[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

https://github.com/nikic closed https://github.com/llvm/llvm-project/pull/93823 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

https://github.com/nikic updated https://github.com/llvm/llvm-project/pull/93823 >From 7fbc0366638de3262294c1923a1b45aa6338fe8f Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Thu, 30 May 2024 09:57:21 +0200 Subject: [PATCH 1/2] [ConstantFold] Remove non-trivial gep-of-gep fold This fold is

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

https://github.com/aeubanks approved this pull request. this PR looks good, and further dropping the fold is also good https://github.com/llvm/llvm-project/pull/93823 ___ cfe-commits mailing list cfe-commits@lists.llvm.org

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

https://github.com/dtcxzyw approved this pull request. LGTM. https://github.com/llvm/llvm-project/pull/93823 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

nikic wrote: > > because the DL-aware constant folding will take care of this anyway. > > Can you point out where we do this fold? https://github.com/llvm/llvm-project/blob/1f46729a18ef13c3ba4184ead1da4ab3037cb7ae/llvm/lib/Analysis/ConstantFolding.cpp#L865 > > I've only kept the

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

https://github.com/dtcxzyw commented: > because the DL-aware constant folding will take care of this anyway. Can you point out where we do this fold? > I've only kept the straightforward zero-index case, where we just concatenate > two GEPs. Is there a test for this case?

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

llvmbot wrote: @llvm/pr-subscribers-llvm-transforms @llvm/pr-subscribers-llvm-ir Author: Nikita Popov (nikic) Changes This fold is subtly incorrect, because DL-unaware constant folding does not know the correct index type to use, and just performs the addition in the type that happens

[clang] [llvm] [ConstantFold] Remove non-trivial gep-of-gep fold (PR #93823)

https://github.com/nikic created https://github.com/llvm/llvm-project/pull/93823 This fold is subtly incorrect, because DL-unaware constant folding does not know the correct index type to use, and just performs the addition in the type that happens to already be there. This is incorrect, since