[all-commits] [llvm/llvm-project] a3d05e: Remove an incorrect assert in MFMASmallGemmSingleW...

[anjenner via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a3d05e89873654dd1b27979b2bfd82ddd4859ba7
      https://github.com/llvm/llvm-project/commit/a3d05e89873654dd1b27979b2bfd82ddd4859ba7
  Author: anjenner <161845516+anjenner at users.noreply.github.com>
  Date:   2025-04-24 (Thu, 24 Apr 2025)

  Changed paths:
    M llvm/lib/Target/AMDGPU/AMDGPUIGroupLP.cpp
    A llvm/test/CodeGen/AMDGPU/llvm.amdgcn.iglp.AFLCustomIRMutator.opt.ll

  Log Message:
  -----------
  Remove an incorrect assert in MFMASmallGemmSingleWaveOpt. (#130131)

This assert was failing in a fuzzing test. I consulted with @jrbyrnes
who said:

The MFMASmallGemmSingleWaveOpt::apply() method is invoked if and only if
the user has inserted an intrinsic llvm.amdgcn.iglp.opt(i32 1) into
their source code. This intrinsic applies a highly specialized DAG
mutation to result in specific scheduling for a specific set of kernels.
These assertions are really just confirming that the characteristics of
the kernel match what is expected (i.e. The kernels are similar to the
ones this DAG mutation strategy were designed against).

However, if we apply this DAG mutation to kernels for which is was not
designed, then we may not find the types of instructions we are looking
for, and may end up with empty caches.

I think it should be fine to just return false if the cache is empty
instead of the assert.



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