[flang][hlfir] Add hlfir.dot_product intrinsic

[jacob-crawley]

Summary

Adds a new HLFIR operation for the DOT_PRODUCT intrinsic according to
the design set out in flang/docs/HighLevel.md. This patch includes all
the necessary changes to create a new HLFIR operation and lower it into
the fir runtime call.

[tblah]

Thanks for this. The code is very clean. Just some small nits.

flang/lib/Optimizer/HLFIR/IR/HLFIROps.cpp

687

It would be better to check the rank before indexing into the array so that we don't crash when the rank is zero (I'm not sure if this can happen in practice)

flang/test/Lower/HLFIR/dot_product.f90

38

Do you mean "arguments aren't assumed shape"?

[jacob-crawley]

Thanks for the review.

Addressing nit comments

[tblah]

Thanks. LGTM

flang/include/flang/Optimizer/HLFIR/HLFIROps.td

def hlfir_SumOp : hlfir_Op<"sum", [AttrSizedOperandSegments,
 
   let assemblyFormat = [{
     $array (`dim` $dim^)? (`mask` $mask^)? attr-dict `:` functional-type(operands, results)
   }];
 
   let hasVerifier = 1;
 }
 
+def hlifr_DotProductOp : hlfir_Op<"dot_product",
+    [DeclareOpInterfaceMethods<ArithFastMathInterface>]> {
+  let summary = "DOT_PRODUCT transformational intrinsic";
+  let description = [{
+    Dot product of two vectors
+  }];
+
+  let arguments = (ins
+    AnyFortranNumericalOrLogicalArrayObject:$lhs,
+    AnyFortranNumericalOrLogicalArrayObject:$rhs,
+    DefaultValuedAttr<Arith_FastMathAttr,
+                      "::mlir::arith::FastMathFlags::none">:$fastmath
+  );
+
+  let results = (outs AnyFortranValue);
+
+  let assemblyFormat = [{
+    $lhs $rhs attr-dict `:` functional-type(operands, results)
+  }];
+
+  let hasVerifier = 1;
+}
+
 def hlfir_MatmulOp : hlfir_Op<"matmul",
     [DeclareOpInterfaceMethods<ArithFastMathInterface>]> {
   let summary = "MATMUL transformational intrinsic";
   let description = [{
     Matrix multiplication
   }];
 
   let arguments = (ins

flang/lib/Lower/ConvertCall.cpp

genHLFIRIntrinsicRefCore(PreparedActualArguments &loweredActuals,
   if (intrinsicName == "any") {
     return buildReductionIntrinsic(loweredActuals, loc, builder, callContext,
                                    buildAnyOperation, false);
   }
   if (intrinsicName == "all") {
     return buildReductionIntrinsic(loweredActuals, loc, builder, callContext,
                                    buildAllOperation, false);
   }
+  if (intrinsicName == "dot_product") {
+    llvm::SmallVector<mlir::Value> operands = getOperandVector(loweredActuals);
+    mlir::Type resultTy =
+        computeResultType(operands[0], *callContext.resultType);
+    hlfir::DotProductOp dotProductOp = builder.create<hlfir::DotProductOp>(
+        loc, resultTy, operands[0], operands[1]);
+
+    return {hlfir::EntityWithAttributes{dotProductOp.getResult()}};
+  }
 
   // TODO add hlfir operations for other transformational intrinsics here
 
   // fallback to calling the intrinsic via fir.call
   return genIntrinsicRefCore(loweredActuals, intrinsic, argLowering,
                              callContext);
 }
 

flang/lib/Optimizer/HLFIR/IR/HLFIROps.cpp

 // SumOp
 //===----------------------------------------------------------------------===//
 
 mlir::LogicalResult hlfir::SumOp::verify() {
   return verifyNumericalReductionOp<hlfir::SumOp *>(this);
 }
 
 //===----------------------------------------------------------------------===//
+// DotProductOp
+//===----------------------------------------------------------------------===//
+
+mlir::LogicalResult hlfir::DotProductOp::verify() {
+  mlir::Value lhs = getLhs();
+  mlir::Value rhs = getRhs();
+  fir::SequenceType lhsTy =
+      hlfir::getFortranElementOrSequenceType(lhs.getType())
+          .cast<fir::SequenceType>();
+  fir::SequenceType rhsTy =
+      hlfir::getFortranElementOrSequenceType(rhs.getType())
+          .cast<fir::SequenceType>();
+  llvm::ArrayRef<int64_t> lhsShape = lhsTy.getShape();
+  llvm::ArrayRef<int64_t> rhsShape = rhsTy.getShape();
+  int64_t lhsSize = lhsShape[0];
+  int64_t rhsSize = rhsShape[0];
+  std::size_t lhsRank = lhsShape.size();
+  std::size_t rhsRank = rhsShape.size();
+  mlir::Type lhsEleTy = lhsTy.getEleTy();
+  mlir::Type rhsEleTy = rhsTy.getEleTy();
+  mlir::Type resultTy = getResult().getType();
+
+  if ((lhsRank != 1) || (rhsRank != 1))
+    return emitOpError("both arrays must have rank 1");
+
+  if (lhsSize != rhsSize)
+    return emitOpError("both arrays must have the same size");
+
+  if (mlir::isa<fir::LogicalType>(lhsEleTy) !=
+      mlir::isa<fir::LogicalType>(rhsEleTy))
+    return emitOpError("if one array is logical, so should the other be");
+
+  if (mlir::isa<fir::LogicalType>(lhsEleTy) !=
+      mlir::isa<fir::LogicalType>(resultTy))
+    return emitOpError("the result type should be a logical only if the "
+                       "argument types are logical");
+
+  if (!hlfir::isFortranScalarNumericalType(resultTy) &&
+      !mlir::isa<fir::LogicalType>(resultTy))
+    return emitOpError(
+        "the result must be of scalar numerical or logical type");
+
+  return mlir::success();
+}
+
+//===----------------------------------------------------------------------===//
 // MatmulOp
 //===----------------------------------------------------------------------===//
 
 mlir::LogicalResult hlfir::MatmulOp::verify() {
   mlir::Value lhs = getLhs();
   mlir::Value rhs = getRhs();
   fir::SequenceType lhsTy =
       hlfir::getFortranElementOrSequenceType(lhs.getType())

flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp

matchAndRewrite(hlfir::MatmulOp matmul,
     auto [resultExv, mustBeFreed] =
         fir::genIntrinsicCall(builder, loc, "matmul", scalarResultType, args);
 
     processReturnValue(matmul, resultExv, mustBeFreed, builder, rewriter);
     return mlir::success();
   }
 };
 
+struct DotProductOpConversion
+    : public HlfirIntrinsicConversion<hlfir::DotProductOp> {
+  using HlfirIntrinsicConversion<hlfir::DotProductOp>::HlfirIntrinsicConversion;
+
+  mlir::LogicalResult
+  matchAndRewrite(hlfir::DotProductOp dotProduct,
+                  mlir::PatternRewriter &rewriter) const override {
+    fir::KindMapping kindMapping{rewriter.getContext()};
+    fir::FirOpBuilder builder{rewriter, kindMapping};
+    const mlir::Location &loc = dotProduct->getLoc();
+
+    mlir::Value lhs = dotProduct.getLhs();
+    mlir::Value rhs = dotProduct.getRhs();
+    llvm::SmallVector<IntrinsicArgument, 2> inArgs;
+    inArgs.push_back({lhs, lhs.getType()});
+    inArgs.push_back({rhs, rhs.getType()});
+
+    auto *argLowering = fir::getIntrinsicArgumentLowering("dot_product");
+    llvm::SmallVector<fir::ExtendedValue, 2> args =
+        lowerArguments(dotProduct, inArgs, rewriter, argLowering);
+
+    mlir::Type scalarResultType =
+        hlfir::getFortranElementType(dotProduct.getType());
+
+    auto [resultExv, mustBeFreed] = fir::genIntrinsicCall(
+        builder, loc, "dot_product", scalarResultType, args);
+
+    processReturnValue(dotProduct, resultExv, mustBeFreed, builder, rewriter);
+    return mlir::success();
+  }
+};
+
 class TransposeOpConversion
     : public HlfirIntrinsicConversion<hlfir::TransposeOp> {
   using HlfirIntrinsicConversion<hlfir::TransposeOp>::HlfirIntrinsicConversion;
 
   mlir::LogicalResult
   matchAndRewrite(hlfir::TransposeOp transpose,
                   mlir::PatternRewriter &rewriter) const override {
     fir::KindMapping kindMapping{rewriter.getContext()};
void runOnOperation() override {
     // when building a FirOpBuilder and locking around FuncOp and GlobalOp
     // creation, but this needs a bit more thinking, so at this point the pass
     // is scheduled on the moduleOp.
     mlir::ModuleOp module = this->getOperation();
     mlir::MLIRContext *context = &getContext();
     mlir::RewritePatternSet patterns(context);
     patterns.insert<MatmulOpConversion, MatmulTransposeOpConversion,
                     AllOpConversion, AnyOpConversion, SumOpConversion,
-                    ProductOpConversion, TransposeOpConversion>(context);
+                    ProductOpConversion, TransposeOpConversion,
+                    DotProductOpConversion>(context);
     mlir::ConversionTarget target(*context);
     target.addLegalDialect<mlir::BuiltinDialect, mlir::arith::ArithDialect,
                            mlir::func::FuncDialect, fir::FIROpsDialect,
                            hlfir::hlfirDialect>();
     target.addIllegalOp<hlfir::MatmulOp, hlfir::MatmulTransposeOp, hlfir::SumOp,
                         hlfir::ProductOp, hlfir::TransposeOp, hlfir::AnyOp,
-                        hlfir::AllOp>();
+                        hlfir::AllOp, hlfir::DotProductOp>();
     target.markUnknownOpDynamicallyLegal(
         [](mlir::Operation *) { return true; });
     if (mlir::failed(
             mlir::applyFullConversion(module, target, std::move(patterns)))) {
       mlir::emitError(mlir::UnknownLoc::get(context),
                       "failure in HLFIR intrinsic lowering");
       signalPassFailure();
     }
   }
 };
 } // namespace
 
 std::unique_ptr<mlir::Pass> hlfir::createLowerHLFIRIntrinsicsPass() {
   return std::make_unique<LowerHLFIRIntrinsics>();
 }

flang/test/HLFIR/dot_product-lowering.fir

+// Test hlfir.matmul operation lowering to fir runtime call
+// RUN: fir-opt %s -lower-hlfir-intrinsics | FileCheck %s
+
+func.func @_QPdot_product1(%arg0: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "lhs"}, %arg1: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "rhs"}, %arg2: !fir.ref<i32> {fir.bindc_name = "res"}) {
+  %0:2 = hlfir.declare %arg0 {uniq_name = "_QFdot_product1Elhs"} : (!fir.box<!fir.array<?xi32>>) -> (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.array<?xi32>>)
+  %1:2 = hlfir.declare %arg2 {uniq_name = "_QFdot_product1Eres"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+  %2:2 = hlfir.declare %arg1 {uniq_name = "_QFdot_product1Erhs"} : (!fir.box<!fir.array<?xi32>>) -> (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.array<?xi32>>)
+  %3 = hlfir.dot_product %0#0 %2#0 {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.array<?xi32>>) -> i32
+  hlfir.assign %3 to %1#0 : i32, !fir.ref<i32>
+  return
+}
+// CHECK-LABEL: func.func @_QPdot_product1(
+// CHECK:           %[[ARG0:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "lhs"}
+// CHECK:           %[[ARG1:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "rhs"}
+// CHECK:           %[[ARG2:.*]]: !fir.ref<i32> {fir.bindc_name = "res"}
+// CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[ARG0]]
+// CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[ARG1]]
+// CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[ARG2]]
+
+// CHECK-DAG:     %[[LHS_ARG:.*]] = fir.convert %[[LHS_VAR]]#1 : (!fir.box<!fir.array<?xi32>>) -> !fir.box<none>
+// CHECK-DAG:     %[[RHS_ARG:.*]] = fir.convert %[[RHS_VAR]]#1 : (!fir.box<!fir.array<?xi32>>) -> !fir.box<none>
+
+// CHECK:         %[[NONE:.*]] = fir.call @_FortranADotProductInteger4(%[[LHS_ARG]], %[[RHS_ARG]], %[[LOC_STR:.*]], %[[LOC_N:.*]])
+// CHECK-NEXT:    hlfir.assign %[[NONE]] to %[[RES_VAR]]#0 : i32, !fir.ref<i32>
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
+
+func.func @_QPdot_product2(%arg0: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.bindc_name = "lhs"}, %arg1: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.bindc_name = "rhs"}, %arg2: !fir.ref<!fir.logical<4>> {fir.bindc_name = "res"}) {
+  %0:2 = hlfir.declare %arg0 {uniq_name = "_QFdot_product2Elhs"} : (!fir.box<!fir.array<?x!fir.logical<4>>>) -> (!fir.box<!fir.array<?x!fir.logical<4>>>, !fir.box<!fir.array<?x!fir.logical<4>>>)
+  %1:2 = hlfir.declare %arg2 {uniq_name = "_QFdot_product2Eres"} : (!fir.ref<!fir.logical<4>>) -> (!fir.ref<!fir.logical<4>>, !fir.ref<!fir.logical<4>>)
+  %2:2 = hlfir.declare %arg1 {uniq_name = "_QFdot_product2Erhs"} : (!fir.box<!fir.array<?x!fir.logical<4>>>) -> (!fir.box<!fir.array<?x!fir.logical<4>>>, !fir.box<!fir.array<?x!fir.logical<4>>>)
+  %3 = hlfir.dot_product %0#0 %2#0 {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.array<?x!fir.logical<4>>>, !fir.box<!fir.array<?x!fir.logical<4>>>) -> !fir.logical<4>
+  hlfir.assign %3 to %1#0 : !fir.logical<4>, !fir.ref<!fir.logical<4>>
+  return
+}
+// CHECK-LABEL: func.func @_QPdot_product2(
+// CHECK:           %[[ARG0:.*]]: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.bindc_name = "lhs"}
+// CHECK:           %[[ARG1:.*]]: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.bindc_name = "rhs"}
+// CHECK:           %[[ARG2:.*]]: !fir.ref<!fir.logical<4>> {fir.bindc_name = "res"}
+// CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[ARG0]]
+// CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[ARG1]]
+// CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[ARG2]]
+
+// CHECK-DAG:     %[[LHS_ARG:.*]] = fir.convert %[[LHS_VAR]]#1 : (!fir.box<!fir.array<?x!fir.logical<4>>>) -> !fir.box<none>
+// CHECK-DAG:     %[[RHS_ARG:.*]] = fir.convert %[[RHS_VAR]]#1 : (!fir.box<!fir.array<?x!fir.logical<4>>>) -> !fir.box<none>
+
+// CHECK:         %[[NONE:.*]] = fir.call @_FortranADotProductLogical(%[[LHS_ARG]], %[[RHS_ARG]], %[[LOC_STR:.*]], %[[LOC_N:.*]])
+// CHECK-NEXT:    hlfir.assign %[[NONE]] to %[[RES_VAR]]#0 : i1, !fir.ref<!fir.logical<4>>
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
+
+ func.func @_QPdot_product3(%arg0: !fir.ref<!fir.array<5xi32>> {fir.bindc_name = "lhs"}, %arg1: !fir.ref<!fir.array<5xi32>> {fir.bindc_name = "rhs"}, %arg2: !fir.ref<i32> {fir.bindc_name = "res"}) {
+  %c5 = arith.constant 5 : index
+  %0 = fir.shape %c5 : (index) -> !fir.shape<1>
+  %1:2 = hlfir.declare %arg0(%0) {uniq_name = "_QFdot_product3Elhs"} : (!fir.ref<!fir.array<5xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<5xi32>>, !fir.ref<!fir.array<5xi32>>)
+  %2:2 = hlfir.declare %arg2 {uniq_name = "_QFdot_product3Eres"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+  %c5_0 = arith.constant 5 : index
+  %3 = fir.shape %c5_0 : (index) -> !fir.shape<1>
+  %4:2 = hlfir.declare %arg1(%3) {uniq_name = "_QFdot_product3Erhs"} : (!fir.ref<!fir.array<5xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<5xi32>>, !fir.ref<!fir.array<5xi32>>)
+  %5 = hlfir.dot_product %1#0 %4#0 {fastmath = #arith.fastmath<contract>} : (!fir.ref<!fir.array<5xi32>>, !fir.ref<!fir.array<5xi32>>) -> i32
+  hlfir.assign %5 to %2#0 : i32, !fir.ref<i32>
+  return
+}
+// CHECK-LABEL: func.func @_QPdot_product3(
+// CHECK:           %[[ARG0:.*]]: !fir.ref<!fir.array<5xi32>> {fir.bindc_name = "lhs"}
+// CHECK:           %[[ARG1:.*]]: !fir.ref<!fir.array<5xi32>> {fir.bindc_name = "rhs"}
+// CHECK:           %[[ARG2:.*]]: !fir.ref<i32> {fir.bindc_name = "res"}
+// CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[ARG0]]
+// CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[ARG1]]
+// CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[ARG2]]
+
+// CHECK-DAG:     %[[LHS_BOX:.*]] = fir.embox %[[LHS_VAR]]#1
+// CHECK-DAG:     %[[RHS_BOX:.*]] = fir.embox %[[RHS_VAR]]#1
+// CHECK-DAG:     %[[LHS_ARG:.*]] = fir.convert %[[LHS_BOX]] : (!fir.box<!fir.array<5xi32>>) -> !fir.box<none>
+// CHECK-DAG:     %[[RHS_ARG:.*]] = fir.convert %[[RHS_BOX]] : (!fir.box<!fir.array<5xi32>>) -> !fir.box<none>
+
+// CHECK:         %[[NONE:.*]] = fir.call @_FortranADotProductInteger4(%[[LHS_ARG]], %[[RHS_ARG]], %[[LOC_STR:.*]], %[[LOC_N:.*]])
+// CHECK-NEXT:    hlfir.assign %[[NONE]] to %[[RES_VAR]]#0 : i32, !fir.ref<i32>
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
 No newline at end of file

flang/test/HLFIR/dot_product.fir

+// Test hlfir.dot_product operation parse, verify (no errors), and unparse
+
+// RUN: fir-opt %s | fir-opt | FileCheck %s
+
+// arguments are expressions of known shape
+func.func @dot_product0(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<2xi32>) {
+  %res = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<2xi32>) -> i32
+  return
+}
+// CHECK-LABEL: func.func @dot_product0
+// CHECK:           %[[ARG0:.*]]: !hlfir.expr<2xi32>,
+// CHECK:           %[[ARG1:.*]]: !hlfir.expr<2xi32>
+// CHECK-NEXT:    %[[RES:.*]] = hlfir.dot_product %[[ARG0]] %[[ARG1]] : (!hlfir.expr<2xi32>, !hlfir.expr<2xi32>) -> i32
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
+
+// arguments are expressions of assumed shape
+func.func @dot_product1(%arg0: !hlfir.expr<?xi32>, %arg1: !hlfir.expr<?xi32>) {
+  %res = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<?xi32>, !hlfir.expr<?xi32>) -> i32
+  return
+}
+// CHECK-LABEL: func.func @dot_product1
+// CHECK:           %[[ARG0:.*]]: !hlfir.expr<?xi32>,
+// CHECK:           %[[ARG1:.*]]: !hlfir.expr<?xi32>
+// CHECK-NEXT:    %[[RES:.*]] = hlfir.dot_product %[[ARG0]] %[[ARG1]] : (!hlfir.expr<?xi32>, !hlfir.expr<?xi32>) -> i32
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
+
+// arguments are boxed arrays
+func.func @dot_product2(%arg0: !fir.box<!fir.array<2xi32>>, %arg1: !fir.box<!fir.array<2xi32>>) {
+  %res = hlfir.dot_product %arg0 %arg1 : (!fir.box<!fir.array<2xi32>>, !fir.box<!fir.array<2xi32>>) -> i32
+  return
+}
+// CHECK-LABEL: func.func @dot_product2
+// CHECK:           %[[ARG0:.*]]: !fir.box<!fir.array<2xi32>>,
+// CHECK:           %[[ARG1:.*]]: !fir.box<!fir.array<2xi32>>
+// CHECK-NEXT:    %[[RES:.*]] = hlfir.dot_product %[[ARG0]] %[[ARG1]] : (!fir.box<!fir.array<2xi32>>, !fir.box<!fir.array<2xi32>>) -> i32
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
+
+// arguments are logical
+func.func @dot_product3(%arg0: !fir.box<!fir.array<2x!fir.logical<4>>>, %arg1: !fir.box<!fir.array<2x!fir.logical<4>>>) {
+  %res = hlfir.dot_product %arg0 %arg1 : (!fir.box<!fir.array<2x!fir.logical<4>>>, !fir.box<!fir.array<2x!fir.logical<4>>>) -> !fir.logical<4>
+  return
+}
+// CHECK-LABEL: func.func @dot_product3
+// CHECK:           %[[ARG0:.*]]: !fir.box<!fir.array<2x!fir.logical<4>>>,
+// CHECK:           %[[ARG1:.*]]: !fir.box<!fir.array<2x!fir.logical<4>>>
+// CHECK-NEXT:    %[[RES:.*]] = hlfir.dot_product %[[ARG0]] %[[ARG1]] : (!fir.box<!fir.array<2x!fir.logical<4>>>, !fir.box<!fir.array<2x!fir.logical<4>>>) -> !fir.logical<4>
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
 No newline at end of file

flang/test/HLFIR/invalid.fir

 // -----
 func.func @bad_matmul8(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<2x3xi32>) {
   // expected-error@+1 {{'hlfir.matmul' op incorrect result shape}}
   %0 = hlfir.matmul %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<2x3xi32>) -> !hlfir.expr<1x3xi32>
   return
 }
 
 // -----
+func.func @bad_dot_product1(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<2x3xi32>) {
+  // expected-error@+1 {{'hlfir.dot_product' op both arrays must have rank 1}}
+  %0 = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<2x3xi32>) -> i32
+  return
+}
+
+// -----
+func.func @bad_dot_product2(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<3xi32>) {
+  // expected-error@+1 {{'hlfir.dot_product' op both arrays must have the same size}}
+  %0 = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<3xi32>) -> i32
+  return
+}
+
+// -----
+func.func @bad_dot_product3(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<2x!fir.logical<4>>) {
+  // expected-error@+1 {{'hlfir.dot_product' op if one array is logical, so should the other be}}
+  %0 = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<2x!fir.logical<4>>) -> i32
+  return
+}
+
+// -----
+func.func @bad_dot_product4(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<2xi32>) {
+  // expected-error@+1 {{'hlfir.dot_product' op the result type should be a logical only if the argument types are logical}}
+  %0 = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<2xi32>) -> !fir.logical<4>
+  return
+}
+
+// -----
+func.func @bad_dot_product5(%arg0: !hlfir.expr<2xi32>, %arg1: !hlfir.expr<2xi32>) {
+  // expected-error@+1 {{'hlfir.dot_product' op the result must be of scalar numerical or logical type}}
+  %0 = hlfir.dot_product %arg0 %arg1 : (!hlfir.expr<2xi32>, !hlfir.expr<2xi32>) -> !hlfir.expr<i32>
+  return
+}
+
+// -----
 func.func @bad_transpose1(%arg0: !hlfir.expr<2xi32>) {
   // expected-error@+1 {{'hlfir.transpose' op input and output arrays should have rank 2}}
   %0 = hlfir.transpose %arg0 : (!hlfir.expr<2xi32>) -> !hlfir.expr<2xi32>
   return
 }
 
 // -----
 func.func @bad_transpose2(%arg0: !hlfir.expr<2x3xi32>) {

flang/test/Lower/HLFIR/dot_product.f90

+! Test lowering of DOT_PRODUCT intrinsic to HLFIR
+! RUN: bbc -emit-fir -hlfir -o - %s 2>&1 | FileCheck %s
+
+! dot product with numerical arguments
+subroutine dot_product1(lhs, rhs, res)
+  integer lhs(:), rhs(:), res
+  res = DOT_PRODUCT(lhs,rhs)
+end subroutine
+! CHECK-LABEL: func.func @_QPdot_product1
+! CHECK:           %[[LHS:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "lhs"}
+! CHECK:           %[[RHS:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "rhs"}
+! CHECK:           %[[RES:.*]]: !fir.ref<i32> {fir.bindc_name = "res"}
+! CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[LHS]]
+! CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[RHS]]
+! CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[RES]]
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.dot_product %[[LHS_VAR]]#0 %[[RHS_VAR]]#0 {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.array<?xi32>>) -> i32
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[RES_VAR]]#0 : i32, !fir.ref<i32>
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }
+
+! dot product with logical arguments
+subroutine dot_product2(lhs, rhs, res)
+  logical lhs(:), rhs(:), res
+  res = DOT_PRODUCT(lhs,rhs)
+end subroutine
+! CHECK-LABEL: func.func @_QPdot_product2
+! CHECK:           %[[LHS:.*]]: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.bindc_name = "lhs"}
+! CHECK:           %[[RHS:.*]]: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.bindc_name = "rhs"}
+! CHECK:           %[[RES:.*]]: !fir.ref<!fir.logical<4>> {fir.bindc_name = "res"}
+! CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[LHS]]
+! CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[RHS]]
+! CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[RES]]
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.dot_product %[[LHS_VAR]]#0 %[[RHS_VAR]]#0 {fastmath = #arith.fastmath<contract>} : (!fir.box<!fir.array<?x!fir.logical<4>>>, !fir.box<!fir.array<?x!fir.logical<4>>>) -> !fir.logical<4>
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[RES_VAR]]#0 : !fir.logical<4>, !fir.ref<!fir.logical<4>>
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }
+
+! arguments aren't masked
+subroutine dot_product3(lhs, rhs, res)
+  integer lhs(5), rhs(5), res
+  res = DOT_PRODUCT(lhs,rhs)
+end subroutine
+! CHECK-LABEL: func.func @_QPdot_product3
+! CHECK:           %[[LHS:.*]]: !fir.ref<!fir.array<5xi32>> {fir.bindc_name = "lhs"}
+! CHECK:           %[[RHS:.*]]: !fir.ref<!fir.array<5xi32>> {fir.bindc_name = "rhs"}
+! CHECK:           %[[RES:.*]]: !fir.ref<i32> {fir.bindc_name = "res"}
+! CHECK-DAG:     %[[LHS_VAR:.*]]:2 = hlfir.declare %[[LHS]]
+! CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[RHS]]
+! CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[RES]]
+! CHECK-NEXT:    %[[EXPR:.*]] = hlfir.dot_product %[[LHS_VAR]]#0 %[[RHS_VAR]]#0 {fastmath = #arith.fastmath<contract>} : (!fir.ref<!fir.array<5xi32>>, !fir.ref<!fir.array<5xi32>>) -> i32
+! CHECK-NEXT:    hlfir.assign %[[EXPR]] to %[[RES_VAR]]#0 : i32, !fir.ref<i32>
+! CHECK-NEXT:    return
+! CHECK-NEXT:  }