[flang-commits] [flang] 612f8ec - seq_cst is allowed in Flush since OpenMP 5.1. (#114072)

via flang-commits flang-commits at lists.llvm.org
Mon Nov 25 02:38:46 PST 2024


Author: ShashwathiNavada
Date: 2024-11-25T16:08:39+05:30
New Revision: 612f8ec7ac5dcddd16fb027aad64e2e353faa528

URL: https://github.com/llvm/llvm-project/commit/612f8ec7ac5dcddd16fb027aad64e2e353faa528
DIFF: https://github.com/llvm/llvm-project/commit/612f8ec7ac5dcddd16fb027aad64e2e353faa528.diff

LOG: seq_cst is allowed in Flush since OpenMP 5.1. (#114072)

This PR adds support seq_cst (sequential consistency) clause for the
flush directive in OpenMP. The seq_cst clause enforces a stricter memory
ordering, ensuring that all threads observe the memory effects of the
flush in the same order, improving consistency in memory operations
across threads.

---------

Co-authored-by: Shashwathi N <nshashwa at pe28vega.hpc.amslabs.hpecorp.net>
Co-authored-by: CHANDRA GHALE <chandra.nitdgp at gmail.com>

Added: 
    flang/test/Lower/OpenMP/Todo/flush-seq-cst.f90

Modified: 
    clang/docs/OpenMPSupport.rst
    clang/include/clang/AST/OpenMPClause.h
    clang/include/clang/Basic/DiagnosticSemaKinds.td
    clang/lib/Sema/SemaOpenMP.cpp
    clang/test/OpenMP/flush_ast_print.cpp
    clang/test/OpenMP/flush_codegen.cpp
    clang/test/OpenMP/flush_messages.cpp
    flang/test/Semantics/OpenMP/clause-validity01.f90
    flang/test/Semantics/OpenMP/flush02.f90
    llvm/include/llvm/Frontend/OpenMP/OMP.td

Removed: 
    


################################################################################
diff  --git a/clang/docs/OpenMPSupport.rst b/clang/docs/OpenMPSupport.rst
index 3f996ceaff156c..481362dba3f51d 100644
--- a/clang/docs/OpenMPSupport.rst
+++ b/clang/docs/OpenMPSupport.rst
@@ -290,7 +290,7 @@ implementation.
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | memory management            | changes to omp_alloctrait_key enum                           | :none:`unclaimed`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| memory model                 | seq_cst clause on flush construct                            | :none:`unclaimed`        |                                                                       |
+| memory model                 | seq_cst clause on flush construct                            | :good:`done`             | https://github.com/llvm/llvm-project/pull/114072                      |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc                         | 'omp_all_memory' keyword and use in 'depend' clause          | :good:`done`             | D125828, D126321                                                      |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+

diff  --git a/clang/include/clang/AST/OpenMPClause.h b/clang/include/clang/AST/OpenMPClause.h
index 00c87e71bde31b..d2f5267e4da5ea 100644
--- a/clang/include/clang/AST/OpenMPClause.h
+++ b/clang/include/clang/AST/OpenMPClause.h
@@ -2670,8 +2670,8 @@ class OMPCompareClause final : public OMPClause {
   }
 };
 
-/// This represents 'seq_cst' clause in the '#pragma omp atomic'
-/// directive.
+/// This represents 'seq_cst' clause in the '#pragma omp atomic|flush'
+/// directives.
 ///
 /// \code
 /// #pragma omp atomic seq_cst

diff  --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index eb05a6a77978af..6ff24c2bc8faad 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -11396,7 +11396,7 @@ def err_omp_atomic_weak_no_equality : Error<"expected '==' operator for 'weak' c
 def err_omp_atomic_several_clauses : Error<
   "directive '#pragma omp atomic' cannot contain more than one 'read', 'write', 'update', 'capture', or 'compare' clause">;
 def err_omp_several_mem_order_clauses : Error<
-  "directive '#pragma omp %0' cannot contain more than one %select{'seq_cst', 'relaxed', |}1'acq_rel', 'acquire' or 'release' clause">;
+  "directive '#pragma omp %0' cannot contain more than one 'seq_cst',%select{ 'relaxed',|}1 'acq_rel', 'acquire' or 'release' clause">;
 def err_omp_atomic_incompatible_mem_order_clause : Error<
   "directive '#pragma omp atomic%select{ %0|}1' cannot be used with '%2' clause">;
 def note_omp_previous_mem_order_clause : Note<

diff  --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 5d6b835e6da82e..976d48e1249136 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -11102,7 +11102,8 @@ StmtResult SemaOpenMP::ActOnOpenMPFlushDirective(ArrayRef<OMPClause *> Clauses,
   for (const OMPClause *C : Clauses) {
     if (C->getClauseKind() == OMPC_acq_rel ||
         C->getClauseKind() == OMPC_acquire ||
-        C->getClauseKind() == OMPC_release) {
+        C->getClauseKind() == OMPC_release ||
+        C->getClauseKind() == OMPC_seq_cst /*OpenMP 5.1*/) {
       if (MemOrderKind != OMPC_unknown) {
         Diag(C->getBeginLoc(), diag::err_omp_several_mem_order_clauses)
             << getOpenMPDirectiveName(OMPD_flush) << 1

diff  --git a/clang/test/OpenMP/flush_ast_print.cpp b/clang/test/OpenMP/flush_ast_print.cpp
index 9578ada020227a..768282422032fd 100644
--- a/clang/test/OpenMP/flush_ast_print.cpp
+++ b/clang/test/OpenMP/flush_ast_print.cpp
@@ -1,10 +1,10 @@
-// RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s
-// RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -std=c++11 -include-pch %t  -verify %s -ast-print | FileCheck %s
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s
-// RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -std=c++11 -include-pch %t -verify %s -ast-print | FileCheck %s
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -19,6 +19,7 @@ T tmain(T argc) {
 #pragma omp flush acq_rel
 #pragma omp flush acquire
 #pragma omp flush release
+#pragma omp flush seq_cst
 #pragma omp flush(a)
   return a + argc;
 }
@@ -27,18 +28,21 @@ T tmain(T argc) {
 // CHECK-NEXT: #pragma omp flush acq_rel{{$}}
 // CHECK-NEXT: #pragma omp flush acquire{{$}}
 // CHECK-NEXT: #pragma omp flush release{{$}}
+// CHECK-NEXT: #pragma omp flush seq_cst{{$}}
 // CHECK-NEXT: #pragma omp flush (a)
 // CHECK:      static int a;
 // CHECK-NEXT: #pragma omp flush
 // CHECK-NEXT: #pragma omp flush acq_rel{{$}}
 // CHECK-NEXT: #pragma omp flush acquire{{$}}
 // CHECK-NEXT: #pragma omp flush release{{$}}
+// CHECK-NEXT: #pragma omp flush seq_cst{{$}}
 // CHECK-NEXT: #pragma omp flush (a)
 // CHECK:      static char a;
 // CHECK-NEXT: #pragma omp flush
 // CHECK-NEXT: #pragma omp flush acq_rel{{$}}
 // CHECK-NEXT: #pragma omp flush acquire{{$}}
 // CHECK-NEXT: #pragma omp flush release{{$}}
+// CHECK-NEXT: #pragma omp flush seq_cst{{$}}
 // CHECK-NEXT: #pragma omp flush (a)
 
 int main(int argc, char **argv) {
@@ -48,11 +52,13 @@ int main(int argc, char **argv) {
 #pragma omp flush acq_rel
 #pragma omp flush acquire
 #pragma omp flush release
+#pragma omp flush seq_cst
 #pragma omp flush(a)
 // CHECK-NEXT: #pragma omp flush
 // CHECK-NEXT: #pragma omp flush acq_rel
 // CHECK-NEXT: #pragma omp flush acquire{{$}}
 // CHECK-NEXT: #pragma omp flush release
+// CHECK-NEXT: #pragma omp flush seq_cst
 // CHECK-NEXT: #pragma omp flush (a)
   return tmain(argc) + tmain(argv[0][0]) + a;
 }

diff  --git a/clang/test/OpenMP/flush_codegen.cpp b/clang/test/OpenMP/flush_codegen.cpp
index c7dd88ef9ac313..fa2586d9fe258d 100644
--- a/clang/test/OpenMP/flush_codegen.cpp
+++ b/clang/test/OpenMP/flush_codegen.cpp
@@ -1,13 +1,13 @@
-// RUN: %clang_cc1 -verify -fopenmp -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck %s
-// RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -debug-info-kind=limited -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s
-// RUN: %clang_cc1 -verify -fopenmp -fopenmp-enable-irbuilder -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck %s
-// RUN: %clang_cc1 -fopenmp -fopenmp-enable-irbuilder -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -fopenmp-enable-irbuilder -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -debug-info-kind=limited -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -debug-info-kind=limited -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -fopenmp-enable-irbuilder -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -fopenmp-enable-irbuilder -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -fopenmp-enable-irbuilder -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -debug-info-kind=limited -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck --check-prefix SIMD-ONLY0 %s
-// RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp-simd -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -debug-info-kind=limited -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -debug-info-kind=limited -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck --check-prefix SIMD-ONLY0 %s
 // SIMD-ONLY0-NOT: {{__kmpc|__tgt}}
 // expected-no-diagnostics
 #ifndef HEADER
@@ -17,6 +17,7 @@ template <class T>
 T tmain(T argc) {
   static T a;
 #pragma omp flush
+#pragma omp flush seq_cst
 #pragma omp flush acq_rel
 #pragma omp flush acquire
 #pragma omp flush release
@@ -28,6 +29,7 @@ T tmain(T argc) {
 int main() {
   static int a;
 #pragma omp flush
+#pragma omp flush seq_cst
 #pragma omp flush acq_rel
 #pragma omp flush acquire
 #pragma omp flush release
@@ -37,6 +39,7 @@ int main() {
   // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
   // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
   // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
+  // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
   return tmain(a);
   // CHECK: call {{.*}} [[TMAIN:@.+]](
   // CHECK: ret
@@ -48,6 +51,7 @@ int main() {
 // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
 // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
 // CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
+// CHECK: call {{.*}}void @__kmpc_flush(ptr {{(@|%).+}})
 // CHECK: ret
 
 // CHECK-NOT: line: 0,

diff  --git a/clang/test/OpenMP/flush_messages.cpp b/clang/test/OpenMP/flush_messages.cpp
index ad4830b5bf94f9..e78949bc924e15 100644
--- a/clang/test/OpenMP/flush_messages.cpp
+++ b/clang/test/OpenMP/flush_messages.cpp
@@ -134,14 +134,12 @@ label1 : {
 #pragma omp flush(argc) flush(argc) // expected-warning {{extra tokens at the end of '#pragma omp flush' are ignored}}
 #pragma omp parallel flush(argc) // expected-warning {{extra tokens at the end of '#pragma omp parallel' are ignored}}
   ;
-#pragma omp flush seq_cst // expected-error {{unexpected OpenMP clause 'seq_cst' in directive '#pragma omp flush'}}
 #pragma omp flush acq_rel // omp45-error {{unexpected OpenMP clause 'acq_rel' in directive '#pragma omp flush'}}
 #pragma omp flush acquire // omp45-error {{unexpected OpenMP clause 'acquire' in directive '#pragma omp flush'}}
 #pragma omp flush release // omp45-error {{unexpected OpenMP clause 'release' in directive '#pragma omp flush'}}
 #pragma omp flush relaxed // expected-error {{unexpected OpenMP clause 'relaxed' in directive '#pragma omp flush'}}
-#pragma omp flush seq_cst // expected-error {{unexpected OpenMP clause 'seq_cst' in directive '#pragma omp flush'}}
-#pragma omp flush acq_rel acquire // omp45-error {{unexpected OpenMP clause 'acq_rel' in directive '#pragma omp flush'}} omp45-error {{unexpected OpenMP clause 'acquire' in directive '#pragma omp flush'}} omp51-error {{directive '#pragma omp flush' cannot contain more than one 'acq_rel', 'acquire' or 'release' clause}} omp51-note {{'acq_rel' clause used here}}
-#pragma omp flush release acquire // omp45-error {{unexpected OpenMP clause 'release' in directive '#pragma omp flush'}} omp45-error {{unexpected OpenMP clause 'acquire' in directive '#pragma omp flush'}} omp51-error {{directive '#pragma omp flush' cannot contain more than one 'acq_rel', 'acquire' or 'release' clause}} omp51-note {{'release' clause used here}}
+#pragma omp flush acq_rel acquire // omp45-error {{unexpected OpenMP clause 'acq_rel' in directive '#pragma omp flush'}} omp45-error {{unexpected OpenMP clause 'acquire' in directive '#pragma omp flush'}} omp51-error {{directive '#pragma omp flush' cannot contain more than one 'seq_cst', 'acq_rel', 'acquire' or 'release' clause}} omp51-note {{'acq_rel' clause used here}}
+#pragma omp flush release acquire // omp45-error {{unexpected OpenMP clause 'release' in directive '#pragma omp flush'}} omp45-error {{unexpected OpenMP clause 'acquire' in directive '#pragma omp flush'}} omp51-error {{directive '#pragma omp flush' cannot contain more than one 'seq_cst', 'acq_rel', 'acquire' or 'release' clause}} omp51-note {{'release' clause used here}}
 #pragma omp flush acq_rel (argc) // omp45-error {{unexpected OpenMP clause 'acq_rel' in directive '#pragma omp flush'}} expected-warning {{extra tokens at the end of '#pragma omp flush' are ignored}}
 #pragma omp flush(argc) acq_rel // omp45-error {{unexpected OpenMP clause 'acq_rel' in directive '#pragma omp flush'}} omp51-error {{'flush' directive with memory order clause 'acq_rel' cannot have the list}} omp51-note {{memory order clause 'acq_rel' is specified here}}
   return tmain(argc);

diff  --git a/flang/test/Lower/OpenMP/Todo/flush-seq-cst.f90 b/flang/test/Lower/OpenMP/Todo/flush-seq-cst.f90
new file mode 100644
index 00000000000000..753e1cfcd7aa50
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/flush-seq-cst.f90
@@ -0,0 +1,6 @@
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s -fopenmp-version=51 2>&1 | FileCheck %s
+
+! CHECK: not yet implemented: Unhandled clause SEQ_CST in FLUSH construct
+program flush_seq_cst
+  !$omp flush seq_cst
+end program
\ No newline at end of file

diff  --git a/flang/test/Semantics/OpenMP/clause-validity01.f90 b/flang/test/Semantics/OpenMP/clause-validity01.f90
index 406d30b38948ea..8dd6d10200cd3d 100644
--- a/flang/test/Semantics/OpenMP/clause-validity01.f90
+++ b/flang/test/Semantics/OpenMP/clause-validity01.f90
@@ -1,6 +1,6 @@
 ! REQUIRES: openmp_runtime
 
-! RUN: %python %S/../test_errors.py %s %flang_fc1 %openmp_flags %openmp_module_flag -fopenmp-version=50
+! RUN: %python %S/../test_errors.py %s %flang_fc1 %openmp_flags %openmp_module_flag -fopenmp-version=51
 use omp_lib
 ! Check OpenMP clause validity for the following directives:
 !
@@ -507,7 +507,6 @@
   !$omp flush acquire
   !ERROR: If memory-order-clause is RELEASE, ACQUIRE, or ACQ_REL, list items must not be specified on the FLUSH directive
   !$omp flush release (c)
-  !ERROR: SEQ_CST clause is not allowed on the FLUSH directive
   !$omp flush seq_cst
   !ERROR: RELAXED clause is not allowed on the FLUSH directive
   !$omp flush relaxed

diff  --git a/flang/test/Semantics/OpenMP/flush02.f90 b/flang/test/Semantics/OpenMP/flush02.f90
index ed0cf6602d574a..615332c6cf31cb 100644
--- a/flang/test/Semantics/OpenMP/flush02.f90
+++ b/flang/test/Semantics/OpenMP/flush02.f90
@@ -1,6 +1,6 @@
 ! REQUIRES: openmp_runtime
 
-! RUN: %python %S/../test_errors.py %s %flang_fc1 %openmp_flags -fopenmp-version=50
+! RUN: %python %S/../test_errors.py %s %flang_fc1 %openmp_flags -fopenmp-version=51
 
 ! Check OpenMP 5.0 - 2.17.8 flush Construct
 ! Restriction -
@@ -27,7 +27,6 @@
   !Only memory-order-clauses.
   if (omp_get_thread_num() == 1) THEN
     ! Not allowed clauses.
-    !ERROR: SEQ_CST clause is not allowed on the FLUSH directive
     !$omp flush seq_cst
     !ERROR: RELAXED clause is not allowed on the FLUSH directive
     !$omp flush relaxed
@@ -41,7 +40,6 @@
     !$omp flush acquire acquire
 
     ! Mix of allowed and not allowed.
-    !ERROR: SEQ_CST clause is not allowed on the FLUSH directive
     !$omp flush seq_cst acquire
   END IF
 

diff  --git a/llvm/include/llvm/Frontend/OpenMP/OMP.td b/llvm/include/llvm/Frontend/OpenMP/OMP.td
index 75e73bedd9348e..bd7fb2361aaeb1 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMP.td
+++ b/llvm/include/llvm/Frontend/OpenMP/OMP.td
@@ -769,6 +769,7 @@ def OMP_Flush : Directive<"flush"> {
     // OMPKinds.def.
     VersionedClause<OMPC_Flush>,
     VersionedClause<OMPC_Release, 50>,
+    VersionedClause<OMPC_SeqCst, 51>,
   ];
   let association = AS_None;
   let category = CA_Executable;


        


More information about the flang-commits mailing list