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Instead of generating stuff like this:

Browse Source 
mov %ECX, %EAX
        add %ECX, 32768
        mov %SI, WORD PTR [2*%ECX + l13_prev]

Generate this:

        mov %SI, WORD PTR [2*%ECX + l13_prev + 65536]

This occurs when you have a GEP instruction where an index is
"something + imm".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19472 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-01-11 06:36:20 +00:00
parent 5a069f5a7e
commit 51a263434a
1 changed files with 14 additions and 1 deletions
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15
lib/Target/X86/X86ISelPattern.cpp
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@ -429,7 +429,20 @@ bool ISel::SelectAddress(SDOperand N, X86AddressMode &AM) {
unsigned Val = CN->getValue();
if (Val == 1 || Val == 2 || Val == 3) {
AM.Scale = 1 << Val;
AM.IndexReg = SelectExpr(N.Val->getOperand(0));
SDOperand ShVal = N.Val->getOperand(0);
// Okay, we know that we have a scale by now. However, if the scaled
// value is an add of something and a constant, we can fold the
// constant into the disp field here.
if (ShVal.Val->getOpcode() == ISD::ADD &&
isa<ConstantSDNode>(ShVal.Val->getOperand(1))) {
AM.IndexReg = SelectExpr(ShVal.Val->getOperand(0));
ConstantSDNode *AddVal =
cast<ConstantSDNode>(ShVal.Val->getOperand(1));
AM.Disp += AddVal->getValue() << Val;
} else {
AM.IndexReg = SelectExpr(ShVal);
}
return false;
}
}