Optimize pointer comparison into the typesafe form, now that the backends will
handle them efficiently. This is the opposite direction of the transformation
we used to have here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92418 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 6cda71b..e208d69 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -4432,8 +4432,7 @@
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(I))
- return &I;
-
+ return &I;
if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
const APInt &AndRHSMask = AndRHS->getValue();
@@ -7312,6 +7311,25 @@
}
}
break;
+
+ case Instruction::Or: {
+ if (!ICI.isEquality() || !RHS->isNullValue() || !LHSI->hasOneUse())
+ break;
+ Value *P, *Q;
+ if (match(LHSI, m_Or(m_PtrToInt(m_Value(P)), m_PtrToInt(m_Value(Q))))) {
+ // Simplify icmp eq (or (ptrtoint P), (ptrtoint Q)), 0
+ // -> and (icmp eq P, null), (icmp eq Q, null).
+
+ Value *ICIP = Builder->CreateICmp(ICI.getPredicate(), P,
+ Constant::getNullValue(P->getType()));
+ Value *ICIQ = Builder->CreateICmp(ICI.getPredicate(), Q,
+ Constant::getNullValue(Q->getType()));
+ Instruction *And = BinaryOperator::CreateAnd(ICIP, ICIQ, "");
+ And->takeName(&ICI);
+ return And;
+ }
+ break;
+ }
case Instruction::Shl: { // (icmp pred (shl X, ShAmt), CI)
ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1));