[Mlir-commits] [mlir] [MLIR] `remove-dead-values` and RegionBranchOp canononicalizations fixes around the `IsolatedFromAbove` ops (PR #224831)

[Matthias Springer]

https://github.com/matthias-springer approved this pull request.

There is still an issue with nested operations. A coding agent found this:
```mlir
// RUN: mlir-opt %s --pass-pipeline='builtin.module(gpu.module(remove-dead-values{canonicalize=false}))'

module attributes {gpu.container_module} {
  gpu.module @kernels {
    gpu.func @kernel(%arg0: i32, %arg1: i32) kernel attributes {sym_visibility = "nested"} {
      gpu.printf "value: %d", %arg0 : i32
      gpu.return
    }
  }
  func.func @caller(%arg0: i32) {
    %c1 = arith.constant 1 : index
    gpu.launch_func  @kernels::@kernel blocks in (%c1, %c1, %c1) threads in (%c1, %c1, %c1)  args(%arg0 : i32, %arg0 : i32)
    return
  }
}
```

But it seems to be a pre-existing issue and maybe not even valid usage of the pass. So let's not worry about it for now.


https://github.com/llvm/llvm-project/pull/224831