add a simple instcombine xform, simplify another one to use hasAllZeroIndices()
instead of hand rolling a loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92403 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 527d28e..5f210da 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -6427,21 +6427,12 @@
if (Instruction *LHSI = dyn_cast<Instruction>(Op0))
switch (LHSI->getOpcode()) {
case Instruction::GetElementPtr:
- if (RHSC->isNullValue()) {
// icmp pred GEP (P, int 0, int 0, int 0), null -> icmp pred P, null
- bool isAllZeros = true;
- for (unsigned i = 1, e = LHSI->getNumOperands(); i != e; ++i)
- if (!isa<Constant>(LHSI->getOperand(i)) ||
- !cast<Constant>(LHSI->getOperand(i))->isNullValue()) {
- isAllZeros = false;
- break;
- }
- if (isAllZeros)
- return new ICmpInst(I.getPredicate(), LHSI->getOperand(0),
- Constant::getNullValue(LHSI->getOperand(0)->getType()));
- }
+ if (RHSC->isNullValue() &&
+ cast<GetElementPtrInst>(LHSI)->hasAllZeroIndices())
+ return new ICmpInst(I.getPredicate(), LHSI->getOperand(0),
+ Constant::getNullValue(LHSI->getOperand(0)->getType()));
break;
-
case Instruction::PHI:
// Only fold icmp into the PHI if the phi and icmp are in the same
// block. If in the same block, we're encouraging jump threading. If
@@ -6506,6 +6497,14 @@
}
}
break;
+ case Instruction::IntToPtr:
+ // icmp pred inttoptr(X), null -> icmp pred X, 0
+ if (RHSC->isNullValue() && TD &&
+ TD->getIntPtrType(RHSC->getContext()) ==
+ LHSI->getOperand(0)->getType())
+ return new ICmpInst(I.getPredicate(), LHSI->getOperand(0),
+ Constant::getNullValue(LHSI->getOperand(0)->getType()));
+ break;
}
}