[OpenMP] Use compound operators for reduction combiner if available.

The OpenMP spec seems to require the compound operators be used for
+, *, &, |, and ^ reduction.  So use these if a class has those operators.
If not try the simple operators as we did previously to limit the impact
to existing code.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=48584

Differential Revision: https://reviews.llvm.org/D101941

Author: mikerice1969

clang/lib/Sema/SemaOpenMP.cpp

@@ -16315,6 +16315,21 @@ static bool checkOMPArraySectionConstantForReduction(
   return true;
 }
 
+static BinaryOperatorKind
+getRelatedCompoundReductionOp(BinaryOperatorKind BOK) {
+  if (BOK == BO_Add)
+    return BO_AddAssign;
+  if (BOK == BO_Mul)
+    return BO_MulAssign;
+  if (BOK == BO_And)
+    return BO_AndAssign;
+  if (BOK == BO_Or)
+    return BO_OrAssign;
+  if (BOK == BO_Xor)
+    return BO_XorAssign;
+  return BOK;
+}
+
 static bool actOnOMPReductionKindClause(
     Sema &S, DSAStackTy *Stack, OpenMPClauseKind ClauseKind,
     ArrayRef<Expr *> VarList, SourceLocation StartLoc, SourceLocation LParenLoc,
@@ -16840,25 +16855,35 @@ static bool actOnOMPReductionKindClause(
           CallExpr::Create(Context, OVE, Args, Context.VoidTy, VK_RValue, ELoc,
                            S.CurFPFeatureOverrides());
     } else {
-      ReductionOp = S.BuildBinOp(
-          Stack->getCurScope(), ReductionId.getBeginLoc(), BOK, LHSDRE, RHSDRE);
-      if (ReductionOp.isUsable()) {
-        if (BOK != BO_LT && BOK != BO_GT) {
-          ReductionOp =
-              S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(),
-                           BO_Assign, LHSDRE, ReductionOp.get());
-        } else {
-          auto *ConditionalOp = new (Context)
-              ConditionalOperator(ReductionOp.get(), ELoc, LHSDRE, ELoc, RHSDRE,
-                                  Type, VK_LValue, OK_Ordinary);
-          ReductionOp =
-              S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(),
-                           BO_Assign, LHSDRE, ConditionalOp);
+      BinaryOperatorKind CombBOK = getRelatedCompoundReductionOp(BOK);
+      if (Type->isRecordType() && CombBOK != BOK) {
+        Sema::TentativeAnalysisScope Trap(S);
+        ReductionOp =
+            S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(),
+                         CombBOK, LHSDRE, RHSDRE);
+      }
+      if (!ReductionOp.isUsable()) {
+        ReductionOp =
+            S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(), BOK,
+                         LHSDRE, RHSDRE);
+        if (ReductionOp.isUsable()) {
+          if (BOK != BO_LT && BOK != BO_GT) {
+            ReductionOp =
+                S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(),
+                             BO_Assign, LHSDRE, ReductionOp.get());
+          } else {
+            auto *ConditionalOp = new (Context)
+                ConditionalOperator(ReductionOp.get(), ELoc, LHSDRE, ELoc,
+                                    RHSDRE, Type, VK_LValue, OK_Ordinary);
+            ReductionOp =
+                S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(),
+                             BO_Assign, LHSDRE, ConditionalOp);
+          }
         }
-        if (ReductionOp.isUsable())
-          ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get(),
-                                              /*DiscardedValue*/ false);
       }
+      if (ReductionOp.isUsable())
+        ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get(),
+                                            /*DiscardedValue*/ false);
       if (!ReductionOp.isUsable())
         continue;
     }

clang/test/OpenMP/distribute_parallel_for_reduction_messages.cpp

@@ -404,7 +404,7 @@ int main(int argc, char **argv) {
     foo();
 #pragma omp target
 #pragma omp teams
-#pragma omp distribute parallel for reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}} expected-warning {{Type 'S4' is not trivially copyable and not guaranteed to be mapped correctly}} expected-warning {{Type 'S5' is not trivially copyable and not guaranteed to be mapped correctly}}
+#pragma omp distribute parallel for reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}} expected-warning {{Type 'S4' is not trivially copyable and not guaranteed to be mapped correctly}} expected-warning {{Type 'S5' is not trivially copyable and not guaranteed to be mapped correctly}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp target

clang/test/OpenMP/distribute_parallel_for_simd_reduction_messages.cpp

@@ -403,7 +403,7 @@ int main(int argc, char **argv) {
     foo();
 #pragma omp target
 #pragma omp teams
-#pragma omp distribute parallel for simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp distribute parallel for simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp target

clang/test/OpenMP/distribute_simd_reduction_messages.cpp

@@ -409,7 +409,7 @@ int main(int argc, char **argv) {
     foo();
 #pragma omp target
 #pragma omp teams
-#pragma omp distribute simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}} expected-warning {{Type 'S4' is not trivially copyable and not guaranteed to be mapped correctly}} expected-warning {{Type 'S5' is not trivially copyable and not guaranteed to be mapped correctly}}}
+#pragma omp distribute simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}} expected-warning {{Type 'S4' is not trivially copyable and not guaranteed to be mapped correctly}} expected-warning {{Type 'S5' is not trivially copyable and not guaranteed to be mapped correctly}}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp target

clang/test/OpenMP/for_reduction_messages.cpp

@@ -354,7 +354,7 @@ int main(int argc, char **argv) {
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp parallel
-#pragma omp for reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp for reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp parallel

clang/test/OpenMP/for_simd_reduction_messages.cpp

@@ -345,7 +345,7 @@ int main(int argc, char **argv) {
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp parallel
-#pragma omp for simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp for simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp parallel

clang/test/OpenMP/master_taskloop_in_reduction_messages.cpp

@@ -344,7 +344,7 @@ int main(int argc, char **argv) {
 #pragma omp master taskloop in_reduction(&& : S2::S2sc) // expected-error {{const-qualified variable cannot be in_reduction}}
   for (int i = 0; i < 10; ++i)
   foo();
-#pragma omp master taskloop in_reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{nvalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp master taskloop in_reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
   foo();
 #pragma omp taskgroup task_reduction(+:k)

clang/test/OpenMP/master_taskloop_reduction_messages.cpp

@@ -312,7 +312,7 @@ int main(int argc, char **argv) {
 #pragma omp master taskloop reduction(&& : S2::S2sc) // expected-error {{const-qualified variable cannot be reduction}}
   for (int i = 0; i < 10; ++i)
     foo();
-#pragma omp master taskloop reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp master taskloop reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp master taskloop reduction(+ : h, k, B::x) // expected-error 2 {{threadprivate or thread local variable cannot be reduction}}

clang/test/OpenMP/master_taskloop_simd_in_reduction_messages.cpp

@@ -344,7 +344,7 @@ int main(int argc, char **argv) {
 #pragma omp master taskloop simd in_reduction(&& : S2::S2sc) // expected-error {{const-qualified variable cannot be in_reduction}}
   for (int i = 0; i < 10; ++i)
   foo();
-#pragma omp master taskloop simd in_reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{nvalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp master taskloop simd in_reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
   foo();
 #pragma omp taskgroup task_reduction(+:k)

clang/test/OpenMP/master_taskloop_simd_reduction_messages.cpp

@@ -312,7 +312,7 @@ int main(int argc, char **argv) {
 #pragma omp master taskloop simd reduction(&& : S2::S2sc) // expected-error {{const-qualified variable cannot be reduction}}
   for (int i = 0; i < 10; ++i)
     foo();
-#pragma omp master taskloop simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{invalid operands to binary expression ('S4' and 'S4')}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
+#pragma omp master taskloop simd reduction(& : e, g) // expected-error {{calling a private constructor of class 'S4'}} expected-error {{calling a private constructor of class 'S5'}} expected-error {{invalid operands to binary expression ('S5' and 'S5')}}
   for (int i = 0; i < 10; ++i)
     foo();
 #pragma omp master taskloop simd reduction(+ : h, k, B::x) // expected-error 2 {{threadprivate or thread local variable cannot be reduction}}