| Index: xz/src/liblzma/simple/x86.c
|
| ===================================================================
|
| --- xz/src/liblzma/simple/x86.c (revision 0)
|
| +++ xz/src/liblzma/simple/x86.c (revision 0)
|
| @@ -0,0 +1,154 @@
|
| +///////////////////////////////////////////////////////////////////////////////
|
| +//
|
| +/// \file x86.c
|
| +/// \brief Filter for x86 binaries (BCJ filter)
|
| +///
|
| +// Authors: Igor Pavlov
|
| +// Lasse Collin
|
| +//
|
| +// This file has been put into the public domain.
|
| +// You can do whatever you want with this file.
|
| +//
|
| +///////////////////////////////////////////////////////////////////////////////
|
| +
|
| +#include "simple_private.h"
|
| +
|
| +
|
| +#define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)
|
| +
|
| +
|
| +struct lzma_simple_s {
|
| + uint32_t prev_mask;
|
| + uint32_t prev_pos;
|
| +};
|
| +
|
| +
|
| +static size_t
|
| +x86_code(lzma_simple *simple, uint32_t now_pos, bool is_encoder,
|
| + uint8_t *buffer, size_t size)
|
| +{
|
| + static const bool MASK_TO_ALLOWED_STATUS[8]
|
| + = { true, true, true, false, true, false, false, false };
|
| +
|
| + static const uint32_t MASK_TO_BIT_NUMBER[8]
|
| + = { 0, 1, 2, 2, 3, 3, 3, 3 };
|
| +
|
| + uint32_t prev_mask = simple->prev_mask;
|
| + uint32_t prev_pos = simple->prev_pos;
|
| +
|
| + if (size < 5)
|
| + return 0;
|
| +
|
| + if (now_pos - prev_pos > 5)
|
| + prev_pos = now_pos - 5;
|
| +
|
| + const size_t limit = size - 5;
|
| + size_t buffer_pos = 0;
|
| +
|
| + while (buffer_pos <= limit) {
|
| + uint8_t b = buffer[buffer_pos];
|
| + if (b != 0xE8 && b != 0xE9) {
|
| + ++buffer_pos;
|
| + continue;
|
| + }
|
| +
|
| + const uint32_t offset = now_pos + (uint32_t)(buffer_pos)
|
| + - prev_pos;
|
| + prev_pos = now_pos + (uint32_t)(buffer_pos);
|
| +
|
| + if (offset > 5) {
|
| + prev_mask = 0;
|
| + } else {
|
| + for (uint32_t i = 0; i < offset; ++i) {
|
| + prev_mask &= 0x77;
|
| + prev_mask <<= 1;
|
| + }
|
| + }
|
| +
|
| + b = buffer[buffer_pos + 4];
|
| +
|
| + if (Test86MSByte(b)
|
| + && MASK_TO_ALLOWED_STATUS[(prev_mask >> 1) & 0x7]
|
| + && (prev_mask >> 1) < 0x10) {
|
| +
|
| + uint32_t src = ((uint32_t)(b) << 24)
|
| + | ((uint32_t)(buffer[buffer_pos + 3]) << 16)
|
| + | ((uint32_t)(buffer[buffer_pos + 2]) << 8)
|
| + | (buffer[buffer_pos + 1]);
|
| +
|
| + uint32_t dest;
|
| + while (true) {
|
| + if (is_encoder)
|
| + dest = src + (now_pos + (uint32_t)(
|
| + buffer_pos) + 5);
|
| + else
|
| + dest = src - (now_pos + (uint32_t)(
|
| + buffer_pos) + 5);
|
| +
|
| + if (prev_mask == 0)
|
| + break;
|
| +
|
| + const uint32_t i = MASK_TO_BIT_NUMBER[
|
| + prev_mask >> 1];
|
| +
|
| + b = (uint8_t)(dest >> (24 - i * 8));
|
| +
|
| + if (!Test86MSByte(b))
|
| + break;
|
| +
|
| + src = dest ^ ((1 << (32 - i * 8)) - 1);
|
| + }
|
| +
|
| + buffer[buffer_pos + 4]
|
| + = (uint8_t)(~(((dest >> 24) & 1) - 1));
|
| + buffer[buffer_pos + 3] = (uint8_t)(dest >> 16);
|
| + buffer[buffer_pos + 2] = (uint8_t)(dest >> 8);
|
| + buffer[buffer_pos + 1] = (uint8_t)(dest);
|
| + buffer_pos += 5;
|
| + prev_mask = 0;
|
| +
|
| + } else {
|
| + ++buffer_pos;
|
| + prev_mask |= 1;
|
| + if (Test86MSByte(b))
|
| + prev_mask |= 0x10;
|
| + }
|
| + }
|
| +
|
| + simple->prev_mask = prev_mask;
|
| + simple->prev_pos = prev_pos;
|
| +
|
| + return buffer_pos;
|
| +}
|
| +
|
| +
|
| +static lzma_ret
|
| +x86_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
|
| + const lzma_filter_info *filters, bool is_encoder)
|
| +{
|
| + const lzma_ret ret = lzma_simple_coder_init(next, allocator, filters,
|
| + &x86_code, sizeof(lzma_simple), 5, 1, is_encoder);
|
| +
|
| + if (ret == LZMA_OK) {
|
| + next->coder->simple->prev_mask = 0;
|
| + next->coder->simple->prev_pos = (uint32_t)(-5);
|
| + }
|
| +
|
| + return ret;
|
| +}
|
| +
|
| +
|
| +extern lzma_ret
|
| +lzma_simple_x86_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
|
| + const lzma_filter_info *filters)
|
| +{
|
| + return x86_coder_init(next, allocator, filters, true);
|
| +}
|
| +
|
| +
|
| +extern lzma_ret
|
| +lzma_simple_x86_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
|
| + const lzma_filter_info *filters)
|
| +{
|
| + return x86_coder_init(next, allocator, filters, false);
|
| +}
|
|
|
| Property changes on: xz/src/liblzma/simple/x86.c
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|