github.com/prattmic/llgo-embedded@v0.0.0-20150820070356-41cfecea0e1e/third_party/gofrontend/libffi/testsuite/libffi.call/cls_double.c (about)

     1  /* Area:	closure_call
     2     Purpose:	Check return value double.
     3     Limitations:	none.
     4     PR:		none.
     5     Originator:	<andreast@gcc.gnu.org> 20030828	 */
     6  
     7  /* { dg-do run } */
     8  #include "ffitest.h"
     9  
    10  static void cls_ret_double_fn(ffi_cif* cif __UNUSED__, void* resp, void** args,
    11  			      void* userdata __UNUSED__)
    12   {
    13     *(double *)resp = *(double *)args[0];
    14  
    15     printf("%f: %f\n",*(double *)args[0],
    16  	  *(double *)resp);
    17   }
    18  typedef double (*cls_ret_double)(double);
    19  
    20  int main (void)
    21  {
    22    ffi_cif cif;
    23    void *code;
    24    ffi_closure *pcl = ffi_closure_alloc(sizeof(ffi_closure), &code);
    25    ffi_type * cl_arg_types[2];
    26    double res;
    27  
    28    cl_arg_types[0] = &ffi_type_double;
    29    cl_arg_types[1] = NULL;
    30  
    31    /* Initialize the cif */
    32    CHECK(ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1,
    33  		     &ffi_type_double, cl_arg_types) == FFI_OK);
    34  
    35    CHECK(ffi_prep_closure_loc(pcl, &cif, cls_ret_double_fn, NULL, code)  == FFI_OK);
    36  
    37    res = (*((cls_ret_double)code))(21474.789);
    38    /* { dg-output "21474.789000: 21474.789000" } */
    39    printf("res: %.6f\n", res);
    40    /* { dg-output "\nres: 21474.789000" } */
    41  
    42    exit(0);
    43  }