modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/ieee/pr30704.c (about) 1 /* PR middle-end/30704 */ 2 3 typedef __SIZE_TYPE__ size_t; 4 extern void abort (void); 5 extern int memcmp (const void *, const void *, size_t); 6 extern void *memcpy (void *, const void *, size_t); 7 8 long long 9 f1 (void) 10 { 11 long long t; 12 double d = 0x0.fffffffffffff000p-1022; 13 memcpy (&t, &d, sizeof (long long)); 14 return t; 15 } 16 17 double 18 f2 (void) 19 { 20 long long t = 0x000fedcba9876543LL; 21 double d; 22 memcpy (&d, &t, sizeof (long long)); 23 return d; 24 } 25 26 int 27 main () 28 { 29 union 30 { 31 long long ll; 32 double d; 33 } u; 34 35 if (sizeof (long long) != sizeof (double) || __DBL_MIN_EXP__ != -1021) 36 return 0; 37 38 u.ll = f1 (); 39 if (u.d != 0x0.fffffffffffff000p-1022) 40 abort (); 41 42 u.d = f2 (); 43 if (u.ll != 0x000fedcba9876543LL) 44 abort (); 45 46 double b = 234.0; 47 long long c; 48 double d = b; 49 memcpy (&c, &b, sizeof (double)); 50 long long e = c; 51 if (memcmp (&e, &d, sizeof (double)) != 0) 52 abort (); 53 54 return 0; 55 }