 0x" << Twine::utohexstr(Address - getAddress())
|
|
<< '\n');
|
|
|
|
auto *EntryBD = BC.getBinaryDataAtAddress(Address);
|
|
auto *EntrySymbol = EntryBD ? EntryBD->getSymbol() : nullptr;
|
|
|
|
// If we haven't built CFG for the function, we can add a new entry point
|
|
// even if it doesn't have an associated entry in the symbol table.
|
|
if (CurrentState == State::Empty || CurrentState == State::Disassembled) {
|
|
auto Iter = Labels.find(Offset);
|
|
const MCSymbol *OldSym = Iter != Labels.end() ? Iter->second : nullptr;
|
|
if (!EntrySymbol) {
|
|
DEBUG(dbgs() << "creating local label\n");
|
|
EntrySymbol = getOrCreateLocalLabel(Address);
|
|
} else {
|
|
DEBUG(dbgs() << "using global symbol " << EntrySymbol->getName() << '\n');
|
|
}
|
|
addEntryPointAtOffset(Address - getAddress());
|
|
Labels.emplace(Offset, EntrySymbol);
|
|
if (OldSym != nullptr && EntrySymbol != OldSym) {
|
|
updateReferences(OldSym, EntrySymbol);
|
|
}
|
|
return;
|
|
}
|
|
|
|
assert(EntrySymbol && "expected symbol at address");
|
|
|
|
if (isSimple()) {
|
|
// Find basic block corresponding to the address and substitute label.
|
|
auto *BB = getBasicBlockAtOffset(Offset);
|
|
if (!BB) {
|
|
// TODO #14762450: split basic block and process function.
|
|
if (opts::Verbosity || BC.HasRelocations) {
|
|
errs() << "BOLT-WARNING: no basic block at offset 0x"
|
|
<< Twine::utohexstr(Offset) << " in function " << *this
|
|
<< ". Marking non-simple.\n";
|
|
}
|
|
setSimple(false);
|
|
} else {
|
|
BB->setLabel(EntrySymbol);
|
|
BB->setEntryPoint(true);
|
|
}
|
|
}
|
|
|
|
// Fix/append labels list.
|
|
auto LI = Labels.find(Offset);
|
|
if (LI != Labels.end()) {
|
|
LI->second = EntrySymbol;
|
|
} else {
|
|
Labels.emplace(Offset, EntrySymbol);
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::removeConditionalTailCalls() {
|
|
// Blocks to be appended at the end.
|
|
std::vector<std::unique_ptr<BinaryBasicBlock>> NewBlocks;
|
|
|
|
for (auto BBI = begin(); BBI != end(); ++BBI) {
|
|
auto &BB = *BBI;
|
|
auto *CTCInstr = BB.getLastNonPseudoInstr();
|
|
if (!CTCInstr)
|
|
continue;
|
|
|
|
auto TargetAddressOrNone = BC.MIB->getConditionalTailCall(*CTCInstr);
|
|
if (!TargetAddressOrNone)
|
|
continue;
|
|
|
|
// Gather all necessary information about CTC instruction before
|
|
// annotations are destroyed.
|
|
const auto CFIStateBeforeCTC = BB.getCFIStateAtInstr(CTCInstr);
|
|
uint64_t CTCTakenCount = BinaryBasicBlock::COUNT_NO_PROFILE;
|
|
uint64_t CTCMispredCount = BinaryBasicBlock::COUNT_NO_PROFILE;
|
|
if (hasValidProfile()) {
|
|
CTCTakenCount =
|
|
BC.MIB->getAnnotationWithDefault<uint64_t>(*CTCInstr, "CTCTakenCount");
|
|
CTCMispredCount =
|
|
BC.MIB->getAnnotationWithDefault<uint64_t>(*CTCInstr,
|
|
"CTCMispredCount");
|
|
}
|
|
|
|
// Assert that the tail call does not throw.
|
|
assert(!BC.MIB->getEHInfo(*CTCInstr) &&
|
|
"found tail call with associated landing pad");
|
|
|
|
// Create a basic block with an unconditional tail call instruction using
|
|
// the same destination.
|
|
const auto *CTCTargetLabel = BC.MIB->getTargetSymbol(*CTCInstr);
|
|
assert(CTCTargetLabel && "symbol expected for conditional tail call");
|
|
MCInst TailCallInstr;
|
|
BC.MIB->createTailCall(TailCallInstr, CTCTargetLabel, BC.Ctx.get());
|
|
// Link new BBs to the original input offset of the BB where the CTC
|
|
// is, so we can map samples recorded in new BBs back to the original BB
|
|
// seem in the input binary (if using BAT)
|
|
auto TailCallBB = createBasicBlock(BB.getInputOffset(),
|
|
BC.Ctx->createTempSymbol("TC", true));
|
|
TailCallBB->addInstruction(TailCallInstr);
|
|
TailCallBB->setCFIState(CFIStateBeforeCTC);
|
|
|
|
// Add CFG edge with profile info from BB to TailCallBB.
|
|
BB.addSuccessor(TailCallBB.get(), CTCTakenCount, CTCMispredCount);
|
|
|
|
// Add execution count for the block.
|
|
TailCallBB->setExecutionCount(CTCTakenCount);
|
|
|
|
BC.MIB->convertTailCallToJmp(*CTCInstr);
|
|
|
|
BC.MIB->replaceBranchTarget(*CTCInstr, TailCallBB->getLabel(),
|
|
BC.Ctx.get());
|
|
|
|
// Add basic block to the list that will be added to the end.
|
|
NewBlocks.emplace_back(std::move(TailCallBB));
|
|
|
|
// Swap edges as the TailCallBB corresponds to the taken branch.
|
|
BB.swapConditionalSuccessors();
|
|
|
|
// This branch is no longer a conditional tail call.
|
|
BC.MIB->unsetConditionalTailCall(*CTCInstr);
|
|
}
|
|
|
|
insertBasicBlocks(std::prev(end()),
|
|
std::move(NewBlocks),
|
|
/* UpdateLayout */ true,
|
|
/* UpdateCFIState */ false);
|
|
}
|
|
|
|
uint64_t BinaryFunction::getFunctionScore() const {
|
|
if (FunctionScore != -1)
|
|
return FunctionScore;
|
|
|
|
if (!isSimple() || !hasValidProfile()) {
|
|
FunctionScore = 0;
|
|
return FunctionScore;
|
|
}
|
|
|
|
uint64_t TotalScore = 0ULL;
|
|
for (auto BB : layout()) {
|
|
uint64_t BBExecCount = BB->getExecutionCount();
|
|
if (BBExecCount == BinaryBasicBlock::COUNT_NO_PROFILE)
|
|
continue;
|
|
TotalScore += BBExecCount;
|
|
}
|
|
FunctionScore = TotalScore;
|
|
return FunctionScore;
|
|
}
|
|
|
|
void BinaryFunction::annotateCFIState() {
|
|
assert(CurrentState == State::Disassembled && "unexpected function state");
|
|
assert(!BasicBlocks.empty() && "basic block list should not be empty");
|
|
|
|
// This is an index of the last processed CFI in FDE CFI program.
|
|
uint32_t State = 0;
|
|
|
|
// This is an index of RememberState CFI reflecting effective state right
|
|
// after execution of RestoreState CFI.
|
|
//
|
|
// It differs from State iff the CFI at (State-1)
|
|
// was RestoreState (modulo GNU_args_size CFIs, which are ignored).
|
|
//
|
|
// This allows us to generate shorter replay sequences when producing new
|
|
// CFI programs.
|
|
uint32_t EffectiveState = 0;
|
|
|
|
// For tracking RememberState/RestoreState sequences.
|
|
std::stack<uint32_t> StateStack;
|
|
|
|
for (auto *BB : BasicBlocks) {
|
|
BB->setCFIState(EffectiveState);
|
|
|
|
for (const auto &Instr : *BB) {
|
|
const auto *CFI = getCFIFor(Instr);
|
|
if (!CFI)
|
|
continue;
|
|
|
|
++State;
|
|
|
|
switch (CFI->getOperation()) {
|
|
case MCCFIInstruction::OpRememberState:
|
|
StateStack.push(EffectiveState);
|
|
EffectiveState = State;
|
|
break;
|
|
case MCCFIInstruction::OpRestoreState:
|
|
assert(!StateStack.empty() && "corrupt CFI stack");
|
|
EffectiveState = StateStack.top();
|
|
StateStack.pop();
|
|
break;
|
|
case MCCFIInstruction::OpGnuArgsSize:
|
|
// OpGnuArgsSize CFIs do not affect the CFI state.
|
|
break;
|
|
default:
|
|
// Any other CFI updates the state.
|
|
EffectiveState = State;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
assert(StateStack.empty() && "corrupt CFI stack");
|
|
}
|
|
|
|
namespace {
|
|
|
|
/// Our full interpretation of a DWARF CFI machine state at a given point
|
|
struct CFISnapshot {
|
|
/// CFA register number and offset defining the canonical frame at this
|
|
/// point, or the number of a rule (CFI state) that computes it with a
|
|
/// DWARF expression. This number will be negative if it refers to a CFI
|
|
/// located in the CIE instead of the FDE.
|
|
uint32_t CFAReg;
|
|
int32_t CFAOffset;
|
|
int32_t CFARule;
|
|
/// Mapping of rules (CFI states) that define the location of each
|
|
/// register. If absent, no rule defining the location of such register
|
|
/// was ever read. This number will be negative if it refers to a CFI
|
|
/// located in the CIE instead of the FDE.
|
|
DenseMap<int32_t, int32_t> RegRule;
|
|
|
|
/// References to CIE, FDE and expanded instructions after a restore state
|
|
const std::vector<MCCFIInstruction> &CIE;
|
|
const std::vector<MCCFIInstruction> &FDE;
|
|
const DenseMap<int32_t, SmallVector<int32_t, 4>> &FrameRestoreEquivalents;
|
|
|
|
/// Current FDE CFI number representing the state where the snapshot is at
|
|
int32_t CurState;
|
|
|
|
/// Used when we don't have information about which state/rule to apply
|
|
/// to recover the location of either the CFA or a specific register
|
|
constexpr static int32_t UNKNOWN = std::numeric_limits<int32_t>::min();
|
|
|
|
private:
|
|
/// Update our snapshot by executing a single CFI
|
|
void update(const MCCFIInstruction &Instr, int32_t RuleNumber) {
|
|
switch (Instr.getOperation()) {
|
|
case MCCFIInstruction::OpSameValue:
|
|
case MCCFIInstruction::OpRelOffset:
|
|
case MCCFIInstruction::OpOffset:
|
|
case MCCFIInstruction::OpRestore:
|
|
case MCCFIInstruction::OpUndefined:
|
|
case MCCFIInstruction::OpRegister:
|
|
case MCCFIInstruction::OpExpression:
|
|
case MCCFIInstruction::OpValExpression:
|
|
RegRule[Instr.getRegister()] = RuleNumber;
|
|
break;
|
|
case MCCFIInstruction::OpDefCfaRegister:
|
|
CFAReg = Instr.getRegister();
|
|
CFARule = UNKNOWN;
|
|
break;
|
|
case MCCFIInstruction::OpDefCfaOffset:
|
|
CFAOffset = Instr.getOffset();
|
|
CFARule = UNKNOWN;
|
|
break;
|
|
case MCCFIInstruction::OpDefCfa:
|
|
CFAReg = Instr.getRegister();
|
|
CFAOffset = Instr.getOffset();
|
|
CFARule = UNKNOWN;
|
|
break;
|
|
case MCCFIInstruction::OpDefCfaExpression:
|
|
CFARule = RuleNumber;
|
|
break;
|
|
case MCCFIInstruction::OpAdjustCfaOffset:
|
|
case MCCFIInstruction::OpWindowSave:
|
|
case MCCFIInstruction::OpEscape:
|
|
llvm_unreachable("unsupported CFI opcode");
|
|
break;
|
|
case MCCFIInstruction::OpRememberState:
|
|
case MCCFIInstruction::OpRestoreState:
|
|
case MCCFIInstruction::OpGnuArgsSize:
|
|
// do not affect CFI state
|
|
break;
|
|
}
|
|
}
|
|
|
|
public:
|
|
/// Advance state reading FDE CFI instructions up to State number
|
|
void advanceTo(int32_t State) {
|
|
for (int32_t I = CurState, E = State; I != E; ++I) {
|
|
const auto &Instr = FDE[I];
|
|
if (Instr.getOperation() != MCCFIInstruction::OpRestoreState) {
|
|
update(Instr, I);
|
|
continue;
|
|
}
|
|
// If restore state instruction, fetch the equivalent CFIs that have
|
|
// the same effect of this restore. This is used to ensure remember-
|
|
// restore pairs are completely removed.
|
|
auto Iter = FrameRestoreEquivalents.find(I);
|
|
if (Iter == FrameRestoreEquivalents.end())
|
|
continue;
|
|
for (int32_t RuleNumber : Iter->second) {
|
|
update(FDE[RuleNumber], RuleNumber);
|
|
}
|
|
}
|
|
|
|
assert(((CFAReg != (uint32_t)UNKNOWN && CFAOffset != UNKNOWN) ||
|
|
CFARule != UNKNOWN) &&
|
|
"CIE did not define default CFA?");
|
|
|
|
CurState = State;
|
|
}
|
|
|
|
/// Interpret all CIE and FDE instructions up until CFI State number and
|
|
/// populate this snapshot
|
|
CFISnapshot(
|
|
const std::vector<MCCFIInstruction> &CIE,
|
|
const std::vector<MCCFIInstruction> &FDE,
|
|
const DenseMap<int32_t, SmallVector<int32_t, 4>> &FrameRestoreEquivalents,
|
|
int32_t State)
|
|
: CIE(CIE), FDE(FDE), FrameRestoreEquivalents(FrameRestoreEquivalents) {
|
|
CFAReg = UNKNOWN;
|
|
CFAOffset = UNKNOWN;
|
|
CFARule = UNKNOWN;
|
|
CurState = 0;
|
|
|
|
for (int32_t I = 0, E = CIE.size(); I != E; ++I) {
|
|
const auto &Instr = CIE[I];
|
|
update(Instr, -I);
|
|
}
|
|
|
|
advanceTo(State);
|
|
}
|
|
|
|
};
|
|
|
|
/// A CFI snapshot with the capability of checking if incremental additions to
|
|
/// it are redundant. This is used to ensure we do not emit two CFI instructions
|
|
/// back-to-back that are doing the same state change, or to avoid emitting a
|
|
/// CFI at all when the state at that point would not be modified after that CFI
|
|
struct CFISnapshotDiff : public CFISnapshot {
|
|
bool RestoredCFAReg{false};
|
|
bool RestoredCFAOffset{false};
|
|
DenseMap<int32_t, bool> RestoredRegs;
|
|
|
|
CFISnapshotDiff(const CFISnapshot &S) : CFISnapshot(S) {}
|
|
|
|
CFISnapshotDiff(
|
|
const std::vector<MCCFIInstruction> &CIE,
|
|
const std::vector<MCCFIInstruction> &FDE,
|
|
const DenseMap<int32_t, SmallVector<int32_t, 4>> &FrameRestoreEquivalents,
|
|
int32_t State)
|
|
: CFISnapshot(CIE, FDE, FrameRestoreEquivalents, State) {}
|
|
|
|
/// Return true if applying Instr to this state is redundant and can be
|
|
/// dismissed.
|
|
bool isRedundant(const MCCFIInstruction &Instr) {
|
|
switch (Instr.getOperation()) {
|
|
case MCCFIInstruction::OpSameValue:
|
|
case MCCFIInstruction::OpRelOffset:
|
|
case MCCFIInstruction::OpOffset:
|
|
case MCCFIInstruction::OpRestore:
|
|
case MCCFIInstruction::OpUndefined:
|
|
case MCCFIInstruction::OpRegister:
|
|
case MCCFIInstruction::OpExpression:
|
|
case MCCFIInstruction::OpValExpression: {
|
|
if (RestoredRegs[Instr.getRegister()])
|
|
return true;
|
|
RestoredRegs[Instr.getRegister()] = true;
|
|
const int32_t CurRegRule =
|
|
RegRule.find(Instr.getRegister()) != RegRule.end()
|
|
? RegRule[Instr.getRegister()]
|
|
: UNKNOWN;
|
|
if (CurRegRule == UNKNOWN) {
|
|
if (Instr.getOperation() == MCCFIInstruction::OpRestore ||
|
|
Instr.getOperation() == MCCFIInstruction::OpSameValue)
|
|
return true;
|
|
return false;
|
|
}
|
|
const MCCFIInstruction &LastDef =
|
|
CurRegRule < 0 ? CIE[-CurRegRule] : FDE[CurRegRule];
|
|
return LastDef == Instr;
|
|
}
|
|
case MCCFIInstruction::OpDefCfaRegister:
|
|
if (RestoredCFAReg)
|
|
return true;
|
|
RestoredCFAReg = true;
|
|
return CFAReg == Instr.getRegister();
|
|
case MCCFIInstruction::OpDefCfaOffset:
|
|
if (RestoredCFAOffset)
|
|
return true;
|
|
RestoredCFAOffset = true;
|
|
return CFAOffset == Instr.getOffset();
|
|
case MCCFIInstruction::OpDefCfa:
|
|
if (RestoredCFAReg && RestoredCFAOffset)
|
|
return true;
|
|
RestoredCFAReg = true;
|
|
RestoredCFAOffset = true;
|
|
return CFAReg == Instr.getRegister() && CFAOffset == Instr.getOffset();
|
|
case MCCFIInstruction::OpDefCfaExpression:
|
|
if (RestoredCFAReg && RestoredCFAOffset)
|
|
return true;
|
|
RestoredCFAReg = true;
|
|
RestoredCFAOffset = true;
|
|
return false;
|
|
case MCCFIInstruction::OpAdjustCfaOffset:
|
|
case MCCFIInstruction::OpWindowSave:
|
|
case MCCFIInstruction::OpEscape:
|
|
llvm_unreachable("unsupported CFI opcode");
|
|
return false;
|
|
case MCCFIInstruction::OpRememberState:
|
|
case MCCFIInstruction::OpRestoreState:
|
|
case MCCFIInstruction::OpGnuArgsSize:
|
|
// do not affect CFI state
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
bool BinaryFunction::replayCFIInstrs(int32_t FromState, int32_t ToState,
|
|
BinaryBasicBlock *InBB,
|
|
BinaryBasicBlock::iterator InsertIt) {
|
|
if (FromState == ToState)
|
|
return true;
|
|
assert(FromState < ToState && "can only replay CFIs forward");
|
|
|
|
CFISnapshotDiff CFIDiff(CIEFrameInstructions, FrameInstructions,
|
|
FrameRestoreEquivalents, FromState);
|
|
|
|
std::vector<uint32_t> NewCFIs;
|
|
for (auto CurState = FromState; CurState < ToState; ++CurState) {
|
|
MCCFIInstruction *Instr = &FrameInstructions[CurState];
|
|
if (Instr->getOperation() == MCCFIInstruction::OpRestoreState) {
|
|
auto Iter = FrameRestoreEquivalents.find(CurState);
|
|
assert(Iter != FrameRestoreEquivalents.end());
|
|
NewCFIs.insert(NewCFIs.end(), Iter->second.begin(),
|
|
Iter->second.end());
|
|
// RestoreState / Remember will be filtered out later by CFISnapshotDiff,
|
|
// so we might as well fall-through here.
|
|
}
|
|
NewCFIs.push_back(CurState);
|
|
continue;
|
|
}
|
|
|
|
// Replay instructions while avoiding duplicates
|
|
for (auto I = NewCFIs.rbegin(), E = NewCFIs.rend(); I != E; ++I) {
|
|
if (CFIDiff.isRedundant(FrameInstructions[*I]))
|
|
continue;
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, *I);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
SmallVector<int32_t, 4>
|
|
BinaryFunction::unwindCFIState(int32_t FromState, int32_t ToState,
|
|
BinaryBasicBlock *InBB,
|
|
BinaryBasicBlock::iterator &InsertIt) {
|
|
SmallVector<int32_t, 4> NewStates;
|
|
|
|
CFISnapshot ToCFITable(CIEFrameInstructions, FrameInstructions,
|
|
FrameRestoreEquivalents, ToState);
|
|
CFISnapshotDiff FromCFITable(ToCFITable);
|
|
FromCFITable.advanceTo(FromState);
|
|
|
|
auto undoState = [&](const MCCFIInstruction &Instr) {
|
|
switch (Instr.getOperation()) {
|
|
case MCCFIInstruction::OpRememberState:
|
|
case MCCFIInstruction::OpRestoreState:
|
|
break;
|
|
case MCCFIInstruction::OpSameValue:
|
|
case MCCFIInstruction::OpRelOffset:
|
|
case MCCFIInstruction::OpOffset:
|
|
case MCCFIInstruction::OpRestore:
|
|
case MCCFIInstruction::OpUndefined:
|
|
case MCCFIInstruction::OpRegister:
|
|
case MCCFIInstruction::OpExpression:
|
|
case MCCFIInstruction::OpValExpression: {
|
|
if (ToCFITable.RegRule.find(Instr.getRegister()) ==
|
|
ToCFITable.RegRule.end()) {
|
|
FrameInstructions.emplace_back(
|
|
MCCFIInstruction::createRestore(nullptr, Instr.getRegister()));
|
|
if (FromCFITable.isRedundant(FrameInstructions.back())) {
|
|
FrameInstructions.pop_back();
|
|
break;
|
|
}
|
|
NewStates.push_back(FrameInstructions.size() - 1);
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, FrameInstructions.size() - 1);
|
|
++InsertIt;
|
|
break;
|
|
}
|
|
const int32_t Rule = ToCFITable.RegRule[Instr.getRegister()];
|
|
if (Rule < 0) {
|
|
if (FromCFITable.isRedundant(CIEFrameInstructions[-Rule]))
|
|
break;
|
|
NewStates.push_back(FrameInstructions.size());
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, FrameInstructions.size());
|
|
++InsertIt;
|
|
FrameInstructions.emplace_back(CIEFrameInstructions[-Rule]);
|
|
break;
|
|
}
|
|
if (FromCFITable.isRedundant(FrameInstructions[Rule]))
|
|
break;
|
|
NewStates.push_back(Rule);
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, Rule);
|
|
++InsertIt;
|
|
break;
|
|
}
|
|
case MCCFIInstruction::OpDefCfaRegister:
|
|
case MCCFIInstruction::OpDefCfaOffset:
|
|
case MCCFIInstruction::OpDefCfa:
|
|
case MCCFIInstruction::OpDefCfaExpression:
|
|
if (ToCFITable.CFARule == CFISnapshot::UNKNOWN) {
|
|
FrameInstructions.emplace_back(MCCFIInstruction::createDefCfa(
|
|
nullptr, ToCFITable.CFAReg, -ToCFITable.CFAOffset));
|
|
if (FromCFITable.isRedundant(FrameInstructions.back())) {
|
|
FrameInstructions.pop_back();
|
|
break;
|
|
}
|
|
NewStates.push_back(FrameInstructions.size() - 1);
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, FrameInstructions.size() - 1);
|
|
++InsertIt;
|
|
} else if (ToCFITable.CFARule < 0) {
|
|
if (FromCFITable.isRedundant(CIEFrameInstructions[-ToCFITable.CFARule]))
|
|
break;
|
|
NewStates.push_back(FrameInstructions.size());
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, FrameInstructions.size());
|
|
++InsertIt;
|
|
FrameInstructions.emplace_back(
|
|
CIEFrameInstructions[-ToCFITable.CFARule]);
|
|
} else if (!FromCFITable.isRedundant(
|
|
FrameInstructions[ToCFITable.CFARule])) {
|
|
NewStates.push_back(ToCFITable.CFARule);
|
|
InsertIt = addCFIPseudo(InBB, InsertIt, ToCFITable.CFARule);
|
|
++InsertIt;
|
|
}
|
|
break;
|
|
case MCCFIInstruction::OpAdjustCfaOffset:
|
|
case MCCFIInstruction::OpWindowSave:
|
|
case MCCFIInstruction::OpEscape:
|
|
llvm_unreachable("unsupported CFI opcode");
|
|
break;
|
|
case MCCFIInstruction::OpGnuArgsSize:
|
|
// do not affect CFI state
|
|
break;
|
|
}
|
|
};
|
|
|
|
|
|
// Undo all modifications from ToState to FromState
|
|
for (int32_t I = ToState, E = FromState; I != E; ++I) {
|
|
const auto &Instr = FrameInstructions[I];
|
|
if (Instr.getOperation() != MCCFIInstruction::OpRestoreState) {
|
|
undoState(Instr);
|
|
continue;
|
|
}
|
|
auto Iter = FrameRestoreEquivalents.find(I);
|
|
if (Iter == FrameRestoreEquivalents.end())
|
|
continue;
|
|
for (int32_t State : Iter->second)
|
|
undoState(FrameInstructions[State]);
|
|
}
|
|
|
|
return NewStates;
|
|
}
|
|
|
|
void BinaryFunction::normalizeCFIState() {
|
|
// Reordering blocks with remember-restore state instructions can be specially
|
|
// tricky. When rewriting the CFI, we omit remember-restore state instructions
|
|
// entirely. For restore state, we build a map expanding each restore to the
|
|
// equivalent unwindCFIState sequence required at that point to achieve the
|
|
// same effect of the restore. All remember state are then just ignored.
|
|
std::stack<int32_t> Stack;
|
|
for (BinaryBasicBlock *CurBB : BasicBlocksLayout) {
|
|
for (auto II = CurBB->begin(); II != CurBB->end(); ++II) {
|
|
if (auto *CFI = getCFIFor(*II)) {
|
|
if (CFI->getOperation() == MCCFIInstruction::OpRememberState) {
|
|
Stack.push(II->getOperand(0).getImm());
|
|
continue;
|
|
}
|
|
if (CFI->getOperation() == MCCFIInstruction::OpRestoreState) {
|
|
const int32_t RememberState = Stack.top();
|
|
const int32_t CurState = II->getOperand(0).getImm();
|
|
FrameRestoreEquivalents[CurState] =
|
|
unwindCFIState(CurState, RememberState, CurBB, II);
|
|
Stack.pop();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
bool BinaryFunction::finalizeCFIState() {
|
|
DEBUG(dbgs() << "Trying to fix CFI states for each BB after reordering.\n");
|
|
DEBUG(dbgs() << "This is the list of CFI states for each BB of " << *this
|
|
<< ": ");
|
|
|
|
int32_t State = 0;
|
|
bool SeenCold = false;
|
|
auto Sep = "";
|
|
(void)Sep;
|
|
for (auto *BB : BasicBlocksLayout) {
|
|
const auto CFIStateAtExit = BB->getCFIStateAtExit();
|
|
|
|
// Hot-cold border: check if this is the first BB to be allocated in a cold
|
|
// region (with a different FDE). If yes, we need to reset the CFI state.
|
|
if (!SeenCold && BB->isCold()) {
|
|
State = 0;
|
|
SeenCold = true;
|
|
}
|
|
|
|
// We need to recover the correct state if it doesn't match expected
|
|
// state at BB entry point.
|
|
if (BB->getCFIState() < State) {
|
|
// In this case, State is currently higher than what this BB expect it
|
|
// to be. To solve this, we need to insert CFI instructions to undo
|
|
// the effect of all CFI from BB's state to current State.
|
|
auto InsertIt = BB->begin();
|
|
unwindCFIState(State, BB->getCFIState(), BB, InsertIt);
|
|
} else if (BB->getCFIState() > State) {
|
|
// If BB's CFI state is greater than State, it means we are behind in the
|
|
// state. Just emit all instructions to reach this state at the
|
|
// beginning of this BB. If this sequence of instructions involve
|
|
// remember state or restore state, bail out.
|
|
if (!replayCFIInstrs(State, BB->getCFIState(), BB, BB->begin()))
|
|
return false;
|
|
}
|
|
|
|
State = CFIStateAtExit;
|
|
DEBUG(dbgs() << Sep << State; Sep = ", ");
|
|
}
|
|
DEBUG(dbgs() << "\n");
|
|
|
|
for (auto BB : BasicBlocksLayout) {
|
|
for (auto II = BB->begin(); II != BB->end(); ) {
|
|
auto CFI = getCFIFor(*II);
|
|
if (CFI &&
|
|
(CFI->getOperation() == MCCFIInstruction::OpRememberState ||
|
|
CFI->getOperation() == MCCFIInstruction::OpRestoreState)) {
|
|
II = BB->eraseInstruction(II);
|
|
} else {
|
|
++II;
|
|
}
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
uint64_t BinaryFunction::getInstructionCount() const {
|
|
uint64_t Count = 0;
|
|
for (auto &Block : BasicBlocksLayout) {
|
|
Count += Block->getNumNonPseudos();
|
|
}
|
|
return Count;
|
|
}
|
|
|
|
bool BinaryFunction::hasLayoutChanged() const {
|
|
return ModifiedLayout;
|
|
}
|
|
|
|
uint64_t BinaryFunction::getEditDistance() const {
|
|
return ComputeEditDistance<BinaryBasicBlock *>(BasicBlocksPreviousLayout,
|
|
BasicBlocksLayout);
|
|
}
|
|
|
|
void BinaryFunction::emitBody(MCStreamer &Streamer, bool EmitColdPart,
|
|
bool EmitCodeOnly, bool LabelsForOffsets) {
|
|
if (!EmitCodeOnly && EmitColdPart && hasConstantIsland())
|
|
duplicateConstantIslands();
|
|
|
|
// Track first emitted instruction with debug info.
|
|
bool FirstInstr = true;
|
|
for (auto BB : layout()) {
|
|
if (EmitColdPart != BB->isCold())
|
|
continue;
|
|
|
|
if ((opts::AlignBlocks || opts::PreserveBlocksAlignment)
|
|
&& BB->getAlignment() > 1) {
|
|
Streamer.EmitCodeAlignment(BB->getAlignment(),
|
|
BB->getAlignmentMaxBytes());
|
|
}
|
|
Streamer.EmitLabel(BB->getLabel());
|
|
|
|
// Check if special alignment for macro-fusion is needed.
|
|
bool MayNeedMacroFusionAlignment =
|
|
(opts::AlignMacroOpFusion == MFT_ALL) ||
|
|
(opts::AlignMacroOpFusion == MFT_HOT &&
|
|
BB->getKnownExecutionCount());
|
|
BinaryBasicBlock::const_iterator MacroFusionPair;
|
|
if (MayNeedMacroFusionAlignment) {
|
|
MacroFusionPair = BB->getMacroOpFusionPair();
|
|
if (MacroFusionPair == BB->end())
|
|
MayNeedMacroFusionAlignment = false;
|
|
}
|
|
|
|
SMLoc LastLocSeen;
|
|
// Remember if the last instruction emitted was a prefix.
|
|
bool LastIsPrefix = false;
|
|
for (auto I = BB->begin(), E = BB->end(); I != E; ++I) {
|
|
auto &Instr = *I;
|
|
|
|
if (EmitCodeOnly && BC.MII->get(Instr.getOpcode()).isPseudo())
|
|
continue;
|
|
|
|
// Handle pseudo instructions.
|
|
if (BC.MIB->isEHLabel(Instr)) {
|
|
const auto *Label = BC.MIB->getTargetSymbol(Instr);
|
|
assert(Instr.getNumOperands() >= 1 && Label &&
|
|
"bad EH_LABEL instruction");
|
|
Streamer.EmitLabel(const_cast<MCSymbol *>(Label));
|
|
continue;
|
|
}
|
|
if (BC.MIB->isCFI(Instr)) {
|
|
Streamer.EmitCFIInstruction(*getCFIFor(Instr));
|
|
continue;
|
|
}
|
|
|
|
// Handle macro-fusion alignment. If we emitted a prefix as
|
|
// the last instruction, we should've already emitted the associated
|
|
// alignment hint, so don't emit it twice.
|
|
if (MayNeedMacroFusionAlignment && !LastIsPrefix && I == MacroFusionPair){
|
|
// This assumes the second instruction in the macro-op pair will get
|
|
// assigned to its own MCRelaxableFragment. Since all JCC instructions
|
|
// are relaxable, we should be safe.
|
|
Streamer.EmitNeverAlignCodeAtEnd(/*Alignment to avoid=*/64);
|
|
}
|
|
|
|
if (!EmitCodeOnly && opts::UpdateDebugSections && UnitLineTable.first) {
|
|
LastLocSeen = emitLineInfo(Instr.getLoc(), LastLocSeen, FirstInstr);
|
|
FirstInstr = false;
|
|
}
|
|
|
|
// Prepare to tag this location with a label if we need to keep track of
|
|
// the location of calls/returns for BOLT address translation maps
|
|
if (!EmitCodeOnly && LabelsForOffsets &&
|
|
BC.MIB->hasAnnotation(Instr, "Offset")) {
|
|
|
|
MCSymbol *LocSym = BC.Ctx->createTempSymbol(/*CanBeUnnamed=*/true);
|
|
Streamer.EmitLabel(LocSym);
|
|
BC.MIB->addAnnotation(Instr, "LocSym",
|
|
static_cast<uint32_t>(LocSyms.size()));
|
|
LocSyms.push_back(LocSym);
|
|
}
|
|
|
|
// Emit SDT labels
|
|
if (!EmitCodeOnly && BC.MIB->hasAnnotation(Instr, "SDTMarker")) {
|
|
auto OriginalAddress =
|
|
BC.MIB->tryGetAnnotationAs<uint64_t>(Instr, "SDTMarker").get();
|
|
auto *SDTLabel = BC.SDTMarkers[OriginalAddress].Label;
|
|
|
|
// A given symbol should only be emitted as a label once
|
|
if (SDTLabel->isUndefined())
|
|
Streamer.EmitLabel(SDTLabel);
|
|
}
|
|
|
|
Streamer.EmitInstruction(Instr, *BC.STI);
|
|
LastIsPrefix = BC.MIB->isPrefix(Instr);
|
|
}
|
|
}
|
|
|
|
if (!EmitCodeOnly)
|
|
emitConstantIslands(Streamer, EmitColdPart);
|
|
}
|
|
|
|
void BinaryFunction::emitBodyRaw(MCStreamer *Streamer) {
|
|
|
|
// #14998851: Fix gold linker's '--emit-relocs'.
|
|
assert(false &&
|
|
"cannot emit raw body unless relocation accuracy is guaranteed");
|
|
|
|
assert(!isInjected() && "cannot emit raw body of injected function");
|
|
|
|
// Raw contents of the function.
|
|
StringRef SectionContents = InputSection->getContents();
|
|
|
|
// Raw contents of the function.
|
|
StringRef FunctionContents =
|
|
SectionContents.substr(getAddress() - InputSection->getAddress(),
|
|
getSize());
|
|
|
|
if (opts::Verbosity)
|
|
outs() << "BOLT-INFO: emitting function " << *this << " in raw ("
|
|
<< getSize() << " bytes).\n";
|
|
|
|
// We split the function blob into smaller blocks and output relocations
|
|
// and/or labels between them.
|
|
uint64_t FunctionOffset = 0;
|
|
auto LI = Labels.begin();
|
|
auto RI = MoveRelocations.begin();
|
|
while (LI != Labels.end() ||
|
|
RI != MoveRelocations.end()) {
|
|
uint64_t NextLabelOffset = (LI == Labels.end() ? getSize() : LI->first);
|
|
uint64_t NextRelocationOffset =
|
|
(RI == MoveRelocations.end() ? getSize() : RI->first);
|
|
auto NextStop = std::min(NextLabelOffset, NextRelocationOffset);
|
|
assert(NextStop <= getSize() && "internal overflow error");
|
|
if (FunctionOffset < NextStop) {
|
|
Streamer->EmitBytes(
|
|
FunctionContents.slice(FunctionOffset, NextStop));
|
|
FunctionOffset = NextStop;
|
|
}
|
|
if (LI != Labels.end() && FunctionOffset == LI->first) {
|
|
Streamer->EmitLabel(LI->second);
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted label " << LI->second->getName()
|
|
<< " at offset 0x" << Twine::utohexstr(LI->first) << '\n');
|
|
++LI;
|
|
}
|
|
if (RI != MoveRelocations.end() && FunctionOffset == RI->first) {
|
|
auto RelocationSize = RI->second.emit(Streamer);
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted relocation for symbol "
|
|
<< RI->second.Symbol->getName() << " at offset 0x"
|
|
<< Twine::utohexstr(RI->first)
|
|
<< " with size " << RelocationSize << '\n');
|
|
FunctionOffset += RelocationSize;
|
|
++RI;
|
|
}
|
|
}
|
|
assert(FunctionOffset <= getSize() && "overflow error");
|
|
if (FunctionOffset < getSize()) {
|
|
Streamer->EmitBytes(FunctionContents.substr(FunctionOffset));
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::setTrapOnEntry() {
|
|
clearList(Instructions);
|
|
clearList(IgnoredBranches);
|
|
clearList(TakenBranches);
|
|
|
|
for (const auto EntryOffset : EntryOffsets) {
|
|
MCInst TrapInstr;
|
|
BC.MIB->createTrap(TrapInstr);
|
|
addInstruction(EntryOffset, std::move(TrapInstr));
|
|
}
|
|
|
|
TrapsOnEntry = true;
|
|
}
|
|
|
|
void BinaryFunction::emitConstantIslands(
|
|
MCStreamer &Streamer, bool EmitColdPart,
|
|
BinaryFunction *OnBehalfOf) {
|
|
if (DataOffsets.empty() && IslandDependency.empty())
|
|
return;
|
|
|
|
if (!OnBehalfOf) {
|
|
if (!EmitColdPart)
|
|
Streamer.EmitLabel(getFunctionConstantIslandLabel());
|
|
else
|
|
Streamer.EmitLabel(getFunctionColdConstantIslandLabel());
|
|
}
|
|
|
|
assert((!OnBehalfOf || IslandProxies[OnBehalfOf].size() > 0) &&
|
|
"spurious OnBehalfOf constant island emission");
|
|
|
|
assert(!isInjected() &&
|
|
"injected functions should not have constant islands");
|
|
// Raw contents of the function.
|
|
StringRef SectionContents = InputSection->getContents();
|
|
|
|
// Raw contents of the function.
|
|
StringRef FunctionContents =
|
|
SectionContents.substr(getAddress() - InputSection->getAddress(),
|
|
getMaxSize());
|
|
|
|
if (opts::Verbosity && !OnBehalfOf)
|
|
outs() << "BOLT-INFO: emitting constant island for function " << *this
|
|
<< "\n";
|
|
|
|
// We split the island into smaller blocks and output labels between them.
|
|
auto IS = IslandOffsets.begin();
|
|
for (auto DataIter = DataOffsets.begin(); DataIter != DataOffsets.end();
|
|
++DataIter) {
|
|
uint64_t FunctionOffset = *DataIter;
|
|
uint64_t EndOffset = 0ULL;
|
|
|
|
// Determine size of this data chunk
|
|
auto NextData = std::next(DataIter);
|
|
auto CodeIter = CodeOffsets.lower_bound(*DataIter);
|
|
if (CodeIter == CodeOffsets.end() && NextData == DataOffsets.end()) {
|
|
EndOffset = getMaxSize();
|
|
} else if (CodeIter == CodeOffsets.end()) {
|
|
EndOffset = *NextData;
|
|
} else if (NextData == DataOffsets.end()) {
|
|
EndOffset = *CodeIter;
|
|
} else {
|
|
EndOffset = (*CodeIter > *NextData) ? *NextData : *CodeIter;
|
|
}
|
|
|
|
if (FunctionOffset == EndOffset)
|
|
continue; // Size is zero, nothing to emit
|
|
|
|
// Emit labels, relocs and data
|
|
auto RI = MoveRelocations.lower_bound(FunctionOffset);
|
|
while ((IS != IslandOffsets.end() && IS->first < EndOffset) ||
|
|
(RI != MoveRelocations.end() && RI->first < EndOffset)) {
|
|
auto NextLabelOffset = IS == IslandOffsets.end() ? EndOffset : IS->first;
|
|
auto NextRelOffset = RI == MoveRelocations.end() ? EndOffset : RI->first;
|
|
auto NextStop = std::min(NextLabelOffset, NextRelOffset);
|
|
assert(NextStop <= EndOffset && "internal overflow error");
|
|
if (FunctionOffset < NextStop) {
|
|
Streamer.EmitBytes(FunctionContents.slice(FunctionOffset, NextStop));
|
|
FunctionOffset = NextStop;
|
|
}
|
|
if (IS != IslandOffsets.end() && FunctionOffset == IS->first) {
|
|
// This is a slightly complex code to decide which label to emit. We
|
|
// have 4 cases to handle: regular symbol, cold symbol, regular or cold
|
|
// symbol being emitted on behalf of an external function.
|
|
if (!OnBehalfOf) {
|
|
if (!EmitColdPart) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted label "
|
|
<< IS->second->getName() << " at offset 0x"
|
|
<< Twine::utohexstr(IS->first) << '\n');
|
|
if (IS->second->isUndefined())
|
|
Streamer.EmitLabel(IS->second);
|
|
else
|
|
assert(hasName(IS->second->getName()));
|
|
} else if (ColdIslandSymbols.count(IS->second) != 0) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted label "
|
|
<< ColdIslandSymbols[IS->second]->getName() << '\n');
|
|
if (ColdIslandSymbols[IS->second]->isUndefined())
|
|
Streamer.EmitLabel(ColdIslandSymbols[IS->second]);
|
|
}
|
|
} else {
|
|
if (!EmitColdPart) {
|
|
if (MCSymbol *Sym = IslandProxies[OnBehalfOf][IS->second]) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted label " << Sym->getName()
|
|
<< '\n');
|
|
Streamer.EmitLabel(Sym);
|
|
}
|
|
} else if (MCSymbol *Sym =
|
|
ColdIslandProxies[OnBehalfOf][IS->second]) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted label " << Sym->getName()
|
|
<< '\n');
|
|
Streamer.EmitLabel(Sym);
|
|
}
|
|
}
|
|
++IS;
|
|
}
|
|
if (RI != MoveRelocations.end() && FunctionOffset == RI->first) {
|
|
auto RelocationSize = RI->second.emit(&Streamer);
|
|
DEBUG(dbgs() << "BOLT-DEBUG: emitted relocation for symbol "
|
|
<< RI->second.Symbol->getName() << " at offset 0x"
|
|
<< Twine::utohexstr(RI->first)
|
|
<< " with size " << RelocationSize << '\n');
|
|
FunctionOffset += RelocationSize;
|
|
++RI;
|
|
}
|
|
}
|
|
assert(FunctionOffset <= EndOffset && "overflow error");
|
|
if (FunctionOffset < EndOffset) {
|
|
Streamer.EmitBytes(FunctionContents.slice(FunctionOffset, EndOffset));
|
|
}
|
|
}
|
|
assert(IS == IslandOffsets.end() && "some symbols were not emitted!");
|
|
|
|
if (OnBehalfOf)
|
|
return;
|
|
// Now emit constant islands from other functions that we may have used in
|
|
// this function.
|
|
for (auto *ExternalFunc : IslandDependency) {
|
|
ExternalFunc->emitConstantIslands(Streamer, EmitColdPart, this);
|
|
}
|
|
|
|
}
|
|
|
|
void BinaryFunction::duplicateConstantIslands() {
|
|
for (auto BB : layout()) {
|
|
if (!BB->isCold())
|
|
continue;
|
|
|
|
for (auto &Inst : *BB) {
|
|
int OpNum = 0;
|
|
for (auto &Operand : Inst) {
|
|
if (!Operand.isExpr()) {
|
|
++OpNum;
|
|
continue;
|
|
}
|
|
auto *Symbol = BC.MIB->getTargetSymbol(Inst, OpNum);
|
|
// Check if this is an island symbol
|
|
if (!IslandSymbols.count(Symbol) && !ProxyIslandSymbols.count(Symbol))
|
|
continue;
|
|
|
|
// Create cold symbol, if missing
|
|
auto ISym = ColdIslandSymbols.find(Symbol);
|
|
MCSymbol *ColdSymbol;
|
|
if (ISym != ColdIslandSymbols.end()) {
|
|
ColdSymbol = ISym->second;
|
|
} else {
|
|
ColdSymbol = BC.Ctx->getOrCreateSymbol(Symbol->getName() + ".cold");
|
|
ColdIslandSymbols[Symbol] = ColdSymbol;
|
|
// Check if this is a proxy island symbol and update owner proxy map
|
|
if (ProxyIslandSymbols.count(Symbol)) {
|
|
BinaryFunction *Owner = ProxyIslandSymbols[Symbol];
|
|
auto IProxiedSym = Owner->IslandProxies[this].find(Symbol);
|
|
Owner->ColdIslandProxies[this][IProxiedSym->second] = ColdSymbol;
|
|
}
|
|
}
|
|
|
|
// Update instruction reference
|
|
Operand = MCOperand::createExpr(BC.MIB->getTargetExprFor(
|
|
Inst,
|
|
MCSymbolRefExpr::create(ColdSymbol, MCSymbolRefExpr::VK_None,
|
|
*BC.Ctx),
|
|
*BC.Ctx, 0));
|
|
++OpNum;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
namespace {
|
|
|
|
#ifndef MAX_PATH
|
|
#define MAX_PATH 255
|
|
#endif
|
|
|
|
std::string constructFilename(std::string Filename,
|
|
std::string Annotation,
|
|
std::string Suffix) {
|
|
std::replace(Filename.begin(), Filename.end(), '/', '-');
|
|
if (!Annotation.empty()) {
|
|
Annotation.insert(0, "-");
|
|
}
|
|
if (Filename.size() + Annotation.size() + Suffix.size() > MAX_PATH) {
|
|
assert(Suffix.size() + Annotation.size() <= MAX_PATH);
|
|
if (opts::Verbosity >= 1) {
|
|
errs() << "BOLT-WARNING: Filename \"" << Filename << Annotation << Suffix
|
|
<< "\" exceeds the " << MAX_PATH << " size limit, truncating.\n";
|
|
}
|
|
Filename.resize(MAX_PATH - (Suffix.size() + Annotation.size()));
|
|
}
|
|
Filename += Annotation;
|
|
Filename += Suffix;
|
|
return Filename;
|
|
}
|
|
|
|
std::string formatEscapes(const std::string& Str) {
|
|
std::string Result;
|
|
for (unsigned I = 0; I < Str.size(); ++I) {
|
|
auto C = Str[I];
|
|
switch (C) {
|
|
case '\n':
|
|
Result += " ";
|
|
break;
|
|
case '"':
|
|
break;
|
|
default:
|
|
Result += C;
|
|
break;
|
|
}
|
|
}
|
|
return Result;
|
|
}
|
|
|
|
}
|
|
|
|
void BinaryFunction::dumpGraph(raw_ostream& OS) const {
|
|
OS << "strict digraph \"" << getPrintName() << "\" {\n";
|
|
uint64_t Offset = Address;
|
|
for (auto *BB : BasicBlocks) {
|
|
auto LayoutPos = std::find(BasicBlocksLayout.begin(),
|
|
BasicBlocksLayout.end(),
|
|
BB);
|
|
unsigned Layout = LayoutPos - BasicBlocksLayout.begin();
|
|
const char* ColdStr = BB->isCold() ? " (cold)" : "";
|
|
OS << format("\"%s\" [label=\"%s%s\\n(C:%lu,O:%lu,I:%u,L:%u:CFI:%u)\"]\n",
|
|
BB->getName().data(),
|
|
BB->getName().data(),
|
|
ColdStr,
|
|
(BB->ExecutionCount != BinaryBasicBlock::COUNT_NO_PROFILE
|
|
? BB->ExecutionCount
|
|
: 0),
|
|
BB->getOffset(),
|
|
getIndex(BB),
|
|
Layout,
|
|
BB->getCFIState());
|
|
OS << format("\"%s\" [shape=box]\n", BB->getName().data());
|
|
if (opts::DotToolTipCode) {
|
|
std::string Str;
|
|
raw_string_ostream CS(Str);
|
|
Offset = BC.printInstructions(CS, BB->begin(), BB->end(), Offset, this);
|
|
const auto Code = formatEscapes(CS.str());
|
|
OS << format("\"%s\" [tooltip=\"%s\"]\n",
|
|
BB->getName().data(),
|
|
Code.c_str());
|
|
}
|
|
|
|
// analyzeBranch is just used to get the names of the branch
|
|
// opcodes.
|
|
const MCSymbol *TBB = nullptr;
|
|
const MCSymbol *FBB = nullptr;
|
|
MCInst *CondBranch = nullptr;
|
|
MCInst *UncondBranch = nullptr;
|
|
const bool Success = BB->analyzeBranch(TBB,
|
|
FBB,
|
|
CondBranch,
|
|
UncondBranch);
|
|
|
|
const auto *LastInstr = BB->getLastNonPseudoInstr();
|
|
const bool IsJumpTable = LastInstr && BC.MIB->getJumpTable(*LastInstr);
|
|
|
|
auto BI = BB->branch_info_begin();
|
|
for (auto *Succ : BB->successors()) {
|
|
std::string Branch;
|
|
if (Success) {
|
|
if (Succ == BB->getConditionalSuccessor(true)) {
|
|
Branch = CondBranch
|
|
? BC.InstPrinter->getOpcodeName(CondBranch->getOpcode())
|
|
: "TB";
|
|
} else if (Succ == BB->getConditionalSuccessor(false)) {
|
|
Branch = UncondBranch
|
|
? BC.InstPrinter->getOpcodeName(UncondBranch->getOpcode())
|
|
: "FB";
|
|
} else {
|
|
Branch = "FT";
|
|
}
|
|
}
|
|
if (IsJumpTable) {
|
|
Branch = "JT";
|
|
}
|
|
OS << format("\"%s\" -> \"%s\" [label=\"%s",
|
|
BB->getName().data(),
|
|
Succ->getName().data(),
|
|
Branch.c_str());
|
|
|
|
if (BB->getExecutionCount() != COUNT_NO_PROFILE &&
|
|
BI->MispredictedCount != BinaryBasicBlock::COUNT_INFERRED) {
|
|
OS << "\\n(C:" << BI->Count << ",M:" << BI->MispredictedCount << ")";
|
|
} else if (ExecutionCount != COUNT_NO_PROFILE &&
|
|
BI->Count != BinaryBasicBlock::COUNT_NO_PROFILE) {
|
|
OS << "\\n(IC:" << BI->Count << ")";
|
|
}
|
|
OS << "\"]\n";
|
|
|
|
++BI;
|
|
}
|
|
for (auto *LP : BB->landing_pads()) {
|
|
OS << format("\"%s\" -> \"%s\" [constraint=false style=dashed]\n",
|
|
BB->getName().data(),
|
|
LP->getName().data());
|
|
}
|
|
}
|
|
OS << "}\n";
|
|
}
|
|
|
|
void BinaryFunction::viewGraph() const {
|
|
SmallString<MAX_PATH> Filename;
|
|
if (auto EC = sys::fs::createTemporaryFile("bolt-cfg", "dot", Filename)) {
|
|
errs() << "BOLT-ERROR: " << EC.message() << ", unable to create "
|
|
<< " bolt-cfg-XXXXX.dot temporary file.\n";
|
|
return;
|
|
}
|
|
dumpGraphToFile(Filename.str());
|
|
if (DisplayGraph(Filename)) {
|
|
errs() << "BOLT-ERROR: Can't display " << Filename << " with graphviz.\n";
|
|
}
|
|
if (auto EC = sys::fs::remove(Filename)) {
|
|
errs() << "BOLT-WARNING: " << EC.message() << ", failed to remove "
|
|
<< Filename << "\n";
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::dumpGraphForPass(std::string Annotation) const {
|
|
auto Filename = constructFilename(getPrintName(), Annotation, ".dot");
|
|
outs() << "BOLT-DEBUG: Dumping CFG to " << Filename << "\n";
|
|
dumpGraphToFile(Filename);
|
|
}
|
|
|
|
void BinaryFunction::dumpGraphToFile(std::string Filename) const {
|
|
std::error_code EC;
|
|
raw_fd_ostream of(Filename, EC, sys::fs::F_None);
|
|
if (EC) {
|
|
if (opts::Verbosity >= 1) {
|
|
errs() << "BOLT-WARNING: " << EC.message() << ", unable to open "
|
|
<< Filename << " for output.\n";
|
|
}
|
|
return;
|
|
}
|
|
dumpGraph(of);
|
|
}
|
|
|
|
bool BinaryFunction::validateCFG() const {
|
|
bool Valid = true;
|
|
for (auto *BB : BasicBlocks) {
|
|
Valid &= BB->validateSuccessorInvariants();
|
|
}
|
|
|
|
if (!Valid)
|
|
return Valid;
|
|
|
|
// Make sure all blocks in CFG are valid.
|
|
auto validateBlock = [this](const BinaryBasicBlock *BB, StringRef Desc) {
|
|
if (!BB->isValid()) {
|
|
errs() << "BOLT-ERROR: deleted " << Desc << " " << BB->getName()
|
|
<< " detected in:\n";
|
|
this->dump();
|
|
return false;
|
|
}
|
|
return true;
|
|
};
|
|
for (const auto *BB : BasicBlocks) {
|
|
if (!validateBlock(BB, "block"))
|
|
return false;
|
|
for (const auto *PredBB : BB->predecessors())
|
|
if (!validateBlock(PredBB, "predecessor"))
|
|
return false;
|
|
for (const auto *SuccBB: BB->successors())
|
|
if (!validateBlock(SuccBB, "successor"))
|
|
return false;
|
|
for (const auto *LP: BB->landing_pads())
|
|
if (!validateBlock(LP, "landing pad"))
|
|
return false;
|
|
for (const auto *Thrower: BB->throwers())
|
|
if (!validateBlock(Thrower, "thrower"))
|
|
return false;
|
|
}
|
|
|
|
for (const auto *BB : BasicBlocks) {
|
|
std::unordered_set<const BinaryBasicBlock *> BBLandingPads;
|
|
for (const auto *LP : BB->landing_pads()) {
|
|
if (BBLandingPads.count(LP)) {
|
|
errs() << "BOLT-ERROR: duplicate landing pad detected in"
|
|
<< BB->getName() << " in function " << *this << '\n';
|
|
return false;
|
|
}
|
|
BBLandingPads.insert(LP);
|
|
}
|
|
|
|
std::unordered_set<const BinaryBasicBlock *> BBThrowers;
|
|
for (const auto *Thrower : BB->throwers()) {
|
|
if (BBThrowers.count(Thrower)) {
|
|
errs() << "BOLT-ERROR: duplicate thrower detected in"
|
|
<< BB->getName() << " in function " << *this << '\n';
|
|
return false;
|
|
}
|
|
BBThrowers.insert(Thrower);
|
|
}
|
|
|
|
for (const auto *LPBlock : BB->landing_pads()) {
|
|
if (std::find(LPBlock->throw_begin(), LPBlock->throw_end(), BB)
|
|
== LPBlock->throw_end()) {
|
|
errs() << "BOLT-ERROR: inconsistent landing pad detected in "
|
|
<< *this << ": " << BB->getName()
|
|
<< " is in LandingPads but not in " << LPBlock->getName()
|
|
<< " Throwers\n";
|
|
return false;
|
|
}
|
|
}
|
|
for (const auto *Thrower : BB->throwers()) {
|
|
if (std::find(Thrower->lp_begin(), Thrower->lp_end(), BB)
|
|
== Thrower->lp_end()) {
|
|
errs() << "BOLT-ERROR: inconsistent thrower detected in "
|
|
<< *this << ": " << BB->getName()
|
|
<< " is in Throwers list but not in " << Thrower->getName()
|
|
<< " LandingPads\n";
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
return Valid;
|
|
}
|
|
|
|
void BinaryFunction::fixBranches() {
|
|
auto &MIB = BC.MIB;
|
|
auto *Ctx = BC.Ctx.get();
|
|
|
|
for (unsigned I = 0, E = BasicBlocksLayout.size(); I != E; ++I) {
|
|
BinaryBasicBlock *BB = BasicBlocksLayout[I];
|
|
const MCSymbol *TBB = nullptr;
|
|
const MCSymbol *FBB = nullptr;
|
|
MCInst *CondBranch = nullptr;
|
|
MCInst *UncondBranch = nullptr;
|
|
if (!BB->analyzeBranch(TBB, FBB, CondBranch, UncondBranch))
|
|
continue;
|
|
|
|
// We will create unconditional branch with correct destination if needed.
|
|
if (UncondBranch)
|
|
BB->eraseInstruction(BB->findInstruction(UncondBranch));
|
|
|
|
// Basic block that follows the current one in the final layout.
|
|
const BinaryBasicBlock *NextBB = nullptr;
|
|
if (I + 1 != E && BB->isCold() == BasicBlocksLayout[I + 1]->isCold())
|
|
NextBB = BasicBlocksLayout[I + 1];
|
|
|
|
if (BB->succ_size() == 1) {
|
|
// __builtin_unreachable() could create a conditional branch that
|
|
// falls-through into the next function - hence the block will have only
|
|
// one valid successor. Since behaviour is undefined - we replace
|
|
// the conditional branch with an unconditional if required.
|
|
if (CondBranch)
|
|
BB->eraseInstruction(BB->findInstruction(CondBranch));
|
|
if (BB->getSuccessor() == NextBB)
|
|
continue;
|
|
BB->addBranchInstruction(BB->getSuccessor());
|
|
} else if (BB->succ_size() == 2) {
|
|
assert(CondBranch && "conditional branch expected");
|
|
const auto *TSuccessor = BB->getConditionalSuccessor(true);
|
|
const auto *FSuccessor = BB->getConditionalSuccessor(false);
|
|
if (NextBB && NextBB == TSuccessor) {
|
|
std::swap(TSuccessor, FSuccessor);
|
|
{
|
|
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
|
|
MIB->reverseBranchCondition(*CondBranch, TSuccessor->getLabel(), Ctx);
|
|
}
|
|
BB->swapConditionalSuccessors();
|
|
} else {
|
|
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
|
|
MIB->replaceBranchTarget(*CondBranch, TSuccessor->getLabel(), Ctx);
|
|
}
|
|
if (TSuccessor == FSuccessor) {
|
|
BB->removeDuplicateConditionalSuccessor(CondBranch);
|
|
}
|
|
if (!NextBB || (NextBB != TSuccessor && NextBB != FSuccessor)) {
|
|
// If one of the branches is guaranteed to be "long" while the other
|
|
// could be "short", then prioritize short for "taken". This will
|
|
// generate a sequence 1 byte shorter on x86.
|
|
if (BC.isX86() &&
|
|
TSuccessor->isCold() != FSuccessor->isCold() &&
|
|
BB->isCold() != TSuccessor->isCold()) {
|
|
std::swap(TSuccessor, FSuccessor);
|
|
{
|
|
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
|
|
MIB->reverseBranchCondition(*CondBranch, TSuccessor->getLabel(),
|
|
Ctx);
|
|
}
|
|
BB->swapConditionalSuccessors();
|
|
}
|
|
BB->addBranchInstruction(FSuccessor);
|
|
}
|
|
}
|
|
// Cases where the number of successors is 0 (block ends with a
|
|
// terminator) or more than 2 (switch table) don't require branch
|
|
// instruction adjustments.
|
|
}
|
|
assert((!isSimple() || validateCFG())
|
|
&& "Invalid CFG detected after fixing branches");
|
|
}
|
|
|
|
void BinaryFunction::propagateGnuArgsSizeInfo(
|
|
MCPlusBuilder::AllocatorIdTy AllocId) {
|
|
assert(CurrentState == State::Disassembled && "unexpected function state");
|
|
|
|
if (!hasEHRanges() || !usesGnuArgsSize())
|
|
return;
|
|
|
|
// The current value of DW_CFA_GNU_args_size affects all following
|
|
// invoke instructions until the next CFI overrides it.
|
|
// It is important to iterate basic blocks in the original order when
|
|
// assigning the value.
|
|
uint64_t CurrentGnuArgsSize = 0;
|
|
for (auto BB : BasicBlocks) {
|
|
for (auto II = BB->begin(); II != BB->end(); ) {
|
|
auto &Instr = *II;
|
|
if (BC.MIB->isCFI(Instr)) {
|
|
auto CFI = getCFIFor(Instr);
|
|
if (CFI->getOperation() == MCCFIInstruction::OpGnuArgsSize) {
|
|
CurrentGnuArgsSize = CFI->getOffset();
|
|
// Delete DW_CFA_GNU_args_size instructions and only regenerate
|
|
// during the final code emission. The information is embedded
|
|
// inside call instructions.
|
|
II = BB->erasePseudoInstruction(II);
|
|
continue;
|
|
}
|
|
} else if (BC.MIB->isInvoke(Instr)) {
|
|
// Add the value of GNU_args_size as an extra operand to invokes.
|
|
BC.MIB->addGnuArgsSize(Instr, CurrentGnuArgsSize, AllocId);
|
|
}
|
|
++II;
|
|
}
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::postProcessBranches() {
|
|
if (!isSimple())
|
|
return;
|
|
for (auto *BB : BasicBlocksLayout) {
|
|
auto LastInstrRI = BB->getLastNonPseudo();
|
|
if (BB->succ_size() == 1) {
|
|
if (LastInstrRI != BB->rend() &&
|
|
BC.MIB->isConditionalBranch(*LastInstrRI)) {
|
|
// __builtin_unreachable() could create a conditional branch that
|
|
// falls-through into the next function - hence the block will have only
|
|
// one valid successor. Such behaviour is undefined and thus we remove
|
|
// the conditional branch while leaving a valid successor.
|
|
BB->eraseInstruction(std::prev(LastInstrRI.base()));
|
|
DEBUG(dbgs() << "BOLT-DEBUG: erasing conditional branch in "
|
|
<< BB->getName() << " in function " << *this << '\n');
|
|
}
|
|
} else if (BB->succ_size() == 0) {
|
|
// Ignore unreachable basic blocks.
|
|
if (BB->pred_size() == 0 || BB->isLandingPad())
|
|
continue;
|
|
|
|
// If it's the basic block that does not end up with a terminator - we
|
|
// insert a return instruction unless it's a call instruction.
|
|
if (LastInstrRI == BB->rend()) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: at least one instruction expected in BB "
|
|
<< BB->getName() << " in function " << *this << '\n');
|
|
continue;
|
|
}
|
|
if (!BC.MIB->isTerminator(*LastInstrRI) &&
|
|
!BC.MIB->isCall(*LastInstrRI)) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: adding return to basic block "
|
|
<< BB->getName() << " in function " << *this << '\n');
|
|
MCInst ReturnInstr;
|
|
BC.MIB->createReturn(ReturnInstr);
|
|
BB->addInstruction(ReturnInstr);
|
|
}
|
|
}
|
|
}
|
|
assert(validateCFG() && "invalid CFG");
|
|
}
|
|
|
|
const MCSymbol *BinaryFunction::getSymbolForEntry(uint64_t EntryNum) const {
|
|
if (EntryNum == 0)
|
|
return getSymbol();
|
|
|
|
if (!isMultiEntry())
|
|
return nullptr;
|
|
|
|
uint64_t NumEntries = 0;
|
|
for (auto *BB : BasicBlocks) {
|
|
if (!BB->isEntryPoint())
|
|
continue;
|
|
if (NumEntries == EntryNum)
|
|
return BB->getLabel();
|
|
++NumEntries;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
uint64_t BinaryFunction::getEntryForSymbol(const MCSymbol *EntrySymbol) const {
|
|
if (getSymbol() == EntrySymbol)
|
|
return 0;
|
|
|
|
uint64_t NumEntries = 0;
|
|
for (const auto *BB : BasicBlocks) {
|
|
if (!BB->isEntryPoint())
|
|
continue;
|
|
if (BB->getLabel() == EntrySymbol)
|
|
return NumEntries;
|
|
++NumEntries;
|
|
}
|
|
|
|
llvm_unreachable("no entry for symbol");
|
|
}
|
|
|
|
BinaryFunction::BasicBlockOrderType BinaryFunction::dfs() const {
|
|
BasicBlockOrderType DFS;
|
|
unsigned Index = 0;
|
|
std::stack<BinaryBasicBlock *> Stack;
|
|
|
|
// Push entry points to the stack in reverse order.
|
|
//
|
|
// NB: we rely on the original order of entries to match.
|
|
for (auto BBI = layout_rbegin(); BBI != layout_rend(); ++BBI) {
|
|
auto *BB = *BBI;
|
|
if (BB->isEntryPoint())
|
|
Stack.push(BB);
|
|
BB->setLayoutIndex(BinaryBasicBlock::InvalidIndex);
|
|
}
|
|
|
|
while (!Stack.empty()) {
|
|
auto *BB = Stack.top();
|
|
Stack.pop();
|
|
|
|
if (BB->getLayoutIndex() != BinaryBasicBlock::InvalidIndex)
|
|
continue;
|
|
|
|
BB->setLayoutIndex(Index++);
|
|
DFS.push_back(BB);
|
|
|
|
for (auto *SuccBB : BB->landing_pads()) {
|
|
Stack.push(SuccBB);
|
|
}
|
|
|
|
const MCSymbol *TBB = nullptr;
|
|
const MCSymbol *FBB = nullptr;
|
|
MCInst *CondBranch = nullptr;
|
|
MCInst *UncondBranch = nullptr;
|
|
if (BB->analyzeBranch(TBB, FBB, CondBranch, UncondBranch) &&
|
|
CondBranch && BB->succ_size() == 2) {
|
|
if (BC.MIB->getCanonicalBranchOpcode(CondBranch->getOpcode()) ==
|
|
CondBranch->getOpcode()) {
|
|
Stack.push(BB->getConditionalSuccessor(true));
|
|
Stack.push(BB->getConditionalSuccessor(false));
|
|
} else {
|
|
Stack.push(BB->getConditionalSuccessor(false));
|
|
Stack.push(BB->getConditionalSuccessor(true));
|
|
}
|
|
} else {
|
|
for (auto *SuccBB : BB->successors()) {
|
|
Stack.push(SuccBB);
|
|
}
|
|
}
|
|
}
|
|
|
|
return DFS;
|
|
}
|
|
|
|
std::size_t BinaryFunction::hash(bool Recompute, bool UseDFS) const {
|
|
if (size() == 0)
|
|
return 0;
|
|
|
|
assert(hasCFG() && "function is expected to have CFG");
|
|
|
|
if (!Recompute)
|
|
return Hash;
|
|
|
|
const auto &Order = UseDFS ? dfs() : BasicBlocksLayout;
|
|
|
|
// The hash is computed by creating a string of all the opcodes
|
|
// in the function and hashing that string with std::hash.
|
|
std::string Opcodes;
|
|
for (const auto *BB : Order) {
|
|
for (const auto &Inst : *BB) {
|
|
unsigned Opcode = Inst.getOpcode();
|
|
|
|
if (BC.MII->get(Opcode).isPseudo())
|
|
continue;
|
|
|
|
// Ignore unconditional jumps since we check CFG consistency by processing
|
|
// basic blocks in order and do not rely on branches to be in-sync with
|
|
// CFG. Note that we still use condition code of conditional jumps.
|
|
if (BC.MIB->isUnconditionalBranch(Inst))
|
|
continue;
|
|
|
|
if (Opcode == 0) {
|
|
Opcodes.push_back(0);
|
|
continue;
|
|
}
|
|
|
|
while (Opcode) {
|
|
uint8_t LSB = Opcode & 0xff;
|
|
Opcodes.push_back(LSB);
|
|
Opcode = Opcode >> 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
return Hash = std::hash<std::string>{}(Opcodes);
|
|
}
|
|
|
|
void BinaryFunction::insertBasicBlocks(
|
|
BinaryBasicBlock *Start,
|
|
std::vector<std::unique_ptr<BinaryBasicBlock>> &&NewBBs,
|
|
const bool UpdateLayout,
|
|
const bool UpdateCFIState,
|
|
const bool RecomputeLandingPads) {
|
|
const auto StartIndex = Start ? getIndex(Start) : -1;
|
|
const auto NumNewBlocks = NewBBs.size();
|
|
|
|
BasicBlocks.insert(BasicBlocks.begin() + (StartIndex + 1),
|
|
NumNewBlocks,
|
|
nullptr);
|
|
|
|
auto I = StartIndex + 1;
|
|
for (auto &BB : NewBBs) {
|
|
assert(!BasicBlocks[I]);
|
|
BasicBlocks[I++] = BB.release();
|
|
}
|
|
|
|
if (RecomputeLandingPads) {
|
|
recomputeLandingPads();
|
|
} else {
|
|
updateBBIndices(0);
|
|
}
|
|
|
|
if (UpdateLayout) {
|
|
updateLayout(Start, NumNewBlocks);
|
|
}
|
|
|
|
if (UpdateCFIState) {
|
|
updateCFIState(Start, NumNewBlocks);
|
|
}
|
|
}
|
|
|
|
BinaryFunction::iterator BinaryFunction::insertBasicBlocks(
|
|
BinaryFunction::iterator StartBB,
|
|
std::vector<std::unique_ptr<BinaryBasicBlock>> &&NewBBs,
|
|
const bool UpdateLayout,
|
|
const bool UpdateCFIState,
|
|
const bool RecomputeLandingPads) {
|
|
const auto StartIndex = getIndex(&*StartBB);
|
|
const auto NumNewBlocks = NewBBs.size();
|
|
|
|
BasicBlocks.insert(BasicBlocks.begin() + StartIndex + 1,
|
|
NumNewBlocks,
|
|
nullptr);
|
|
auto RetIter = BasicBlocks.begin() + StartIndex + 1;
|
|
|
|
auto I = StartIndex + 1;
|
|
for (auto &BB : NewBBs) {
|
|
assert(!BasicBlocks[I]);
|
|
BasicBlocks[I++] = BB.release();
|
|
}
|
|
|
|
if (RecomputeLandingPads) {
|
|
recomputeLandingPads();
|
|
} else {
|
|
updateBBIndices(0);
|
|
}
|
|
|
|
if (UpdateLayout) {
|
|
updateLayout(*std::prev(RetIter), NumNewBlocks);
|
|
}
|
|
|
|
if (UpdateCFIState) {
|
|
updateCFIState(*std::prev(RetIter), NumNewBlocks);
|
|
}
|
|
|
|
return RetIter;
|
|
}
|
|
|
|
void BinaryFunction::updateBBIndices(const unsigned StartIndex) {
|
|
for (auto I = StartIndex; I < BasicBlocks.size(); ++I) {
|
|
BasicBlocks[I]->Index = I;
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::updateCFIState(BinaryBasicBlock *Start,
|
|
const unsigned NumNewBlocks) {
|
|
const auto CFIState = Start->getCFIStateAtExit();
|
|
const auto StartIndex = getIndex(Start) + 1;
|
|
for (unsigned I = 0; I < NumNewBlocks; ++I) {
|
|
BasicBlocks[StartIndex + I]->setCFIState(CFIState);
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::updateLayout(BinaryBasicBlock *Start,
|
|
const unsigned NumNewBlocks) {
|
|
// If start not provided insert new blocks at the beginning
|
|
if (!Start) {
|
|
BasicBlocksLayout.insert(layout_begin(), BasicBlocks.begin(),
|
|
BasicBlocks.begin() + NumNewBlocks);
|
|
updateLayoutIndices();
|
|
return;
|
|
}
|
|
|
|
// Insert new blocks in the layout immediately after Start.
|
|
auto Pos = std::find(layout_begin(), layout_end(), Start);
|
|
assert(Pos != layout_end());
|
|
auto Begin = &BasicBlocks[getIndex(Start) + 1];
|
|
auto End = &BasicBlocks[getIndex(Start) + NumNewBlocks + 1];
|
|
BasicBlocksLayout.insert(Pos + 1, Begin, End);
|
|
updateLayoutIndices();
|
|
}
|
|
|
|
bool BinaryFunction::checkForAmbiguousJumpTables() {
|
|
SmallPtrSet<uint64_t, 4> JumpTables;
|
|
for (auto &BB : BasicBlocks) {
|
|
for (auto &Inst : *BB) {
|
|
if (!BC.MIB->isIndirectBranch(Inst))
|
|
continue;
|
|
auto JTAddress = BC.MIB->getJumpTable(Inst);
|
|
if (!JTAddress)
|
|
continue;
|
|
// This address can be inside another jump table, but we only consider
|
|
// it ambiguous when the same start address is used, not the same JT
|
|
// object.
|
|
auto Iter = JumpTables.find(JTAddress);
|
|
if (Iter == JumpTables.end()) {
|
|
JumpTables.insert(JTAddress);
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void BinaryFunction::disambiguateJumpTables() {
|
|
assert((opts::JumpTables != JTS_BASIC && isSimple()) || BC.HasRelocations);
|
|
SmallPtrSet<JumpTable *, 4> JumpTables;
|
|
for (auto &BB : BasicBlocks) {
|
|
for (auto &Inst : *BB) {
|
|
if (!BC.MIB->isIndirectBranch(Inst))
|
|
continue;
|
|
auto *JT = getJumpTable(Inst);
|
|
if (!JT)
|
|
continue;
|
|
auto Iter = JumpTables.find(JT);
|
|
if (Iter == JumpTables.end()) {
|
|
JumpTables.insert(JT);
|
|
continue;
|
|
}
|
|
// This instruction is an indirect jump using a jump table, but it is
|
|
// using the same jump table of another jump. Try all our tricks to
|
|
// extract the jump table symbol and make it point to a new, duplicated JT
|
|
uint64_t Scale;
|
|
const MCSymbol *Target;
|
|
MCInst *JTLoadInst = &Inst;
|
|
// Try a standard indirect jump matcher, scale 8
|
|
auto IndJmpMatcher = BC.MIB->matchIndJmp(
|
|
BC.MIB->matchReg(), BC.MIB->matchImm(Scale), BC.MIB->matchReg(),
|
|
/*Offset=*/BC.MIB->matchSymbol(Target));
|
|
if (!BC.MIB->hasPCRelOperand(Inst) ||
|
|
!IndJmpMatcher->match(
|
|
*BC.MRI, *BC.MIB,
|
|
MutableArrayRef<MCInst>(&*BB->begin(), &Inst + 1), -1) ||
|
|
Scale != 8) {
|
|
// Standard JT matching failed. Trying now:
|
|
// PIC-style matcher, scale 4
|
|
// addq %rdx, %rsi
|
|
// addq %rdx, %rdi
|
|
// leaq DATAat0x402450(%rip), %r11
|
|
// movslq (%r11,%rdx,4), %rcx
|
|
// addq %r11, %rcx
|
|
// jmpq *%rcx # JUMPTABLE @0x402450
|
|
MCPhysReg BaseReg1;
|
|
MCPhysReg BaseReg2;
|
|
uint64_t Offset;
|
|
auto PICIndJmpMatcher = BC.MIB->matchIndJmp(BC.MIB->matchAdd(
|
|
BC.MIB->matchReg(BaseReg1),
|
|
BC.MIB->matchLoad(BC.MIB->matchReg(BaseReg2),
|
|
BC.MIB->matchImm(Scale), BC.MIB->matchReg(),
|
|
BC.MIB->matchImm(Offset))));
|
|
auto LEAMatcherOwner =
|
|
BC.MIB->matchLoadAddr(BC.MIB->matchSymbol(Target));
|
|
auto LEAMatcher = LEAMatcherOwner.get();
|
|
auto PICBaseAddrMatcher = BC.MIB->matchIndJmp(BC.MIB->matchAdd(
|
|
std::move(LEAMatcherOwner), BC.MIB->matchAnyOperand()));
|
|
if (!PICIndJmpMatcher->match(
|
|
*BC.MRI, *BC.MIB,
|
|
MutableArrayRef<MCInst>(&*BB->begin(), &Inst + 1), -1) ||
|
|
Scale != 4 || BaseReg1 != BaseReg2 || Offset != 0 ||
|
|
!PICBaseAddrMatcher->match(
|
|
*BC.MRI, *BC.MIB,
|
|
MutableArrayRef<MCInst>(&*BB->begin(), &Inst + 1), -1)) {
|
|
llvm_unreachable("Failed to extract jump table base");
|
|
continue;
|
|
}
|
|
// Matched PIC
|
|
JTLoadInst = &*LEAMatcher->CurInst;
|
|
}
|
|
|
|
uint64_t NewJumpTableID{0};
|
|
const MCSymbol *NewJTLabel;
|
|
std::tie(NewJumpTableID, NewJTLabel) =
|
|
BC.duplicateJumpTable(*this, JT, Target);
|
|
BC.MIB->replaceMemOperandDisp(*JTLoadInst, NewJTLabel, BC.Ctx.get());
|
|
// We use a unique ID with the high bit set as address for this "injected"
|
|
// jump table (not originally in the input binary).
|
|
BC.MIB->setJumpTable(Inst, NewJumpTableID, 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool BinaryFunction::replaceJumpTableEntryIn(BinaryBasicBlock *BB,
|
|
BinaryBasicBlock *OldDest,
|
|
BinaryBasicBlock *NewDest) {
|
|
auto *Instr = BB->getLastNonPseudoInstr();
|
|
if (!Instr || !BC.MIB->isIndirectBranch(*Instr))
|
|
return false;
|
|
auto JTAddress = BC.MIB->getJumpTable(*Instr);
|
|
assert(JTAddress && "Invalid jump table address");
|
|
auto *JT = getJumpTableContainingAddress(JTAddress);
|
|
assert(JT && "No jump table structure for this indirect branch");
|
|
bool Patched = JT->replaceDestination(JTAddress, OldDest->getLabel(),
|
|
NewDest->getLabel());
|
|
assert(Patched && "Invalid entry to be replaced in jump table");
|
|
return true;
|
|
}
|
|
|
|
BinaryBasicBlock *BinaryFunction::splitEdge(BinaryBasicBlock *From,
|
|
BinaryBasicBlock *To) {
|
|
// Create intermediate BB
|
|
MCSymbol *Tmp;
|
|
{
|
|
std::unique_lock<std::shared_timed_mutex> WrLock(BC.CtxMutex);
|
|
Tmp = BC.Ctx->createTempSymbol("SplitEdge", true);
|
|
}
|
|
// Link new BBs to the original input offset of the From BB, so we can map
|
|
// samples recorded in new BBs back to the original BB seem in the input
|
|
// binary (if using BAT)
|
|
auto NewBB = createBasicBlock(From->getInputOffset(), Tmp);
|
|
auto NewBBPtr = NewBB.get();
|
|
|
|
// Update "From" BB
|
|
auto I = From->succ_begin();
|
|
auto BI = From->branch_info_begin();
|
|
for (; I != From->succ_end(); ++I) {
|
|
if (*I == To)
|
|
break;
|
|
++BI;
|
|
}
|
|
assert(I != From->succ_end() && "Invalid CFG edge in splitEdge!");
|
|
uint64_t OrigCount{BI->Count};
|
|
uint64_t OrigMispreds{BI->MispredictedCount};
|
|
replaceJumpTableEntryIn(From, To, NewBBPtr);
|
|
From->replaceSuccessor(To, NewBBPtr, OrigCount, OrigMispreds);
|
|
|
|
NewBB->addSuccessor(To, OrigCount, OrigMispreds);
|
|
NewBB->setExecutionCount(OrigCount);
|
|
NewBB->setIsCold(From->isCold());
|
|
|
|
// Update CFI and BB layout with new intermediate BB
|
|
std::vector<std::unique_ptr<BinaryBasicBlock>> NewBBs;
|
|
NewBBs.emplace_back(std::move(NewBB));
|
|
insertBasicBlocks(From, std::move(NewBBs), true, true,
|
|
/*RecomputeLandingPads=*/false);
|
|
return NewBBPtr;
|
|
}
|
|
|
|
bool BinaryFunction::isDataMarker(const SymbolRef &Symbol,
|
|
uint64_t SymbolSize) const {
|
|
// For aarch64, the ABI defines mapping symbols so we identify data in the
|
|
// code section (see IHI0056B). $d identifies a symbol starting data contents.
|
|
if (BC.isAArch64() && Symbol.getType() &&
|
|
cantFail(Symbol.getType()) == SymbolRef::ST_Unknown && SymbolSize == 0 &&
|
|
Symbol.getName() && cantFail(Symbol.getName()) == "$d")
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
bool BinaryFunction::isCodeMarker(const SymbolRef &Symbol,
|
|
uint64_t SymbolSize) const {
|
|
// For aarch64, the ABI defines mapping symbols so we identify data in the
|
|
// code section (see IHI0056B). $x identifies a symbol starting code or the
|
|
// end of a data chunk inside code.
|
|
if (BC.isAArch64() && Symbol.getType() &&
|
|
cantFail(Symbol.getType()) == SymbolRef::ST_Unknown && SymbolSize == 0 &&
|
|
Symbol.getName() && cantFail(Symbol.getName()) == "$x")
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
bool BinaryFunction::isSymbolValidInScope(const SymbolRef &Symbol,
|
|
uint64_t SymbolSize) const {
|
|
// If this symbol is in a different section from the one where the
|
|
// function symbol is, don't consider it as valid.
|
|
if (!getSection().containsAddress(
|
|
cantFail(Symbol.getAddress(), "cannot get symbol address")))
|
|
return false;
|
|
|
|
// Some symbols are tolerated inside function bodies, others are not.
|
|
// The real function boundaries may not be known at this point.
|
|
if (isDataMarker(Symbol, SymbolSize) || isCodeMarker(Symbol, SymbolSize))
|
|
return true;
|
|
|
|
// It's okay to have a zero-sized symbol in the middle of non-zero-sized
|
|
// function.
|
|
if (SymbolSize == 0 && containsAddress(cantFail(Symbol.getAddress())))
|
|
return true;
|
|
|
|
if (cantFail(Symbol.getType()) != SymbolRef::ST_Unknown)
|
|
return false;
|
|
|
|
if (Symbol.getFlags() & SymbolRef::SF_Global)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
SMLoc BinaryFunction::emitLineInfo(SMLoc NewLoc, SMLoc PrevLoc,
|
|
bool FirstInstr) const {
|
|
auto *FunctionCU = UnitLineTable.first;
|
|
const auto *FunctionLineTable = UnitLineTable.second;
|
|
assert(FunctionCU && "cannot emit line info for function without CU");
|
|
|
|
auto RowReference = DebugLineTableRowRef::fromSMLoc(NewLoc);
|
|
|
|
// Check if no new line info needs to be emitted.
|
|
if (RowReference == DebugLineTableRowRef::NULL_ROW ||
|
|
NewLoc.getPointer() == PrevLoc.getPointer())
|
|
return PrevLoc;
|
|
|
|
unsigned CurrentFilenum = 0;
|
|
const auto *CurrentLineTable = FunctionLineTable;
|
|
|
|
// If the CU id from the current instruction location does not
|
|
// match the CU id from the current function, it means that we
|
|
// have come across some inlined code. We must look up the CU
|
|
// for the instruction's original function and get the line table
|
|
// from that.
|
|
const auto FunctionUnitIndex = FunctionCU->getOffset();
|
|
const auto CurrentUnitIndex = RowReference.DwCompileUnitIndex;
|
|
if (CurrentUnitIndex != FunctionUnitIndex) {
|
|
CurrentLineTable = BC.DwCtx->getLineTableForUnit(
|
|
BC.DwCtx->getCompileUnitForOffset(CurrentUnitIndex));
|
|
// Add filename from the inlined function to the current CU.
|
|
CurrentFilenum =
|
|
BC.addDebugFilenameToUnit(FunctionUnitIndex, CurrentUnitIndex,
|
|
CurrentLineTable->Rows[RowReference.RowIndex - 1].File);
|
|
}
|
|
|
|
const auto &CurrentRow = CurrentLineTable->Rows[RowReference.RowIndex - 1];
|
|
if (!CurrentFilenum)
|
|
CurrentFilenum = CurrentRow.File;
|
|
|
|
unsigned Flags = (DWARF2_FLAG_IS_STMT * CurrentRow.IsStmt) |
|
|
(DWARF2_FLAG_BASIC_BLOCK * CurrentRow.BasicBlock) |
|
|
(DWARF2_FLAG_PROLOGUE_END * CurrentRow.PrologueEnd) |
|
|
(DWARF2_FLAG_EPILOGUE_BEGIN * CurrentRow.EpilogueBegin);
|
|
|
|
// Always emit is_stmt at the beginning of function fragment.
|
|
if (FirstInstr)
|
|
Flags |= DWARF2_FLAG_IS_STMT;
|
|
|
|
BC.Ctx->setCurrentDwarfLoc(
|
|
CurrentFilenum,
|
|
CurrentRow.Line,
|
|
CurrentRow.Column,
|
|
Flags,
|
|
CurrentRow.Isa,
|
|
CurrentRow.Discriminator);
|
|
BC.Ctx->setDwarfCompileUnitID(FunctionUnitIndex);
|
|
|
|
return NewLoc;
|
|
}
|
|
|
|
void BinaryFunction::adjustExecutionCount(uint64_t Count) {
|
|
if (getKnownExecutionCount() == 0 || Count == 0)
|
|
return;
|
|
|
|
if (ExecutionCount < Count)
|
|
Count = ExecutionCount;
|
|
|
|
double AdjustmentRatio = ((double) ExecutionCount - Count) / ExecutionCount;
|
|
if (AdjustmentRatio < 0.0)
|
|
AdjustmentRatio = 0.0;
|
|
|
|
for (auto &BB : layout())
|
|
BB->adjustExecutionCount(AdjustmentRatio);
|
|
|
|
ExecutionCount -= Count;
|
|
}
|
|
|
|
BinaryFunction::~BinaryFunction() {
|
|
for (auto BB : BasicBlocks) {
|
|
delete BB;
|
|
}
|
|
for (auto BB : DeletedBasicBlocks) {
|
|
delete BB;
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::emitJumpTables(MCStreamer *Streamer) {
|
|
if (JumpTables.empty())
|
|
return;
|
|
if (opts::PrintJumpTables) {
|
|
outs() << "BOLT-INFO: jump tables for function " << *this << ":\n";
|
|
}
|
|
for (auto &JTI : JumpTables) {
|
|
auto &JT = *JTI.second;
|
|
if (opts::PrintJumpTables)
|
|
JT.print(outs());
|
|
if ((opts::JumpTables == JTS_BASIC || !isSimple()) && BC.HasRelocations) {
|
|
JT.updateOriginal();
|
|
} else {
|
|
MCSection *HotSection, *ColdSection;
|
|
if (opts::JumpTables == JTS_BASIC) {
|
|
std::string Name = ".local." + JT.Labels[0]->getName().str();
|
|
std::replace(Name.begin(), Name.end(), '/', '.');
|
|
auto &Section = BC.registerOrUpdateSection(Name,
|
|
ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC);
|
|
Section.setAnonymous(true);
|
|
JT.setOutputSection(Section);
|
|
HotSection = BC.Ctx->getELFSection(Name,
|
|
ELF::SHT_PROGBITS,
|
|
ELF::SHF_ALLOC);
|
|
ColdSection = HotSection;
|
|
} else {
|
|
if (isSimple()) {
|
|
HotSection = BC.MOFI->getReadOnlySection();
|
|
ColdSection = BC.MOFI->getReadOnlyColdSection();
|
|
} else {
|
|
HotSection = hasProfile() ? BC.MOFI->getReadOnlySection()
|
|
: BC.MOFI->getReadOnlyColdSection();
|
|
ColdSection = HotSection;
|
|
}
|
|
}
|
|
JT.emit(Streamer, HotSection, ColdSection);
|
|
}
|
|
}
|
|
}
|
|
|
|
void BinaryFunction::calculateLoopInfo() {
|
|
// Discover loops.
|
|
BinaryDominatorTree DomTree;
|
|
DomTree.recalculate(*this);
|
|
BLI.reset(new BinaryLoopInfo());
|
|
BLI->analyze(DomTree);
|
|
|
|
// Traverse discovered loops and add depth and profile information.
|
|
std::stack<BinaryLoop *> St;
|
|
for (auto I = BLI->begin(), E = BLI->end(); I != E; ++I) {
|
|
St.push(*I);
|
|
++BLI->OuterLoops;
|
|
}
|
|
|
|
while (!St.empty()) {
|
|
BinaryLoop *L = St.top();
|
|
St.pop();
|
|
++BLI->TotalLoops;
|
|
BLI->MaximumDepth = std::max(L->getLoopDepth(), BLI->MaximumDepth);
|
|
|
|
// Add nested loops in the stack.
|
|
for (BinaryLoop::iterator I = L->begin(), E = L->end(); I != E; ++I) {
|
|
St.push(*I);
|
|
}
|
|
|
|
// Skip if no valid profile is found.
|
|
if (!hasValidProfile()) {
|
|
L->EntryCount = COUNT_NO_PROFILE;
|
|
L->ExitCount = COUNT_NO_PROFILE;
|
|
L->TotalBackEdgeCount = COUNT_NO_PROFILE;
|
|
continue;
|
|
}
|
|
|
|
// Compute back edge count.
|
|
SmallVector<BinaryBasicBlock *, 1> Latches;
|
|
L->getLoopLatches(Latches);
|
|
|
|
for (BinaryBasicBlock *Latch : Latches) {
|
|
auto BI = Latch->branch_info_begin();
|
|
for (BinaryBasicBlock *Succ : Latch->successors()) {
|
|
if (Succ == L->getHeader()) {
|
|
assert(BI->Count != BinaryBasicBlock::COUNT_NO_PROFILE &&
|
|
"profile data not found");
|
|
L->TotalBackEdgeCount += BI->Count;
|
|
}
|
|
++BI;
|
|
}
|
|
}
|
|
|
|
// Compute entry count.
|
|
L->EntryCount = L->getHeader()->getExecutionCount() - L->TotalBackEdgeCount;
|
|
|
|
// Compute exit count.
|
|
SmallVector<BinaryLoop::Edge, 1> ExitEdges;
|
|
L->getExitEdges(ExitEdges);
|
|
for (BinaryLoop::Edge &Exit : ExitEdges) {
|
|
const BinaryBasicBlock *Exiting = Exit.first;
|
|
const BinaryBasicBlock *ExitTarget = Exit.second;
|
|
auto BI = Exiting->branch_info_begin();
|
|
for (BinaryBasicBlock *Succ : Exiting->successors()) {
|
|
if (Succ == ExitTarget) {
|
|
assert(BI->Count != BinaryBasicBlock::COUNT_NO_PROFILE &&
|
|
"profile data not found");
|
|
L->ExitCount += BI->Count;
|
|
}
|
|
++BI;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
DebugAddressRangesVector BinaryFunction::getOutputAddressRanges() const {
|
|
DebugAddressRangesVector OutputRanges;
|
|
|
|
if (IsFragment)
|
|
return OutputRanges;
|
|
|
|
OutputRanges.emplace_back(getOutputAddress(),
|
|
getOutputAddress() + getOutputSize());
|
|
if (isSplit()) {
|
|
assert(isEmitted() && "split function should be emitted");
|
|
OutputRanges.emplace_back(cold().getAddress(),
|
|
cold().getAddress() + cold().getImageSize());
|
|
}
|
|
|
|
if (isSimple())
|
|
return OutputRanges;
|
|
|
|
for (auto *Frag : Fragments) {
|
|
assert(!Frag->isSimple() &&
|
|
"fragment of non-simple function should also be non-simple");
|
|
OutputRanges.emplace_back(Frag->getOutputAddress(),
|
|
Frag->getOutputAddress() + Frag->getOutputSize());
|
|
}
|
|
|
|
return OutputRanges;
|
|
}
|
|
|
|
uint64_t BinaryFunction::translateInputToOutputAddress(uint64_t Address) const {
|
|
// If the function hasn't changed return the same address.
|
|
if (!isEmitted() && !BC.HasRelocations)
|
|
return Address;
|
|
|
|
if (Address < getAddress())
|
|
return 0;
|
|
|
|
// FIXME: #18950828 - we rely on relative offsets inside basic blocks to stay
|
|
// intact. Instead we can use pseudo instructions and/or annotations.
|
|
const auto Offset = Address - getAddress();
|
|
const auto *BB = getBasicBlockContainingOffset(Offset);
|
|
if (!BB) {
|
|
// Special case for address immediately past the end of the function.
|
|
if (Offset == getSize())
|
|
return getOutputAddress() + getOutputSize();
|
|
|
|
return 0;
|
|
}
|
|
|
|
return std::min(BB->getOutputAddressRange().first + Offset - BB->getOffset(),
|
|
BB->getOutputAddressRange().second);
|
|
}
|
|
|
|
DebugAddressRangesVector BinaryFunction::translateInputToOutputRanges(
|
|
const DWARFAddressRangesVector &InputRanges) const {
|
|
DebugAddressRangesVector OutputRanges;
|
|
|
|
// If the function hasn't changed return the same ranges.
|
|
if (!isEmitted() && !BC.HasRelocations) {
|
|
OutputRanges.resize(InputRanges.size());
|
|
std::transform(InputRanges.begin(), InputRanges.end(),
|
|
OutputRanges.begin(),
|
|
[](const DWARFAddressRange &Range) {
|
|
return DebugAddressRange(Range.LowPC, Range.HighPC);
|
|
});
|
|
return OutputRanges;
|
|
}
|
|
|
|
// Even though we will merge ranges in a post-processing pass, we attempt to
|
|
// merge them in a main processing loop as it improves the processing time.
|
|
uint64_t PrevEndAddress = 0;
|
|
for (const auto &Range : InputRanges) {
|
|
if (!containsAddress(Range.LowPC)) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: invalid debug address range detected for "
|
|
<< *this << " : [0x" << Twine::utohexstr(Range.LowPC)
|
|
<< ", 0x" << Twine::utohexstr(Range.HighPC) << "]\n");
|
|
PrevEndAddress = 0;
|
|
continue;
|
|
}
|
|
auto InputOffset = Range.LowPC - getAddress();
|
|
const auto InputEndOffset = std::min(Range.HighPC - getAddress(), getSize());
|
|
|
|
auto BBI = std::upper_bound(BasicBlockOffsets.begin(),
|
|
BasicBlockOffsets.end(),
|
|
BasicBlockOffset(InputOffset, nullptr),
|
|
CompareBasicBlockOffsets());
|
|
--BBI;
|
|
do {
|
|
const auto *BB = BBI->second;
|
|
if (InputOffset < BB->getOffset() || InputOffset >= BB->getEndOffset()) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: invalid debug address range detected for "
|
|
<< *this << " : [0x" << Twine::utohexstr(Range.LowPC)
|
|
<< ", 0x" << Twine::utohexstr(Range.HighPC) << "]\n");
|
|
PrevEndAddress = 0;
|
|
break;
|
|
}
|
|
|
|
// Skip the range if the block was deleted.
|
|
if (const auto OutputStart = BB->getOutputAddressRange().first) {
|
|
const auto StartAddress = OutputStart + InputOffset - BB->getOffset();
|
|
auto EndAddress = BB->getOutputAddressRange().second;
|
|
if (InputEndOffset < BB->getEndOffset())
|
|
EndAddress = StartAddress + InputEndOffset - InputOffset;
|
|
|
|
if (StartAddress == PrevEndAddress) {
|
|
OutputRanges.back().HighPC = std::max(OutputRanges.back().HighPC,
|
|
EndAddress);
|
|
} else {
|
|
OutputRanges.emplace_back(StartAddress,
|
|
std::max(StartAddress, EndAddress));
|
|
}
|
|
PrevEndAddress = OutputRanges.back().HighPC;
|
|
}
|
|
|
|
InputOffset = BB->getEndOffset();
|
|
++BBI;
|
|
} while (InputOffset < InputEndOffset);
|
|
}
|
|
|
|
// Post-processing pass to sort and merge ranges.
|
|
std::sort(OutputRanges.begin(), OutputRanges.end());
|
|
DebugAddressRangesVector MergedRanges;
|
|
PrevEndAddress = 0;
|
|
for (const auto &Range : OutputRanges) {
|
|
if (Range.LowPC <= PrevEndAddress) {
|
|
MergedRanges.back().HighPC = std::max(MergedRanges.back().HighPC,
|
|
Range.HighPC);
|
|
} else {
|
|
MergedRanges.emplace_back(Range.LowPC, Range.HighPC);
|
|
}
|
|
PrevEndAddress = MergedRanges.back().HighPC;
|
|
}
|
|
|
|
return MergedRanges;
|
|
}
|
|
|
|
MCInst *BinaryFunction::getInstructionAtOffset(uint64_t Offset) {
|
|
if (CurrentState == State::Disassembled) {
|
|
auto II = Instructions.find(Offset);
|
|
return (II == Instructions.end()) ? nullptr : &II->second;
|
|
} else if (CurrentState == State::CFG) {
|
|
auto *BB = getBasicBlockContainingOffset(Offset);
|
|
if (!BB)
|
|
return nullptr;
|
|
|
|
for (auto &Inst : *BB) {
|
|
constexpr auto InvalidOffset = std::numeric_limits<uint32_t>::max();
|
|
if (Offset == BC.MIB->getAnnotationWithDefault<uint32_t>(Inst, "Offset",
|
|
InvalidOffset))
|
|
return &Inst;
|
|
}
|
|
|
|
return nullptr;
|
|
} else {
|
|
llvm_unreachable("invalid CFG state to use getInstructionAtOffset()");
|
|
}
|
|
}
|
|
|
|
std::set<BinaryData *> BinaryFunction::dataUses(bool OnlyHot) const {
|
|
std::set<BinaryData *> Uses;
|
|
for (auto *BB : BasicBlocks) {
|
|
if (OnlyHot && BB->isCold())
|
|
continue;
|
|
|
|
for (const auto &Inst : *BB) {
|
|
if (auto Mem =
|
|
BC.MIB->tryGetAnnotationAs<uint64_t>(Inst, "MemDataOffset")) {
|
|
for (auto &MI : getMemData()->getMemInfoRange(Mem.get())) {
|
|
if (auto *BD = MI.Addr.IsSymbol
|
|
? BC.getBinaryDataByName(MI.Addr.Name)
|
|
: BC.getBinaryDataContainingAddress(MI.Addr.Offset)) {
|
|
Uses.insert(BD);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return Uses;
|
|
}
|
|
|
|
DWARFDebugLoc::LocationList BinaryFunction::translateInputToOutputLocationList(
|
|
const DWARFDebugLoc::LocationList &InputLL,
|
|
BaseAddress BaseAddr) const {
|
|
uint64_t BAddr = BaseAddr.Address;
|
|
// If the function wasn't changed - there's nothing to update.
|
|
if (!isEmitted() && !BC.HasRelocations) {
|
|
if (!BAddr) {
|
|
return InputLL;
|
|
} else {
|
|
auto OutputLL = std::move(InputLL);
|
|
for (auto &Entry : OutputLL.Entries) {
|
|
Entry.Begin += BAddr;
|
|
Entry.End += BAddr;
|
|
}
|
|
return OutputLL;
|
|
}
|
|
}
|
|
|
|
uint64_t PrevEndAddress = 0;
|
|
SmallVectorImpl<char> *PrevLoc = nullptr;
|
|
DWARFDebugLoc::LocationList OutputLL;
|
|
for (auto &Entry : InputLL.Entries) {
|
|
const auto Start = Entry.Begin + BAddr;
|
|
const auto End = Entry.End + BAddr;
|
|
if (!containsAddress(Start)) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: invalid debug address range detected for "
|
|
<< *this << " : [0x" << Twine::utohexstr(Start)
|
|
<< ", 0x" << Twine::utohexstr(End) << "]\n");
|
|
continue;
|
|
}
|
|
auto InputOffset = Start - getAddress();
|
|
const auto InputEndOffset = std::min(End - getAddress(), getSize());
|
|
auto BBI = std::upper_bound(BasicBlockOffsets.begin(),
|
|
BasicBlockOffsets.end(),
|
|
BasicBlockOffset(InputOffset, nullptr),
|
|
CompareBasicBlockOffsets());
|
|
--BBI;
|
|
do {
|
|
const auto *BB = BBI->second;
|
|
if (InputOffset < BB->getOffset() || InputOffset >= BB->getEndOffset()) {
|
|
DEBUG(dbgs() << "BOLT-DEBUG: invalid debug address range detected for "
|
|
<< *this << " : [0x" << Twine::utohexstr(Start)
|
|
<< ", 0x" << Twine::utohexstr(End) << "]\n");
|
|
PrevEndAddress = 0;
|
|
break;
|
|
}
|
|
|
|
// Skip the range if the block was deleted.
|
|
if (const auto OutputStart = BB->getOutputAddressRange().first) {
|
|
const auto StartAddress = OutputStart + InputOffset - BB->getOffset();
|
|
auto EndAddress = BB->getOutputAddressRange().second;
|
|
if (InputEndOffset < BB->getEndOffset())
|
|
EndAddress = StartAddress + InputEndOffset - InputOffset;
|
|
|
|
if (StartAddress == PrevEndAddress && Entry.Loc == *PrevLoc) {
|
|
OutputLL.Entries.back().End = std::max(OutputLL.Entries.back().End,
|
|
EndAddress);
|
|
} else {
|
|
OutputLL.Entries.emplace_back(
|
|
DWARFDebugLoc::Entry{StartAddress,
|
|
std::max(StartAddress, EndAddress),
|
|
Entry.Loc});
|
|
}
|
|
PrevEndAddress = OutputLL.Entries.back().End;
|
|
PrevLoc = &OutputLL.Entries.back().Loc;
|
|
}
|
|
|
|
++BBI;
|
|
InputOffset = BB->getEndOffset();
|
|
} while (InputOffset < InputEndOffset);
|
|
}
|
|
|
|
// Sort and merge adjacent entries with identical location.
|
|
std::stable_sort(OutputLL.Entries.begin(), OutputLL.Entries.end(),
|
|
[] (const DWARFDebugLoc::Entry &A, const DWARFDebugLoc::Entry &B) {
|
|
return A.Begin < B.Begin;
|
|
});
|
|
DWARFDebugLoc::LocationList MergedLL;
|
|
PrevEndAddress = 0;
|
|
PrevLoc = nullptr;
|
|
for (const auto &Entry : OutputLL.Entries) {
|
|
if (Entry.Begin <= PrevEndAddress && *PrevLoc == Entry.Loc) {
|
|
MergedLL.Entries.back().End = std::max(Entry.End,
|
|
MergedLL.Entries.back().End);
|
|
} else {
|
|
const auto Begin = std::max(Entry.Begin, PrevEndAddress);
|
|
const auto End = std::max(Begin, Entry.End);
|
|
MergedLL.Entries.emplace_back(DWARFDebugLoc::Entry{Begin,
|
|
End,
|
|
Entry.Loc});
|
|
}
|
|
PrevEndAddress = MergedLL.Entries.back().End;
|
|
PrevLoc = &MergedLL.Entries.back().Loc;
|
|
}
|
|
|
|
return MergedLL;
|
|
}
|
|
|
|
void BinaryFunction::printLoopInfo(raw_ostream &OS) const {
|
|
OS << "Loop Info for Function \"" << *this << "\"";
|
|
if (hasValidProfile()) {
|
|
OS << " (count: " << getExecutionCount() << ")";
|
|
}
|
|
OS << "\n";
|
|
|
|
std::stack<BinaryLoop *> St;
|
|
for (auto I = BLI->begin(), E = BLI->end(); I != E; ++I) {
|
|
St.push(*I);
|
|
}
|
|
while (!St.empty()) {
|
|
BinaryLoop *L = St.top();
|
|
St.pop();
|
|
|
|
for (BinaryLoop::iterator I = L->begin(), E = L->end(); I != E; ++I) {
|
|
St.push(*I);
|
|
}
|
|
|
|
if (!hasValidProfile())
|
|
continue;
|
|
|
|
OS << (L->getLoopDepth() > 1 ? "Nested" : "Outer") << " loop header: "
|
|
<< L->getHeader()->getName();
|
|
OS << "\n";
|
|
OS << "Loop basic blocks: ";
|
|
auto Sep = "";
|
|
for (auto BI = L->block_begin(), BE = L->block_end(); BI != BE; ++BI) {
|
|
OS << Sep << (*BI)->getName();
|
|
Sep = ", ";
|
|
}
|
|
OS << "\n";
|
|
if (hasValidProfile()) {
|
|
OS << "Total back edge count: " << L->TotalBackEdgeCount << "\n";
|
|
OS << "Loop entry count: " << L->EntryCount << "\n";
|
|
OS << "Loop exit count: " << L->ExitCount << "\n";
|
|
if (L->EntryCount > 0) {
|
|
OS << "Average iters per entry: "
|
|
<< format("%.4lf", (double)L->TotalBackEdgeCount / L->EntryCount)
|
|
<< "\n";
|
|
}
|
|
}
|
|
OS << "----\n";
|
|
}
|
|
|
|
OS << "Total number of loops: "<< BLI->TotalLoops << "\n";
|
|
OS << "Number of outer loops: " << BLI->OuterLoops << "\n";
|
|
OS << "Maximum nested loop depth: " << BLI->MaximumDepth << "\n\n";
|
|
}
|
|
|
|
bool BinaryFunction::isAArch64Veneer() const {
|
|
if (BasicBlocks.size() != 1)
|
|
return false;
|
|
|
|
auto &BB = **BasicBlocks.begin();
|
|
if (BB.size() != 3)
|
|
return false;
|
|
|
|
for (auto &Inst : BB) {
|
|
if (!BC.MIB->hasAnnotation(Inst, "AArch64Veneer"))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace bolt
|
|
} // namespace llvm
|