[all-commits] [llvm/llvm-project] 43adf5: [flang][acc] Handle ViewLike ops with OutlineRemat...

[khaki3 via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 43adf574134cb86ef46b38e29171779e4d844864
      https://github.com/llvm/llvm-project/commit/43adf574134cb86ef46b38e29171779e4d844864
  Author: khaki3 <47756807+khaki3 at users.noreply.github.com>
  Date:   2026-03-05 (Thu, 05 Mar 2026)

  Changed paths:
    M flang/lib/Optimizer/OpenACC/Support/RegisterOpenACCExtensions.cpp
    M flang/test/Fir/OpenACC/offload-livein-value-canonicalization.fir
    M mlir/lib/Dialect/OpenACC/Transforms/OffloadLiveInValueCanonicalization.cpp

  Log Message:
  -----------
  [flang][acc] Handle ViewLike ops with OutlineRematerializationOpInterface in OffloadLiveInValueCanonicalization (#184218)

`fir::ConvertOp` implements both `ViewLikeOpInterface` and
`OutlineRematerializationOpInterface`. `fir.convert` is also used for
ptr-to-int conversions like `(!fir.ref<i32>) -> i64`. That is not really
a "view" — it converts a pointer to an integer — but
`ViewLikeOpInterface` is still attached, so `getOriginalValue` traces
through it to the underlying value.

When the underlying value is not a rematerialization candidate (e.g.,
`fir.alloca`, a block argument, or a `fir.call` result),
`isRematerializationCandidate` returns false and the `fir.convert` is
left as a live-in. This prevents `ACCImplicitData` from tracing back to
the original pointer to create the data mapping.

This PR:
1. Registers `fir::ConvertOp` with
`OutlineRematerializationOpInterface`.
2. Adds a fallback in `isRematerializationCandidate`: when the traced
original op is not a candidate, check the direct defining op (the
`fir.convert` itself) for `OutlineRematerializationOpInterface`.

```fortran
subroutine test()
  integer :: x
  !$acc declare create(x)
  !$acc parallel
    x = 1
  !$acc end parallel
end subroutine
```

Before: CSE merges `fir.convert` outside the region; `ACCImplicitData`
cannot map the pointer.
After: `fir.convert` is sunk/rematerialized inside the ACC region
regardless of its input source.



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