#-------------------------------------------------------------------------------
# GraphBLAS/cmake_modules/GraphBLAS_complex.cmake
#-------------------------------------------------------------------------------

# SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2024, All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0

#-------------------------------------------------------------------------------

# Check for C compiler support for complex floating point numbers and used API

include ( CheckSourceCompiles )

# Check for C99 complex number arithmetic

check_source_compiles ( C
    "#include <complex.h>
    int main(void) {
    double _Complex z1 = 1.0;
    double _Complex z2 = 1.0 * I;
    double _Complex z3 = z1 * z2;
    return 0;
    }"
    GxB_HAVE_COMPLEX_C99 )

if ( NOT GxB_HAVE_COMPLEX_C99 )
    # Check for complex number arithmetic as implemented by MSVC

    check_source_compiles ( C
        "#include <complex.h>
        int main(void) {
        _Dcomplex z1 = {1., 0.};
        _Dcomplex z2 = {0., 1.};
        _Dcomplex z3 = _Cmulcc(z1, z2);
        return 0;
        }"
        GxB_HAVE_COMPLEX_MSVC )
endif ( )

if ( NOT GxB_HAVE_COMPLEX_C99 AND NOT GxB_HAVE_COMPLEX_MSVC )
    message ( FATAL_ERROR "Complex floating point numbers are not supported by the used compiler." )
endif ( )