Hal Finkel 64fa501b10 Apply the InstCombine fptrunc sqrt optimization to llvm.sqrt ...

InstCombine, in visitFPTrunc, applies the following optimization to sqrt calls:

  (fptrunc (sqrt (fpext x))) -> (sqrtf x)

but does not apply the same optimization to llvm.sqrt. This is a problem
because, to enable vectorization, Clang generates llvm.sqrt instead of sqrt in
fast-math mode, and because this optimization is being applied to sqrt and not
applied to llvm.sqrt, sometimes the fast-math code is slower.

This change makes InstCombine apply this optimization to llvm.sqrt as well.

This fixes the specific problem in PR17758, although the same underlying issue
(optimizations applied to libcalls are not applied to intrinsics) exists for
other optimizations in SimplifyLibCalls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194935 91177308-0d34-0410-b5e6-96231b3b80d8

2013-11-16 21:29:08 +00:00

..

CMakeLists.txt

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InstCombine.h

Add instcombine visitor for addrspacecast

2013-11-15 05:45:08 +00:00

InstCombineAddSub.cpp

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InstCombineAndOrXor.cpp

Update the docs to match the function name.

2013-11-13 01:12:01 +00:00

InstCombineCalls.cpp

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InstCombineCasts.cpp

Apply the InstCombine fptrunc sqrt optimization to llvm.sqrt

2013-11-16 21:29:08 +00:00

InstCombineCompares.cpp

InstCombine: fold (A >> C) == (B >> C) --> (A^B) < (1 << C) for constant Cs.

2013-11-16 16:00:48 +00:00

InstCombineLoadStoreAlloca.cpp

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InstCombineMulDivRem.cpp

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InstCombinePHI.cpp

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InstCombineSelect.cpp

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InstCombineShifts.cpp

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InstCombineSimplifyDemanded.cpp

Remove x86_sse42_crc32_64_8 intrinsic. It has no functional difference from x86_sse42_crc32_32_8 and was not mapped to a clang builtin. I'm not even sure why this form of the instruction is even called out explicitly in the docs. Also add AutoUpgrade support to convert it into the other intrinsic with appropriate trunc and zext.

2013-10-15 05:20:47 +00:00

InstCombineVectorOps.cpp

Scalarize select vector arguments when extracted.

2013-11-04 20:36:06 +00:00

InstCombineWorklist.h

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InstructionCombining.cpp

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LLVMBuild.txt

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Makefile

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