diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 14 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/extract-insert.ll | 4 |
2 files changed, 12 insertions, 6 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 16834dc1a26..7ec5fac390b 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -15499,13 +15499,15 @@ SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) { // converts. } - // extract_vector_elt (v2i32 (bitcast i64:x)), EltTrunc -> i32 (trunc i64:x) - bool isLE = DAG.getDataLayout().isLittleEndian(); - unsigned EltTrunc = isLE ? 0 : VT.getVectorNumElements() - 1; - if (ConstEltNo && InVec.getOpcode() == ISD::BITCAST && InVec.hasOneUse() && - ConstEltNo->getZExtValue() == EltTrunc && VT.isInteger()) { + if (ConstEltNo && InVec.getOpcode() == ISD::BITCAST) { + // The vector index of the LSBs of the source depend on the endian-ness. + bool IsLE = DAG.getDataLayout().isLittleEndian(); + + // extract_elt (v2i32 (bitcast i64:x)), BCTruncElt -> i32 (trunc i64:x) + unsigned BCTruncElt = IsLE ? 0 : VT.getVectorNumElements() - 1; SDValue BCSrc = InVec.getOperand(0); - if (BCSrc.getValueType().isScalarInteger()) + if (InVec.hasOneUse() && ConstEltNo->getZExtValue() == BCTruncElt && + VT.isInteger() && BCSrc.getValueType().isScalarInteger()) return DAG.getNode(ISD::TRUNCATE, SDLoc(N), NVT, BCSrc); } diff --git a/llvm/test/CodeGen/X86/extract-insert.ll b/llvm/test/CodeGen/X86/extract-insert.ll index de8ee704b88..b3fb50de718 100644 --- a/llvm/test/CodeGen/X86/extract-insert.ll +++ b/llvm/test/CodeGen/X86/extract-insert.ll @@ -28,6 +28,10 @@ define i8 @extractelt_bitcast(i32 %x) nounwind { ret i8 %ext } +; TODO: This should have folded to avoid vector ops, but the transform +; is guarded by 'hasOneUse'. That limitation apparently makes some AMDGPU +; codegen better. + define i8 @extractelt_bitcast_extra_use(i32 %x, <4 x i8>* %p) nounwind { ; X86-LABEL: extractelt_bitcast_extra_use: ; X86: # %bb.0: |
