src/liblzma/simple/ia64.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       ia64.c
   4 /// \brief      Filter for IA64 (Itanium) binaries
   5 ///
   6 //  Authors:    Igor Pavlov
   7 //              Lasse Collin
   8 //
   9 //  This file has been put into the public domain.
  10 //  You can do whatever you want with this file.
  11 //
  12 ///////////////////////////////////////////////////////////////////////////////
  13
  14 #include "simple_private.h"
  15
  16
  17 static size_t
  18 ia64_code(void *simple lzma_attribute((__unused__)),
  19                 uint32_t now_pos, bool is_encoder,
  20                 uint8_t *buffer, size_t size)
  21 {
  22         static const uint32_t BRANCH_TABLE[32] = {
  23                 0, 0, 0, 0, 0, 0, 0, 0,
  24                 0, 0, 0, 0, 0, 0, 0, 0,
  25                 4, 4, 6, 6, 0, 0, 7, 7,
  26                 4, 4, 0, 0, 4, 4, 0, 0
  27         };
  28
  29         size_t i;
  30         for (i = 0; i + 16 <= size; i += 16) {
  31                 const uint32_t instr_template = buffer[i] & 0x1F;
  32                 const uint32_t mask = BRANCH_TABLE[instr_template];
  33                 uint32_t bit_pos = 5;
  34
  35                 for (size_t slot = 0; slot < 3; ++slot, bit_pos += 41) {
  36                         if (((mask >> slot) & 1) == 0)
  37                                 continue;
  38
  39                         const size_t byte_pos = (bit_pos >> 3);
  40                         const uint32_t bit_res = bit_pos & 0x7;
  41                         uint64_t instruction = 0;
  42
  43                         for (size_t j = 0; j < 6; ++j)
  44                                 instruction += (uint64_t)(
  45                                                 buffer[i + j + byte_pos])
  46                                                 << (8 * j);
  47
  48                         uint64_t inst_norm = instruction >> bit_res;
  49
  50                         if (((inst_norm >> 37) & 0xF) == 0x5
  51                                         && ((inst_norm >> 9) & 0x7) == 0
  52                                         /* &&  (inst_norm & 0x3F)== 0 */
  53                                         ) {
  54                                 uint32_t src = (uint32_t)(
  55                                                 (inst_norm >> 13) & 0xFFFFF);
  56                                 src |= ((inst_norm >> 36) & 1) << 20;
  57
  58                                 src <<= 4;
  59
  60                                 uint32_t dest;
  61                                 if (is_encoder)
  62                                         dest = now_pos + (uint32_t)(i) + src;
  63                                 else
  64                                         dest = src - (now_pos + (uint32_t)(i));
  65
  66                                 dest >>= 4;
  67
  68                                 inst_norm &= ~((uint64_t)(0x8FFFFF) << 13);
  69                                 inst_norm |= (uint64_t)(dest & 0xFFFFF) << 13;
  70                                 inst_norm |= (uint64_t)(dest & 0x100000)
  71                                                 << (36 - 20);
  72
  73                                 instruction &= (1U << bit_res) - 1;
  74                                 instruction |= (inst_norm << bit_res);
  75
  76                                 for (size_t j = 0; j < 6; j++)
  77                                         buffer[i + j + byte_pos] = (uint8_t)(
  78                                                         instruction
  79                                                         >> (8 * j));
  80                         }
  81                 }
  82         }
  83
  84         return i;
  85 }
  86
  87
  88 static lzma_ret
  89 ia64_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
  90                 const lzma_filter_info *filters, bool is_encoder)
  91 {
  92         return lzma_simple_coder_init(next, allocator, filters,
  93                         &ia64_code, 0, 16, 16, is_encoder);
  94 }
  95
  96
  97 #ifdef HAVE_ENCODER_IA64
  98 extern lzma_ret
  99 lzma_simple_ia64_encoder_init(lzma_next_coder *next,
 100                 const lzma_allocator *allocator,
 101                 const lzma_filter_info *filters)
 102 {
 103         return ia64_coder_init(next, allocator, filters, true);
 104 }
 105 #endif
 106
 107
 108 #ifdef HAVE_DECODER_IA64
 109 extern lzma_ret
 110 lzma_simple_ia64_decoder_init(lzma_next_coder *next,
 111                 const lzma_allocator *allocator,
 112                 const lzma_filter_info *filters)
 113 {
 114         return ia64_coder_init(next, allocator, filters, false);
 115 }
 116 #endif