[llvm] [ConstantFolding] Support ptrtoaddr in ConstantFoldCompareInstOperands (PR #162653)

[Alexander Richardson via llvm-commits]

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@@ -1225,7 +1225,8 @@ Constant *llvm::ConstantFoldCompareInstOperands(
 
       // Only do this transformation if the int is intptrty in size, otherwise
       // there is a truncation or extension that we aren't modeling.
-      if (CE0->getOpcode() == Instruction::PtrToInt) {
+      if (CE0->getOpcode() == Instruction::PtrToInt ||
+          CE0->getOpcode() == Instruction::PtrToAddr) {
         Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
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arichardson wrote:

Since we seem to be aligned on using address width only for `icmp ptr`, I believe all of these DL.getIntPtrType() should be DL.getAddressType()? This change probably won't be caught by existing tests since we won't have many for index size != pointer size.

https://github.com/llvm/llvm-project/pull/162653