xref: /freebsd/contrib/xz/src/liblzma/simple/ia64.c (revision a831d7d1c538b93ffec095657d9a6e6e778db195)
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(lzma_simple *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 &= (1 << 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 extern lzma_ret
98 lzma_simple_ia64_encoder_init(lzma_next_coder *next,
99 		const lzma_allocator *allocator,
100 		const lzma_filter_info *filters)
101 {
102 	return ia64_coder_init(next, allocator, filters, true);
103 }
104 
105 
106 extern lzma_ret
107 lzma_simple_ia64_decoder_init(lzma_next_coder *next,
108 		const lzma_allocator *allocator,
109 		const lzma_filter_info *filters)
110 {
111 	return ia64_coder_init(next, allocator, filters, false);
112 }
113