mirror of
https://github.com/google/brotli.git
synced 2024-11-23 04:00:05 +00:00
65f3fc55f5
* Fix an out-of-bounds access to depth_histo in the
bit cost calculation function.
* Change type of distance symbol to uint16_t in block
splitter, because if all postfix bits are used, there
can be 520 distance symbols.
* Save the distance cache between meta-blocks at the
correct place. This fixes a roundtrip failure that
can occur when there is an uncompressed metablock
between two compressed metablocks.
* Fix a bug when setting lgwin to 24 in the encoder parameters
It ended up making metablocks larger than 24 bits in size.
* Fix out-of-bounds memory accesses in parallel encoder.
CreateBackwardReferences can read up to 4 bytes past end of
input if the end of input is before mask.
* Add missing header for memcpy() in port.h
152 lines
4.4 KiB
C
152 lines
4.4 KiB
C
// Copyright 2013 Google Inc. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Macros for endianness, branch prediction and unaligned loads and stores.
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#ifndef BROTLI_ENC_PORT_H_
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#define BROTLI_ENC_PORT_H_
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#include <string.h>
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#if defined OS_LINUX || defined OS_CYGWIN
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#include <endian.h>
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#elif defined OS_FREEBSD
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#include <machine/endian.h>
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#elif defined OS_MACOSX
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#include <machine/endian.h>
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/* Let's try and follow the Linux convention */
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#define __BYTE_ORDER BYTE_ORDER
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#define __LITTLE_ENDIAN LITTLE_ENDIAN
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#define __BIG_ENDIAN BIG_ENDIAN
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#endif
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// define the macros IS_LITTLE_ENDIAN or IS_BIG_ENDIAN
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// using the above endian definitions from endian.h if
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// endian.h was included
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#ifdef __BYTE_ORDER
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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#define IS_LITTLE_ENDIAN
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#endif
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#if __BYTE_ORDER == __BIG_ENDIAN
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#define IS_BIG_ENDIAN
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#endif
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#else
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#if defined(__LITTLE_ENDIAN__)
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#define IS_LITTLE_ENDIAN
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#elif defined(__BIG_ENDIAN__)
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#define IS_BIG_ENDIAN
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#endif
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#endif // __BYTE_ORDER
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// Enable little-endian optimization for x64 architecture on Windows.
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#if (defined(_WIN32) || defined(_WIN64)) && defined(_M_X64)
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#define IS_LITTLE_ENDIAN
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#endif
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/* Compatibility with non-clang compilers. */
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#ifndef __has_builtin
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#define __has_builtin(x) 0
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#endif
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#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ > 95) || \
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(defined(__llvm__) && __has_builtin(__builtin_expect))
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#define PREDICT_FALSE(x) (__builtin_expect(x, 0))
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#define PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
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#else
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#define PREDICT_FALSE(x) (x)
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#define PREDICT_TRUE(x) (x)
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#endif
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// Portable handling of unaligned loads, stores, and copies.
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// On some platforms, like ARM, the copy functions can be more efficient
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// then a load and a store.
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#if defined(ARCH_PIII) || defined(ARCH_ATHLON) || \
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defined(ARCH_K8) || defined(_ARCH_PPC)
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// x86 and x86-64 can perform unaligned loads/stores directly;
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// modern PowerPC hardware can also do unaligned integer loads and stores;
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// but note: the FPU still sends unaligned loads and stores to a trap handler!
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#define BROTLI_UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32_t *>(_p))
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#define BROTLI_UNALIGNED_LOAD64(_p) (*reinterpret_cast<const uint64_t *>(_p))
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#define BROTLI_UNALIGNED_STORE32(_p, _val) \
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(*reinterpret_cast<uint32_t *>(_p) = (_val))
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#define BROTLI_UNALIGNED_STORE64(_p, _val) \
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(*reinterpret_cast<uint64_t *>(_p) = (_val))
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#elif defined(__arm__) && \
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!defined(__ARM_ARCH_5__) && \
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!defined(__ARM_ARCH_5T__) && \
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!defined(__ARM_ARCH_5TE__) && \
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!defined(__ARM_ARCH_5TEJ__) && \
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!defined(__ARM_ARCH_6__) && \
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!defined(__ARM_ARCH_6J__) && \
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!defined(__ARM_ARCH_6K__) && \
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!defined(__ARM_ARCH_6Z__) && \
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!defined(__ARM_ARCH_6ZK__) && \
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!defined(__ARM_ARCH_6T2__)
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// ARMv7 and newer support native unaligned accesses, but only of 16-bit
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// and 32-bit values (not 64-bit); older versions either raise a fatal signal,
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// do an unaligned read and rotate the words around a bit, or do the reads very
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// slowly (trip through kernel mode).
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#define BROTLI_UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32_t *>(_p))
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#define BROTLI_UNALIGNED_STORE32(_p, _val) \
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(*reinterpret_cast<uint32_t *>(_p) = (_val))
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inline uint64_t BROTLI_UNALIGNED_LOAD64(const void *p) {
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uint64_t t;
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memcpy(&t, p, sizeof t);
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return t;
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}
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inline void BROTLI_UNALIGNED_STORE64(void *p, uint64_t v) {
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memcpy(p, &v, sizeof v);
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}
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#else
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// These functions are provided for architectures that don't support
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// unaligned loads and stores.
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inline uint32_t BROTLI_UNALIGNED_LOAD32(const void *p) {
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uint32_t t;
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memcpy(&t, p, sizeof t);
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return t;
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}
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inline uint64_t BROTLI_UNALIGNED_LOAD64(const void *p) {
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uint64_t t;
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memcpy(&t, p, sizeof t);
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return t;
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}
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inline void BROTLI_UNALIGNED_STORE32(void *p, uint32_t v) {
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memcpy(p, &v, sizeof v);
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}
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inline void BROTLI_UNALIGNED_STORE64(void *p, uint64_t v) {
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memcpy(p, &v, sizeof v);
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}
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#endif
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#endif // BROTLI_ENC_PORT_H_
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