| /* |
| (C) Copyright 2001,2006, |
| International Business Machines Corporation, |
| Sony Computer Entertainment, Incorporated, |
| Toshiba Corporation, |
| |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| |
| * Redistributions of source code must retain the above copyright notice, |
| this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the names of the copyright holders nor the names of their |
| contributors may be used to endorse or promote products derived from this |
| software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. |
| */ |
| #include <spu_intrinsics.h> |
| #include <stddef.h> |
| #include "vec_literal.h" |
| |
| /* 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)); |
| } |