1  /* PRE tree-optimization/90626 - fold strcmp(a, b) == 0 to zero when
       2     one string length is exact and the other is unequal
       3     { dg-do run }
       4     { dg-options "-O2 -Wall" } */
       5  
       6  #include "strlenopt.h"
       7  
       8  #define A(expr)                                                 \
       9    ((expr)                                                       \
      10     ? (void)0                                                    \
      11     : (__builtin_printf ("assertion failed on line %i: %s\n",    \
      12                          __LINE__, #expr),                       \
      13        __builtin_abort ()))
      14  
      15  
      16  __attribute__ ((noclone, noinline, noipa)) void
      17  clobber (void *p, int x, size_t n)
      18  {
      19    for (volatile unsigned char *q = p; n--; )
      20      *q = x;
      21  }
      22  
      23  __attribute__ ((noclone, noinline, noipa)) void
      24  test_strcmp (void)
      25  {
      26    char a[8], b[8];
      27    strcpy (a, "1235");
      28    strcpy (b, "1234");
      29  
      30    A (strcmp (a, b));
      31  
      32    clobber (a, 0, sizeof a);
      33    clobber (b, 0, sizeof b);
      34    clobber (b + 4, '5', 1);
      35  
      36    memcpy (a, "1234", 4);
      37    memcpy (b, "1234", 4);
      38  
      39    A (0 > strcmp (a, b));
      40    A (0 < strcmp (b, a));
      41  }
      42  
      43  __attribute__ ((noclone, noinline, noipa)) void
      44  test_strncmp (void)
      45  {
      46    char a[8], b[8];
      47    strcpy (a, "1235");
      48    strcpy (b, "1234");
      49  
      50    A (0 == strncmp (a, b, 1));
      51    A (0 == strncmp (a, b, 2));
      52    A (0 == strncmp (a, b, 3));
      53    A (0 <  strncmp (a, b, 4));
      54    A (0 >  strncmp (b, a, 4));
      55  
      56    clobber (a, 0, sizeof a);
      57    clobber (b, 0, sizeof b);
      58    clobber (b + 4, '5', 1);
      59  
      60    memcpy (a, "1234", 4);
      61    memcpy (b, "1234", 4);
      62  
      63    A (0 == strncmp (a, b, 4));
      64    A (0 >  strncmp (a, b, 5));
      65    A (0 <  strncmp (b, a, 5));
      66  }
      67  
      68  
      69  __attribute__ ((noclone, noinline, noipa)) void
      70  test_strncmp_a4_cond_s5_s2_2 (const char *s, int i)
      71  {
      72    char a4[4];
      73    strcpy (a4, s);
      74    A (0 == strncmp (a4, i ? "12345" : "12", 2));
      75  }
      76  
      77  
      78  __attribute__ ((noclone, noinline, noipa)) void
      79  test_strncmp_a4_cond_a5_s2_5 (const char *s, const char *t, int i)
      80  {
      81    char a4[4], a5[5];
      82    strcpy (a4, s);
      83    strcpy (a5, t);
      84    A (0 == strncmp (a4, i ? a5 : "12", 5));
      85  }
      86  
      87  __attribute__ ((noclone, noinline, noipa)) void
      88  test_strncmp_a4_cond_a5_a3_n (const char *s1, const char *s2, const char *s3,
      89  			      int i, unsigned n)
      90  {
      91    char a3[3], a4[4], a5[5];
      92    strcpy (a3, s1);
      93    strcpy (a4, s2);
      94    strcpy (a5, s3);
      95    A (0 == strncmp (a4, i ? a5 : a3, n));
      96  }
      97  
      98  
      99  int main (void)
     100  {
     101    test_strcmp ();
     102    test_strncmp ();
     103    test_strncmp_a4_cond_s5_s2_2 ("12", 0);
     104    test_strncmp_a4_cond_a5_s2_5 ("12", "1234", 0);
     105  
     106    test_strncmp_a4_cond_a5_a3_n ("12", "1", "1",    0, 1);
     107    test_strncmp_a4_cond_a5_a3_n ("",   "1", "1234", 1, 1);
     108  
     109    test_strncmp_a4_cond_a5_a3_n ("12", "12", "1",    0, 2);
     110    test_strncmp_a4_cond_a5_a3_n ("",   "12", "1234", 1, 2);
     111  
     112    test_strncmp_a4_cond_a5_a3_n ("12", "123", "1",    0, 2);
     113    test_strncmp_a4_cond_a5_a3_n ("",   "123", "1234", 1, 3);
     114  }