src/liblzma/simple/ia64.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       ia64.c
   4 /// \brief      Filter for IA64 (Itanium) binaries
   5 //
   6 //  Copyright (C) 1999-2006 Igor Pavlov
   7 //  Copyright (C) 2007 Lasse Collin
   8 //
   9 //  This library is free software; you can redistribute it and/or
  10 //  modify it under the terms of the GNU Lesser General Public
  11 //  License as published by the Free Software Foundation; either
  12 //  version 2.1 of the License, or (at your option) any later version.
  13 //
  14 //  This library is distributed in the hope that it will be useful,
  15 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 //  Lesser General Public License for more details.
  18 //
  19 ///////////////////////////////////////////////////////////////////////////////
  20
  21 #include "simple_private.h"
  22
  23
  24 static size_t
  25 ia64_code(lzma_simple *simple lzma_attribute((unused)),
  26                 uint32_t now_pos, bool is_encoder,
  27                 uint8_t *buffer, size_t size)
  28 {
  29         static const uint32_t BRANCH_TABLE[32] = {
  30                 0, 0, 0, 0, 0, 0, 0, 0,
  31                 0, 0, 0, 0, 0, 0, 0, 0,
  32                 4, 4, 6, 6, 0, 0, 7, 7,
  33                 4, 4, 0, 0, 4, 4, 0, 0
  34         };
  35
  36         size_t i;
  37         for (i = 0; i + 16 <= size; i += 16) {
  38                 const uint32_t instr_template = buffer[i] & 0x1F;
  39                 const uint32_t mask = BRANCH_TABLE[instr_template];
  40                 uint32_t bit_pos = 5;
  41
  42                 for (size_t slot = 0; slot < 3; ++slot, bit_pos += 41) {
  43                         if (((mask >> slot) & 1) == 0)
  44                                 continue;
  45
  46                         const size_t byte_pos = (bit_pos >> 3);
  47                         const uint32_t bit_res = bit_pos & 0x7;
  48                         uint64_t instruction = 0;
  49
  50                         for (size_t j = 0; j < 6; ++j)
  51                                 instruction += (uint64_t)(
  52                                                 buffer[i + j + byte_pos])
  53                                                 << (8 * j);
  54
  55                         uint64_t inst_norm = instruction >> bit_res;
  56
  57                         if (((inst_norm >> 37) & 0xF) == 0x5
  58                                         && ((inst_norm >> 9) & 0x7) == 0
  59                                         /* &&  (inst_norm & 0x3F)== 0 */
  60                                         ) {
  61                                 uint32_t src = (uint32_t)(
  62                                                 (inst_norm >> 13) & 0xFFFFF);
  63                                 src |= ((inst_norm >> 36) & 1) << 20;
  64
  65                                 src <<= 4;
  66
  67                                 uint32_t dest;
  68                                 if (is_encoder)
  69                                         dest = now_pos + (uint32_t)(i) + src;
  70                                 else
  71                                         dest = src - (now_pos + (uint32_t)(i));
  72
  73                                 dest >>= 4;
  74
  75                                 inst_norm &= ~((uint64_t)(0x8FFFFF) << 13);
  76                                 inst_norm |= (uint64_t)(dest & 0xFFFFF) << 13;
  77                                 inst_norm |= (uint64_t)(dest & 0x100000)
  78                                                 << (36 - 20);
  79
  80                                 instruction &= (1 << bit_res) - 1;
  81                                 instruction |= (inst_norm << bit_res);
  82
  83                                 for (size_t j = 0; j < 6; j++)
  84                                         buffer[i + j + byte_pos] = (uint8_t)(
  85                                                         instruction
  86                                                         >> (8 * j));
  87                         }
  88                 }
  89         }
  90
  91         return i;
  92 }
  93
  94
  95 static lzma_ret
  96 ia64_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
  97                 const lzma_filter_info *filters, bool is_encoder)
  98 {
  99         return lzma_simple_coder_init(next, allocator, filters,
 100                         &ia64_code, 0, 4, is_encoder);
 101 }
 102
 103
 104 extern lzma_ret
 105 lzma_simple_ia64_encoder_init(lzma_next_coder *next,
 106                 lzma_allocator *allocator, const lzma_filter_info *filters)
 107 {
 108         return ia64_coder_init(next, allocator, filters, true);
 109 }
 110
 111
 112 extern lzma_ret
 113 lzma_simple_ia64_decoder_init(lzma_next_coder *next,
 114                 lzma_allocator *allocator, const lzma_filter_info *filters)
 115 {
 116         return ia64_coder_init(next, allocator, filters, false);
 117 }