Viewing file:  StrIntUtilsNoStrictAliasing.cpp (7.53 KB) -rw-r--r--
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/*
* Phusion Passenger - https://www.phusionpassenger.com/
* Copyright (c) 2014-2018 Phusion Holding B.V.
*
* "Passenger", "Phusion Passenger" and "Union Station" are registered
* trademarks of Phusion Holding B.V.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <boost/cstdint.hpp>
#include <cstddef>
#include <oxt/macros.hpp>
#include <StrIntTools/StrIntUtils.h>
namespace Passenger {
using namespace std;
// This file implements StrIntUtils functions that violate strict aliasing
// in order to gain more performance.
#if defined(__x86_64__) || defined(__x86__)
OXT_NO_SANITIZE("undefined")
void
convertLowerCase(const unsigned char * restrict data,
unsigned char * restrict output,
size_t len)
{
/*
* Parts of this function is taken from stringencoders and modified to add
* 64-bit support. https://code.google.com/p/stringencoders/
*
* Copyright 2005, 2006, 2007
* Nick Galbreath -- nickg [at] modp [dot] com
* 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 name of the modp.com nor the names of its
* 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.
*
* This is the standard "new" BSD license:
* http://www.opensource.org/licenses/bsd-license.php
*/
static const boost::uint8_t gsToLowerMap[256] = {
'\0', 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, '\t',
'\n', 0x0b, 0x0c, '\r', 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
0x1e, 0x1f, ' ', '!', '"', '#', '$', '%', '&', '\'',
'(', ')', '*', '+', ',', '-', '.', '/', '0', '1',
'2', '3', '4', '5', '6', '7', '8', '9', ':', ';',
'<', '=', '>', '?', '@', 'a', 'b', 'c', 'd', 'e',
'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y',
'z', '[', '\\', ']', '^', '_', '`', 'a', 'b', 'c',
'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', '{', '|', '}', '~', 0x7f, 0x80, 0x81,
0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b,
0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9,
0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3,
0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd,
0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1,
0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb,
0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5,
0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9,
0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
};
#if defined(__x86_64__)
size_t i;
boost::uint64_t eax, ebx;
const boost::uint8_t *ustr = (const boost::uint8_t *) data;
const size_t leftover = len % 8;
const size_t imax = len / 8;
const boost::uint64_t *s = (const boost::uint64_t *) data;
boost::uint64_t *d = (boost::uint64_t *) output;
for (i = 0; i != imax; ++i) {
eax = s[i];
/*
* This is based on the algorithm by Paul Hsieh
* http://www.azillionmonkeys.com/qed/asmexample.html
*/
ebx = (0x7f7f7f7f7f7f7f7fu & eax) + 0x2525252525252525u;
ebx = (0x7f7f7f7f7f7f7f7fu & ebx) + 0x1a1a1a1a1a1a1a1au;
ebx = ((ebx & ~eax) >> 2) & 0x2020202020202020u;
*d++ = eax + ebx;
}
i = imax * 8;
output = (unsigned char *) d;
switch (leftover) {
case 7: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 6: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 5: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 4: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 3: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 2: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 1: *output++ = (unsigned char) gsToLowerMap[ustr[i]]; /* Falls through. */
case 0: break;
}
#elif defined(__x86__)
size_t i;
boost::uint32_t eax, ebx;
const boost::uint8_t *ustr = (const boost::uint8_t *) data;
const size_t leftover = len % 4;
const size_t imax = len / 4;
const boost::uint32_t *s = (const boost::uint32_t *) data;
boost::uint32_t *d = (boost::uint32_t *) output;
for (i = 0; i != imax; ++i) {
eax = s[i];
/*
* This is based on the algorithm by Paul Hsieh
* http://www.azillionmonkeys.com/qed/asmexample.html
*/
ebx = (0x7f7f7f7fu & eax) + 0x525252525u;
ebx = (0x7f7f7f7fu & ebx) + 0x1a1a1a1au;
ebx = ((ebx & ~eax) >> 2) & 0x20202020u;
*d++ = eax + ebx;
}
i = imax * 4;
output = (unsigned char *) d;
switch (leftover) {
case 3: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 2: *output++ = (unsigned char) gsToLowerMap[ustr[i++]]; /* Falls through. */
case 1: *output++ = (unsigned char) gsToLowerMap[ustr[i]]; /* Falls through. */
case 0: break;
}
#else
#error "Unsupported architecture"
#endif
}
#endif
} // namespace Passenger
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