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Minor optimization: when doing eq/ne comparions and RHS is a constant - swap operands, this will allow us to fold imm into comparison. 

llvm-svn: 89574
This commit is contained in:
Anton Korobeynikov 2009-11-22 01:14:08 +00:00
parent 3a31644c7a
commit abdf86d2be
1 changed files with 8 additions and 0 deletions
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8
llvm/lib/Target/MSP430/MSP430ISelLowering.cpp
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@ -594,9 +594,17 @@ static SDValue EmitCMP(SDValue &LHS, SDValue &RHS, SDValue &TargetCC,
default: llvm_unreachable("Invalid integer condition!");
case ISD::SETEQ:
TCC = MSP430CC::COND_E; // aka COND_Z
// Minor optimization: if RHS is a constant, swap operands, then the
// constant can be folded into comparison.
if (RHS.getOpcode() == ISD::Constant)
std::swap(LHS, RHS);
break;
case ISD::SETNE:
TCC = MSP430CC::COND_NE; // aka COND_NZ
// Minor optimization: if RHS is a constant, swap operands, then the
// constant can be folded into comparison.
if (RHS.getOpcode() == ISD::Constant)
std::swap(LHS, RHS);
break;
case ISD::SETULE:
std::swap(LHS, RHS); // FALLTHROUGH