libffi/testsuite/libffi.call/float1.c

   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 }