none/tests/arm64/bug489338.c

   1 /*
   2 cat fp-valgrind-test.c
   3 gcc -g -O2 fp-valgrind-test.c -o fp-valgrind-test
   4 ./fp-valgrind-test
   5 valgrind ./fp-valgrind-test
   6 gdb -q --args ./fp-valgrind-test
   7 disassemble main
   8 q
   9 */
  10
  11 #include <stdio.h>
  12 #include <math.h>
  13
  14 double value(int s)
  15 {
  16   switch (s) {
  17     case 0:  return -322.500001; break;
  18     case 1:  return -322.5;       break;
  19     case 2:  return -322.499999; break;
  20     case 3:  return  322.499999; break;
  21     case 4:  return  322.5;       break;
  22     default: return  322.500001; break;
  23   }
  24 }
  25
  26 int main()
  27 {
  28   for (int i = 0; i < 6; i++) {
  29     volatile double a = value(i);
  30     int b = (int)round(a);
  31     printf("i=%d a=%f a=0x%llx b=%d\n", i, a, *(long long unsigned int*)&a, b);
  32   }
  33 }