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Fix a miscompilation in the addr mode code trying to implement X | C and 

X + C to promote LEA formation.  We would incorrectly apply it in some cases
(test) and miss it in others.

This fixes CodeGen/X86/2007-02-04-OrAddrMode.ll

llvm-svn: 33884
This commit is contained in:
Chris Lattner 2007-02-04 20:18:17 +00:00
parent 03503b5e31
commit fe8c530d79
1 changed files with 17 additions and 20 deletions
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37
llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
View File

@ -677,7 +677,7 @@ bool X86DAGToDAGISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM,
if (!Available &&
AM.BaseType == X86ISelAddressMode::RegBase &&
AM.Base.Reg.Val == 0 &&
AM.IndexReg.Val == 0)
AM.IndexReg.Val == 0) {
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1)))
if (CN->getValue() == 3 || CN->getValue() == 5 || CN->getValue() == 9) {
AM.Scale = unsigned(CN->getValue())-1;
@ -705,9 +705,10 @@ bool X86DAGToDAGISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM,
AM.IndexReg = AM.Base.Reg = Reg;
return false;
}
}
break;
case ISD::ADD: {
case ISD::ADD:
if (!Available) {
X86ISelAddressMode Backup = AM;
if (!MatchAddress(N.Val->getOperand(0), AM, false) &&
@ -720,32 +721,28 @@ bool X86DAGToDAGISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM,
AM = Backup;
}
break;
}
case ISD::OR: {
case ISD::OR:
// Handle "X | C" as "X + C" iff X is known to have C bits clear.
if (!Available) {
X86ISelAddressMode Backup = AM;
// Look for (x << c1) | c2 where (c2 < c1)
ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(0));
if (CN && !MatchAddress(N.Val->getOperand(1), AM, false)) {
if (AM.GV == NULL && AM.Disp == 0 && CN->getValue() < AM.Scale) {
AM.Disp = CN->getValue();
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
X86ISelAddressMode Backup = AM;
// Start with the LHS as an addr mode.
if (!MatchAddress(N.getOperand(0), AM, false) &&
// Address could not have picked a GV address for the displacement.
AM.GV == NULL &&
// On x86-64, the resultant disp must fit in 32-bits.
isInt32(AM.Disp + CN->getSignExtended()) &&
// Check to see if the LHS & C is zero.
TLI.MaskedValueIsZero(N.getOperand(0), CN->getValue())) {
AM.Disp += CN->getValue();
return false;
}
AM = Backup;
}
AM = Backup;
CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1));
if (CN && !MatchAddress(N.Val->getOperand(0), AM, false)) {
if (AM.GV == NULL && AM.Disp == 0 && CN->getValue() < AM.Scale) {
AM.Disp = CN->getValue();
return false;
}
}
AM = Backup;
}
break;
}
}
// Is the base register already occupied?
if (AM.BaseType != X86ISelAddressMode::RegBase || AM.Base.Reg.Val) {