[all-commits] [llvm/llvm-project] 553723: [InstSimplify] Fix a scalable-vector crash

[Fraser Cormack via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 55372309a4c757af17f7dc33e5b686cf8565997f
      https://github.com/llvm/llvm-project/commit/55372309a4c757af17f7dc33e5b686cf8565997f
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2023-06-28 (Wed, 28 Jun 2023)

  Changed paths:
    M llvm/lib/Analysis/InstructionSimplify.cpp
    M llvm/test/Transforms/InstSimplify/fp-nan.ll

  Log Message:
  -----------
  [InstSimplify] Fix a scalable-vector crash

D143505 fixed/simplified folding of operations with SNaN operands. In
doing so it introduced a crash when handling scalable vector types,
wherein the scalable-vector ConstantVector was cast to a ConstantFP.

Since we know by that point in the code that if we've found a NaN, we're
dealing with a scalable-vector splat (as there are no other kinds of
scalable-vector constant for which that holds), we can grab the splatted
value and re-use the existing code, which will automatically splat the
new NaN back to a scalable vector for us.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D153566