diff options
Diffstat (limited to 'llvm/lib/Transforms/Vectorize/LoopVectorize.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp index 836a38d9813..080f265b258 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -4284,15 +4284,17 @@ void InnerLoopVectorizer::fixFirstOrderRecurrence(PHINode *Phi) { auto *VecPhi = Builder.CreatePHI(VectorInit->getType(), 2, "vector.recur"); VecPhi->addIncoming(VectorInit, LoopVectorPreHeader); - // Get the vectorized previous value. We ensured the previous values was an - // instruction when detecting the recurrence. + // Get the vectorized previous value. auto &PreviousParts = getVectorValue(Previous); - // Set the insertion point to be after this instruction. We ensured the - // previous value dominated all uses of the phi when detecting the - // recurrence. - Builder.SetInsertPoint( - &*++BasicBlock::iterator(cast<Instruction>(PreviousParts[UF - 1]))); + // Set the insertion point after the previous value if it is an instruction. + // Note that the previous value may have been constant-folded so it is not + // guaranteed to be an instruction in the vector loop. + if (LI->getLoopFor(LoopVectorBody)->isLoopInvariant(PreviousParts[UF - 1])) + Builder.SetInsertPoint(&*LoopVectorBody->getFirstInsertionPt()); + else + Builder.SetInsertPoint( + &*++BasicBlock::iterator(cast<Instruction>(PreviousParts[UF - 1]))); // We will construct a vector for the recurrence by combining the values for // the current and previous iterations. This is the required shuffle mask. |
