When writing a label to shadow memory, don't write if the value is already set to the value being written. This dramatically reduces real memory consumption in programs with sparse use of labels.
Test Plan: It would be nice to test that unnecessary writes are skipped, but I do not see how a unit test could do this.
Patch by Sam Kerner!
Differential Revision: http://reviews.llvm.org/D4894
llvm-svn: 215961
Avoid RAUW-ing `ConstantExpr` when an operand changes unless the new
`ConstantExpr` already has users. This prevents the RAUW from rippling
up the expression tree unnecessarily.
This commit indirectly adds test coverage for r215953 (this is how I
came across the bug).
This is part of PR20515.
llvm-svn: 215960
Rewrite `ConstantUniqueMap` to be more similar to
`ConstantAggrUniqueMap`.
- Use a `DenseMap` with custom MapInfo instead of a `std::map` with
linear lookups and deletion.
- Don't waste memory explicitly storing (heavyweight) keys.
Only `ConstantExpr` and `InlineAsm` actually use this data structure, so
I also updated them to use it.
This code cleanup is a precursor to reducing RAUW traffic on
`ConstantExpr` -- I felt badly adding a new (linear) call to
`ConstantUniqueMap::FindExistingKey`, so this designs away the concern.
A follow-up commit will transition the users of `ConstantAggrUniqueMap`
over.
llvm-svn: 215957
This code had a homemade RAUW that was incorrect when a user was a
constant: instead of calling `replaceUsersWithOnConstant()` it would
incorrectly update the operand in-place, invalidating
`LLVMContextImpl::ExprConstants`. RAUW does the job better.
The ValueHandle that `GVMap` is holding onto needs to be removed first,
so this commit also removes each variable from the map on-the-fly.
Since deletions from `ExprConstants` use a linear search that compares
directly on the pointer value (instead of using the key), there isn't an
obvious way to expose this with a testcase.
llvm-svn: 215953
Previously all `blockaddress()` constants were treated as forward
references. They were resolved twice: once at the end of the function
in question, and again at the end of the module. Furthermore, if the
same blockaddress was referenced N times, the parser created N distinct
`GlobalVariable`s (one for each reference).
Instead, resolve all block addresses at the beginning of the function,
creating the standard `BasicBlock` forward references used for all other
basic block references. After the function, all references can be
resolved immediately. To check for the condition of parsing block
addresses from within the same function, I created a reference to the
current per-function-state in `BlockAddressPFS`.
Also, create only one forward-reference per basic block. Because
forward references to block addresses are rare, the data structure here
shouldn't matter. If somehow it does someday, this can be pretty easily
changed to a `DenseMap<std::pair<ValID, ValID>, GV>`.
This is part of PR20515.
llvm-svn: 215952
Call `verifyModule()` after parsing and after every transformation.
Also convert some `DEBUG(dbgs())` to `errs()` to increase visibility
into what's going on.
llvm-svn: 215951
another sanitizer.
A user may run both LSan and LSan+ASan. It is weird to pass path to leak
suppression file (or other common sanitizer flags, like "verbosity") in
"LSAN_OPTIONS" in the first case and in "ASAN_OPTIONS" in the second case.
llvm-svn: 215949
- add check for volatile (probably unneeded, but I agree that we should be conservative about it).
- strengthen condition from isUnordered() to isSimple(), as I don't understand well enough Unordered semantics (and it also matches the comment better this way) to be confident in the previous behaviour (thanks for catching that one, I had missed the case Monotonic/Unordered).
- separate a condition in two.
- lengthen comment about aliasing and loads
- add tests in GVN/atomic.ll
llvm-svn: 215943
1. Always put static sanitizer runtimes to the front of the linker
invocation line. This was already done for all sanitizers except UBSan:
in case user provides static libstdc++ we need to make sure that new/delete
operator definitions are picked from sanitizer runtimes instead of libstdc++.
We have to put UBSan runtime first for similar reasons: it depends on some
libstdc++ parts (e.g. __dynamic_cast function), and has to go first in
link line to ensure these functions will be picked up from libstdc++.
2. Put sanitizer libraries system dependencies (-ldl, -lpthread etc.) right
after sanitizer runtimes. This will ensure these libraries participate in
the link even if user provided -Wl,-as-needed flag. This should fix PR15823.
3. In case we link in several sanitizer runtimes (e.g. "ubsan", "ubsan_cxx"
and "san"), add system dependencies (-ldl, -lpthread, ...) only once.
llvm-svn: 215940
file with -macho, the Mach-O specific object file parser option.
After some discussion I chose to do this implementation contained in the logic
of llvm-objdump’s MachODump.cpp using a second disassembler for thumb when
needed and with updates mostly contained in the MachOObjectFile class.
llvm-svn: 215931
Predefined decls like 'Protocol' in objc are not loaded from AST files,
so we cannot rely on loading the canonical decl to complete the redecl
chain for redeclarations of these decls. The broken redecl chain was
non-circular, so looping over redecls() would hang.
llvm-svn: 215929
