[all-commits] [llvm/llvm-project] f22547: [LSV] Fix the ContextInst for computeKnownBits.

[Justin Lebar via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f225471c68881d31835a06c6b2f2b40bdaa287d5
      https://github.com/llvm/llvm-project/commit/f225471c68881d31835a06c6b2f2b40bdaa287d5
  Author: Justin Lebar <justin.lebar at gmail.com>
  Date:   2023-05-28 (Sun, 28 May 2023)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp
    M llvm/test/Transforms/LoadStoreVectorizer/AMDGPU/gep-bitcast.ll

  Log Message:
  -----------
  [LSV] Fix the ContextInst for computeKnownBits.

Previously we used the later of GEPA or GEPB.  This is hacky because
really we should be using the later of the two load/store instructions
being considered.  But also it's flat-out incorrect, because GEPA and
GEPB might be in different BBs, in which case we cannot ask which one
comes last (assertion failure,
https://reviews.llvm.org/D149893#4378332).

Fixed, now we use the correct context instruction.

Differential Revision: https://reviews.llvm.org/D151630