Canonicalize ConstantInts to the right operand of commutative
operators.
The test difference is just due to the multiplication operands
being commuted (and thus requiring a more elaborate match). In
optimized code, that expression would be folded.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96816 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index f3f9a51..1d23fe0 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -794,8 +794,8 @@
// it is casted back to a pointer, see if the expression can be
// converted into a GEP.
if (CE->getOpcode() == Instruction::Add)
- if (ConstantInt *L = dyn_cast<ConstantInt>(CE->getOperand(0)))
- if (ConstantExpr *R = dyn_cast<ConstantExpr>(CE->getOperand(1)))
+ if (ConstantInt *L = dyn_cast<ConstantInt>(CE->getOperand(1)))
+ if (ConstantExpr *R = dyn_cast<ConstantExpr>(CE->getOperand(0)))
if (R->getOpcode() == Instruction::PtrToInt)
if (GlobalVariable *GV =
dyn_cast<GlobalVariable>(R->getOperand(0))) {
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index c79eb7e..36b307c 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -1105,6 +1105,10 @@
return ConstantExpr::getLShr(C1, C2);
break;
}
+ } else if (isa<ConstantInt>(C1)) {
+ // If C1 is a ConstantInt and C2 is not, swap the operands.
+ if (Instruction::isCommutative(Opcode))
+ return ConstantExpr::get(Opcode, C2, C1);
}
// At this point we know neither constant is an UndefValue.