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

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -1773,11 +1773,11 @@ static void genTaskloopClauses(lower::AbstractConverter &converter,
   cp.processGrainsize(stmtCtx, clauseOps);
   cp.processNumTasks(stmtCtx, clauseOps);
 
-  cp.processTODO<clause::Allocate, clause::Collapse, clause::Default,
-                 clause::Final, clause::If, clause::InReduction,
-                 clause::Lastprivate, clause::Mergeable, clause::Nogroup,
-                 clause::Priority, clause::Reduction, clause::Shared,
-                 clause::Untied>(loc, llvm::omp::Directive::OMPD_taskloop);
+  cp.processTODO<clause::Allocate, clause::Default, clause::Final, clause::If,
+                 clause::InReduction, clause::Lastprivate, clause::Mergeable,
+                 clause::Nogroup, clause::Priority, clause::Reduction,
+                 clause::Shared, clause::Untied>(
+      loc, llvm::omp::Directive::OMPD_taskloop);
 }
 
 static void genTaskwaitClauses(lower::AbstractConverter &converter,

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

flang/test/Semantics/OpenMP/taskloop04.f90

@@ -0,0 +1,15 @@
+! When lowering Taskloop, it is possible for the TileSizes clause to be lowered, but this is not a supported clause.
+! We should make sure that any use of Tilesizes with Taskloop is correctly rejected by the Semantics.
+! RUN: %python %S/../test_errors.py %s %flang -fopenmp
+
+subroutine test
+    integer :: i, sum
+
+    !ERROR: TILE cannot follow TASKLOOP
+    !ERROR: SIZES clause is not allowed on the TASKLOOP directive
+    !$omp taskloop tile sizes(2)
+    do i=1,10
+        sum = sum + i
+    end do
+    !$omp end taskloop
+end subroutine