Adding parsing support for scan directive.

anchuraj · anchuraj · commit 5bf0f84e8133 · 2024-08-13T14:29:10.000-05:00
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -2199,6 +2199,9 @@ static void genOMPDispatch(lower::AbstractConverter &converter,
   case llvm::omp::Directive::OMPD_parallel:
     genStandaloneParallel(converter, symTable, semaCtx, eval, loc, queue, item);
     break;
+  case llvm::omp::Directive::OMPD_scan:
+    TODO(loc, "Unhandled directive " + llvm::omp::getOpenMPDirectiveName(dir));
+    break;
   case llvm::omp::Directive::OMPD_section:
     llvm_unreachable("genOMPDispatch: OMPD_section");
     // Lowered in the enclosing genSectionsOp.
diff --git a/flang/lib/Parser/openmp-parsers.cpp b/flang/lib/Parser/openmp-parsers.cpp
@@ -267,6 +267,8 @@ TYPE_PARSER(
         construct<OmpClause>(construct<OmpClause::DynamicAllocators>()) ||
     "ENTER" >> construct<OmpClause>(construct<OmpClause::Enter>(
                    parenthesized(Parser<OmpObjectList>{}))) ||
+    "EXCLUSIVE" >> construct<OmpClause>(construct<OmpClause::Exclusive>(
+                       parenthesized(Parser<OmpObjectList>{}))) ||
     "FILTER" >> construct<OmpClause>(construct<OmpClause::Filter>(
                     parenthesized(scalarIntExpr))) ||
     "FINAL" >> construct<OmpClause>(construct<OmpClause::Final>(
@@ -286,6 +288,8 @@ TYPE_PARSER(
     "IF" >> construct<OmpClause>(construct<OmpClause::If>(
                 parenthesized(Parser<OmpIfClause>{}))) ||
     "INBRANCH" >> construct<OmpClause>(construct<OmpClause::Inbranch>()) ||
+    "INCLUSIVE" >> construct<OmpClause>(construct<OmpClause::Inclusive>(
+                       parenthesized(Parser<OmpObjectList>{}))) ||
     "IS_DEVICE_PTR" >> construct<OmpClause>(construct<OmpClause::IsDevicePtr>(
                            parenthesized(Parser<OmpObjectList>{}))) ||
     "LASTPRIVATE" >> construct<OmpClause>(construct<OmpClause::Lastprivate>(
@@ -481,6 +485,7 @@ TYPE_PARSER(sourced(construct<OpenMPFlushConstruct>(verbatim("FLUSH"_tok),
 TYPE_PARSER(sourced(construct<OmpSimpleStandaloneDirective>(first(
     "BARRIER" >> pure(llvm::omp::Directive::OMPD_barrier),
     "ORDERED" >> pure(llvm::omp::Directive::OMPD_ordered),
+    "SCAN" >> pure(llvm::omp::Directive::OMPD_scan),
     "TARGET ENTER DATA" >> pure(llvm::omp::Directive::OMPD_target_enter_data),
     "TARGET EXIT DATA" >> pure(llvm::omp::Directive::OMPD_target_exit_data),
     "TARGET UPDATE" >> pure(llvm::omp::Directive::OMPD_target_update),
diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
@@ -2295,6 +2295,9 @@ class UnparseVisitor {
     case llvm::omp::Directive::OMPD_barrier:
       Word("BARRIER ");
       break;
+    case llvm::omp::Directive::OMPD_scan:
+      Word("SCAN ");
+      break;
     case llvm::omp::Directive::OMPD_taskwait:
       Word("TASKWAIT ");
       break;
diff --git a/flang/lib/Semantics/check-omp-structure.cpp b/flang/lib/Semantics/check-omp-structure.cpp
@@ -532,62 +532,70 @@ void OmpStructureChecker::CheckSIMDNest(const parser::OpenMPConstruct &c) {
   // current context yet.
   // TODO: Check for declare simd regions.
   bool eligibleSIMD{false};
-  common::visit(Fortran::common::visitors{
-                    // Allow `!$OMP ORDERED SIMD`
-                    [&](const parser::OpenMPBlockConstruct &c) {
-                      const auto &beginBlockDir{
-                          std::get<parser::OmpBeginBlockDirective>(c.t)};
-                      const auto &beginDir{
-                          std::get<parser::OmpBlockDirective>(beginBlockDir.t)};
-                      if (beginDir.v == llvm::omp::Directive::OMPD_ordered) {
-                        const auto &clauses{
-                            std::get<parser::OmpClauseList>(beginBlockDir.t)};
-                        for (const auto &clause : clauses.v) {
-                          if (std::get_if<parser::OmpClause::Simd>(&clause.u)) {
-                            eligibleSIMD = true;
-                            break;
-                          }
-                        }
-                      }
-                    },
-                    [&](const parser::OpenMPSimpleStandaloneConstruct &c) {
-                      const auto &dir{
-                          std::get<parser::OmpSimpleStandaloneDirective>(c.t)};
-                      if (dir.v == llvm::omp::Directive::OMPD_ordered) {
-                        const auto &clauses{
-                            std::get<parser::OmpClauseList>(c.t)};
-                        for (const auto &clause : clauses.v) {
-                          if (std::get_if<parser::OmpClause::Simd>(&clause.u)) {
-                            eligibleSIMD = true;
-                            break;
-                          }
-                        }
-                      }
-                    },
-                    // Allowing SIMD construct
-                    [&](const parser::OpenMPLoopConstruct &c) {
-                      const auto &beginLoopDir{
-                          std::get<parser::OmpBeginLoopDirective>(c.t)};
-                      const auto &beginDir{
-                          std::get<parser::OmpLoopDirective>(beginLoopDir.t)};
-                      if ((beginDir.v == llvm::omp::Directive::OMPD_simd) ||
-                          (beginDir.v == llvm::omp::Directive::OMPD_do_simd)) {
-                        eligibleSIMD = true;
-                      }
-                    },
-                    [&](const parser::OpenMPAtomicConstruct &c) {
-                      // Allow `!$OMP ATOMIC`
-                      eligibleSIMD = true;
-                    },
-                    [&](const auto &c) {},
-                },
+  common::visit(
+      Fortran::common::visitors{
+          // Allow `!$OMP ORDERED SIMD`
+          [&](const parser::OpenMPBlockConstruct &c) {
+            const auto &beginBlockDir{
+                std::get<parser::OmpBeginBlockDirective>(c.t)};
+            const auto &beginDir{
+                std::get<parser::OmpBlockDirective>(beginBlockDir.t)};
+            if (beginDir.v == llvm::omp::Directive::OMPD_ordered) {
+              const auto &clauses{
+                  std::get<parser::OmpClauseList>(beginBlockDir.t)};
+              for (const auto &clause : clauses.v) {
+                if (std::get_if<parser::OmpClause::Simd>(&clause.u)) {
+                  eligibleSIMD = true;
+                  break;
+                }
+              }
+            }
+          },
+          [&](const parser::OpenMPStandaloneConstruct &c) {
+            if (const auto &simpleConstruct =
+                    std::get_if<parser::OpenMPSimpleStandaloneConstruct>(
+                        &c.u)) {
+              const auto &dir{std::get<parser::OmpSimpleStandaloneDirective>(
+                  simpleConstruct->t)};
+              if (dir.v == llvm::omp::Directive::OMPD_ordered) {
+                const auto &clauses{
+                    std::get<parser::OmpClauseList>(simpleConstruct->t)};
+                for (const auto &clause : clauses.v) {
+                  if (std::get_if<parser::OmpClause::Simd>(&clause.u)) {
+                    eligibleSIMD = true;
+                    break;
+                  }
+                }
+              } else if (dir.v == llvm::omp::Directive::OMPD_scan) {
+                eligibleSIMD = true;
+              }
+            }
+          },
+          // Allowing SIMD construct
+          [&](const parser::OpenMPLoopConstruct &c) {
+            const auto &beginLoopDir{
+                std::get<parser::OmpBeginLoopDirective>(c.t)};
+            const auto &beginDir{
+                std::get<parser::OmpLoopDirective>(beginLoopDir.t)};
+            if ((beginDir.v == llvm::omp::Directive::OMPD_simd) ||
+                (beginDir.v == llvm::omp::Directive::OMPD_parallel_do_simd) ||
+                (beginDir.v == llvm::omp::Directive::OMPD_do_simd)) {
+              eligibleSIMD = true;
+            }
+          },
+          [&](const parser::OpenMPAtomicConstruct &c) {
+            // Allow `!$OMP ATOMIC`
+            eligibleSIMD = true;
+          },
+          [&](const auto &c) {},
+      },
       c.u);
   if (!eligibleSIMD) {
     context_.Say(parser::FindSourceLocation(c),
         "The only OpenMP constructs that can be encountered during execution "
         "of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, "
-        "the `SIMD` construct and the `ORDERED` construct with the `SIMD` "
-        "clause."_err_en_US);
+        "the `SIMD` construct, the `SCAN` construct and the `ORDERED` "
+        "construct with the `SIMD` clause."_err_en_US);
   }
 }
 
@@ -2531,6 +2539,9 @@ void OmpStructureChecker::CheckReductionModifier(
     switch (dirCtx.directive) {
     case llvm::omp::Directive::OMPD_do: // worksharing-loop
     case llvm::omp::Directive::OMPD_do_simd: // worksharing-loop simd
+    case llvm::omp::Directive::
+        OMPD_parallel_do_simd: // worksharing-parallel-loop
+                               // simd
     case llvm::omp::Directive::OMPD_simd: // "simd"
       break;
     default:
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
@@ -1578,9 +1578,11 @@ bool OmpAttributeVisitor::Pre(
     const parser::OpenMPSimpleStandaloneConstruct &x) {
   const auto &standaloneDir{
       std::get<parser::OmpSimpleStandaloneDirective>(x.t)};
+  const auto &parentContext{GetContextIf()};
   switch (standaloneDir.v) {
   case llvm::omp::Directive::OMPD_barrier:
   case llvm::omp::Directive::OMPD_ordered:
+  case llvm::omp::Directive::OMPD_scan:
   case llvm::omp::Directive::OMPD_target_enter_data:
   case llvm::omp::Directive::OMPD_target_exit_data:
   case llvm::omp::Directive::OMPD_target_update:
@@ -1591,6 +1593,20 @@ bool OmpAttributeVisitor::Pre(
   default:
     break;
   }
+  if (standaloneDir.v == llvm::omp::Directive::OMPD_scan) {
+    if ((std::get<parser::OmpClauseList>(x.t).v.size() != 1)) {
+      context_.Say(standaloneDir.source,
+          "Exactly one of `exclusive` or `inclusive` clause is expected"_err_en_US);
+    }
+    if (!parentContext ||
+        (llvm::omp::getDirectiveAssociation(parentContext->directive) !=
+            llvm::omp::Association::Loop)) {
+      context_.Say(standaloneDir.source,
+          "Orphaned `omp scan` directives are prohibited; perhaps you forgot "
+          "to enclose the directive in to a worksharing loop, a worksharing "
+          "loop simd or a simd directive."_err_en_US);
+    }
+  }
   ClearDataSharingAttributeObjects();
   return true;
 }
diff --git a/flang/test/Parser/OpenMP/scan.f90 b/flang/test/Parser/OpenMP/scan.f90
@@ -0,0 +1,40 @@
+! RUN: %flang_fc1 -fdebug-unparse -fopenmp %s | FileCheck --ignore-case %s
+! RUN: %flang_fc1 -fdebug-dump-parse-tree -fopenmp %s | FileCheck --check-prefix="PARSE-TREE" %s
+
+! Check for parsing scan directive
+subroutine test_scan_inclusive()
+  implicit none
+  integer, parameter :: n = 100
+  integer a(n), b(n)
+  integer x, k
+
+  ! initialization
+  x = 0
+  do k = 1, n
+   a(k) = k
+  end do
+
+  ! a(k) is included in the computation of producing results in b(k)
+  !$omp parallel do simd reduction(inscan,+: x)
+  do k = 1, n
+    x = x + a(k)
+    !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPStandaloneConstruct -> OpenMPSimpleStandaloneConstruct
+    !PARSE-TREE-NEXT: OmpSimpleStandaloneDirective -> llvm::omp::Directive = scan
+    !PARSE-TREE-NEXT: OmpClauseList -> OmpClause -> Inclusive -> OmpObjectList -> OmpObject -> Designator -> DataRef -> Name = 'x'
+    !CHECK: !$omp scan inclusive(x)
+    !$omp scan inclusive(x)
+      b(k) = x
+  end do
+
+  ! a(k) is not included in the computation of producing results in b(k)
+  !$omp parallel do simd reduction(inscan,+: x)
+  do k = 1, n
+    b(k) = x
+    !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPStandaloneConstruct -> OpenMPSimpleStandaloneConstruct
+    !PARSE-TREE-NEXT: OmpSimpleStandaloneDirective -> llvm::omp::Directive = scan
+    !PARSE-TREE-NEXT: OmpClauseList -> OmpClause -> Exclusive -> OmpObjectList -> OmpObject -> Designator -> DataRef -> Name = 'x'
+    !CHECK: !$omp scan exclusive(x)
+    !$omp scan exclusive(x)
+    x = x + a(k)
+  end do
+end subroutine
diff --git a/flang/test/Semantics/OpenMP/do05.f90 b/flang/test/Semantics/OpenMP/do05.f90
@@ -39,7 +39,7 @@ program omp_do
     if( i == 5 ) then
         cycle
     end if
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: A worksharing region may not be closely nested inside a worksharing, explicit task, taskloop, critical, ordered, atomic, or master region
     !$omp single
     do j=1,10
@@ -70,7 +70,7 @@ program omp_do
     if( i == 3 ) then
         cycle
     end if
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: A worksharing region may not be closely nested inside a worksharing, explicit task, taskloop, critical, ordered, atomic, or master region
     !$omp single
     do j=1,10
@@ -93,7 +93,7 @@ program omp_do
 
   !$omp target parallel do simd
   do i=1,10
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: A worksharing region may not be closely nested inside a worksharing, explicit task, taskloop, critical, ordered, atomic, or master region
     !$omp single
     do j=1,10
@@ -116,7 +116,7 @@ program omp_do
 
   !$omp target teams distribute parallel do simd
   do i=1,10
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: A worksharing region may not be closely nested inside a worksharing, explicit task, taskloop, critical, ordered, atomic, or master region
     !$omp single
     do j=1,10
diff --git a/flang/test/Semantics/OpenMP/nested-barrier.f90 b/flang/test/Semantics/OpenMP/nested-barrier.f90
@@ -17,7 +17,7 @@ program omp_nest_barrier
   !$omp do simd
   do i = 1, 10
     k = k + 1
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: `BARRIER` region may not be closely nested inside of `WORKSHARING`, `LOOP`, `TASK`, `TASKLOOP`,`CRITICAL`, `ORDERED`, `ATOMIC` or `MASTER` region.
     !$omp barrier
     j = j -1
@@ -34,7 +34,7 @@ program omp_nest_barrier
   !$omp parallel do simd
   do i = 1, 10
     k = k + 1
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: `BARRIER` region may not be closely nested inside of `WORKSHARING`, `LOOP`, `TASK`, `TASKLOOP`,`CRITICAL`, `ORDERED`, `ATOMIC` or `MASTER` region.
     !$omp barrier
     j = j -1
diff --git a/flang/test/Semantics/OpenMP/nested-master.f90 b/flang/test/Semantics/OpenMP/nested-master.f90
@@ -64,7 +64,7 @@ program omp_nest_master
   do i = 1, 10
     k = k + 1
     !WARNING: OpenMP directive 'master' has been deprecated, please use 'masked' instead.
-    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct and the `ORDERED` construct with the `SIMD` clause.
+    !ERROR: The only OpenMP constructs that can be encountered during execution of a 'SIMD' region are the `ATOMIC` construct, the `LOOP` construct, the `SIMD` construct, the `SCAN` construct and the `ORDERED` construct with the `SIMD` clause.
     !ERROR: `MASTER` region may not be closely nested inside of `WORKSHARING`, `LOOP`, `TASK`, `TASKLOOP`, or `ATOMIC` region.
     !$omp master
     j = j -1
diff --git a/flang/test/Semantics/OpenMP/nested-simd.f90 b/flang/test/Semantics/OpenMP/nested-simd.f90
diff --git a/flang/test/Semantics/OpenMP/ordered-simd.f90 b/flang/test/Semantics/OpenMP/ordered-simd.f90
diff --git a/flang/test/Semantics/OpenMP/scan.f90 b/flang/test/Semantics/OpenMP/scan.f90
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMP.td b/llvm/include/llvm/Frontend/OpenMP/OMP.td
