xref: /freebsd/contrib/xz/src/liblzma/simple/ia64.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 // SPDX-License-Identifier: 0BSD
2 
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file       ia64.c
6 /// \brief      Filter for IA64 (Itanium) binaries
7 ///
8 //  Authors:    Igor Pavlov
9 //              Lasse Collin
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12 
13 #include "simple_private.h"
14 
15 
16 static size_t
17 ia64_code(void *simple lzma_attribute((__unused__)),
18 		uint32_t now_pos, bool is_encoder,
19 		uint8_t *buffer, size_t size)
20 {
21 	static const uint32_t BRANCH_TABLE[32] = {
22 		0, 0, 0, 0, 0, 0, 0, 0,
23 		0, 0, 0, 0, 0, 0, 0, 0,
24 		4, 4, 6, 6, 0, 0, 7, 7,
25 		4, 4, 0, 0, 4, 4, 0, 0
26 	};
27 
28 	size_t i;
29 	for (i = 0; i + 16 <= size; i += 16) {
30 		const uint32_t instr_template = buffer[i] & 0x1F;
31 		const uint32_t mask = BRANCH_TABLE[instr_template];
32 		uint32_t bit_pos = 5;
33 
34 		for (size_t slot = 0; slot < 3; ++slot, bit_pos += 41) {
35 			if (((mask >> slot) & 1) == 0)
36 				continue;
37 
38 			const size_t byte_pos = (bit_pos >> 3);
39 			const uint32_t bit_res = bit_pos & 0x7;
40 			uint64_t instruction = 0;
41 
42 			for (size_t j = 0; j < 6; ++j)
43 				instruction += (uint64_t)(
44 						buffer[i + j + byte_pos])
45 						<< (8 * j);
46 
47 			uint64_t inst_norm = instruction >> bit_res;
48 
49 			if (((inst_norm >> 37) & 0xF) == 0x5
50 					&& ((inst_norm >> 9) & 0x7) == 0
51 					/* &&  (inst_norm & 0x3F)== 0 */
52 					) {
53 				uint32_t src = (uint32_t)(
54 						(inst_norm >> 13) & 0xFFFFF);
55 				src |= ((inst_norm >> 36) & 1) << 20;
56 
57 				src <<= 4;
58 
59 				uint32_t dest;
60 				if (is_encoder)
61 					dest = now_pos + (uint32_t)(i) + src;
62 				else
63 					dest = src - (now_pos + (uint32_t)(i));
64 
65 				dest >>= 4;
66 
67 				inst_norm &= ~((uint64_t)(0x8FFFFF) << 13);
68 				inst_norm |= (uint64_t)(dest & 0xFFFFF) << 13;
69 				inst_norm |= (uint64_t)(dest & 0x100000)
70 						<< (36 - 20);
71 
72 				instruction &= (1U << bit_res) - 1;
73 				instruction |= (inst_norm << bit_res);
74 
75 				for (size_t j = 0; j < 6; j++)
76 					buffer[i + j + byte_pos] = (uint8_t)(
77 							instruction
78 							>> (8 * j));
79 			}
80 		}
81 	}
82 
83 	return i;
84 }
85 
86 
87 static lzma_ret
88 ia64_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
89 		const lzma_filter_info *filters, bool is_encoder)
90 {
91 	return lzma_simple_coder_init(next, allocator, filters,
92 			&ia64_code, 0, 16, 16, is_encoder);
93 }
94 
95 
96 #ifdef HAVE_ENCODER_IA64
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 #endif
105 
106 
107 #ifdef HAVE_DECODER_IA64
108 extern lzma_ret
109 lzma_simple_ia64_decoder_init(lzma_next_coder *next,
110 		const lzma_allocator *allocator,
111 		const lzma_filter_info *filters)
112 {
113 	return ia64_coder_init(next, allocator, filters, false);
114 }
115 #endif
116