1 /* PR tree-optimization/83821 - local aggregate initialization defeats
2 strlen optimization
3 Verify that a strlen() call is eliminated for a pointer to a region
4 of memory allocated by calloc() even if one or more nul bytes are
5 written into it.
6 { dg-do compile }
7 { dg-options "-O2 -fdump-tree-optimized" } */
8
9 unsigned n0, n1;
10
elim_strlen_calloc_store_memset_1(unsigned a,unsigned b)11 void* elim_strlen_calloc_store_memset_1 (unsigned a, unsigned b)
12 {
13 char *p = __builtin_calloc (a, 1);
14
15 p[0] = '\0';
16 p[1] = '\0';
17 p[2] = '\0';
18 p[3] = '\0';
19
20 __builtin_memset (p, 0, b);
21
22 n0 = __builtin_strlen (p);
23
24 return p;
25 }
26
elim_strlen_calloc_store_memset_2(unsigned a,unsigned b,unsigned c)27 void* elim_strlen_calloc_store_memset_2 (unsigned a, unsigned b, unsigned c)
28 {
29 char *p = __builtin_calloc (a, 1);
30
31 p[1] = '\0';
32 __builtin_memset (p, 0, b);
33
34 n0 = __builtin_strlen (p);
35
36 p[3] = 0;
37 __builtin_memset (p, 0, c);
38
39 n1 = __builtin_strlen (p);
40
41 return p;
42 }
43
44 /* { dg-final { scan-tree-dump-not "__builtin_strlen" "optimized" } } */
45