Don't try to compute the size of an "array" element if the index is 0:

the size may be unknown, and is not needed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4153 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index ec27d9e028e794dde213a20595fd5c5341db1d20..fae5e103e6697d903f247e40a79c112fa3d9851c 100644 (file)
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -170,11 +170,10 @@ uint64_t TargetData::getIndexedOffset(const Type *ptrTy,
       Ty = cast<SequentialType>(Ty)->getElementType();
 
       // Get the array index and the size of each array element.
-      // Both must be known constants, or this will fail.
-      // Also, the product needs to be sign-extended from 32 to 64 bits.
-      int64_t elementSize = (int64_t)getTypeSize(Ty);
+      // Both must be known constants, or the index shd be 0; else this fails.
       int64_t arrayIdx = cast<ConstantSInt>(Idx[CurIDX])->getValue();
-      Result += (uint64_t)(arrayIdx * elementSize);
+      Result += arrayIdx == 0? 0
+                : (uint64_t) (arrayIdx * (int64_t) getTypeSize(Ty)); 
 
     } else if (const StructType *STy = dyn_cast<const StructType>(Ty)) {
       assert(Idx[CurIDX]->getType() == Type::UByteTy && "Illegal struct idx");