gcc/testsuite/gcc.target/arm/fp16-rounding-alt-1.c

   1 /* Test intermediate rounding of double to float and then to __fp16, using
   2    an example of a number that would round differently if it went directly
   3    from double to __fp16.  */
   4
   5 /* { dg-do run } */
   6 /* { dg-options "-mfp16-format=alternative" } */
   7
   8 #include <stdlib.h>
   9
  10 /* The original double value.  */
  11 #define ORIG 0x1.0020008p0
  12
  13 /* The expected (double)((__fp16)((float)ORIG)) value.  */
  14 #define ROUNDED 0x1.0000000p0
  15
  16 typedef union u {
  17   __fp16 f;
  18   unsigned short h;
  19 } ufh;
  20
  21 ufh s = { ORIG };
  22 ufh r = { ROUNDED };
  23
  24 double d = ORIG;
  25
  26 int
  27 main (void)
  28 {
  29   ufh x;
  30
  31   /* Test that the rounding is correct for static initializers.  */
  32   if (s.h != r.h)
  33     abort ();
  34
  35   /* Test that the rounding is correct for a casted constant expression
  36      not in a static initializer.  */
  37   x.f = (__fp16)ORIG;
  38   if (x.h != r.h)
  39     abort ();
  40
  41   /* Test that the rounding is correct for a runtime conversion.  */
  42   x.f = (__fp16)d;
  43   if (x.h != r.h)
  44     abort ();
  45
  46   return 0;
  47 }