libffi/testsuite/libffi.call/float4.c

   1 /* Area:        ffi_call
   2    Purpose:     Check denorm double value.
   3    Limitations: none.
   4    PR:          PR26483.
   5    Originator:  From the original ffitest.c  */
   6
   7 /* { dg-do run } */
   8 /* { dg-options "-mieee" { target alpha*-*-* } } */
   9
  10 #include "ffitest.h"
  11 #include "float.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(double d)
  22 {
  23   return d;
  24 }
  25
  26 int main (void)
  27 {
  28   ffi_cif cif;
  29   ffi_type *args[MAX_ARGS];
  30   void *values[MAX_ARGS];
  31   double d;
  32   value_type result[2];
  33   unsigned int i;
  34
  35   args[0] = &ffi_type_double;
  36   values[0] = &d;
  37
  38   /* Initialize the cif */
  39   CHECK(ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1,
  40                      &ffi_type_double, args) == FFI_OK);
  41
  42   d = DBL_MIN / 2;
  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   /* The standard delta check doesn't work for denorms.  Since we didn't do
  51      any arithmetic, we should get the original result back, and hence an
  52      exact check should be OK here.  */
  53
  54   CHECK(result[0].d == dblit(d));
  55
  56   /* Check the canary.  */
  57   for (i = 0; i < sizeof (double); ++i)
  58     CHECK(result[1].c[i] == CANARY);
  59
  60   exit(0);
  61
  62 }