Make sure that ConstantExpr offsets also aren't off of extern
symbols.
Thanks to Duncan Sands for the testcase!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95877 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 1371fa7..43419eb 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -331,9 +331,15 @@
if (CE->getOpcode() != Instruction::GetElementPtr) break;
GEPOperator *GEP = cast<GEPOperator>(CE);
+ // Make sure we're not a constant offset from an external
+ // global.
+ Value *Operand = GEP->getPointerOperand();
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Operand))
+ if (!GV->hasDefinitiveInitializer()) break;
+
// Get what we're pointing to and its size.
const PointerType *PT =
- cast<PointerType>(GEP->getPointerOperand()->getType());
+ cast<PointerType>(Operand->getType());
size_t Size = TD->getTypeAllocSize(PT->getElementType());
// Get the current byte offset into the thing.
@@ -345,7 +351,7 @@
Constant *RetVal = ConstantInt::get(ReturnTy, Size-Offset);
return ReplaceInstUsesWith(CI, RetVal);
- }
+ }
}
case Intrinsic::bswap:
// bswap(bswap(x)) -> x