tests/tcg/i386/test-i386-pseudo-denormal.c

   1 /* Test pseudo-denormal operations.  */
   2
   3 #include <stdint.h>
   4 #include <stdio.h>
   5
   6 union u {
   7     struct { uint64_t sig; uint16_t sign_exp; } s;
   8     long double ld;
   9 };
  10
  11 volatile union u ld_pseudo_m16382 = { .s = { UINT64_C(1) << 63, 0 } };
  12
  13 volatile long double ld_res;
  14
  15 int main(void)
  16 {
  17     short cw;
  18     int ret = 0;
  19     ld_res = ld_pseudo_m16382.ld + ld_pseudo_m16382.ld;
  20     if (ld_res != 0x1p-16381L) {
  21         printf("FAIL: pseudo-denormal add\n");
  22         ret = 1;
  23     }
  24     if (ld_pseudo_m16382.ld != 0x1p-16382L) {
  25         printf("FAIL: pseudo-denormal compare\n");
  26         ret = 1;
  27     }
  28     /* Set round-upward.  */
  29     __asm__ volatile ("fnstcw %0" : "=m" (cw));
  30     cw = (cw & ~0xc00) | 0x800;
  31     __asm__ volatile ("fldcw %0" : : "m" (cw));
  32     __asm__ ("frndint" : "=t" (ld_res) : "0" (ld_pseudo_m16382.ld));
  33     if (ld_res != 1.0L) {
  34         printf("FAIL: pseudo-denormal round-to-integer\n");
  35         ret = 1;
  36     }
  37     return ret;
  38 }