[Mlir-commits] [mlir] [mlir][ODS] Reuse collective builders for zero-result ops (NFC) (PR #226059)

[Mehdi Amini]

https://github.com/joker-eph created https://github.com/llvm/llvm-project/pull/226059

Forward the no-result separate-argument builder to its collective counterpart instead of generating the same operand, attribute, and region construction twice. This cuts OpenMPDialect.cpp build time by 1.5% and its machine-code text by about 71 KB.

Assisted-by: Codex

>From 6cd8f103a7743785b636694f5d3f35a391bf844c Mon Sep 17 00:00:00 2001
From: Mehdi Amini <joker.eph at gmail.com>
Date: Wed, 23 Sep 2026 08:34:29 -0700
Subject: [PATCH] [mlir][ODS] Reuse collective builders for zero-result ops

Forward the no-result separate-argument builder to its collective
counterpart instead of generating the same operand, attribute, and
region construction twice. This cuts OpenMPDialect.cpp compiler work
by 1.5% and its machine-code text by about 71 KB.

Assisted-by: Codex
(cherry picked from commit b452f58f7c29795f5bcee4426940ac8b80729825)
---
 mlir/test/mlir-tblgen/op-decl-and-defs.td   | 2 ++
 mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/mlir/test/mlir-tblgen/op-decl-and-defs.td b/mlir/test/mlir-tblgen/op-decl-and-defs.td
index 32c4bb88d188b..bd39c4a013ba3 100644
--- a/mlir/test/mlir-tblgen/op-decl-and-defs.td
+++ b/mlir/test/mlir-tblgen/op-decl-and-defs.td
@@ -205,6 +205,8 @@ def NS_BOp : NS_Op<"op_with_no_operand", []> {
 
 // CHECK-LABEL: NS::BOp declarations
 // CHECK: OpTrait::ZeroOperands
+// DEFS-LABEL: void BOp::build(::mlir::OpBuilder &odsBuilder, ::mlir::OperationState &odsState) {
+// DEFS-NEXT:   build(odsBuilder, odsState, ::mlir::TypeRange{});
 
 def NS_COp : NS_Op<"op_with_one_operand", []> {
   let arguments = (ins I32:$operand);
diff --git a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
index aa9ff159903bc..6bda98d00e50f 100644
--- a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
@@ -2485,6 +2485,15 @@ void OpEmitter::genSeparateArgParamBuilder() {
     genInlineCreateBody(paramList);
 
     auto &body = m->body();
+    // The no-result builder can reuse the collective builder. Both forms
+    // otherwise emit identical operand, attribute, and region handling.
+    if (paramKind == TypeParamKind::Separate && op.getNumResults() == 0) {
+      body << "  build(odsBuilder, odsState, ::mlir::TypeRange{}";
+      for (const MethodParameter &param : llvm::drop_begin(paramList, 2))
+        body << ", " << param.getName();
+      body << ");\n";
+      return;
+    }
     genCodeForAddingArgAndRegionForBuilder(body, inferredAttributes,
                                            /*isRawValueAttr=*/attrType ==
                                                AttrParamKind::UnwrappedValue);