[all-commits] [llvm/llvm-project] e0aac8: [mlir][gpu] Align reduction operations with vector...

[Jakub Kuderski via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e0aac8c88d0d30e8da0f8a240ad1e6b4d88782e0
      https://github.com/llvm/llvm-project/commit/e0aac8c88d0d30e8da0f8a240ad1e6b4d88782e0
  Author: Jakub Kuderski <jakub at nod-labs.com>
  Date:   2023-11-27 (Mon, 27 Nov 2023)

  Changed paths:
    M mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
    M mlir/include/mlir/IR/CommonTypeConstraints.td
    M mlir/lib/Conversion/GPUToNVVM/LowerGpuOpsToNVVMOps.cpp
    M mlir/lib/Conversion/GPUToSPIRV/GPUToSPIRV.cpp
    M mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
    M mlir/lib/Dialect/GPU/Transforms/AllReduceLowering.cpp
    M mlir/test/Conversion/GPUToNVVM/gpu-to-nvvm.mlir
    M mlir/test/Conversion/GPUToSPIRV/reductions.mlir
    A mlir/test/Dialect/GPU/all-reduce-add.mlir
    R mlir/test/Dialect/GPU/all-reduce-max.mlir
    A mlir/test/Dialect/GPU/all-reduce-maxf.mlir
    R mlir/test/Dialect/GPU/all-reduce.mlir
    M mlir/test/Dialect/GPU/invalid.mlir

  Log Message:
  -----------
  [mlir][gpu] Align reduction operations with vector combining kinds (#73423)

The motivation for this change is explained in
https://github.com/llvm/llvm-project/issues/72354.

Before this change, we could not tell between signed/unsigned
minimum/maximum and NaN treatment for floating point values.

The mapping of old reduction operations to the new ones is as follows:
*  `min` --> `minsi` for ints, `minf` for floats
*  `max` --> `maxsi` for ints, `maxf` for floats

New reduction kinds not represented in the old enum: `minui`, `maxui`,
`minimumf`, `maximumf`.

As a next step, I would like to have a common definition of combining
kinds used by the `vector` and `gpu` dialects. Separately, the GPU to
SPIR-V lowering does not yet properly handle zero and NaN values -- the
behavior of floating point min/max group reductions is not specified by
the SPIR-V spec, see https://github.com/llvm/llvm-project/issues/73459. 

Issue: https://github.com/llvm/llvm-project/issues/72354