Viewing file:  strlenopt-20.c (2.19 KB) -rw-r--r--
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/* { dg-do run } */
/* { dg-options "-O2 -fdump-tree-strlen" } */
#include "strlenopt.h"
__attribute__((noinline, noclone)) const char *
fn1 (int x, int y)
{
const char *p;
switch (x)
{
case 0:
p = "abcd";
/* Prevent cswitch optimization. */
asm volatile ("" : : : "memory");
break;
case 1:
p = "efgh";
break;
case 2:
p = "ijkl";
break;
default:
p = "mnop";
break;
}
if (y)
/* strchr should be optimized into p + 4 here. */
return strchr (p, '\0');
else
/* and strlen into 3. */
return p + strlen (p + 1);
}
__attribute__((noinline, noclone)) size_t
fn2 (char *p, char *q)
{
size_t l;
/* Both strcpy calls can be optimized into memcpy, strlen needs to stay. */
strcpy (p, "abc");
p[3] = 'd';
l = strlen (p);
strcpy (q, p);
return l;
}
__attribute__((noinline, noclone)) char *
fn3 (char *p)
{
char *c;
/* The strcpy call can be optimized into memcpy, strchr needs to stay,
strcat is optimized into memcpy. */
strcpy (p, "abc");
p[3] = 'd';
c = strchr (p, '\0');
strcat (p, "efgh");
return c;
}
int
main ()
{
int i;
char buf[64], buf2[64];
for (i = 0; i < 5; i++)
{
const char *p = "abcdefghijklmnop" + (i < 3 ? i : 3) * 4;
const char *q;
q = fn1 (i, 1);
if (memcmp (q - 4, p, 4) != 0 || q[0] != '\0')
abort ();
q = fn1 (i, 0);
if (memcmp (q - 3, p, 4) != 0 || q[1] != '\0')
abort ();
}
memset (buf, '\0', sizeof buf);
memset (buf + 4, 'z', 2);
if (fn2 (buf, buf2) != 6
|| memcmp (buf, "abcdzz", 7) != 0
|| memcmp (buf2, "abcdzz", 7) != 0)
abort ();
memset (buf, '\0', sizeof buf);
memset (buf + 4, 'z', 2);
if (fn3 (buf) != buf + 6 || memcmp (buf, "abcdzzefgh", 11) != 0)
abort ();
return 0;
}
/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen1" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen1" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen1" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen1" } } */
/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen1" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen1" } } */
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