Files
eigen/blas/complexdots.cpp
Rasmus Munk Larsen 4ad90a60f1 Replace blas/f2c with clean C++ implementations
libeigen/eigen!2402

Co-authored-by: Rasmus Munk Larsen <rmlarsen@gmail.com>
2026-04-05 16:04:41 -07:00

73 lines
2.8 KiB
C++

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// C++ replacements for the f2c complex dot product wrappers.
// These are thin wrappers around the worker functions (cdotcw_, etc.)
// defined in level1_cplx_impl.h.
//
// Note: blas.h declares these as void, but gfortran expects complex functions
// to return by value. We define the correct signatures here and do not include
// blas.h to avoid the conflicting declarations.
#if defined(_WIN32)
#if defined(EIGEN_BLAS_BUILD_DLL)
#define EIGEN_BLAS_CDOT_API __declspec(dllexport)
#else
#define EIGEN_BLAS_CDOT_API
#endif
#elif ((defined(__GNUC__) && __GNUC__ >= 4) || defined(__clang__)) && defined(EIGEN_BLAS_BUILD_DLL)
#define EIGEN_BLAS_CDOT_API __attribute__((visibility("default")))
#else
#define EIGEN_BLAS_CDOT_API
#endif
extern "C" {
// Worker function declarations (defined in level1_cplx_impl.h via complex_single.cpp / complex_double.cpp).
void cdotcw_(int *n, float *cx, int *incx, float *cy, int *incy, float *res);
void cdotuw_(int *n, float *cx, int *incx, float *cy, int *incy, float *res);
void zdotcw_(int *n, double *cx, int *incx, double *cy, int *incy, double *res);
void zdotuw_(int *n, double *cx, int *incx, double *cy, int *incy, double *res);
// POD complex types for C-compatible return values (matches Fortran complex layout).
struct eigen_blas_complex_float {
float r, i;
};
struct eigen_blas_complex_double {
double r, i;
};
// CDOTC computes the conjugated dot product of two single-precision complex vectors.
EIGEN_BLAS_CDOT_API eigen_blas_complex_float cdotc_(int *n, float *cx, int *incx, float *cy, int *incy) {
eigen_blas_complex_float res = {0.0f, 0.0f};
cdotcw_(n, cx, incx, cy, incy, &res.r);
return res;
}
// CDOTU computes the unconjugated dot product of two single-precision complex vectors.
EIGEN_BLAS_CDOT_API eigen_blas_complex_float cdotu_(int *n, float *cx, int *incx, float *cy, int *incy) {
eigen_blas_complex_float res = {0.0f, 0.0f};
cdotuw_(n, cx, incx, cy, incy, &res.r);
return res;
}
// ZDOTC computes the conjugated dot product of two double-precision complex vectors.
EIGEN_BLAS_CDOT_API eigen_blas_complex_double zdotc_(int *n, double *cx, int *incx, double *cy, int *incy) {
eigen_blas_complex_double res = {0.0, 0.0};
zdotcw_(n, cx, incx, cy, incy, &res.r);
return res;
}
// ZDOTU computes the unconjugated dot product of two double-precision complex vectors.
EIGEN_BLAS_CDOT_API eigen_blas_complex_double zdotu_(int *n, double *cx, int *incx, double *cy, int *incy) {
eigen_blas_complex_double res = {0.0, 0.0};
zdotuw_(n, cx, incx, cy, incy, &res.r);
return res;
}
} // extern "C"