[mlir][openacc] Add attributes to parallel op async, wait and self clauses

[clementval]

Summary

Add attributes for the async, wait and self clauses. These clauses can be present without
values. When this is the case they are modelled with an attribute instead of operands.

[ftynse]

mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td

97

Unit attributes give extra semantics to the operation by their mere presence, there is no point in explicitly marking them optional as they can be omitted in any case.

Also, all other names in this op use camelCase rather than snake_case.

[clementval]

Remove optional from attr since it makes no sense. Switch from snake_case to camelCase.

[clementval]

mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td

97

Sure, I should have think twice before sending the patch :-) I pushed a new version.

mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td

let description = [{
     acc.parallel num_gangs(%c10) num_workers(%c10)
         private(%c : memref<10xf32>) {
       // parallel region
     }
     ```
   }];
 
   let arguments = (ins Optional<IntOrIndex>:$async,
+                       UnitAttr:$asyncAttr,
                        Variadic<IntOrIndex>:$waitOperands,
+                       UnitAttr:$waitAttr,
                        Optional<IntOrIndex>:$numGangs,
                        Optional<IntOrIndex>:$numWorkers,
                        Optional<IntOrIndex>:$vectorLength,
                        Optional<I1>:$ifCond,
                        Optional<I1>:$selfCond,
+                       UnitAttr:$selfAttr,
                        OptionalAttr<OpenACC_ReductionOpAttr>:$reductionOp,
                        Variadic<AnyType>:$reductionOperands,
                        Variadic<AnyType>:$copyOperands,
                        Variadic<AnyType>:$copyinOperands,
                        Variadic<AnyType>:$copyinReadonlyOperands,
                        Variadic<AnyType>:$copyoutOperands,
                        Variadic<AnyType>:$copyoutZeroOperands,
                        Variadic<AnyType>:$createOperands,
                        Variadic<AnyType>:$createZeroOperands,
                        Variadic<AnyType>:$noCreateOperands,
                        Variadic<AnyType>:$presentOperands,
                        Variadic<AnyType>:$devicePtrOperands,
                        Variadic<AnyType>:$attachOperands,
                        Variadic<AnyType>:$gangPrivateOperands,
                        Variadic<AnyType>:$gangFirstPrivateOperands,
                        OptionalAttr<OpenACC_DefaultAttr>:$defaultAttr);
 
   let regions = (region AnyRegion:$region);
 
   let extraClassDeclaration = [{
     static StringRef getAsyncKeyword() { return "async"; }
+    static StringRef getAsyncAttrName() { return "asyncAttr"; }
     static StringRef getWaitKeyword() { return "wait"; }
+    static StringRef getWaitAttrName() { return "waitAttr"; }
     static StringRef getNumGangsKeyword() { return "num_gangs"; }
     static StringRef getNumWorkersKeyword() { return "num_workers"; }
     static StringRef getVectorLengthKeyword() { return "vector_length"; }
     static StringRef getIfKeyword() { return "if"; }
     static StringRef getSelfKeyword() { return "self"; }
+    static StringRef getSelfAttrName() { return "selfAttr"; }
     static StringRef getReductionKeyword() { return "reduction"; }
     static StringRef getCopyKeyword() { return "copy"; }
     static StringRef getCopyinKeyword() { return "copyin"; }
     static StringRef getCopyinReadonlyKeyword() { return "copyin_readonly"; }
     static StringRef getCopyoutKeyword() { return "copyout"; }
     static StringRef getCopyoutZeroKeyword() { return "copyout_zero"; }
     static StringRef getCreateKeyword() { return "create"; }
     static StringRef getCreateZeroKeyword() { return "create_zero"; }
def OpenACC_YieldOp : OpenACC_Op<"yield", [Terminator,
   ];
 
   let verifier = ?;
 
   let assemblyFormat = "attr-dict ($operands^ `:` type($operands))?";
 }
 
 #endif // OPENACC_OPS
-

mlir/test/Dialect/OpenACC/ops.mlir

func @testparallelop(%a: memref<10xf32>, %b: memref<10xf32>, %c: memref<10x10xf32>) -> () {
   acc.parallel deviceptr(%a: memref<10xf32>) attach(%b: memref<10xf32>, %c: memref<10x10xf32>) {
   }
   acc.parallel private(%a: memref<10xf32>, %c: memref<10x10xf32>) firstprivate(%b: memref<10xf32>) {
   }
   acc.parallel {
   } attributes {defaultAttr = "none"}
   acc.parallel {
   } attributes {defaultAttr = "present"}
+  acc.parallel {
+  } attributes {asyncAttr}
+  acc.parallel {
+  } attributes {waitAttr}
+  acc.parallel {
+  } attributes {selfAttr}
   return
 }
 
 // CHECK:      func @testparallelop([[ARGA:%.*]]: memref<10xf32>, [[ARGB:%.*]]: memref<10xf32>, [[ARGC:%.*]]: memref<10x10xf32>) {
 // CHECK:      [[I64VALUE:%.*]] = constant 1 : i64
 // CHECK:      [[I32VALUE:%.*]] = constant 1 : i32
 // CHECK:      [[IDXVALUE:%.*]] = constant 1 : index
 // CHECK:      acc.parallel async([[I64VALUE]]: i64) {

 // CHECK:      acc.parallel deviceptr([[ARGA]]: memref<10xf32>) attach([[ARGB]]: memref<10xf32>, [[ARGC]]: memref<10x10xf32>) {
 // CHECK-NEXT: }
 // CHECK:      acc.parallel private([[ARGA]]: memref<10xf32>, [[ARGC]]: memref<10x10xf32>) firstprivate([[ARGB]]: memref<10xf32>) {
 // CHECK-NEXT: }
 // CHECK:      acc.parallel {
 // CHECK-NEXT: } attributes {defaultAttr = "none"}
 // CHECK:      acc.parallel {
 // CHECK-NEXT: } attributes {defaultAttr = "present"}
+// CHECK:      acc.parallel {
+// CHECK-NEXT: } attributes {asyncAttr}
+// CHECK:      acc.parallel {
+// CHECK-NEXT: } attributes {waitAttr}
+// CHECK:      acc.parallel {
+// CHECK-NEXT: } attributes {selfAttr}
 
 // -----
 
 func @testdataop(%a: memref<10xf32>, %b: memref<10xf32>, %c: memref<10x10xf32>) -> () {
   acc.data present(%a: memref<10xf32>, %b: memref<10xf32>, %c: memref<10x10xf32>) {
   }
   acc.data copy(%a: memref<10xf32>, %b: memref<10xf32>, %c: memref<10x10xf32>) {
   }