Fix X86FastISel's add folding to actually work, and not fall back
to SelectionDAG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107376 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index f371796..1c700b2 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -430,6 +430,14 @@
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
Disp += CI->getSExtValue() * S;
+ } else if (isa<AddOperator>(Op) &&
+ isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
+ // An add with a constant operand. Fold the constant.
+ ConstantInt *CI =
+ cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
+ Disp += CI->getSExtValue() * S;
+ // Add the other operand back to the work list.
+ Worklist.push_back(cast<AddOperator>(Op)->getOperand(0));
} else if (IndexReg == 0 &&
(!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
(S == 1 || S == 2 || S == 4 || S == 8)) {
@@ -438,10 +446,6 @@
IndexReg = getRegForGEPIndex(Op).first;
if (IndexReg == 0)
return false;
- } else if (const AddOperator *Add = dyn_cast<AddOperator>(Op)) {
- // An add. Try to fold both operands.
- Worklist.push_back(Add->getOperand(0));
- Worklist.push_back(Add->getOperand(1));
} else
// Unsupported.
goto unsupported_gep;