diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelDAGToDAG.cpp | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp index df7f1fc524b..dd387e5e57c 100644 --- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp +++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp @@ -592,6 +592,15 @@ X86DAGToDAGISel::IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const { Imm->getAPIntValue().isIntN(32)) return false; + // If this really a zext_inreg that can be represented with a movzx + // instruction, prefer that. + // TODO: We could shrink the load and fold if it is non-volatile. + if (U->getOpcode() == ISD::AND && + (Imm->getAPIntValue() == UINT8_MAX || + Imm->getAPIntValue() == UINT16_MAX || + Imm->getAPIntValue() == UINT32_MAX)) + return false; + // ADD/SUB with can negate the immediate and use the opposite operation // to fit 128 into a sign extended 8 bit immediate. if ((U->getOpcode() == ISD::ADD || U->getOpcode() == ISD::SUB) && |
