[PATCH] D143437: [llvm] Use pointer index type for more GEP offsets (pre-codegen)

Thu Feb 16 16:38:32 PST 2023

jrtc27 added inline comments.

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Comment at: llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp:927

-  Value *ResultPtr = Builder.CreatePtrToInt(Variadic->getOperand(0), IntPtrTy);
+  Value *ResultPtr = Builder.CreatePtrToInt(Variadic->getOperand(0), PtrIdxTy);
   gep_type_iterator GTI = gep_type_begin(*Variadic);
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arichardson wrote:
> jrtc27 wrote:
> > krzysz00 wrote:
> > > arsenm wrote:
> > > > Doesn't creating a ptrtoint from a non-integral pointer break horribly?
> > > Good catch, I've added guards to make sure non-integral address spaces don't get sent this direction. And that fat pointers don't enter this code path either.
> > Hm, weirdly I don't see any changes to this function in CHERI LLVM, which makes me wonder how we don't hit issues here on CHERI-RISC-V given the RISC-V backend doesn't return true for STI->useAA()...
> Probably due to the `DL->getIntPtrType` hack that we have (which been hopefully be deleted soon after merging up to this change).
It would still generate a metadata-stripping ptrtoint+...+inttoptr sequence though, that would only stop it asserting on using the wrong type for ptrtoint

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D143437/new/

https://reviews.llvm.org/D143437