diff options
Diffstat (limited to 'newlib/libc/machine/spu/strncmp.c')
| -rw-r--r-- | newlib/libc/machine/spu/strncmp.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/newlib/libc/machine/spu/strncmp.c b/newlib/libc/machine/spu/strncmp.c new file mode 100644 index 000000000..0f5860903 --- /dev/null +++ b/newlib/libc/machine/spu/strncmp.c @@ -0,0 +1,131 @@ +/* + (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" + +/* 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. + */ + +int strncmp(const char *s1, const char *s2, size_t n) +{ + 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, end_v, neq_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 = VEC_SPLAT_U8(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_LITERAL(vec_uint4, 0x00010203, 0x04050607, 0x08090A0B, 0x0C0D0E0F)); + shuffle2 = (vec_uchar16)spu_add((vec_uint4)spu_splats((unsigned char)offset2), + VEC_LITERAL(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)); + + end1_v = spu_gather(spu_cmpeq(data1, 0)); + end2_v = spu_gather(spu_cmpeq(data2, 0)); + end_v = spu_or(end1_v, end2_v), 0; + + n_v = spu_add(n_v, -16); + + /* Repeat until either + * 1) the character count expired, + * 2) a null character is discovered in one of the input strings, or + * 3) the strings do not compare equal. + */ + } while (spu_extract(spu_and(spu_cmpeq(spu_or(end_v, neq_v), 0), spu_cmpgt(n_v, 0)), 0)); + + /* Construct a mask to eliminate characters that are not of interest + * in the comparison. Theses include characters that are beyond the + * n character count and beyond the first null character. + */ + 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)); + + 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)); + 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); + + /* 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). + */ + 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)); +} |