gcc/testsuite/gcc.dg/builtin-arith-overflow-2.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2 -fdump-tree-optimized" } */
   3
   4 /* MUL_OVERFLOW should not be folded into unsigned multiplication,
   5    because it sometimes overflows and sometimes does not.  */
   6 __attribute__((noinline, noclone)) long int
   7 fn1 (long int x, long int y, int *ovf)
   8 {
   9   long int res;
  10   x &= 65535;
  11   y = (y & 65535) - (__LONG_MAX__ / 65535 + 32768);
  12   *ovf = __builtin_mul_overflow (x, y, &res);
  13   return res;
  14 }
  15
  16 /* MUL_OVERFLOW should not be folded into unsigned multiplication,
  17    because it sometimes overflows and sometimes does not.  */
  18 __attribute__((noinline, noclone)) signed char
  19 fn2 (long int x, long int y, int *ovf)
  20 {
  21   signed char res;
  22   x = (x & 63) + (__SCHAR_MAX__ / 4);
  23   y = (y & 3) + 4;
  24   *ovf = __builtin_mul_overflow (x, y, &res);
  25   return res;
  26 }
  27
  28 /* ADD_OVERFLOW should be folded into unsigned additrion,
  29    because it sometimes overflows and sometimes does not.  */
  30 __attribute__((noinline, noclone)) unsigned char
  31 fn3 (unsigned char x, unsigned char y, int *ovf)
  32 {
  33   unsigned char res;
  34   x = (x & 63) + ((unsigned char) ~0 - 65);
  35   y = (y & 3);
  36   *ovf = __builtin_add_overflow (x, y, &res);
  37   return res;
  38 }
  39
  40 /* ADD_OVERFLOW should be folded into unsigned additrion,
  41    because it sometimes overflows and sometimes does not.  */
  42 __attribute__((noinline, noclone)) unsigned char
  43 fn4 (unsigned char x, unsigned char y, int *ovf)
  44 {
  45   unsigned char res;
  46   x = (x & 15) + ((unsigned char) ~0 - 16);
  47   y = (y & 3) + 16;
  48   *ovf = __builtin_add_overflow (x, y, &res);
  49   return res;
  50 }
  51
  52 /* MUL_OVERFLOW should not be folded into unsigned multiplication,
  53    because it sometimes overflows and sometimes does not.  */
  54 __attribute__((noinline, noclone)) long int
  55 fn5 (long int x, unsigned long int y, int *ovf)
  56 {
  57   long int res;
  58   y = -65536UL + (y & 65535);
  59   *ovf = __builtin_mul_overflow (x, y, &res);
  60   return res;
  61 }
  62
  63 int
  64 main ()
  65 {
  66   int ovf;
  67   if (fn1 (0, 0, &ovf) != 0
  68       || ovf
  69       || fn1 (65535, 0, &ovf) != (long int) ((__LONG_MAX__ / 65535 + 32768UL) * -65535UL)
  70       || !ovf)
  71     __builtin_abort ();
  72   if (fn2 (0, 0, &ovf) != (signed char) (__SCHAR_MAX__ / 4 * 4U)
  73       || ovf
  74       || fn2 (0, 1, &ovf) != (signed char) (__SCHAR_MAX__ / 4 * 5U)
  75       || !ovf)
  76     __builtin_abort ();
  77   if (fn3 (0, 0, &ovf) != (unsigned char) ~0 - 65
  78       || ovf
  79       || fn3 (63, 2, &ovf) != (unsigned char) ~0
  80       || ovf
  81       || fn3 (62, 3, &ovf) != (unsigned char) ~0
  82       || ovf
  83       || fn3 (63, 3, &ovf) != 0
  84       || !ovf)
  85     __builtin_abort ();
  86   if (fn4 (0, 0, &ovf) != (unsigned char) ~0
  87       || ovf
  88       || fn4 (1, 0, &ovf) != 0
  89       || !ovf
  90       || fn4 (0, 1, &ovf) != 0
  91       || !ovf
  92       || fn4 (63, 3, &ovf) != 17
  93       || !ovf)
  94     __builtin_abort ();
  95   if (fn5 (0, 0, &ovf) != 0
  96       || ovf
  97       || fn5 (1, 0, &ovf) != -65536L
  98       || !ovf
  99       || fn5 (2, 32768, &ovf) != -65536L
 100       || !ovf
 101       || fn5 (4, 32768 + 16384 + 8192, &ovf) != -32768L
 102       || !ovf)
 103     __builtin_abort ();
 104   return 0;
 105 }
 106
 107 /* { dg-final { scan-tree-dump-times "ADD_OVERFLOW" 2 "optimized" } } */
 108 /* { dg-final { scan-tree-dump-times "SUB_OVERFLOW" 0 "optimized" } } */
 109 /* { dg-final { scan-tree-dump-times "MUL_OVERFLOW" 3 "optimized" } } */