gcc/testsuite/gcc.dg/strlenopt-6.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2 -fdump-tree-strlen" } */
   3
   4 #include "strlenopt.h"
   5
   6 __attribute__((noinline, noclone)) char *
   7 foo (char *x)
   8 {
   9 #ifdef PR50262_FIXED
  10   /* Once PTA is fixed, we'll need just one strlen here,
  11      without the memcpy.  */
  12   char *p = x;
  13   char *q = malloc (strlen (p) + 64);
  14 #else
  15   /* This is here just because PTA can't figure that
  16      *q = '\0' store below can't change p's length.
  17      In this case we have one strlen and one memcpy here.  */
  18   char b[64];
  19   char *q = malloc (strlen (x) + 64);
  20   char *p = strcpy (b, x);
  21 #endif
  22   char *r;
  23   if (q == NULL) return NULL;
  24   /* This store can be optimized away once strcat is
  25      replaced with memcpy.  */
  26   *q = '\0';
  27   /* These two strcat calls can be optimized into memcpy calls.  */
  28   strcat (q, p);
  29   strcat (q, "/");
  30   /* The strchr can be optimized away, as we know the current
  31      string length as well as end pointer.  */
  32   r = strchr (q, '\0');
  33   /* This store can go, as it is overwriting '\0' with the same
  34      character.  */
  35   *r = '\0';
  36   /* And this strcat can be again optimized into memcpy call.  */
  37   strcat (q, "abcde");
  38   return q;
  39 }
  40
  41 __attribute__((noinline, noclone)) char *
  42 bar (char *p)
  43 {
  44   char buf[26];
  45   char *r;
  46   if (strlen (p) + 9 > 26)
  47     return NULL;
  48   *buf = '\0';
  49   strcat (buf, p);
  50   strcat (buf, "/");
  51   r = strchr (buf, '\0');
  52   *r = '\0';
  53   strcat (buf, "abcde");
  54   return strdup (buf);
  55 }
  56
  57 int
  58 main ()
  59 {
  60   char *volatile p = "string1";
  61   char *volatile r = "string2";
  62   char *q = foo (p);
  63   if (q != NULL)
  64     {
  65       if (strcmp (q, "string1/abcde"))
  66         abort ();
  67       memset (q, '\0', 14);
  68       free (q);
  69     }
  70   q = bar (p);
  71   if (q != NULL)
  72     {
  73       if (strcmp (q, "string1/abcde"))
  74         abort ();
  75       free (q);
  76     }
  77   return 0;
  78 }
  79
  80 /* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
  81 /* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen" } } */
  82 /* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
  83 /* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
  84 /* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
  85 /* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */