129 lines
3.7 KiB
C++
129 lines
3.7 KiB
C++
/* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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#include "skip_trailing.h"
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namespace skip_trailing_space_unittest {
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/* SPACE_INT is a word that contains only spaces */
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#if SIZEOF_INT == 4
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static const unsigned SPACE_INT= 0x20202020U;
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#elif SIZEOF_INT == 8
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static const unsigned SPACE_INT= 0x2020202020202020ULL;
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#else
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#error define the appropriate constant for a word full of spaces
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#endif
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// A copy of the original version of skip_trailing_space
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const uchar *skip_trailing_orig(const uchar *ptr,size_t len)
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{
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const uchar *end= ptr + len;
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if (len > 20)
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{
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const uchar *end_words= (const uchar *)(intptr)
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(((ulonglong)(intptr)end) / SIZEOF_INT * SIZEOF_INT);
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const uchar *start_words= (const uchar *)(intptr)
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((((ulonglong)(intptr)ptr) + SIZEOF_INT - 1) / SIZEOF_INT * SIZEOF_INT);
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DBUG_ASSERT(((ulonglong)(intptr)ptr) >= SIZEOF_INT);
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if (end_words > ptr)
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{
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while (end > end_words && end[-1] == 0x20)
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end--;
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if (end[-1] == 0x20 && start_words < end_words)
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while (end > start_words && ((unsigned *)end)[-1] == SPACE_INT)
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end -= SIZEOF_INT;
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}
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}
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while (end > ptr && end[-1] == 0x20)
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end--;
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return (end);
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}
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// Read 8 bytes at a time, ignoring alignment.
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// We use uint8korr which is fast on all platforms, except sparc.
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const uchar *skip_trailing_unalgn(const uchar *ptr, size_t len)
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{
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const uchar *end= ptr + len;
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while (end - ptr >= 8)
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{
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if (uint8korr(end-8) != 0x2020202020202020ULL)
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break;
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end-= 8;
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}
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while (end > ptr && end[-1] == 0x20)
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end--;
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return (end);
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}
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// Same as the original, except we skip a test which is always true.
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const uchar *skip_trailing_4byte(const uchar *ptr, size_t len)
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{
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const uchar *end= ptr + len;
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if (len > 20)
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{
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const uchar *end_words= (const uchar *)(intptr)
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(((ulonglong)(intptr)end) / SIZEOF_INT * SIZEOF_INT);
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const uchar *start_words= (const uchar *)(intptr)
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((((ulonglong)(intptr)ptr) + SIZEOF_INT - 1) / SIZEOF_INT * SIZEOF_INT);
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DBUG_ASSERT(end_words > ptr);
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{
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while (end > end_words && end[-1] == 0x20)
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end--;
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if (end[-1] == 0x20 && start_words < end_words)
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while (end > start_words && ((unsigned *)end)[-1] == SPACE_INT)
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end -= SIZEOF_INT;
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}
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}
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while (end > ptr && end[-1] == 0x20)
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end--;
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return (end);
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}
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// Same as skip_trailing_4byte, except we read 8 bytes at a time (aligned).
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const uchar *skip_trailing_8byte(const uchar *ptr, size_t len)
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{
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const uchar *end= ptr + len;
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if (len > 20)
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{
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const uchar *end_words= (const uchar *)(longlong)
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(((ulonglong)(longlong)end) / 8 * 8);
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const uchar *start_words= (const uchar *)(longlong)
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((((ulonglong)(longlong)ptr) + 8 - 1) / 8 * 8);
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DBUG_ASSERT(end_words > ptr);
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{
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while (end > end_words && end[-1] == 0x20)
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end--;
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if (end[-1] == 0x20 && start_words < end_words)
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while (end > start_words &&
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((ulonglong *)end)[-1] == 0x2020202020202020ULL)
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end -= 8;
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}
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}
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while (end > ptr && end[-1] == 0x20)
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end--;
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return (end);
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}
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}
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