| /* |
| (C) Copyright 2001,2006,2008 |
| 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> |
| |
| /* |
| * Internal _strncmp_internal for strncmp and memcmp: |
| * |
| * Compare the two strings s1 and s2 of length n. Returns an integer less |
| * than, equal to, or greater than zero if s1 is found, respectively, |
| * to be less than, to match, or be greater than s2. Check for zero bytes |
| * only if check_zeroes is set. In additin, the vector value *end_v will |
| * contain all zeroes if we hit a NUL character that caused the comparison |
| * to complete, *end_v is modified only if check_zeroes is set. |
| */ |
| static inline int |
| _strncmp_internal(const char *s1, const char *s2, size_t n, vec_uint4 |
| *end_v, int check_zeroes) |
| { |
| unsigned int offset1, offset2; |
| vec_int4 n_v; |
| vec_uint4 cnt1_v, cnt2_v, max_cnt_v; |
| vec_uint4 gt_v, lt_v, mask_v, end1_v, end2_v, neq_v, tmp1_v; |
| vec_uint4 shift_n_v, shift_eos_v, max_shift_v; |
| vec_uchar16 shuffle1, shuffle2; |
| vec_uchar16 data1A, data1B, data1, data2A, data2B, data2; |
| vec_uchar16 *ptr1, *ptr2; |
| |
| data1 = data2 = spu_splats((unsigned char)0); |
| |
| ptr1 = (vec_uchar16 *)s1; |
| ptr2 = (vec_uchar16 *)s2; |
| |
| offset1 = (unsigned int)(ptr1) & 15; |
| offset2 = (unsigned int)(ptr2) & 15; |
| |
| shuffle1 = (vec_uchar16) |
| spu_add((vec_uint4)spu_splats((unsigned char)offset1), |
| ((vec_uint4) {0x00010203, 0x04050607, 0x08090A0B, 0x0C0D0E0F})); |
| shuffle2 = (vec_uchar16) |
| spu_add((vec_uint4)spu_splats((unsigned char)offset2), |
| ((vec_uint4) {0x00010203, 0x04050607, 0x08090A0B, 0x0C0D0E0F})); |
| data1A = *ptr1++; |
| data2A = *ptr2++; |
| |
| n_v = spu_promote((int)n, 0); |
| |
| do { |
| data1B = *ptr1++; |
| data2B = *ptr2++; |
| |
| /* |
| * Quadword align each of the input strings so that we operate on full |
| * quadwords. |
| */ |
| data1 = spu_shuffle(data1A, data1B, shuffle1); |
| data2 = spu_shuffle(data2A, data2B, shuffle2); |
| |
| data1A = data1B; |
| data2A = data2B; |
| |
| neq_v = spu_gather(spu_xor(spu_cmpeq(data1, data2), -1)); |
| |
| if (check_zeroes) { |
| end1_v = spu_gather(spu_cmpeq(data1, 0)); |
| end2_v = spu_gather(spu_cmpeq(data2, 0)); |
| *end_v = spu_or(end1_v, end2_v); |
| } |
| |
| n_v = spu_add(n_v, -16); |
| |
| /* |
| * Repeat until either |
| * 1) the character count expired |
| * 2) check_zeroes is set and a null character is discovered in one of |
| * the input strings |
| * 3) the strings do not compare equal |
| */ |
| if (check_zeroes) { |
| tmp1_v = spu_or(*end_v, neq_v); |
| tmp1_v = spu_cmpeq(tmp1_v, 0); |
| } else { |
| tmp1_v = spu_cmpeq(neq_v, 0); |
| } |
| tmp1_v = spu_and(tmp1_v, spu_cmpgt(n_v, 0)); |
| } while (spu_extract(tmp1_v, 0)); |
| |
| /* |
| * Construct a mask to eliminate characters that are not of interest |
| * in the comparison. |
| */ |
| mask_v = spu_splats((unsigned int)0xFFFF); |
| shift_n_v = |
| spu_andc((__vector unsigned int)spu_sub(0, n_v), spu_cmpgt(n_v, -1)); |
| if (check_zeroes) { |
| cnt1_v = spu_cntlz(end1_v); |
| cnt2_v = spu_cntlz(end2_v); |
| max_cnt_v = spu_sel(cnt1_v, cnt2_v, spu_cmpgt(cnt2_v, cnt1_v)); |
| shift_eos_v = spu_sub(32, max_cnt_v); |
| max_shift_v = |
| spu_sel(shift_n_v, shift_eos_v, spu_cmpgt(shift_eos_v, shift_n_v)); |
| mask_v = spu_and(spu_sl(mask_v, spu_extract(max_shift_v, 0)), mask_v); |
| } else { |
| mask_v = spu_and(spu_sl(mask_v, spu_extract(shift_n_v, 0)), mask_v); |
| } |
| |
| /* |
| * Determine if greater then or less then in the case that they are |
| * not equal. gt_v is either 1 (in the case s1 is greater then s2), or |
| * -1 (in the case that s2 is greater then s1). |
| * |
| * There are no byte vector math instructions, so we can't subtract |
| * data1 from data2. |
| */ |
| gt_v = spu_gather(spu_cmpgt(data1, data2)); |
| lt_v = spu_gather(spu_cmpgt(data2, data1)); |
| gt_v = spu_sub(-1, spu_sl(spu_cmpgt(gt_v, lt_v), 1)); |
| |
| /* |
| * Construct a mask to be applied to gt_v if the strings are discovered |
| * to be equal. |
| */ |
| mask_v = spu_cmpeq(spu_and(neq_v, mask_v), 0); |
| return (spu_extract(spu_andc(gt_v, mask_v), 0)); |
| } |