diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 81889d0a745..06a61cbba64 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -9063,6 +9063,18 @@ static SDValue getINSERTPS(ShuffleVectorSDNode *SVOp, SDLoc &dl, To = V2; DestIndex = std::find_if(Mask.begin(), Mask.end(), FromV1Predicate) - Mask.begin(); + + // If we have 1 element from each vector, we have to check if we're + // changing V1's element's place. If so, we're done. Otherwise, we + // should assume we're changing V2's element's place and behave + // accordingly. + int FromV2 = std::count_if(Mask.begin(), Mask.end(), FromV2Predicate); + if (FromV1 == FromV2 && DestIndex == Mask[DestIndex] % 4) { + From = V2; + To = V1; + DestIndex = + std::find_if(Mask.begin(), Mask.end(), FromV2Predicate) - Mask.begin(); + } } else { assert(std::count_if(Mask.begin(), Mask.end(), FromV2Predicate) == 1 && "More than one element from V1 and from V2, or no elements from one " @@ -9074,6 +9086,8 @@ static SDValue getINSERTPS(ShuffleVectorSDNode *SVOp, SDLoc &dl, std::find_if(Mask.begin(), Mask.end(), FromV2Predicate) - Mask.begin(); } + // Get an index into the source vector in the range [0,4) (the mask is + // in the range [0,8) because it can address V1 and V2) unsigned SrcIndex = Mask[DestIndex] % 4; if (MayFoldLoad(From)) { // Trivial case, when From comes from a load and is only used by the |
