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| author | Sanjay Patel <spatel@rotateright.com> | 2015-12-14 21:59:03 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2015-12-14 21:59:03 +0000 |
| commit | fa54acedd1fd1183143c0a7f4b77554fd8cdb1ec (patch) | |
| tree | 6e7cbff67fd8ec8795d8a0cb7a4e3f1d00a92302 /llvm/lib/Bitcode/Writer | |
| parent | 46642ffeebde1743980735e96303140f5f1a7b8b (diff) | |
| download | bcm5719-llvm-fa54acedd1fd1183143c0a7f4b77554fd8cdb1ec.tar.gz bcm5719-llvm-fa54acedd1fd1183143c0a7f4b77554fd8cdb1ec.zip | |
add fast-math-flags to 'call' instructions (PR21290)
This patch adds optional fast-math-flags (the same that apply to fmul/fadd/fsub/fdiv/frem/fcmp)
to call instructions in IR. Follow-up patches would use these flags in LibCallSimplifier, add
support to clang, and extend FMF to the DAG for calls.
Motivating example:
%y = fmul fast float %x, %x
%z = tail call float @sqrtf(float %y)
We'd like to be able to optimize sqrt(x*x) into fabs(x). We do this today using a function-wide
attribute for unsafe-math, but we really want to trigger on the instructions themselves:
%z = tail call fast float @sqrtf(float %y)
because in an LTO build it's possible that calls with fast semantics have been inlined into a
function with non-fast semantics.
The code changes and tests are based on the recent commits that added "notail":
http://reviews.llvm.org/rL252368
and added FMF to fcmp:
http://reviews.llvm.org/rL241901
Differential Revision: http://reviews.llvm.org/D14707
llvm-svn: 255555
Diffstat (limited to 'llvm/lib/Bitcode/Writer')
| -rw-r--r-- | llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp index dd4a16d985f..e34ce5ac430 100644 --- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp +++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp @@ -2153,11 +2153,17 @@ static void WriteInstruction(const Instruction &I, unsigned InstID, Code = bitc::FUNC_CODE_INST_CALL; Vals.push_back(VE.getAttributeID(CI.getAttributes())); + + unsigned Flags = GetOptimizationFlags(&I); Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV | unsigned(CI.isTailCall()) << bitc::CALL_TAIL | unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL | 1 << bitc::CALL_EXPLICIT_TYPE | - unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL); + unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL | + unsigned(Flags != 0) << bitc::CALL_FMF); + if (Flags != 0) + Vals.push_back(Flags); + Vals.push_back(VE.getTypeID(FTy)); PushValueAndType(CI.getCalledValue(), InstID, Vals, VE); // Callee |
