[InstCombine] Don't handle non-canonical index type in icmp of load fold (#151346)
We should just bail out and wait for it to be canonicalized. The current
implementation could emit a trunc without actually performing the
transform.
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index da9b126..b268fea 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -163,6 +163,11 @@
LaterIndices.push_back(IdxVal);
}
+ Value *Idx = GEP->getOperand(2);
+ // If the index type is non-canonical, wait for it to be canonicalized.
+ if (Idx->getType() != DL.getIndexType(GEP->getType()))
+ return nullptr;
+
enum { Overdefined = -3, Undefined = -2 };
// Variables for our state machines.
@@ -290,17 +295,6 @@
// Now that we've scanned the entire array, emit our new comparison(s). We
// order the state machines in complexity of the generated code.
- Value *Idx = GEP->getOperand(2);
-
- // If the index is larger than the pointer offset size of the target, truncate
- // the index down like the GEP would do implicitly. We don't have to do this
- // for an inbounds GEP because the index can't be out of range.
- if (!GEP->isInBounds()) {
- Type *PtrIdxTy = DL.getIndexType(GEP->getType());
- unsigned OffsetSize = PtrIdxTy->getIntegerBitWidth();
- if (Idx->getType()->getPrimitiveSizeInBits().getFixedValue() > OffsetSize)
- Idx = Builder.CreateTrunc(Idx, PtrIdxTy);
- }
// If inbounds keyword is not present, Idx * ElementSize can overflow.
// Let's assume that ElementSize is 2 and the wanted value is at offset 0.
