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author | Nadav Rotem <nrotem@apple.com> | 2012-12-11 18:58:10 +0000 |
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committer | Nadav Rotem <nrotem@apple.com> | 2012-12-11 18:58:10 +0000 |
commit | 5e9efa10fc7eea582bb1ad216364fb2c467e4477 (patch) | |
tree | 33a68bbe3bbfcb608a9f31cd49d104ed5929e5af /lib | |
parent | 37a9830d20018dee5557a3a72f750d965ba383c5 (diff) | |
download | external_llvm-5e9efa10fc7eea582bb1ad216364fb2c467e4477.zip external_llvm-5e9efa10fc7eea582bb1ad216364fb2c467e4477.tar.gz external_llvm-5e9efa10fc7eea582bb1ad216364fb2c467e4477.tar.bz2 |
Loop Vectorize: optimize the vectorization of trunc(induction_var). The truncation is now done on scalars.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169904 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Transforms/Vectorize/LoopVectorize.cpp | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index a691240..9550e8a 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -1204,8 +1204,20 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, case Instruction::Trunc: case Instruction::FPTrunc: case Instruction::BitCast: { - /// Vectorize bitcasts. CastInst *CI = dyn_cast<CastInst>(it); + /// Optimize the special case where the source is the induction + /// variable. Notice that we can only optimize the 'trunc' case + /// because: a. FP conversions lose precision, b. sext/zext may wrap, + /// c. other casts depend on pointer size. + if (CI->getOperand(0) == OldInduction && + it->getOpcode() == Instruction::Trunc) { + Value *ScalarCast = Builder.CreateCast(CI->getOpcode(), Induction, + CI->getType()); + Value *Broadcasted = getBroadcastInstrs(ScalarCast); + WidenMap[it] = getConsecutiveVector(Broadcasted); + break; + } + /// Vectorize casts. Value *A = getVectorValue(it->getOperand(0)); Type *DestTy = VectorType::get(CI->getType()->getScalarType(), VF); WidenMap[it] = Builder.CreateCast(CI->getOpcode(), A, DestTy); |