[llvm] [InstCombine] Make indexed compare fold GEP source type independent (PR #71663)

[via llvm-commits]

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@@ -609,23 +597,14 @@ static Value *rewriteGEPAsOffset(Type *ElemTy, Value *Start, Value *Base,
     }
   }
 
-  PointerType *PtrTy = PointerType::get(
-      Base->getContext(), Start->getType()->getPointerAddressSpace());
   for (Value *Val : Explored) {
     if (Val == Base)
       continue;
 
-    // Depending on the type, for external users we have to emit
-    // a GEP or a GEP + ptrtoint.
     setInsertionPoint(Builder, Val, false);
-
-    // Cast base to the expected type.
-    Value *NewVal = Builder.CreateBitOrPointerCast(
-        Base, PtrTy, Start->getName() + "to.ptr");
-    NewVal = Builder.CreateInBoundsGEP(ElemTy, NewVal, ArrayRef(NewInsts[Val]),
-                                       Val->getName() + ".ptr");
-    NewVal = Builder.CreateBitOrPointerCast(
-        NewVal, Val->getType(), Val->getName() + ".conv");
+    // Create GEP for external users.
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goldsteinn wrote:

I'm clearly missing something as its not there in original, but would expect a check that `Val` is not a phi node here.

https://github.com/llvm/llvm-project/pull/71663