mirror of
https://github.com/VectorCamp/vectorscan.git
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85 lines
3.5 KiB
C
85 lines
3.5 KiB
C
/*
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* Copyright (c) 2015-2017, Intel Corporation
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* Copyright (c) 2021, Arm Limited
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of Intel Corporation nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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static really_inline
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size_t countMatches(svuint8_t chars, svbool_t pg, const u8 *buf) {
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svuint8_t vec = svld1_u8(pg, buf);
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return svcntp_b8(svptrue_b8(), svmatch(pg, vec, chars));
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}
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static really_inline
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bool countLoopBody(svuint8_t chars, svbool_t pg, const u8 *d,
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u32 target_count, u32 *count_inout, const u8 **d_out) {
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*count_inout += countMatches(chars, pg, d);
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if (*count_inout >= target_count) {
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*d_out = d;
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return true;
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}
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return false;
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}
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static really_inline
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bool countOnce(svuint8_t chars, const u8 *d, const u8 *d_end,
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u32 target_count, u32 *count_inout, const u8 **d_out) {
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assert(d <= d_end);
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svbool_t pg = svwhilelt_b8_s64(0, d_end - d);
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return countLoopBody(chars, pg, d, target_count, count_inout, d_out);
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}
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static really_inline
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bool roseCountingMiracleScan(u8 c, const u8 *d, const u8 *d_end,
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u32 target_count, u32 *count_inout,
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const u8 **d_out) {
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assert(d <= d_end);
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svuint8_t chars = svdup_u8(c);
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size_t len = d_end - d;
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if (len <= svcntb()) {
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bool rv = countOnce(chars, d, d_end, target_count, count_inout, d_out);
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return rv;
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}
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// peel off first part to align to the vector size
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const u8 *aligned_d_end = ROUNDDOWN_PTR(d_end, svcntb_pat(SV_POW2));
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assert(d < aligned_d_end);
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if (d_end != aligned_d_end) {
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if (countOnce(chars, aligned_d_end, d_end,
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target_count, count_inout, d_out)) return true;
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d_end = aligned_d_end;
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}
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size_t loops = (d_end - d) / svcntb();
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for (size_t i = 0; i < loops; i++) {
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d_end -= svcntb();
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if (countLoopBody(chars, svptrue_b8(), d_end,
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target_count, count_inout, d_out)) return true;
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}
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if (d != d_end) {
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if (countOnce(chars, d, d_end,
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target_count, count_inout, d_out)) return true;
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}
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return false;
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} |