diff options
Diffstat (limited to 'lib/Target/X86/X86ISelPattern.cpp')
-rw-r--r-- | lib/Target/X86/X86ISelPattern.cpp | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/lib/Target/X86/X86ISelPattern.cpp b/lib/Target/X86/X86ISelPattern.cpp index 8073342895..40e4c414ff 100644 --- a/lib/Target/X86/X86ISelPattern.cpp +++ b/lib/Target/X86/X86ISelPattern.cpp @@ -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; } } |