[all-commits] [llvm/llvm-project] 91c260: [flang][acc] Avoid implicitly privatizing IVs alre...

[Razvan Lupusoru via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 91c2607aace5ce910d0514dc5627651eade9c7d0
      https://github.com/llvm/llvm-project/commit/91c2607aace5ce910d0514dc5627651eade9c7d0
  Author: Razvan Lupusoru <razvan.lupusoru at gmail.com>
  Date:   2025-04-17 (Thu, 17 Apr 2025)

  Changed paths:
    M flang/lib/Lower/OpenACC.cpp
    M flang/test/Lower/OpenACC/acc-kernels-loop.f90
    M flang/test/Lower/OpenACC/acc-loop.f90
    M flang/test/Lower/OpenACC/acc-parallel-loop.f90
    M flang/test/Lower/OpenACC/acc-private-unwrap-defaultbounds.f90
    M flang/test/Lower/OpenACC/acc-private.f90
    M flang/test/Lower/OpenACC/acc-serial-loop.f90

  Log Message:
  -----------
  [flang][acc] Avoid implicitly privatizing IVs already privatized (#136181)

When generating `acc.loop`, the IV was always implicitly privatized.
However, if the user explicitly privatized it, the IR generated wasn't
quite right.

For example:
```
  !$acc loop private(i)
  do i = 1, n
    a(i) = b(i)
  end do
```

The IR generated looked like:
```
    %65 = acc.private varPtr(%19#0 : !fir.ref<i32>) -> !fir.ref<i32>
{implicit = true, name = "i"}
    %66:2 = hlfir.declare %65 {uniq_name = "_QFEi"} : (!fir.ref<i32>) ->
(!fir.ref<i32>, !fir.ref<i32>)
    %67 = acc.private varPtr(%66#0 : !fir.ref<i32>) -> !fir.ref<i32>
{name = "i"}
    acc.loop  private(@privatization_ref_i32 -> %65 : !fir.ref<i32>,
@privatization_ref_i32 -> %67 : !fir.ref<i32>) control(%arg0 : i32) =
(%c1_i32_46 : i32) to (%c10_i32_47 : i32)  step (%c1_i32_48 : i32) {
      fir.store %arg0 to %66#0 : !fir.ref<i32>
```

In order to fix this, we first process all of the clauses. Then when
attempting to generate implicit private IV, we look for an already
existing data clause operation.

The result is the following IR:
```
    %65 = acc.private varPtr(%19#0 : !fir.ref<i32>) -> !fir.ref<i32>
{name = "i"}
    %66:2 = hlfir.declare %65 {uniq_name = "_QFEi"} : (!fir.ref<i32>) ->
(!fir.ref<i32>, !fir.ref<i32>)
    acc.loop  private(@privatization_ref_i32 -> %65 : !fir.ref<i32>)
control(%arg0 : i32) = (%c1_i32_46 : i32) to (%c10_i32_47 : i32)  step
(%c1_i32_48 : i32) {
      fir.store %arg0 to %66#0 : !fir.ref<i32>
```



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