[Mlir-commits] [mlir] [OpenMP][MLIR] Add num_teams clause with dims modifier support (PR #169883)

llvmlistbot at llvm.org llvmlistbot at llvm.org
Fri Nov 28 00:54:52 PST 2025


https://github.com/skc7 created https://github.com/llvm/llvm-project/pull/169883

This is WIP PR for support for openmp 6.2 feature `num_teams` with dims modifier support.

To not break the current code, named the clause as `num_teams_multi_dim`. Will name it back to num_teams once the ompIRBuilder supports creating `teams` with dims modifier argument.



>From f82593248ecb6218345ce03a59271a4589c3c17a Mon Sep 17 00:00:00 2001
From: skc7 <Krishna.Sankisa at amd.com>
Date: Fri, 28 Nov 2025 13:37:14 +0530
Subject: [PATCH 1/2] [OpenMP][MLIR] Add num_teams clause with dims modifier
 support

---
 .../mlir/Dialect/OpenMP/OpenMPClauses.td      | 72 +++++++++++++++++++
 mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td |  3 +-
 mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp  | 64 +++++++++++++++++
 mlir/test/Dialect/OpenMP/invalid.mlir         |  4 +-
 mlir/test/Dialect/OpenMP/ops.mlir             |  6 ++
 5 files changed, 146 insertions(+), 3 deletions(-)

diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPClauses.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPClauses.td
index 8e43c4284d078..ac452177b5cf7 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPClauses.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPClauses.td
@@ -1532,4 +1532,76 @@ class OpenMP_UseDevicePtrClauseSkip<
 
 def OpenMP_UseDevicePtrClause : OpenMP_UseDevicePtrClauseSkip<>;
 
+//===----------------------------------------------------------------------===//
+// V6.2: Multidimensional `num_teams` clause with dims modifier
+//===----------------------------------------------------------------------===//
+
+class OpenMP_NumTeamsMultiDimClauseSkip<
+    bit traits = false, bit arguments = false, bit assemblyFormat = false,
+    bit description = false, bit extraClassDeclaration = false
+  > : OpenMP_Clause<traits, arguments, assemblyFormat, description,
+            extraClassDeclaration> {
+  let arguments = (ins
+    ConfinedAttr<OptionalAttr<I64Attr>, [IntPositive]>:$num_teams_dims,
+    Variadic<AnyInteger>:$num_teams_values
+  );
+
+  let optAssemblyFormat = [{
+    `num_teams_multi_dim` `(` custom<NumTeamsMultiDimClause>($num_teams_dims,
+                                                    $num_teams_values,
+                                                    type($num_teams_values)) `)`
+  }];
+
+  let description = [{
+    The `num_teams_multi_dim` clause with dims modifier support specifies the limit on
+    the number of teams to be created in a multidimensional team space.
+
+    The dims modifier for the num_teams_multi_dim clause specifies the number of
+    dimensions for the league space (team space) that the clause arranges.
+    The dimensions argument in the dims modifier specifies the number of
+    dimensions and determines the length of the list argument. The list items
+    are specified in ascending order according to the ordinal number of the
+    dimensions (dimension 0, 1, 2, ..., N-1).
+
+    - If `dims` is not specified: The space is unidimensional (1D) with a single value
+    - If `dims(1)` is specified: The space is explicitly unidimensional (1D)
+    - If `dims(N)` where N > 1: The space is strictly multidimensional (N-D)
+
+    **Examples:**
+    - `num_teams_multi_dim(dims(3): %nt0, %nt1, %nt2 : i32, i32, i32)` creates a
+      3-dimensional team space with limits nt0, nt1, nt2 for dimensions 0, 1, 2.
+    - `num_teams_multi_dim(%nt : i32)` creates a unidimensional team space with limit nt.
+  }];
+
+  let extraClassDeclaration = [{
+    /// Returns true if the dims modifier is explicitly present
+    bool hasDimsModifier() {
+      return getNumTeamsDims().has_value();
+    }
+
+    /// Returns the number of dimensions specified by dims modifier
+    /// Returns 1 if dims modifier is not present (unidimensional by default)
+    unsigned getNumDimensions() {
+      if (!hasDimsModifier())
+        return 1;
+      return static_cast<unsigned>(*getNumTeamsDims());
+    }
+
+    /// Returns all dimension values as an operand range
+    ::mlir::OperandRange getDimensionValues() {
+      return getNumTeamsValues();
+    }
+
+    /// Returns the value for a specific dimension index
+    /// Index must be less than getNumDimensions()
+    ::mlir::Value getDimensionValue(unsigned index) {
+    assert(index < getDimensionValues().size() &&
+        "Dimension index out of bounds");
+      return getDimensionValues()[index];
+    }
+  }];
+}
+
+def OpenMP_NumTeamsMultiDimClause : OpenMP_NumTeamsMultiDimClauseSkip<>;
+
 #endif // OPENMP_CLAUSES
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index bbfe805eefe48..ea440cf924a95 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -241,7 +241,8 @@ def TeamsOp : OpenMP_Op<"teams", traits = [
     AttrSizedOperandSegments, RecursiveMemoryEffects, OutlineableOpenMPOpInterface
   ], clauses = [
     OpenMP_AllocateClause, OpenMP_IfClause, OpenMP_NumTeamsClause,
-    OpenMP_PrivateClause, OpenMP_ReductionClause, OpenMP_ThreadLimitClause
+    OpenMP_NumTeamsMultiDimClause, OpenMP_PrivateClause, OpenMP_ReductionClause,
+    OpenMP_ThreadLimitClause
   ], singleRegion = true> {
   let summary = "teams construct";
   let description = [{
diff --git a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
index 0d6b2870c625a..b9fbd38aebadb 100644
--- a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
+++ b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
@@ -2621,6 +2621,7 @@ void TeamsOp::build(OpBuilder &builder, OperationState &state,
   // TODO Store clauses in op: privateVars, privateSyms, privateNeedsBarrier
   TeamsOp::build(builder, state, clauses.allocateVars, clauses.allocatorVars,
                  clauses.ifExpr, clauses.numTeamsLower, clauses.numTeamsUpper,
+                 clauses.numTeamsDims, clauses.numTeamsValues,
                  /*private_vars=*/{}, /*private_syms=*/nullptr,
                  /*private_needs_barrier=*/nullptr, clauses.reductionMod,
                  clauses.reductionVars,
@@ -4453,6 +4454,69 @@ LogicalResult WorkdistributeOp::verify() {
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// Parser and printer for NumTeamsMultiDim Clause (with dims modifier)
+//===----------------------------------------------------------------------===//
+// num_teams_multidim ::= `num_teams` `(` [`dims` `(` dim-count `)` `:`] values
+// `)` Example: num_teams(dims(3): %v0, %v1, %v2 : i32, i32, i32) Or:
+// num_teams(%v : i32)
+static ParseResult parseNumTeamsMultiDimClause(
+    OpAsmParser &parser, IntegerAttr &dimsAttr,
+    SmallVectorImpl<OpAsmParser::UnresolvedOperand> &values,
+    SmallVectorImpl<Type> &types) {
+  std::optional<int64_t> dims;
+  // Try to parse optional dims modifier: dims(N):
+  if (succeeded(parser.parseOptionalKeyword("dims"))) {
+    int64_t dimsValue;
+    if (parser.parseLParen() || parser.parseInteger(dimsValue) ||
+        parser.parseRParen() || parser.parseColon()) {
+      return failure();
+    }
+    dims = dimsValue;
+  }
+  // Parse the operand list
+  if (parser.parseOperandList(values))
+    return failure();
+  // Parse colon and types
+  if (parser.parseColon() || parser.parseTypeList(types))
+    return failure();
+
+  // Verify dims matches number of values if specified
+  if (dims.has_value() && values.size() != static_cast<size_t>(*dims)) {
+    return parser.emitError(parser.getCurrentLocation())
+           << "dims(" << *dims << ") specified but " << values.size()
+           << " values provided";
+  }
+
+  // If dims not specified but we have values, it's implicitly unidimensional
+  if (!dims.has_value() && values.size() != 1) {
+    return parser.emitError(parser.getCurrentLocation())
+           << "expected 1 value without dims modifier, got " << values.size();
+  }
+
+  // Convert to IntegerAttr
+  if (dims.has_value()) {
+    dimsAttr = parser.getBuilder().getI64IntegerAttr(*dims);
+  }
+  return success();
+}
+
+static void printNumTeamsMultiDimClause(OpAsmPrinter &p, Operation *op,
+                                        IntegerAttr dimsAttr,
+                                        OperandRange values, TypeRange types) {
+  // Print dims modifier if present
+  if (dimsAttr) {
+    p << "dims(" << dimsAttr.getInt() << "): ";
+  }
+
+  // Print operands
+  p.printOperands(values);
+
+  // Print types
+  p << " : ";
+  llvm::interleaveComma(types, p);
+}
+
 #define GET_ATTRDEF_CLASSES
 #include "mlir/Dialect/OpenMP/OpenMPOpsAttributes.cpp.inc"
 
diff --git a/mlir/test/Dialect/OpenMP/invalid.mlir b/mlir/test/Dialect/OpenMP/invalid.mlir
index af24d969064ab..62619f07d6573 100644
--- a/mlir/test/Dialect/OpenMP/invalid.mlir
+++ b/mlir/test/Dialect/OpenMP/invalid.mlir
@@ -1438,7 +1438,7 @@ func.func @omp_teams_allocate(%data_var : memref<i32>) {
     // expected-error @below {{expected equal sizes for allocate and allocator variables}}
     "omp.teams" (%data_var) ({
       omp.terminator
-    }) {operandSegmentSizes = array<i32: 1,0,0,0,0,0,0,0>} : (memref<i32>) -> ()
+    }) {operandSegmentSizes = array<i32: 1,0,0,0,0,0,0,0,0>} : (memref<i32>) -> ()
     omp.terminator
   }
   return
@@ -1451,7 +1451,7 @@ func.func @omp_teams_num_teams1(%lb : i32) {
     // expected-error @below {{expected num_teams upper bound to be defined if the lower bound is defined}}
     "omp.teams" (%lb) ({
       omp.terminator
-    }) {operandSegmentSizes = array<i32: 0,0,0,1,0,0,0,0>} : (i32) -> ()
+    }) {operandSegmentSizes = array<i32: 0,0,0,1,0,0,0,0,0>} : (i32) -> ()
     omp.terminator
   }
   return
diff --git a/mlir/test/Dialect/OpenMP/ops.mlir b/mlir/test/Dialect/OpenMP/ops.mlir
index ac29e20907b55..bb154fad12742 100644
--- a/mlir/test/Dialect/OpenMP/ops.mlir
+++ b/mlir/test/Dialect/OpenMP/ops.mlir
@@ -1108,6 +1108,12 @@ func.func @omp_teams(%lb : i32, %ub : i32, %if_cond : i1, %num_threads : i32,
     omp.terminator
   }
 
+  // CHECK: omp.teams num_teams_multi_dim(dims(3): %{{.*}}, %{{.*}}, %{{.*}} : i32, i32, i32)
+  omp.teams num_teams_multi_dim(dims(3): %lb, %ub, %ub : i32, i32, i32) {
+    // CHECK: omp.terminator
+    omp.terminator
+  }
+
   // Test if.
   // CHECK: omp.teams if(%{{.+}})
   omp.teams if(%if_cond) {

>From 20d58da6af969212d6ee751f0d22a9a8942aa51a Mon Sep 17 00:00:00 2001
From: skc7 <Krishna.Sankisa at amd.com>
Date: Fri, 28 Nov 2025 14:20:39 +0530
Subject: [PATCH 2/2] fix comment

---
 mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
index b9fbd38aebadb..b26e22e9a781c 100644
--- a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
+++ b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
@@ -4457,9 +4457,8 @@ LogicalResult WorkdistributeOp::verify() {
 //===----------------------------------------------------------------------===//
 // Parser and printer for NumTeamsMultiDim Clause (with dims modifier)
 //===----------------------------------------------------------------------===//
-// num_teams_multidim ::= `num_teams` `(` [`dims` `(` dim-count `)` `:`] values
-// `)` Example: num_teams(dims(3): %v0, %v1, %v2 : i32, i32, i32) Or:
-// num_teams(%v : i32)
+// num_teams_multi_dim(dims(3): %v0, %v1, %v2 : i32, i32, i32) Or:
+// num_teams_multi_dim(%v : i32)
 static ParseResult parseNumTeamsMultiDimClause(
     OpAsmParser &parser, IntegerAttr &dimsAttr,
     SmallVectorImpl<OpAsmParser::UnresolvedOperand> &values,



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