2c96639eb2
From a logcat profile:
```
|--95.06%-- convertPrintable(char*, char const*, unsigned long)
| |--13.95%-- [hit in function]
| |
| |--35.96%-- mbrtoc32
| | |--82.72%-- [hit in function]
| | |
| | |--11.07%-- mbsinit
| | |
| | |--5.96%-- @plt
```
I think we'd assumed that mbsinit() would be inlined, but since these
functions aren't all in wchar.cpp it wasn't being. This change moves the
implementation into a (more clearly named) inline function so we can
trivially reclaim that 11%+6%.
Benchmarks before:
```
-------------------------------------------------------------------
Benchmark Time CPU Iterations
-------------------------------------------------------------------
BM_stdlib_mbrtowc_1 8.03 ns 7.95 ns 87144997
BM_stdlib_mbrtowc_2 22.0 ns 21.8 ns 32002437
BM_stdlib_mbrtowc_3 30.0 ns 29.7 ns 23517699
BM_stdlib_mbrtowc_4 37.4 ns 37.1 ns 18895204
BM_stdlib_mbstowcs_ascii 792373 ns 782484 ns 890 bytes_per_second=609.389M/s
BM_stdlib_mbstowcs_wide 15836785 ns 15678316 ns 44 bytes_per_second=30.4138M/s
```
Benchmarks after:
```
-------------------------------------------------------------------
Benchmark Time CPU Iterations
-------------------------------------------------------------------
BM_stdlib_mbrtowc_1 5.76 ns 5.72 ns 121863813
BM_stdlib_mbrtowc_2 17.1 ns 16.9 ns 41487260
BM_stdlib_mbrtowc_3 24.2 ns 24.0 ns 29141629
BM_stdlib_mbrtowc_4 30.3 ns 30.1 ns 23229291
BM_stdlib_mbstowcs_ascii 783506 ns 775389 ns 903 bytes_per_second=614.965M/s
BM_stdlib_mbstowcs_wide 12787003 ns 12672642 ns 55 bytes_per_second=37.6273M/s
```
Bug: http://b/206523398
Test: treehugger
Change-Id: If8c6c39880096ddd2cbd323c68dca82e9849ace6
97 lines
3.2 KiB
C++
97 lines
3.2 KiB
C++
/*
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* Copyright (C) 2014 The Android Open Source Project
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* All rights reserved.
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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
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, 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
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <errno.h>
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#include <uchar.h>
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#include <wchar.h>
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#include "private/bionic_mbstate.h"
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size_t c32rtomb(char* s, char32_t c32, mbstate_t* ps) {
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static mbstate_t __private_state;
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mbstate_t* state = (ps == nullptr) ? &__private_state : ps;
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if (s == nullptr) {
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// Equivalent to c32rtomb(buf, U'\0', ps).
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return mbstate_reset_and_return(1, state);
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}
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// POSIX states that if char32_t is a null wide character, a null byte shall
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// be stored, preceded by any shift sequence needed to restore the initial
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// shift state. Since shift states are not supported, only the null byte is
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// stored.
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if (c32 == U'\0') {
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*s = '\0';
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return mbstate_reset_and_return(1, state);
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}
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if (!mbstate_is_initial(state)) {
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return mbstate_reset_and_return_illegal(EILSEQ, state);
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}
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if ((c32 & ~0x7f) == 0) {
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// Fast path for plain ASCII characters.
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*s = c32;
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return 1;
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}
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// Determine the number of octets needed to represent this character.
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// We always output the shortest sequence possible. Also specify the
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// first few bits of the first octet, which contains the information
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// about the sequence length.
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uint8_t lead;
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size_t length;
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if ((c32 & ~0x7f) == 0) {
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lead = 0;
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length = 1;
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} else if ((c32 & ~0x7ff) == 0) {
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lead = 0xc0;
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length = 2;
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} else if ((c32 & ~0xffff) == 0) {
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lead = 0xe0;
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length = 3;
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} else if ((c32 & ~0x1fffff) == 0) {
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lead = 0xf0;
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length = 4;
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} else {
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errno = EILSEQ;
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return __MB_ERR_ILLEGAL_SEQUENCE;
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}
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// Output the octets representing the character in chunks
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// of 6 bits, least significant last. The first octet is
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// a special case because it contains the sequence length
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// information.
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for (size_t i = length - 1; i > 0; i--) {
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s[i] = (c32 & 0x3f) | 0x80;
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c32 >>= 6;
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}
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*s = (c32 & 0xff) | lead;
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return length;
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}
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