diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index d02dcb6f443..d1a5a98607c 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -15013,6 +15013,11 @@ static SDValue combineTruncationShuffle(ShuffleVectorSDNode *SVN, unsigned NumElts = VT.getVectorNumElements(); unsigned EltSizeInBits = VT.getScalarSizeInBits(); unsigned ExtSrcSizeInBits = N00.getScalarValueSizeInBits(); + unsigned ExtDstSizeInBits = N0.getScalarValueSizeInBits(); + + if (ExtDstSizeInBits % ExtSrcSizeInBits != 0) + return SDValue(); + unsigned ExtScale = ExtDstSizeInBits / ExtSrcSizeInBits; // (v4i32 truncate_vector_inreg(v2i64)) == shuffle<0,2-1,-1> // (v8i16 truncate_vector_inreg(v4i32)) == shuffle<0,2,4,6,-1,-1,-1,-1> @@ -15034,11 +15039,10 @@ static SDValue combineTruncationShuffle(ShuffleVectorSDNode *SVN, if (EltSizeInBits != ExtSrcSizeInBits) return SDValue(); - // Attempt to match a 'truncate_vector_inreg' shuffle, we just search for - // power-of-2 truncations as they are the most likely. - for (unsigned Scale = 2; Scale < NumElts; Scale *= 2) - if (isTruncate(Scale)) - return DAG.getBitcast(VT, N00); + // We can remove *extend_vector_inreg only if the truncation happens at + // the same scale as the extension. + if (isTruncate(ExtScale)) + return DAG.getBitcast(VT, N00); return SDValue(); } |
