[flang-commits] [flang] [flang][Multi-Image] Moving Mutli-image lowering to PRIF into the MIF dialect (PR #161179)

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+//===-- MIFOps.td - MIF operation definitions ------*- tablegen -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Definition of the MIF dialect operations
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_DIALECT_MIF_MIF_OPS
+#define FORTRAN_DIALECT_MIF_MIF_OPS
+
+include "flang/Optimizer/Dialect/MIF/MIFDialect.td"
+include "flang/Optimizer/Dialect/FIRTypes.td"
+include "flang/Optimizer/Dialect/FIRAttr.td"
+include "mlir/Dialect/LLVMIR/LLVMAttrDefs.td"
+include "mlir/Dialect/LLVMIR/LLVMOpBase.td"
+include "mlir/Interfaces/LoopLikeInterface.td"
+include "mlir/IR/BuiltinAttributes.td"
+
+class mif_Op<string mnemonic, list<Trait> traits>
+    : Op<MIFDialect, mnemonic, traits>;
+
+//===----------------------------------------------------------------------===//
+// Initialization and Finalization
+//===----------------------------------------------------------------------===//
+
+def mif_InitOp : mif_Op<"init", []> {
+  let summary = "Initialize the parallel environment";
+  let description = [{This operation will initialize the parallel environment}];
+
+  let results = (outs I32:$stat);
+  let assemblyFormat = "`->` type($stat) attr-dict";
+}
+
+//===----------------------------------------------------------------------===//
+// Image Queries
+//===----------------------------------------------------------------------===//
+
+def mif_NumImagesOp
+    : mif_Op<"num_images", [NoMemoryEffect, AttrSizedOperandSegments]> {
+  let summary = "Query the number of images in the specified or current team";
+  let description = [{
+    This operation query the number of images in the specified or current
+    team and can be called with 3 differents way :
+    - `num_images()`
+    - `num_images(team)`
+    - `num_images(team_number)`
+
+    Arguments:
+    - `team` : Shall be a scalar of type `team_type` from the `ISO_FORTRAN_ENV`
+            module with a value that identifies the current or ancestor team.
+    - `team_number` :  Shall be an integer scalar. It shall identify the
+            initial team or a sibling team of the current team.
+
+    Result Value: The number of images in the specified team, or in the current
+    team if no team is specified.
+  }];
+
+  let arguments = (ins Optional<AnyInteger>:$team_number,
+                       Optional<AnyRefOrBoxType>:$team);
+  let results = (outs I32:$res);
+
+  let builders = [OpBuilder<(ins CArg<"mlir::Value", "{}">:$teamArg)>];
+
+  let hasVerifier = 1;
+  let assemblyFormat = [{
+    ( `team_number` `(` $team_number^ `:` type($team_number) `)` )? 
+    ( `team` `(` $team^ `:` type($team) `)` )? 
+    attr-dict `->` type($res)
+  }];
+}
+
+def mif_ThisImageOp
+    : mif_Op<"this_image", [NoMemoryEffect, AttrSizedOperandSegments]> {
+  let summary = "Determine the image index of the current image";
+  let description = [{
+    Arguments:
+    - `coarray` :  Shall be a coarray of any type.
+    - `dim` : Shall be an integer scalar. Its value shall be in the range of
+          1 <= DIM <= N, where N is the corank of the coarray.
+    - `team`(optional) : Shall be a scalar of type `team_type` from
+          ISO_FORTRAN_ENV. If the `coarray` is present, it shall be
+          established in that team.
+
+    Results:
+    - Case(1) : The result of `this_image([team])` is a scalar with a value
+          equal to the index of the image in the current or specified team.
+    - Case(2) : The result of `this_image(coarray [,team])` is the sequence of
+          cosubscript values for `coarray`.
+    - Case(3) : The result of `this_image(coarray, dim [,team])` is the value of
+          cosubscript `dim` in the sequence of cosubscript values for `coarray`.
+
+    Example:
+    ```fortran
+      REAL :: A[10, 0:9, 0:*]
+    ```
+    If we take a look on the example and we are on image 5, `this_image` has the
+    value 5, `this_image(A)` has the value [5, 0, 0].
+  }];
+
+  let arguments = (ins Optional<fir_BoxType>:$coarray,
+                       Optional<AnyInteger>:$dim, Optional<fir_BoxType>:$team);
+  let results = (outs I32:$res);
+
+  let builders = [OpBuilder<(ins "mlir::Value":$coarray, "mlir::Value":$team)>,
+                  OpBuilder<(ins "mlir::Value":$team)>];
+
+  let hasVerifier = 1;
+  let assemblyFormat = [{
+    ( `coarray` `(` $coarray^ `:` type($coarray) `)` )? 
----------------
jeanPerier wrote:

Most of FIR/HLFIR pretty printer just use the functional type in the end to print the argument types.

Unless everyone strongly prefer the approach you took of having:
```
mif.this_image coarray (%a : !fir.box<!fir.array<T1>>) team (%b : !fir.box<fir.type<T2>>) dim (%c : i32) -> i32`
```

I would suggest aligning with the more usual format:
```
 mif.this_image coarray %a team %b dim %c : (!fir.box<!fir.array<T1>>, !fir.box<fir.type<T2>>, i32) -> i32
````

I find that with the latter, it is easier for a human to parse the IR and understand the use def chains. Types are useful but they also bloat the IR readability.

Other reviewers are welcome to voice different opinion here.

https://github.com/llvm/llvm-project/pull/161179