[all-commits] [llvm/llvm-project] 591456: [Utils][SPIR-V] Adding spirv-sim to LLVM (#107094)

[Nathan Gauër via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5914566474de29309b0b4815ecd406805793de1f
      https://github.com/llvm/llvm-project/commit/5914566474de29309b0b4815ecd406805793de1f
  Author: Nathan Gauër <brioche at google.com>
  Date:   2024-09-04 (Wed, 04 Sep 2024)

  Changed paths:
    A llvm/test/Other/spirv-sim/branch.spv
    A llvm/test/Other/spirv-sim/call.spv
    A llvm/test/Other/spirv-sim/constant.spv
    A llvm/test/Other/spirv-sim/lit.local.cfg
    A llvm/test/Other/spirv-sim/loop.spv
    A llvm/test/Other/spirv-sim/simple-bad-result.spv
    A llvm/test/Other/spirv-sim/simple.spv
    A llvm/test/Other/spirv-sim/simulator-args.spv
    A llvm/test/Other/spirv-sim/switch.spv
    A llvm/test/Other/spirv-sim/wave-get-lane-index.spv
    A llvm/test/Other/spirv-sim/wave-read-lane-first.spv
    M llvm/test/lit.cfg.py
    A llvm/utils/spirv-sim/instructions.py
    A llvm/utils/spirv-sim/spirv-sim.py

  Log Message:
  -----------
  [Utils][SPIR-V] Adding spirv-sim to LLVM (#107094)

### 2nd submission
The buildbots are using python 3.8, and some type annotations I was
using are only available starting 3.9. The last commit on the pile is
the additional changes compared to the original submission
https://github.com/llvm/llvm-project/pull/104020.

### Original text:
Currently, the testing infrastructure for SPIR-V is based on FileCheck.
Those tests are great to check some level of codegen, but when the test
needs check both the CFG layout and the content of each basic-block,
things becomes messy.

Because the CHECK/CHECK-DAG/CHECK-NEXT state is limited, it is sometimes
hard to catch the good block: if 2 basic blocks have similar
instructions, FileCheck can match the wrong one.

Cross-lane interaction can be a bit difficult to understand, and
writting a FileCheck test that is strong enough to catch bad CFG
transforms while not being broken everytime some unrelated codegen part
changes is hard.

And lastly, the spirv-val tooling we have checks that the generated
SPIR-V respects the spec, not that it is correct in regards to the
source IR.

For those reasons, I believe the best way to test the structurizer is
to:

run spirv-val to make sure the CFG respects the spec.
simulate the function to validate result for each lane, making sure the
generated code is correct.
This simulator has no other dependencies than core python. It also only
supports a very limited set of instructions as we can test most features
through control-flow and some basic cross-lane interactions.

As-is, the added tests are just a harness for the simulator itself. If
this gets merged, the structurizer PR will benefit from this as I'll be
able to add extensive testing using this.

---------

Signed-off-by: Nathan Gauër <brioche at google.com>



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications