gcc/testsuite/gcc.dg/strlenopt-83.c

   1 /* PR tree-optimization/83821 - local aggregate initialization defeats
   2    strlen optimization
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall -fdump-tree-optimized" }
   5    { dg-require-effective-target alloca } */
   6
   7 #include "strlenopt.h"
   8 char *p_p2, *p_p5, *p_p9, *p_p14;
   9
  10 unsigned n0, n1, n2, n3, n4;
  11
  12
  13 static inline __attribute__ ((always_inline)) void
  14 elim_strlen_of_consecutive_strcpy (char *p)
  15 {
  16   p_p2 = p + 2;
  17   __builtin_strcpy (p_p2, "12");
  18
  19   p_p5 = p_p2 + 3;
  20   __builtin_strcpy (p_p5, "124");
  21
  22   p_p9 = p_p5 + 4;
  23   __builtin_strcpy (p_p9, "1245");
  24
  25   p_p14 = p_p9 + 5;
  26
  27   n0 = __builtin_strlen (p);
  28   n1 = __builtin_strlen (p_p2);
  29   n2 = __builtin_strlen (p_p5);
  30   n3 = __builtin_strlen (p_p9);
  31
  32   /* The following isn't handled yet:
  33      n4 = __builtin_strlen (p_p14); */
  34
  35   if (n0 || n1 != 2 || n2 != 3 || n3 != 4)
  36     __builtin_abort ();
  37 }
  38
  39
  40 void elim_strlen_of_consecutive_strcpy_in_alloca (unsigned n)
  41 {
  42   /* Only known sizes are handled so far.  */
  43   n = 14;
  44
  45   char *p = __builtin_alloca (n);
  46
  47   *p = '\0';
  48
  49   elim_strlen_of_consecutive_strcpy (p);
  50 }
  51
  52
  53 void elim_strlen_of_consecutive_strcpy_in_vla (unsigned n)
  54 {
  55   /* Only known sizes are handled so far.  */
  56   n = 14;
  57
  58   char vla[n];
  59
  60   *vla = '\0';
  61
  62   elim_strlen_of_consecutive_strcpy (vla);
  63 }
  64
  65 void elim_strlen_of_consecutive_strcpy_in_malloc (unsigned n)
  66 {
  67   char *p = __builtin_malloc (n);
  68
  69   *p = '\0';
  70
  71   elim_strlen_of_consecutive_strcpy (p);
  72 }
  73
  74
  75 void elim_strlen_of_consecutive_strcpy_in_calloc (unsigned n)
  76 {
  77   char *p = __builtin_calloc (n, 1);
  78
  79   /* Do not store into *P to verify that strlen knows it's zero.  */
  80
  81   elim_strlen_of_consecutive_strcpy (p);
  82 }
  83
  84 /* { dg-final { scan-tree-dump-not "abort" "optimized" } } */