[Flang][OpenMP] Add Lowering support for Collapse with Taskloop

[Stylie777]

Supprot for lowering collapse already exists within genLoopNestClauses, which is called when lowering taskloop. However, the TODO message still included the Collapse clause, so it was not activated. By removing this, it enables lowering of the Collapse clause in taskloop.

[llvmbot]

@llvm/pr-subscribers-flang-semantics
@llvm/pr-subscribers-flang-openmp

@llvm/pr-subscribers-flang-fir-hlfir

Author: Jack Styles (Stylie777)

Changes

Supprot for lowering collapse already exists within genLoopNestClauses, which is called when lowering taskloop. However, the TODO message still included the Collapse clause, so it was not activated. By removing this, it enables lowering of the Collapse clause in taskloop.

---

Full diff: https://github.com/llvm/llvm-project/pull/166791.diff

2 Files Affected:

• (modified) flang/lib/Lower/OpenMP/OpenMP.cpp (+1-1)
• (added) flang/test/Lower/OpenMP/taskloop-collapse.f90 (+34)

diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index ad456d89bc432..e271a84bc5b4e 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -1773,7 +1773,7 @@ static void genTaskloopClauses(lower::AbstractConverter &converter,
   cp.processGrainsize(stmtCtx, clauseOps);
   cp.processNumTasks(stmtCtx, clauseOps);
 
-  cp.processTODO<clause::Allocate, clause::Collapse, clause::Default,
+  cp.processTODO<clause::Allocate, clause::Default,
                  clause::Final, clause::If, clause::InReduction,
                  clause::Lastprivate, clause::Mergeable, clause::Nogroup,
                  clause::Priority, clause::Reduction, clause::Shared,
diff --git a/flang/test/Lower/OpenMP/taskloop-collapse.f90 b/flang/test/Lower/OpenMP/taskloop-collapse.f90
new file mode 100644
index 0000000000000..48243640d07b9
--- /dev/null
+++ b/flang/test/Lower/OpenMP/taskloop-collapse.f90
@@ -0,0 +1,34 @@
+! Test the collapse clause when being used with the taskloop construct
+! RUN: bbc -emit-hlfir -fopenmp -fopenmp-version=45 %s -o - 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=45 %s -o - 2>&1 | FileCheck %s
+
+! CHECK-LABEL: omp.private
+! CHECK-SAME: {type = private} @[[J_PRIVATE:.*]] : i32
+! CHECK-LABEL: omp.private
+! CHECK-SAME: {type = private} @[[I_PRIVATE:.*]] : i32
+! CHECK-LABEL: omp.private
+! CHECK-SAME: {type = firstprivate} @[[SUM_FIRSTPRIVATE:.*]] : i32 copy
+
+! CHECK-LABEL: func.func @_QPtest()
+! CHECK: %[[ALLOCA_I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFtestEi"}
+! CHECK: %[[DECLARE_I:.*]]:2 = hlfir.declare %1 {uniq_name = "_QFtestEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+! CHECK: %[[ALLOCA_J:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFtestEj"}
+! CHECK: %[[DECLARE_J:.*]]:2 = hlfir.declare %3 {uniq_name = "_QFtestEj"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+! CHECK: %[[ALLOCA_SUM:.*]] = fir.alloca i32 {bindc_name = "sum", uniq_name = "_QFtestEsum"}
+! CHECK: %[[DECLARE_SUM:.*]]:2 = hlfir.declare %5 {uniq_name = "_QFtestEsum"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+
+subroutine test()
+    integer :: i, j, sum
+
+    !$omp taskloop collapse(2)
+    ! CHECK-LABEL: omp.taskloop
+    ! CHECK-SAME: private(@_QFtestEsum_firstprivate_i32 %[[DECLARE_SUM]]#0 -> %arg0, @_QFtestEi_private_i32 %[[DECLARE_I]]#0 -> %arg1, @_QFtestEj_private_i32 %[[DECLARE_J]]#0 -> %arg2 : !fir.ref<i32>, !fir.ref<i32>, !fir.ref<i32>)
+    ! CHECK-LABEL: omp.loop_nest
+    ! CHECK-SAME: (%arg3, %arg4) : i32 = (%c1_i32, %c1_i32_1) to (%c10_i32, %c5_i32) inclusive step (%c1_i32_0, %c1_i32_2) collapse(2)
+    do i = 1, 10
+        do j = 1, 5
+            sum = sum + i + j
+        end do
+    end do
+    !$omp end taskloop
+end subroutine

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.