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Fix a SETCC / BRCOND folding bug. 

llvm-svn: 25259
This commit is contained in:
Evan Cheng 2006-01-13 01:03:02 +00:00
parent 6d47166964
commit fb22e86c4d
1 changed files with 37 additions and 12 deletions
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49
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -1572,14 +1572,24 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
bool isFP = MVT::isFloatingPoint(VT);
bool isFPStack = isFP && (X86Vector < SSE2);
bool isFPSSE = isFP && (X86Vector >= SSE2);
bool isValid = false;
bool addTest = false;
SDOperand Op0 = Op.getOperand(0);
SDOperand Cond, CC;
if (Op0.getOpcode() == X86ISD::SETCC) {
CC = Op0.getOperand(0);
Cond = Op0.getOperand(1);
isValid =
!(isFPStack && !hasFPCMov(cast<ConstantSDNode>(CC)->getSignExtended()));
// If condition flag is set by a X86ISD::CMP, then make a copy of it
// (since flag operand cannot be shared). If the X86ISD::SETCC does not
// have another use it will be eliminated.
// If the X86ISD::SETCC has more than one use, then it's probably better
// to use a test instead of duplicating the X86ISD::CMP (for register
// pressure reason).
if (Cond.hasOneUse() && Cond.getOperand(1).getOpcode() == X86ISD::CMP) {
CC = Op0.getOperand(0);
Cond = Op0.getOperand(1);
addTest =
!(isFPStack &&
!hasFPCMov(cast<ConstantSDNode>(CC)->getSignExtended()));
} else
addTest = true;
} else if (Op0.getOpcode() == ISD::SETCC) {
CC = Op0.getOperand(2);
bool isFP = MVT::isFloatingPoint(Op0.getOperand(1).getValueType());
@ -1587,10 +1597,11 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
CC = DAG.getConstant(X86CC, MVT::i8);
Cond = DAG.getNode(X86ISD::CMP, MVT::Flag,
Op0.getOperand(0), Op0.getOperand(1));
isValid = true;
}
addTest = true;
} else
addTest = true;
if (!isValid) {
if (!addTest) {
CC = DAG.getConstant(X86ISD::COND_E, MVT::i8);
Cond = DAG.getNode(X86ISD::TEST, MVT::Flag, Op0, Op0);
}
@ -1606,13 +1617,24 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
return DAG.getNode(X86ISD::CMOV, Tys, Ops);
}
case ISD::BRCOND: {
bool addTest = false;
SDOperand Cond = Op.getOperand(1);
SDOperand Dest = Op.getOperand(2);
SDOperand CC;
// TODO: handle Cond == OR / AND / XOR
if (Cond.getOpcode() == X86ISD::SETCC) {
CC = Cond.getOperand(0);
Cond = Cond.getOperand(1);
// If condition flag is set by a X86ISD::CMP, then make a copy of it
// (since flag operand cannot be shared). If the X86ISD::SETCC does not
// have another use it will be eliminated.
// If the X86ISD::SETCC has more than one use, then it's probably better
// to use a test instead of duplicating the X86ISD::CMP (for register
// pressure reason).
if (Cond.hasOneUse() && Cond.getOperand(1).getOpcode() == X86ISD::CMP) {
CC = Cond.getOperand(0);
Cond = DAG.getNode(X86ISD::CMP, MVT::Flag,
Cond.getOperand(1).getOperand(0),
Cond.getOperand(1).getOperand(1));
} else
addTest = true;
} else if (Cond.getOpcode() == ISD::SETCC) {
CC = Cond.getOperand(2);
bool isFP = MVT::isFloatingPoint(Cond.getOperand(1).getValueType());
@ -1620,7 +1642,10 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
CC = DAG.getConstant(X86CC, MVT::i8);
Cond = DAG.getNode(X86ISD::CMP, MVT::Flag,
Cond.getOperand(0), Cond.getOperand(1));
} else {
} else
addTest = true;
if (addTest) {
CC = DAG.getConstant(X86ISD::COND_NE, MVT::i8);
Cond = DAG.getNode(X86ISD::TEST, MVT::Flag, Cond, Cond);
}