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/* $Id: ffs-1.c,v 1.1 2007/02/06 12:29:21 dmix Exp $ */
#include <stdlib.h>
#include <string.h>
int main ()
{
static struct t_s {
int val;
unsigned char pattern;
} t[] = {
{ 0, 0 },
{ 1, 1 },
{ 0xffff, 1 },
{ 0x0002, 2 },
{ 0x8002, 2 },
{ 0xfff2, 2 },
{ 0x0040, 7 },
{ 0x0140, 7 },
{ 0x0080, 8 },
{ 0xff80, 8 },
{ 0x0100, 9 },
{ 0xff00, 9 },
{ 0x8000, 16 },
};
volatile int vx;
int i;
/* Possibly, this is an inline substitution. */
for (i = 0; i != (int)(sizeof(t)/sizeof(t[0])); i++) {
if (ffs(t[i].val) != t[i].pattern)
exit (1 + i);
}
/* Force a function call (against inline substitution). */
for (i = 0; i != (int)(sizeof(t)/sizeof(t[0])); i++) {
int (* volatile vffs)(int) = ffs;
if (vffs(t[i].val) != t[i].pattern)
exit (101 + i);
}
/* Side effects? */
vx = 7;
if (ffs(++vx) != 4 || vx != 8)
exit (__LINE__);
vx = 16;
if (ffs(vx++) != 5 || vx != 17)
exit (__LINE__);
vx = 127;
if (ffs(ffs(++vx)) != 4 || vx != 128)
exit (__LINE__);
/* Implicit check */
vx = 1;
if (__builtin_constant_p(++vx) || __builtin_constant_p(vx = -1))
exit (__LINE__);
if (vx != 1)
exit (__LINE__);
return 0;
}
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