[flang-commits] [flang] [flang][OpenMP] Support for nocontext and novariants clauses for dispatch construct (PR #227954)

[Sairudra More via flang-commits]

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@@ -1,39 +1,372 @@
 !RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=51 %s -o - | FileCheck %s --check-prefix=HLFIR
-!RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=52 %s -o - | FileCheck %s --check-prefix=HLFIR
-!RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=60 %s -o - | FileCheck %s --check-prefix=HLFIR
 
-! Dispatch lowers to a no-op omp.dispatch region wrapping the associated call.
-! Variant selection and the nocontext/novariants clauses are added separately;
-! here the call inside the region targets the base procedure unchanged.
+! Variant selection is provided by DECLARE VARIANT with a `construct={dispatch}`
+! match: inside a dispatch region the call to the base procedure `foo_dispatch`
+! is replaced by a call to its variant `foo_variant`. `base_routine` additionally
+! carries a `device={kind(host)}` variant to exercise re-resolution under
+! `nocontext` when more than one variant matches.
 
 module funcs
   implicit none
 
 contains
 
+  !HLFIR-LABEL: func @_QMfuncsPfoo_no_variant
+  subroutine foo_no_variant()
+  end subroutine
+
+  !novariants clause : base & variant subroutines
+  !HLFIR-LABEL: func @_QMfuncsPfoo_variant
+  subroutine foo_variant()
+    print *, "in foo_variant"
+  end subroutine
+
   !HLFIR-LABEL: func @_QMfuncsPfoo_dispatch
   subroutine foo_dispatch()
+    !$omp declare variant(foo_dispatch:foo_variant) match(construct={dispatch})
     print *, "in foo_dispatch"
   end subroutine
 
+  !nocontext clause : base & variant subroutines
+  !HLFIR-LABEL: func @_QMfuncsPdispatch_variant
+  subroutine dispatch_variant()
+    print *, "in dispatch_variant"
+  end subroutine
+
+  !HLFIR-LABEL: func @_QMfuncsPhost_variant
+  subroutine host_variant()
+    print *, "in host_variant"
+  end subroutine
+
+  ! `base_routine` has two variants: `dispatch_variant` matches
+  ! `construct={dispatch}` and `host_variant` matches `device={kind(host)}`.
+  !HLFIR-LABEL: func @_QMfuncsPbase_routine
+  subroutine base_routine()
+    !$omp declare variant(base_routine:dispatch_variant) match(construct={dispatch})
+    !$omp declare variant(base_routine:host_variant) match(device={kind(host)})
----------------
Saieiei wrote:

Thanks, the first pair now works in either declaration order. The other five pairs still depend on the scoring tie: 207/208, 250/251, 262/263 and 340/341 here, and 135/136 in Integration/OpenMP/dispatch.f90. Could they use the same `user={condition(score(2): .true.)}`? With that change, both files pass in either order.

https://github.com/llvm/llvm-project/pull/227954