[Mlir-commits] [mlir] [MLIR] add C-API bindings for complex dialect (PR #173228)

Sergio Sánchez Ramírez llvmlistbot at llvm.org
Mon Dec 22 00:54:39 PST 2025


https://github.com/mofeing created https://github.com/llvm/llvm-project/pull/173228

The `complex` dialect is missing from the MLIR's C-API. This PR adds the functions for registration of the dialect and handling of `complex::NumberAttr`.

>From 73db5e5cbc1a0c22df84a97da5084c573b16e210 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergio=20S=C3=A1nchez=20Ram=C3=ADrez?=
 <15837247+mofeing at users.noreply.github.com>
Date: Mon, 22 Dec 2025 01:40:27 +0100
Subject: [PATCH 1/3] add capi for complex::NumberAttr

---
 mlir/include/mlir-c/Dialect/Complex.h | 53 +++++++++++++++++++++++++++
 mlir/lib/CAPI/Dialect/CMakeLists.txt  |  9 +++++
 mlir/lib/CAPI/Dialect/Complex.cpp     | 44 ++++++++++++++++++++++
 3 files changed, 106 insertions(+)
 create mode 100644 mlir/include/mlir-c/Dialect/Complex.h
 create mode 100644 mlir/lib/CAPI/Dialect/Complex.cpp

diff --git a/mlir/include/mlir-c/Dialect/Complex.h b/mlir/include/mlir-c/Dialect/Complex.h
new file mode 100644
index 0000000000000..eb0df0aa63ff9
--- /dev/null
+++ b/mlir/include/mlir-c/Dialect/Complex.h
@@ -0,0 +1,53 @@
+//===-- mlir-c/Dialect/Complex.h - C API for Complex dialect ------*- C -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_C_DIALECT_COMPLEX_H
+#define MLIR_C_DIALECT_COMPLEX_H
+
+#include "mlir-c/IR.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+MLIR_DECLARE_CAPI_DIALECT_REGISTRATION(Func, func);
+
+/// Checks whether the given attribute is a complex attribute.
+MLIR_CAPI_EXPORTED bool mlirAttributeIsAComplex(MlirAttribute attr);
+
+/// Creates a complex attribute in the given context with the given
+/// double real and imaginary values and double-precision FP semantics.
+MLIR_CAPI_EXPORTED MlirAttribute mlirComplexAttrDoubleGet(MlirContext ctx,
+                                                        MlirType type,
+                                                        double real,
+                                                        double imag);
+
+/// Same as "mlirComplexAttrDoubleGet", but if the type is not valid for a
+/// construction of a ComplexAttr, returns a null MlirAttribute.
+MLIR_CAPI_EXPORTED MlirAttribute mlirComplexAttrDoubleGetChecked(MlirLocation loc,
+                                                               MlirType type,
+                                                               double real,
+                                                               double imag);
+
+/// Returns the real value stored in the given complex attribute, interpreting
+/// the value as double. 
+MLIR_CAPI_EXPORTED double mlirComplexAttrGetRealDouble(MlirAttribute attr);
+
+/// Returns the imaginaryvalue stored in the given complex attribute,
+/// interpreting the value as double.
+MLIR_CAPI_EXPORTED double mlirComplexAttrGetImagDouble(MlirAttribute attr);
+
+/// Returns the typeID of a Complex attribute.
+MLIR_CAPI_EXPORTED MlirTypeID mlirComplexAttrGetTypeID(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIR_C_DIALECT_COMPLEX_H
diff --git a/mlir/lib/CAPI/Dialect/CMakeLists.txt b/mlir/lib/CAPI/Dialect/CMakeLists.txt
index bb1fdf8be3c8f..30c9cb0593371 100644
--- a/mlir/lib/CAPI/Dialect/CMakeLists.txt
+++ b/mlir/lib/CAPI/Dialect/CMakeLists.txt
@@ -31,6 +31,15 @@ add_mlir_upstream_c_api_library(MLIRCAPIAsync
   MLIRPass
 )
 
+add_mlir_upstream_c_api_library(MLIRCAPIComplex
+  Complex.cpp
+
+  PARTIAL_SOURCES_INTENDED
+  LINK_LIBS PUBLIC
+  MLIRCAPIIR
+  MLIRComplexDialect
+)
+
 add_mlir_upstream_c_api_library(MLIRCAPIControlFlow
   ControlFlow.cpp
 
diff --git a/mlir/lib/CAPI/Dialect/Complex.cpp b/mlir/lib/CAPI/Dialect/Complex.cpp
new file mode 100644
index 0000000000000..0b1f5e477bab3
--- /dev/null
+++ b/mlir/lib/CAPI/Dialect/Complex.cpp
@@ -0,0 +1,44 @@
+//===- Complex.cpp - C Interface for Complex dialect ----------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir-c/Dialect/Complex.h"
+#include "mlir-c/IR.h"
+#include "mlir-c/Support.h"
+#include "mlir/CAPI/Registration.h"
+
+MLIR_DEFINE_CAPI_DIALECT_REGISTRATION(Complex, complex,
+                                     mlir::complex::ComplexDialect)
+
+bool mlirAttributeIsAComplex(MlirAttribute attr) {
+  return llvm::isa<ComplexAttr>(unwrap(attr));
+}
+
+MlirAttribute mlirComplexAttrDoubleGet(MlirContext ctx, MlirType type,
+                                       double real, double imag) {
+  return wrap(
+      complex::NumberAttr::get(cast<ComplexType>(unwrap(type)), real, imag));
+}
+
+MlirAttribute mlirComplexAttrDoubleGetChecked(MlirLocation loc, MlirType type,
+                                              double real, double imag) {
+  return wrap(complex::NumberAttr::getChecked(
+      unwrap(loc), cast<ComplexType>(unwrap(type)), real, imag));
+}
+
+double mlirComplexAttrGetRealDouble(MlirAttribute attr) {
+  return llvm::cast<complex::NumberAttr>(unwrap(attr)).getRealAsDouble();
+}
+
+double mlirComplexAttrGetImagDouble(MlirAttribute attr) {
+  return llvm::cast<complex::NumberAttr>(unwrap(attr)).getImagAsDouble();
+}
+
+MlirTypeID mlirComplexAttrGetTypeID(void) {
+  return wrap(complex::NumberAttr::getTypeID());
+}
+

>From 1d262f93e046fc1d6f40229b6c661627c4bb088b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergio=20S=C3=A1nchez=20Ram=C3=ADrez?=
 <15837247+mofeing at users.noreply.github.com>
Date: Mon, 22 Dec 2025 09:49:51 +0100
Subject: [PATCH 2/3] format comment

---
 mlir/include/mlir-c/Dialect/Complex.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mlir/include/mlir-c/Dialect/Complex.h b/mlir/include/mlir-c/Dialect/Complex.h
index eb0df0aa63ff9..3a656a3ccf6cb 100644
--- a/mlir/include/mlir-c/Dialect/Complex.h
+++ b/mlir/include/mlir-c/Dialect/Complex.h
@@ -36,7 +36,7 @@ MLIR_CAPI_EXPORTED MlirAttribute mlirComplexAttrDoubleGetChecked(MlirLocation lo
                                                                double imag);
 
 /// Returns the real value stored in the given complex attribute, interpreting
-/// the value as double. 
+/// the value as double.
 MLIR_CAPI_EXPORTED double mlirComplexAttrGetRealDouble(MlirAttribute attr);
 
 /// Returns the imaginaryvalue stored in the given complex attribute,

>From d9eb3a529ddaf59d721e9d589bf40ac0bf790aa3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergio=20S=C3=A1nchez=20Ram=C3=ADrez?=
 <15837247+mofeing at users.noreply.github.com>
Date: Mon, 22 Dec 2025 09:51:09 +0100
Subject: [PATCH 3/3] format code

---
 mlir/include/mlir-c/Dialect/Complex.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mlir/include/mlir-c/Dialect/Complex.h b/mlir/include/mlir-c/Dialect/Complex.h
index 3a656a3ccf6cb..b5912cf457643 100644
--- a/mlir/include/mlir-c/Dialect/Complex.h
+++ b/mlir/include/mlir-c/Dialect/Complex.h
@@ -30,10 +30,9 @@ MLIR_CAPI_EXPORTED MlirAttribute mlirComplexAttrDoubleGet(MlirContext ctx,
 
 /// Same as "mlirComplexAttrDoubleGet", but if the type is not valid for a
 /// construction of a ComplexAttr, returns a null MlirAttribute.
-MLIR_CAPI_EXPORTED MlirAttribute mlirComplexAttrDoubleGetChecked(MlirLocation loc,
-                                                               MlirType type,
-                                                               double real,
-                                                               double imag);
+MLIR_CAPI_EXPORTED MlirAttribute
+mlirComplexAttrDoubleGetChecked(MlirLocation loc, MlirType type, double real,
+                                double imag);
 
 /// Returns the real value stored in the given complex attribute, interpreting
 /// the value as double.



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