[llvm] [LLVM][IR] When evaluting GEP offsets don't assume ConstantInt is a scalar. (PR #117162)

[Nikita Popov via llvm-commits]

================
@@ -163,28 +165,30 @@ bool GEPOperator::accumulateConstantOffset(
     Value *V = GTI.getOperand();
     StructType *STy = GTI.getStructTypeOrNull();
     // Handle ConstantInt if possible.
-    if (auto ConstOffset = dyn_cast<ConstantInt>(V)) {
-      if (ConstOffset->isZero())
-        continue;
-      // if the type is scalable and the constant is not zero (vscale * n * 0 =
-      // 0) bailout.
-      if (ScalableType)
-        return false;
-      // Handle a struct index, which adds its field offset to the pointer.
-      if (STy) {
-        unsigned ElementIdx = ConstOffset->getZExtValue();
-        const StructLayout *SL = DL.getStructLayout(STy);
-        // Element offset is in bytes.
-        if (!AccumulateOffset(
-                APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx)),
-                1))
+    if (V->getType()->isIntegerTy()) {
+      if (auto ConstOffset = dyn_cast<ConstantInt>(V)) {
----------------
nikic wrote:

In the interest of keeping the indentation down, I'd write this as:
```
auto *ConstOffset = dyn_cast<ConstantInt>(V);
if (ConstOffset && ConstOffset->getType()->isIntegerTy()) {
}
```

https://github.com/llvm/llvm-project/pull/117162