int main(int argc, char **argv) {
int i;
vector unsigned int all_ones = (vector unsigned int)
{0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF};
vector unsigned int all_zeroes = (vector unsigned int)
{0x00000000, 0x00000000, 0x00000000, 0x00000000};
/* These bits will form the selection mask */
unsigned short mask = 0x9;
/* Each bit in 0x9 forms a word in the mask */
vector unsigned int resultw =
spu_sel(all_zeroes, all_ones, spu_maskw(mask));
printf("resultw: ");
for (i=0; i<4; i++) {
printf("%08x", spu_extract(resultw, i));
}
/* Each bit in 0x09 forms a halfword in the mask */
vector unsigned short resulth =
spu_sel((vector unsigned short)all_zeroes,
(vector unsigned short)all_ones,
spu_maskh(mask));
printf("\nresulth: ");
for (i=0; i<8; i++) {
printf("%04x", spu_extract(resulth, i));
}
/* Each bit in 0x0009 forms a byte in the mask */
vector unsigned char resultb =
spu_sel((vector unsigned char)all_zeroes,
(vector unsigned char)all_ones,
spu_maskb(mask));
printf("\nresultb: ");
for (i=0; i<16; i++) {
printf("%02x", spu_extract(resultb, i));
}
printf("\n");
return 0;
}
/* Scans the string pointed to by s for the character c and
* returns a pointer to the last occurance of c. If
* c is not found, then NULL is returned.
*/
char * strrchr(const char *s, int c)
{
int nskip;
vec_uchar16 *ptr, data, vc;
vec_uint4 cmp_c, cmp_0, cmp;
vec_uint4 res_ptr, res_cmp;
vec_uint4 mask, result;
vec_uint4 one = spu_splats(0xffffU);
/* Scan memory array a quadword at a time. Skip leading
* mis-aligned bytes.
*/
ptr = (vec_uchar16 *)s;
nskip = -((unsigned int)(ptr) & 15);
mask = spu_rlmask(one, nskip);
vc = spu_splats((unsigned char)(c));
data = *ptr++;
ptr = (vec_uchar16 *)((unsigned int)ptr & ~15);
cmp_c = spu_and(spu_gather(spu_cmpeq(data, vc)), mask);
cmp_0 = spu_and(spu_gather(spu_cmpeq(data, 0)), mask);
res_ptr = spu_splats(0U);
res_cmp = spu_splats(0U);
while (spu_extract(cmp_0, 0) == 0) {
cmp = spu_cmpeq(cmp_c, 0);
res_ptr = spu_sel(spu_promote((unsigned int)(ptr), 0), res_ptr, cmp);
res_cmp = spu_sel(cmp_c, res_cmp, cmp);
data = *ptr++;
cmp_c = spu_gather(spu_cmpeq(data, vc));
cmp_0 = spu_gather(spu_cmpeq(data, 0));
cmp = spu_cmpeq(cmp_c, 0);
}
/* Compute the location of the last character before termination
* character.
*
* First mask off compare results following the first termination character.
*/
mask = spu_sl(one, 31 - spu_extract(spu_cntlz(cmp_0), 0));
cmp_c = spu_and(cmp_c, mask);
/* Conditionally update res_ptr and res_cmd if a match was found in the last
* quadword.
*/
cmp = spu_cmpeq(cmp_c, 0);
res_ptr = spu_sel(spu_promote((unsigned int)(ptr), 0), res_ptr, cmp);
res_cmp = spu_sel(cmp_c, res_cmp, cmp);
/* Bit reserve res_cmp for locating last occurance.
*/
mask = spu_cmpeq(res_cmp, 0);
res_cmp = (vec_uint4)spu_maskb(spu_extract(res_cmp, 0));
res_cmp = spu_gather((vec_uchar16)spu_shuffle(res_cmp, res_cmp,
VEC_LITERAL(vec_uchar16,
15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)));
/* Compute the location (ptr) of the last occurance of c. If no
* occurance was found (ie, element 0 of res_cmp == 0, then return
* NULL.
*/
result = spu_sub(spu_add(res_ptr, 15), spu_cntlz(res_cmp));
result = spu_andc(result, mask);
return ((char *)spu_extract(result, 0));
}
