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 typedef union
  12 {
  13   double d;
  14   unsigned char c[sizeof (double)];
  15 } value_type;
  16
  17 #define CANARY 0xba
  18
  19 static double dblit(float f)
  20 {
  21   return f/3.0;
  22 }
  23
  24 int main (void)
  25 {
  26   ffi_cif cif;
  27   ffi_type *args[MAX_ARGS];
  28   void *values[MAX_ARGS];
  29   float f;
  30   value_type result[2];
  31   unsigned int i;
  32
  33   args[0] = &ffi_type_float;
  34   values[0] = &f;
  35
  36   /* Initialize the cif */
  37   CHECK(ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1,
  38                      &ffi_type_double, args) == FFI_OK);
  39
  40   f = 3.14159;
  41
  42   /* Put a canary in the return array.  This is a regression test for
  43      a buffer overrun.  */
  44   memset(result[1].c, CANARY, sizeof (double));
  45
  46   ffi_call(&cif, FFI_FN(dblit), &result[0].d, values);
  47
  48   /* These are not always the same!! Check for a reasonable delta */
  49
  50   CHECK(result[0].d - dblit(f) < DBL_EPSILON);
  51
  52   /* Check the canary.  */
  53   for (i = 0; i < sizeof (double); ++i)
  54     CHECK(result[1].c[i] == CANARY);
  55
  56   exit(0);
  57
  58 }