[flang][openacc] Support .eqv. reduction operator

[clementval]

Summary

Add support for the .eqv. reduction operator for
Flang/OpenACC lowering.

Depends on D154898

[razvanlupusoru]

Looks correct!

flang/lib/Lower/OpenACC.cpp

static mlir::Value genLogicalCombiner(fir::FirOpBuilder &builder,
                                       mlir::Value value2) {
   mlir::Type i1 = builder.getI1Type();
   mlir::Value v1 = builder.create<fir::ConvertOp>(loc, i1, value1);
   mlir::Value v2 = builder.create<fir::ConvertOp>(loc, i1, value2);
   mlir::Value add = builder.create<Op>(loc, v1, v2);
   return builder.create<fir::ConvertOp>(loc, value1.getType(), add);
 }
 
+static mlir::Value genComparisonCombiner(fir::FirOpBuilder &builder,
+                                         mlir::Location loc,
+                                         mlir::arith::CmpIPredicate pred,
+                                         mlir::Value value1,
+                                         mlir::Value value2) {
+  mlir::Type i1 = builder.getI1Type();
+  mlir::Value v1 = builder.create<fir::ConvertOp>(loc, i1, value1);
+  mlir::Value v2 = builder.create<fir::ConvertOp>(loc, i1, value2);
+  mlir::Value add = builder.create<mlir::arith::CmpIOp>(loc, pred, v1, v2);
+  return builder.create<fir::ConvertOp>(loc, value1.getType(), add);
+}
+
 static mlir::Value genCombiner(fir::FirOpBuilder &builder, mlir::Location loc,
                                mlir::acc::ReductionOperator op, mlir::Type ty,
                                mlir::Value value1, mlir::Value value2) {
 
   // Handle combiner on arrays.
   if (auto refTy = mlir::dyn_cast<fir::ReferenceType>(ty)) {
     if (auto seqTy = mlir::dyn_cast<fir::SequenceType>(refTy.getEleTy())) {
       if (seqTy.hasDynamicExtents())
static mlir::Value genCombiner(fir::FirOpBuilder &builder, mlir::Location loc,
 
   if (op == mlir::acc::ReductionOperator::AccLand)
     return genLogicalCombiner<mlir::arith::AndIOp>(builder, loc, value1,
                                                    value2);
 
   if (op == mlir::acc::ReductionOperator::AccLor)
     return genLogicalCombiner<mlir::arith::OrIOp>(builder, loc, value1, value2);
 
+  if (op == mlir::acc::ReductionOperator::AccEqv)
+    return genComparisonCombiner(builder, loc, mlir::arith::CmpIPredicate::eq,
+                                 value1, value2);
+
   TODO(loc, "reduction operator");
 }
 
 mlir::acc::ReductionRecipeOp Fortran::lower::createOrGetReductionRecipe(
     fir::FirOpBuilder &builder, llvm::StringRef recipeName, mlir::Location loc,
     mlir::Type ty, mlir::acc::ReductionOperator op) {
   mlir::ModuleOp mod =
       builder.getBlock()->getParent()->getParentOfType<mlir::ModuleOp>();

flang/test/Lower/OpenACC/acc-reduction.f90

 ! This test checks lowering of OpenACC reduction clause.
 
 ! RUN: bbc -fopenacc -emit-fir %s -o - | FileCheck %s
 
+! CHECK-LABEL: acc.reduction.recipe @reduction_eqv_l32 : !fir.logical<4> reduction_operator <eqv> init {
+! CHECK: ^bb0(%{{.*}}: !fir.logical<4>):
+! CHECK:   %[[CST:.*]] = arith.constant true
+! CHECK:   acc.yield %[[CST]] : i1
+! CHECK: } combiner {
+! CHECK: ^bb0(%[[ARG0:.*]]: !fir.logical<4>, %[[ARG1:.*]]: !fir.logical<4>):
+! CHECK:   %[[V1:.*]] = fir.convert %[[ARG0]] : (!fir.logical<4>) -> i1
+! CHECK:   %[[V2:.*]] = fir.convert %[[ARG1]] : (!fir.logical<4>) -> i1
+! CHECK:   %[[EQV:.*]] = arith.cmpi eq, %[[V1]], %[[V2]] : i1
+! CHECK:   %[[CONV:.*]] = fir.convert %[[EQV]] : (i1) -> !fir.logical<4>
+! CHECK:   acc.yield %[[CONV]] : !fir.logical<4>
+! CHECK: }
+
 ! CHECK-LABEL: acc.reduction.recipe @reduction_lor_l32 : !fir.logical<4> reduction_operator <lor> init {
 ! CHECK: ^bb0(%{{.*}}: !fir.logical<4>):
 ! CHECK:   %[[CST:.*]] = arith.constant false
 ! CHECK:   acc.yield %[[CST]] : i1
 ! CHECK: } combiner {
 ! CHECK: ^bb0(%[[ARG0:.*]]: !fir.logical<4>, %[[ARG1:.*]]: !fir.logical<4>):
 ! CHECK:   %[[V1:.*]] = fir.convert %[[ARG0]] : (!fir.logical<4>) -> i1
 ! CHECK:   %[[V2:.*]] = fir.convert %[[ARG1]] : (!fir.logical<4>) -> i1
subroutine acc_reduction_or()
   logical :: l
   !$acc parallel reduction(.or.:l)
   !$acc end parallel
 end subroutine
 
 ! CHECK-LABEL: func.func @_QPacc_reduction_or()
 ! CHECK: %[[RED:.*]] = acc.reduction varPtr(%{{.*}} : !fir.ref<!fir.logical<4>>) -> !fir.ref<!fir.logical<4>> {name = "l"}
 ! CHECK: acc.parallel reduction(@reduction_lor_l32 -> %[[RED]] : !fir.ref<!fir.logical<4>>)
+
+subroutine acc_reduction_eqv()
+  logical :: l
+  !$acc parallel reduction(.eqv.:l)
+  !$acc end parallel
+end subroutine
+
+! CHECK-LABEL: func.func @_QPacc_reduction_eqv()
+! CHECK: %[[RED:.*]] = acc.reduction varPtr(%{{.*}} : !fir.ref<!fir.logical<4>>) -> !fir.ref<!fir.logical<4>> {name = "l"}
+! CHECK: acc.parallel reduction(@reduction_eqv_l32 -> %[[RED]] : !fir.ref<!fir.logical<4>>)