diff options
Diffstat (limited to 'Utilities/cmzstd/lib/common/bitstream.h')
| -rw-r--r-- | Utilities/cmzstd/lib/common/bitstream.h | 77 |
1 files changed, 38 insertions, 39 deletions
diff --git a/Utilities/cmzstd/lib/common/bitstream.h b/Utilities/cmzstd/lib/common/bitstream.h index d955bd6..37b99c0 100644 --- a/Utilities/cmzstd/lib/common/bitstream.h +++ b/Utilities/cmzstd/lib/common/bitstream.h @@ -1,35 +1,15 @@ /* ****************************************************************** - bitstream - Part of FSE library - Copyright (C) 2013-present, Yann Collet. - - BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) - - 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. - - 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. - - You can contact the author at : - - Source repository : https://github.com/Cyan4973/FiniteStateEntropy + * bitstream + * Part of FSE library + * Copyright (c) 2013-2020, Yann Collet, Facebook, Inc. + * + * You can contact the author at : + * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. ****************************************************************** */ #ifndef BITSTREAM_H_MODULE #define BITSTREAM_H_MODULE @@ -48,6 +28,7 @@ extern "C" { * Dependencies ******************************************/ #include "mem.h" /* unaligned access routines */ +#include "compiler.h" /* UNLIKELY() */ #include "debug.h" /* assert(), DEBUGLOG(), RAWLOG() */ #include "error_private.h" /* error codes and messages */ @@ -57,6 +38,8 @@ extern "C" { =========================================*/ #if defined(__BMI__) && defined(__GNUC__) # include <immintrin.h> /* support for bextr (experimental) */ +#elif defined(__ICCARM__) +# include <intrinsics.h> #endif #define STREAM_ACCUMULATOR_MIN_32 25 @@ -159,10 +142,11 @@ MEM_STATIC unsigned BIT_highbit32 (U32 val) { # if defined(_MSC_VER) /* Visual */ unsigned long r=0; - _BitScanReverse ( &r, val ); - return (unsigned) r; + return _BitScanReverse ( &r, val ) ? (unsigned)r : 0; # elif defined(__GNUC__) && (__GNUC__ >= 3) /* Use GCC Intrinsic */ - return 31 - __builtin_clz (val); + return __builtin_clz (val) ^ 31; +# elif defined(__ICCARM__) /* IAR Intrinsic */ + return 31 - __CLZ(val); # else /* Software version */ static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, @@ -240,9 +224,9 @@ MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC) { size_t const nbBytes = bitC->bitPos >> 3; assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8); + assert(bitC->ptr <= bitC->endPtr); MEM_writeLEST(bitC->ptr, bitC->bitContainer); bitC->ptr += nbBytes; - assert(bitC->ptr <= bitC->endPtr); bitC->bitPos &= 7; bitC->bitContainer >>= nbBytes*8; } @@ -256,6 +240,7 @@ MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC) { size_t const nbBytes = bitC->bitPos >> 3; assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8); + assert(bitC->ptr <= bitC->endPtr); MEM_writeLEST(bitC->ptr, bitC->bitContainer); bitC->ptr += nbBytes; if (bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr; @@ -406,6 +391,23 @@ MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits) return value; } +/*! BIT_reloadDStreamFast() : + * Similar to BIT_reloadDStream(), but with two differences: + * 1. bitsConsumed <= sizeof(bitD->bitContainer)*8 must hold! + * 2. Returns BIT_DStream_overflow when bitD->ptr < bitD->limitPtr, at this + * point you must use BIT_reloadDStream() to reload. + */ +MEM_STATIC BIT_DStream_status BIT_reloadDStreamFast(BIT_DStream_t* bitD) +{ + if (UNLIKELY(bitD->ptr < bitD->limitPtr)) + return BIT_DStream_overflow; + assert(bitD->bitsConsumed <= sizeof(bitD->bitContainer)*8); + bitD->ptr -= bitD->bitsConsumed >> 3; + bitD->bitsConsumed &= 7; + bitD->bitContainer = MEM_readLEST(bitD->ptr); + return BIT_DStream_unfinished; +} + /*! BIT_reloadDStream() : * Refill `bitD` from buffer previously set in BIT_initDStream() . * This function is safe, it guarantees it will not read beyond src buffer. @@ -417,10 +419,7 @@ MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD) return BIT_DStream_overflow; if (bitD->ptr >= bitD->limitPtr) { - bitD->ptr -= bitD->bitsConsumed >> 3; - bitD->bitsConsumed &= 7; - bitD->bitContainer = MEM_readLEST(bitD->ptr); - return BIT_DStream_unfinished; + return BIT_reloadDStreamFast(bitD); } if (bitD->ptr == bitD->start) { if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer; |