[flang-commits] [flang] 8e10a3f - [flang][OpenMP] don't privatise loop index marked shared (#108176)

via flang-commits flang-commits at lists.llvm.org
Fri Sep 13 04:57:15 PDT 2024


Author: Mats Petersson
Date: 2024-09-13T12:57:11+01:00
New Revision: 8e10a3f80e264aaa186ab3cc74fea840f453c66d

URL: https://github.com/llvm/llvm-project/commit/8e10a3f80e264aaa186ab3cc74fea840f453c66d
DIFF: https://github.com/llvm/llvm-project/commit/8e10a3f80e264aaa186ab3cc74fea840f453c66d.diff

LOG: [flang][OpenMP] don't privatise loop index marked shared (#108176)

Mark the symbol with OmpShared, and then check that later in lowering to
avoid making a local loop index.

OpenMP 5.2 says: "Loop iteration variables of loops that are not associated 
with any OpenMP directive maybe listed in data-sharing attribute clauses on
the surrounding teams, parallel or taskgenerating construct, and on enclosed
constructs, subject to other restrictions."

Tests updated to match the extra OmpShared attribute.

Add regression test for lowering to hlfir.

Closes #102961

---------

Co-authored-by: Tom Eccles <tom.eccles at arm.com>

Added: 
    flang/test/Lower/OpenMP/shared-loop.f90

Modified: 
    flang/lib/Lower/Bridge.cpp
    flang/lib/Semantics/resolve-directives.cpp
    flang/test/Semantics/OpenMP/do20.f90
    flang/test/Semantics/OpenMP/implicit-dsa.f90
    flang/test/Semantics/OpenMP/symbol01.f90
    flang/test/Semantics/OpenMP/symbol02.f90
    flang/test/Semantics/OpenMP/symbol03.f90
    flang/test/Semantics/OpenMP/symbol07.f90
    flang/test/Semantics/OpenMP/symbol09.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 3e9db06b61d502..79e5a04463e00b 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -1317,7 +1317,8 @@ class FirConverter : public Fortran::lower::AbstractConverter {
                                      bool isUnordered) {
     if (isUnordered || sym.has<Fortran::semantics::HostAssocDetails>() ||
         sym.has<Fortran::semantics::UseDetails>()) {
-      if (!shallowLookupSymbol(sym)) {
+      if (!shallowLookupSymbol(sym) &&
+          !sym.test(Fortran::semantics::Symbol::Flag::OmpShared)) {
         // Do concurrent loop variables are not mapped yet since they are local
         // to the Do concurrent scope (same for OpenMP loops).
         mlir::OpBuilder::InsertPoint insPt = builder->saveInsertionPoint();

diff  --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index 3b20d9e77e1cfe..723596ad6ce454 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -2121,11 +2121,14 @@ void OmpAttributeVisitor::CreateImplicitSymbols(
       }
       return lastDeclSymbol;
     };
-    auto makeSharedSymbol = [&]() {
+    auto makeSharedSymbol = [&](std::optional<Symbol::Flag> flag = {}) {
       const Symbol *hostSymbol =
           lastDeclSymbol ? lastDeclSymbol : &symbol->GetUltimate();
-      MakeAssocSymbol(symbol->name(), *hostSymbol,
+      Symbol &assocSymbol = MakeAssocSymbol(symbol->name(), *hostSymbol,
           context_.FindScope(dirContext.directiveSource));
+      if (flag) {
+        assocSymbol.set(*flag);
+      }
     };
     auto useLastDeclSymbol = [&]() {
       if (lastDeclSymbol) {
@@ -2140,8 +2143,9 @@ void OmpAttributeVisitor::CreateImplicitSymbols(
 
     if (dsa.has_value()) {
       if (dsa.value() == Symbol::Flag::OmpShared &&
-          (parallelDir || taskGenDir || teamsDir))
-        makeSharedSymbol();
+          (parallelDir || taskGenDir || teamsDir)) {
+        makeSharedSymbol(Symbol::Flag::OmpShared);
+      }
       // Private symbols will have been declared already.
       prevDSA = dsa;
       continue;
@@ -2155,10 +2159,11 @@ void OmpAttributeVisitor::CreateImplicitSymbols(
       if (!parallelDir && !taskGenDir && !teamsDir) {
         return;
       }
-      if (dirContext.defaultDSA != Symbol::Flag::OmpShared)
+      if (dirContext.defaultDSA != Symbol::Flag::OmpShared) {
         makePrivateSymbol(dirContext.defaultDSA);
-      else
+      } else {
         makeSharedSymbol();
+      }
       dsa = dirContext.defaultDSA;
     } else if (parallelDir) {
       // 2) parallel -> shared

diff  --git a/flang/test/Lower/OpenMP/shared-loop.f90 b/flang/test/Lower/OpenMP/shared-loop.f90
new file mode 100644
index 00000000000000..191fa05be421a5
--- /dev/null
+++ b/flang/test/Lower/OpenMP/shared-loop.f90
@@ -0,0 +1,120 @@
+! RUN: bbc -emit-hlfir -fopenmp %s -o - | FileCheck %s
+! RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
+
+! --- Check that with shared(i) the variable outside the parallel section
+! --- is updated. 
+! CHECK-LABEL:  func.func @_QPomploop()
+! CHECK:    %[[ALLOC_I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFomploopEi"}
+! CHECK:    %[[DECL_I:.*]]:2 = hlfir.declare %[[ALLOC_I]] {uniq_name = "_QFomploopEi"} :
+! CHECK:    omp.parallel {
+! CHECK:      omp.sections {
+! CHECK:        omp.section {
+! CHECK:          %[[RES:.*]]:2 = fir.do_loop %[[ARG0:.*]] = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%[[ARG1:.*]] = 
+! CHECK:            fir.store %[[ARG1]] to %[[DECL_I]]#1
+! CHECK:            %[[UPDATE_ITER:.*]] = arith.addi %[[ARG0]], %{{.*}}
+! CHECK:            %[[LOAD_I:.*]] = fir.load %[[DECL_I]]#1
+! CHECK:            %[[RES_I:.*]] = arith.addi %[[LOAD_I]], %{{.*}}
+! CHECK:            fir.result %[[UPDATE_ITER]], %[[RES_I]]
+! CHECK:          }
+! CHECK:          fir.store %[[RES]]#1 to %[[DECL_I]]#1
+! CHECK:          omp.terminator
+! CHECK:        }
+! CHECK:        omp.terminator
+! CHECK:      }
+! CHECK:      return
+! CHECK:    }
+subroutine omploop
+  implicit none
+  integer :: i, j
+  i = 1
+  j = 0
+  !$omp parallel shared(i)
+    !$omp sections
+      do i=1,10
+         j = j + i
+      end do
+    !$omp end sections
+  !$omp end parallel
+end subroutine
+
+! --- Check that with default(shared) the variable outside the parallel section
+! --- is NOT updated (i is private to the omp.parallel code)
+! CHECK-LABEL:  func.func @_QPomploop2()
+! CHECK:    %[[ALLOC_I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFomploop2Ei"}
+! CHECK:    %[[DECL_I:.*]]:2 = hlfir.declare %[[ALLOC_I]] {uniq_name = "_QFomploop2Ei"} :
+! CHECK:    omp.parallel {
+! CHECK:      %[[ALLOC_PRIV_I:.*]] = fir.alloca i32 {bindc_name = "i", pinned}
+! CHECK:      %[[DECL_PRIV_I:.*]]:2 = hlfir.declare %[[ALLOC_PRIV_I]]
+! CHECK:      omp.sections {
+! CHECK:        omp.section {
+! CHECK:          %[[RES:.*]]:2 = fir.do_loop %[[ARG0:.*]] = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%[[ARG1:.*]] = 
+! CHECK-NOT:            fir.store %[[ARG1]] to %[[DECL_I]]#1
+! CHECK:            fir.store %[[ARG1]] to %[[DECL_PRIV_I]]#1
+! CHECK:            %[[UPDATE_ITER:.*]] = arith.addi %[[ARG0]], %{{.*}}
+! CHECK:            %[[LOAD_I:.*]] = fir.load %[[DECL_PRIV_I]]#1
+! CHECK:            %[[RES_I:.*]] = arith.addi %[[LOAD_I]], %{{.*}}
+! CHECK:            fir.result %[[UPDATE_ITER]], %[[RES_I]]
+! CHECK:          }
+! CHECK:          fir.store %[[RES]]#1 to %[[DECL_PRIV_I]]#1
+! CHECK:          omp.terminator
+! CHECK:        }
+! CHECK:        omp.terminator
+! CHECK:      }
+! CHECK:      return
+! CHECK:    }
+subroutine omploop2
+  implicit none
+  integer :: i, j
+  i = 1
+  j = 0
+  !$omp parallel default(shared)
+    !$omp sections
+      do i=1,10
+         j = j + i
+      end do
+    !$omp end sections
+  !$omp end parallel
+end subroutine
+
+
+! --- Check that with no data-sharing the variable outside the parallel section
+! --- is NOT updated (i is private to the omp.parallel code)
+! CHECK-LABEL:  func.func @_QPomploop3()
+! CHECK:    %[[ALLOC_I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFomploop3Ei"}
+! CHECK:    %[[DECL_I:.*]]:2 = hlfir.declare %[[ALLOC_I]] {uniq_name = "_QFomploop3Ei"} :
+! CHECK:    omp.parallel {
+! CHECK:      %[[ALLOC_PRIV_I:.*]] = fir.alloca i32 {bindc_name = "i", pinned}
+! CHECK:      %[[DECL_PRIV_I:.*]]:2 = hlfir.declare %[[ALLOC_PRIV_I]]
+! CHECK:      omp.sections {
+! CHECK:        omp.section {
+! CHECK:          %[[RES:.*]]:2 = fir.do_loop %[[ARG0:.*]] = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%[[ARG1:.*]] = 
+! CHECK-NOT:            fir.store %[[ARG1]] to %[[DECL_I]]#1
+! CHECK:            fir.store %[[ARG1]] to %[[DECL_PRIV_I]]#1
+! CHECK:            %[[UPDATE_ITER:.*]] = arith.addi %[[ARG0]], %{{.*}}
+! CHECK:            %[[LOAD_I:.*]] = fir.load %[[DECL_PRIV_I]]#1
+! CHECK:            %[[RES_I:.*]] = arith.addi %[[LOAD_I]], %{{.*}}
+! CHECK:            fir.result %[[UPDATE_ITER]], %[[RES_I]]
+! CHECK:          }
+! CHECK:          fir.store %[[RES]]#1 to %[[DECL_PRIV_I]]#1
+! CHECK:          omp.terminator
+! CHECK:        }
+! CHECK:        omp.terminator
+! CHECK:      }
+! CHECK:      return
+! CHECK:    }
+subroutine omploop3
+  implicit none
+  integer :: i, j
+  i = 1
+  j = 0
+  !$omp parallel
+    !$omp sections
+      do i=1,10
+         j = j + i
+      end do
+    !$omp end sections
+  !$omp end parallel
+end subroutine
+
+
+ 

diff  --git a/flang/test/Semantics/OpenMP/do20.f90 b/flang/test/Semantics/OpenMP/do20.f90
index 0cafae76b86b00..040a82079590f0 100644
--- a/flang/test/Semantics/OpenMP/do20.f90
+++ b/flang/test/Semantics/OpenMP/do20.f90
@@ -10,7 +10,7 @@ subroutine shared_iv
 
   !$omp parallel shared(i)
     !$omp single
-      !DEF: /shared_iv/OtherConstruct1/i HostAssoc INTEGER(4)
+      !DEF: /shared_iv/OtherConstruct1/i (OmpShared) HostAssoc INTEGER(4)
       do i = 0, 1
       end do
     !$omp end single

diff  --git a/flang/test/Semantics/OpenMP/implicit-dsa.f90 b/flang/test/Semantics/OpenMP/implicit-dsa.f90
index 2abe3a0e16d624..a7ed834b0f1c60 100644
--- a/flang/test/Semantics/OpenMP/implicit-dsa.f90
+++ b/flang/test/Semantics/OpenMP/implicit-dsa.f90
@@ -15,7 +15,7 @@ subroutine implicit_dsa_test1
   !$omp task private(y) shared(z)
     !DEF: /implicit_dsa_test1/OtherConstruct1/x (OmpFirstPrivate, OmpImplicit) HostAssoc INTEGER(4)
     !DEF: /implicit_dsa_test1/OtherConstruct1/y (OmpPrivate) HostAssoc INTEGER(4)
-    !DEF: /implicit_dsa_test1/OtherConstruct1/z HostAssoc INTEGER(4)
+    !DEF: /implicit_dsa_test1/OtherConstruct1/z (OmpShared) HostAssoc INTEGER(4)
     x = y + z
   !$omp end task
 
@@ -133,7 +133,7 @@ subroutine implicit_dsa_test6
     !$omp end parallel
 
     !$omp parallel default(firstprivate) shared(y)
-      !DEF: /implicit_dsa_test6/OtherConstruct1/OtherConstruct2/y HostAssoc INTEGER(4)
+      !DEF: /implicit_dsa_test6/OtherConstruct1/OtherConstruct2/y (OmpShared) HostAssoc INTEGER(4)
       !DEF: /implicit_dsa_test6/OtherConstruct1/OtherConstruct2/x (OmpFirstPrivate) HostAssocINTEGER(4)
       !DEF: /implicit_dsa_test6/OtherConstruct1/OtherConstruct2/z (OmpFirstPrivate) HostAssocINTEGER(4)
       y = x + z

diff  --git a/flang/test/Semantics/OpenMP/symbol01.f90 b/flang/test/Semantics/OpenMP/symbol01.f90
index ecfb8622f81794..a40a8563fde1f8 100644
--- a/flang/test/Semantics/OpenMP/symbol01.f90
+++ b/flang/test/Semantics/OpenMP/symbol01.f90
@@ -62,7 +62,7 @@ program mm
   !REF: /mm/OtherConstruct1/i
   !REF: /mm/OtherConstruct1/y
   x = a+i+y
-  !DEF: /mm/OtherConstruct1/c HostAssoc REAL(4)
+  !DEF: /mm/OtherConstruct1/c (OmpShared) HostAssoc REAL(4)
   c = 3.0
  end do
 end program

diff  --git a/flang/test/Semantics/OpenMP/symbol02.f90 b/flang/test/Semantics/OpenMP/symbol02.f90
index c199c526e1fa8c..31d9cb2e46ba8a 100644
--- a/flang/test/Semantics/OpenMP/symbol02.f90
+++ b/flang/test/Semantics/OpenMP/symbol02.f90
@@ -15,9 +15,9 @@
   a = 3.
   !DEF: /MainProgram1/OtherConstruct1/b (OmpPrivate) HostAssoc REAL(4)
   b = 4
-  !DEF: /MainProgram1/OtherConstruct1/c HostAssoc REAL(4)
+  !DEF: /MainProgram1/OtherConstruct1/c (OmpShared) HostAssoc REAL(4)
   c = 5
-  !DEF: /MainProgram1/OtherConstruct1/d HostAssoc REAL(4)
+  !DEF: /MainProgram1/OtherConstruct1/d (OmpShared) HostAssoc REAL(4)
   d = 6
   !$omp end parallel
   !DEF: /MainProgram1/a (Implicit) ObjectEntity REAL(4)

diff  --git a/flang/test/Semantics/OpenMP/symbol03.f90 b/flang/test/Semantics/OpenMP/symbol03.f90
index ba941b9c9e7c4e..08defb40e56a71 100644
--- a/flang/test/Semantics/OpenMP/symbol03.f90
+++ b/flang/test/Semantics/OpenMP/symbol03.f90
@@ -9,10 +9,10 @@
   !$omp parallel  private(a) shared(b)
   !DEF: /MainProgram1/OtherConstruct1/a (OmpPrivate) HostAssoc REAL(4)
   a = 3.
-  !DEF: /MainProgram1/OtherConstruct1/b HostAssoc REAL(4)
+  !DEF: /MainProgram1/OtherConstruct1/b (OmpShared) HostAssoc REAL(4)
   b = 4
   !$omp parallel  private(b) shared(a)
-  !DEF: /MainProgram1/OtherConstruct1/OtherConstruct1/a HostAssoc REAL(4)
+  !DEF: /MainProgram1/OtherConstruct1/OtherConstruct1/a (OmpShared) HostAssoc REAL(4)
   a = 5.
   !DEF: /MainProgram1/OtherConstruct1/OtherConstruct1/b (OmpPrivate) HostAssoc REAL(4)
   b = 6

diff  --git a/flang/test/Semantics/OpenMP/symbol07.f90 b/flang/test/Semantics/OpenMP/symbol07.f90
index 8b4716999820b1..a375942ebb1d9a 100644
--- a/flang/test/Semantics/OpenMP/symbol07.f90
+++ b/flang/test/Semantics/OpenMP/symbol07.f90
@@ -23,7 +23,7 @@ subroutine function_call_in_region
   !$omp parallel  default(none) private(a) shared(b)
   !DEF: /function_call_in_region/OtherConstruct1/a (OmpPrivate) HostAssoc REAL(4)
   !REF: /function_call_in_region/foo
-  !DEF: /function_call_in_region/OtherConstruct1/b HostAssoc REAL(4)
+  !DEF: /function_call_in_region/OtherConstruct1/b (OmpShared) HostAssoc REAL(4)
   a = foo(b)
   !$omp end parallel
   !REF: /function_call_in_region/a

diff  --git a/flang/test/Semantics/OpenMP/symbol09.f90 b/flang/test/Semantics/OpenMP/symbol09.f90
index 8b4716999820b1..a375942ebb1d9a 100644
--- a/flang/test/Semantics/OpenMP/symbol09.f90
+++ b/flang/test/Semantics/OpenMP/symbol09.f90
@@ -23,7 +23,7 @@ subroutine function_call_in_region
   !$omp parallel  default(none) private(a) shared(b)
   !DEF: /function_call_in_region/OtherConstruct1/a (OmpPrivate) HostAssoc REAL(4)
   !REF: /function_call_in_region/foo
-  !DEF: /function_call_in_region/OtherConstruct1/b HostAssoc REAL(4)
+  !DEF: /function_call_in_region/OtherConstruct1/b (OmpShared) HostAssoc REAL(4)
   a = foo(b)
   !$omp end parallel
   !REF: /function_call_in_region/a


        


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