1  /* Area:	ffi_call
       2     Purpose:	Check return value double.
       3     Limitations:	none.
       4     PR:		none.
       5     Originator:	From the original ffitest.c  */
       6  
       7  /* { dg-do run } */
       8  #include "ffitest.h"
       9  #include "float.h"
      10  
      11  #include <math.h>
      12  
      13  typedef union
      14  {
      15    double d;
      16    unsigned char c[sizeof (double)];
      17  } value_type;
      18  
      19  #define CANARY 0xba
      20  
      21  static double dblit(float f)
      22  {
      23    return f/3.0;
      24  }
      25  
      26  int main (void)
      27  {
      28    ffi_cif cif;
      29    ffi_type *args[MAX_ARGS];
      30    void *values[MAX_ARGS];
      31    float f;
      32    value_type result[2];
      33    unsigned int i;
      34  
      35    args[0] = &ffi_type_float;
      36    values[0] = &f;
      37  
      38    /* Initialize the cif */
      39    CHECK(ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1,
      40  		     &ffi_type_double, args) == FFI_OK);
      41  
      42    f = 3.14159;
      43  
      44    /* Put a canary in the return array.  This is a regression test for
      45       a buffer overrun.  */
      46    memset(result[1].c, CANARY, sizeof (double));
      47  
      48    ffi_call(&cif, FFI_FN(dblit), &result[0].d, values);
      49  
      50    /* These are not always the same!! Check for a reasonable delta */
      51  
      52    CHECK(fabs(result[0].d - dblit(f)) < DBL_EPSILON);
      53  
      54    /* Check the canary.  */
      55    for (i = 0; i < sizeof (double); ++i)
      56      CHECK(result[1].c[i] == CANARY);
      57  
      58    exit(0);
      59  
      60  }