diff options
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 4baa1a6bbbc..57f61ab38fc 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -8271,7 +8271,13 @@ SDValue X86TargetLowering::EmitTest(SDValue Op, unsigned X86CC, // Otherwise use a regular EFLAGS-setting instruction. switch (Op.getNode()->getOpcode()) { default: llvm_unreachable("unexpected operator!"); - case ISD::SUB: Opcode = X86ISD::SUB; break; + case ISD::SUB: + // If the only use of SUB is EFLAGS, use CMP instead. + if (Op.hasOneUse()) + Opcode = X86ISD::CMP; + else + Opcode = X86ISD::SUB; + break; case ISD::OR: Opcode = X86ISD::OR; break; case ISD::XOR: Opcode = X86ISD::XOR; break; case ISD::AND: Opcode = X86ISD::AND; break; @@ -8297,6 +8303,13 @@ SDValue X86TargetLowering::EmitTest(SDValue Op, unsigned X86CC, return DAG.getNode(X86ISD::CMP, dl, MVT::i32, Op, DAG.getConstant(0, Op.getValueType())); + if (Opcode == X86ISD::CMP) { + SDValue New = DAG.getNode(Opcode, dl, MVT::i32, Op.getOperand(0), + Op.getOperand(1)); + DAG.ReplaceAllUsesWith(Op, New); + return SDValue(New.getNode(), 0); + } + SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32); SmallVector<SDValue, 4> Ops; for (unsigned i = 0; i != NumOperands; ++i) |
