From f305ac3d5d0e02df68efbad42ab9c209f99d51a7 Mon Sep 17 00:00:00 2001
From: Peixin-Qiao <qiaopeixin@huawei.com>
Date: Tue, 17 May 2022 15:07:52 +0800
Subject: [PATCH] [flang][OpenMP] Support lowering to MLIR for ordered clause

This supports the lowering parse-tree to MLIR for ordered clause in
worksharing-loop directive. Also add the test case for operation
conversion.

Part of this patch is from the fir-dev branch of
https://github.com/flang-compiler/f18-llvm-project.

Co-authored-by: Sourabh Singh Tomar <SourabhSingh.Tomar@amd.com>

Reviewed By: kiranchandramohan, NimishMishra

Differential Revision: https://reviews.llvm.org/D125456
---
 flang/lib/Lower/OpenMP.cpp                     | 16 +++++++++--
 flang/test/Lower/OpenMP/omp-wsloop-ordered.f90 | 40 ++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 flang/test/Lower/OpenMP/omp-wsloop-ordered.f90

diff --git a/flang/lib/Lower/OpenMP.cpp b/flang/lib/Lower/OpenMP.cpp
index 156aa89..06f546d 100644
--- a/flang/lib/Lower/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP.cpp
@@ -440,8 +440,20 @@ static void genOMP(Fortran::lower::AbstractConverter &converter,
 
   // Handle attribute based clauses.
   for (const Fortran::parser::OmpClause &clause : wsLoopOpClauseList.v) {
-    if (const auto &scheduleClause =
-            std::get_if<Fortran::parser::OmpClause::Schedule>(&clause.u)) {
+    if (const auto &orderedClause =
+            std::get_if<Fortran::parser::OmpClause::Ordered>(&clause.u)) {
+      if (orderedClause->v.has_value()) {
+        const auto *expr = Fortran::semantics::GetExpr(orderedClause->v);
+        const std::optional<std::int64_t> orderedClauseValue =
+            Fortran::evaluate::ToInt64(*expr);
+        wsLoopOp.ordered_valAttr(
+            firOpBuilder.getI64IntegerAttr(*orderedClauseValue));
+      } else {
+        wsLoopOp.ordered_valAttr(firOpBuilder.getI64IntegerAttr(0));
+      }
+    } else if (const auto &scheduleClause =
+                   std::get_if<Fortran::parser::OmpClause::Schedule>(
+                       &clause.u)) {
       mlir::MLIRContext *context = firOpBuilder.getContext();
       const auto &scheduleType = scheduleClause->v;
       const auto &scheduleKind =
diff --git a/flang/test/Lower/OpenMP/omp-wsloop-ordered.f90 b/flang/test/Lower/OpenMP/omp-wsloop-ordered.f90
new file mode 100644
index 0000000..7548d7a
--- /dev/null
+++ b/flang/test/Lower/OpenMP/omp-wsloop-ordered.f90
@@ -0,0 +1,40 @@
+! This test checks lowering of worksharing-loop construct with ordered clause.
+
+! RUN: bbc -fopenmp -emit-fir %s -o - | FileCheck %s
+
+! This checks lowering ordered clause specified without parameter
+subroutine wsloop_ordered_no_para()
+  integer :: a(10), i
+
+! CHECK:  omp.wsloop ordered(0) for (%{{.*}}) : i32 = (%{{.*}}) to (%{{.*}}) inclusive step (%{{.*}}) {
+! CHECK:    omp.yield
+! CHECK:  }
+
+  !$omp do ordered
+  do i = 2, 10
+    !$omp ordered
+    a(i) = a(i-1) + 1
+    !$omp end ordered
+  end do
+  !$omp end do
+
+end
+
+! This checks lowering ordered clause specified with a parameter
+subroutine wsloop_ordered_with_para()
+  integer :: a(10), i
+
+! CHECK: func @_QPwsloop_ordered_with_para() {
+! CHECK:  omp.wsloop ordered(1) for (%{{.*}}) : i32 = (%{{.*}}) to (%{{.*}}) inclusive step (%{{.*}}) {
+! CHECK:    omp.yield
+! CHECK:  }
+
+  !$omp do ordered(1)
+  do i = 2, 10
+    !!$omp ordered depend(sink: i-1)
+    a(i) = a(i-1) + 1
+    !!$omp ordered depend(source)
+  end do
+  !$omp end do
+
+end
-- 
2.7.4