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https://github.com/intel/llvm.git
synced 2026-01-19 09:31:59 +08:00
48ae32a33b
Summary: Refactor architecture-specific code out of llvm into llvm-bolt. Introduce MCPlusBuilder, a class that is taking over MCInstrAnalysis responsibilities, i.e. creating, analyzing, and modifying instructions. To access the builder use BC->MIB, i.e. substitute MIA with MIB. MIB is an acronym for MCInstBuilder, that's what MCPlusBuilder used to be. The name stuck, and I find it better than MPB. Instructions are still MCInst, and a bunch of BOLT-specific code still lives in LLVM, but the staff under Target/* is significantly reduced. (cherry picked from FBD7300101)
94 lines
2.4 KiB
C++
94 lines
2.4 KiB
C++
//===--- Passes/PLTCall.h - PLT call optimization -------------------------===//
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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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// Replace calls to PLT entries with indirect calls against GOT.
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//
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//===----------------------------------------------------------------------===//
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#include "PLTCall.h"
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#include "llvm/Support/Options.h"
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#define DEBUG_TYPE "bolt-plt"
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using namespace llvm;
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namespace opts {
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extern cl::OptionCategory BoltOptCategory;
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cl::opt<bolt::PLTCall::OptType>
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PLT("plt",
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cl::desc("optimize PLT calls (requires linking with -znow)"),
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cl::init(bolt::PLTCall::OT_NONE),
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cl::values(clEnumValN(bolt::PLTCall::OT_NONE,
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"none",
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"do not optimize PLT calls"),
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clEnumValN(bolt::PLTCall::OT_HOT,
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"hot",
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"optimize executed (hot) PLT calls"),
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clEnumValN(bolt::PLTCall::OT_ALL,
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"all",
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"optimize all PLT calls")),
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cl::ZeroOrMore,
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cl::cat(BoltOptCategory));
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}
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namespace llvm {
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namespace bolt {
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void PLTCall::runOnFunctions(
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BinaryContext &BC,
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std::map<uint64_t, BinaryFunction> &BFs,
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std::set<uint64_t> &) {
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if (opts::PLT == OT_NONE)
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return;
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uint64_t NumCallsOptimized = 0;
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for (auto &It : BFs) {
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auto &Function = It.second;
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if (!shouldOptimize(Function))
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continue;
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if (opts::PLT == OT_HOT &&
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Function.getExecutionCount() == BinaryFunction::COUNT_NO_PROFILE)
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continue;
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for (auto *BB : Function.layout()) {
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if (opts::PLT == OT_HOT && !BB->getKnownExecutionCount())
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continue;
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for (auto &Instr : *BB) {
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if (!BC.MIB->isCall(Instr))
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continue;
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const auto *CallSymbol = BC.MIB->getTargetSymbol(Instr);
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if (!CallSymbol)
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continue;
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const auto *CalleeBF = BC.getFunctionForSymbol(CallSymbol);
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if (!CalleeBF || !CalleeBF->isPLTFunction())
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continue;
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BC.MIB->convertCallToIndirectCall(Instr,
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CalleeBF->getPLTSymbol(),
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BC.Ctx.get());
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++NumCallsOptimized;
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}
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}
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}
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if (NumCallsOptimized) {
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BC.RequiresZNow = true;
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outs() << "BOLT-INFO: " << NumCallsOptimized
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<< " PLT calls in the binary were optimized.\n";
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}
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}
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} // namespace bolt
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} // namespace llvm
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