[llvm] [SeparateConstOffsetFromGEP] Support GEP reordering for different types (PR #90802)

[Nikita Popov via llvm-commits]

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@@ -1017,6 +1016,51 @@ bool SeparateConstOffsetFromGEP::reorderGEP(GetElementPtrInst *GEP,
       IsChainInBounds &= KnownPtrGEPIdx.isNonNegative();
     }
   }
+  TypeSize GEPSize = DL->getTypeSizeInBits(GEP->getSourceElementType());
+  TypeSize PtrGEPSize = DL->getTypeSizeInBits(PtrGEP->getSourceElementType());
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nikic wrote:

You're working on the wrong type sizes here. You need to use the alloc sizes.

But more generally, maybe I don't get what this code is doing, but can't you also swap the GEP source element types when swapping the indices? That's how you usually reassociate GEPs. Why do you need/want to rewrite them?

https://github.com/llvm/llvm-project/pull/90802