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authorIgor Pavlov <87184205+ip7z@users.noreply.github.com>2023-06-21 00:00:00 +0000
committerIgor Pavlov <87184205+ip7z@users.noreply.github.com>2023-12-17 14:59:19 +0500
commit5b39dc76f1bc82f941d5c800ab9f34407a06b53a (patch)
treefe5e17420300b715021a76328444088d32047963 /C/Bra86.c
parent93be7d4abfd4233228f58ee1fbbcd76d91be66a4 (diff)
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Diffstat (limited to 'C/Bra86.c')
-rw-r--r--C/Bra86.c221
1 files changed, 163 insertions, 58 deletions
diff --git a/C/Bra86.c b/C/Bra86.c
index 10a0fbd..d81f392 100644
--- a/C/Bra86.c
+++ b/C/Bra86.c
@@ -1,82 +1,187 @@
1/* Bra86.c -- Converter for x86 code (BCJ) 1/* Bra86.c -- Branch converter for X86 code (BCJ)
22021-02-09 : Igor Pavlov : Public domain */ 22023-04-02 : Igor Pavlov : Public domain */
3 3
4#include "Precomp.h" 4#include "Precomp.h"
5 5
6#include "Bra.h" 6#include "Bra.h"
7#include "CpuArch.h"
7 8
8#define Test86MSByte(b) ((((b) + 1) & 0xFE) == 0)
9 9
10SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding) 10#if defined(MY_CPU_SIZEOF_POINTER) \
11 && ( MY_CPU_SIZEOF_POINTER == 4 \
12 || MY_CPU_SIZEOF_POINTER == 8)
13 #define BR_CONV_USE_OPT_PC_PTR
14#endif
15
16#ifdef BR_CONV_USE_OPT_PC_PTR
17#define BR_PC_INIT pc -= (UInt32)(SizeT)p; // (MY_uintptr_t)
18#define BR_PC_GET (pc + (UInt32)(SizeT)p)
19#else
20#define BR_PC_INIT pc += (UInt32)size;
21#define BR_PC_GET (pc - (UInt32)(SizeT)(lim - p))
22// #define BR_PC_INIT
23// #define BR_PC_GET (pc + (UInt32)(SizeT)(p - data))
24#endif
25
26#define BR_CONVERT_VAL(v, c) if (encoding) v += c; else v -= c;
27// #define BR_CONVERT_VAL(v, c) if (!encoding) c = (UInt32)0 - c; v += c;
28
29#define Z7_BRANCH_CONV_ST(name) z7_BranchConvSt_ ## name
30
31#define BR86_NEED_CONV_FOR_MS_BYTE(b) ((((b) + 1) & 0xfe) == 0)
32
33#ifdef MY_CPU_LE_UNALIGN
34 #define BR86_PREPARE_BCJ_SCAN const UInt32 v = GetUi32(p) ^ 0xe8e8e8e8;
35 #define BR86_IS_BCJ_BYTE(n) ((v & ((UInt32)0xfe << (n) * 8)) == 0)
36#else
37 #define BR86_PREPARE_BCJ_SCAN
38 // bad for MSVC X86 (partial write to byte reg):
39 #define BR86_IS_BCJ_BYTE(n) ((p[n - 4] & 0xfe) == 0xe8)
40 // bad for old MSVC (partial write to byte reg):
41 // #define BR86_IS_BCJ_BYTE(n) (((*p ^ 0xe8) & 0xfe) == 0)
42#endif
43
44static
45Z7_FORCE_INLINE
46Z7_ATTRIB_NO_VECTOR
47Byte *Z7_BRANCH_CONV_ST(X86)(Byte *p, SizeT size, UInt32 pc, UInt32 *state, int encoding)
11{ 48{
12 SizeT pos = 0;
13 UInt32 mask = *state & 7;
14 if (size < 5) 49 if (size < 5)
15 return 0; 50 return p;
16 size -= 4; 51 {
17 ip += 5; 52 // Byte *p = data;
53 const Byte *lim = p + size - 4;
54 unsigned mask = (unsigned)*state; // & 7;
55#ifdef BR_CONV_USE_OPT_PC_PTR
56 /* if BR_CONV_USE_OPT_PC_PTR is defined: we need to adjust (pc) for (+4),
57 because call/jump offset is relative to the next instruction.
58 if BR_CONV_USE_OPT_PC_PTR is not defined : we don't need to adjust (pc) for (+4),
59 because BR_PC_GET uses (pc - (lim - p)), and lim was adjusted for (-4) before.
60 */
61 pc += 4;
62#endif
63 BR_PC_INIT
64 goto start;
18 65
19 for (;;) 66 for (;; mask |= 4)
20 { 67 {
21 Byte *p = data + pos; 68 // cont: mask |= 4;
22 const Byte *limit = data + size; 69 start:
23 for (; p < limit; p++) 70 if (p >= lim)
24 if ((*p & 0xFE) == 0xE8) 71 goto fin;
25 break;
26
27 { 72 {
28 SizeT d = (SizeT)(p - data) - pos; 73 BR86_PREPARE_BCJ_SCAN
29 pos = (SizeT)(p - data); 74 p += 4;
30 if (p >= limit) 75 if (BR86_IS_BCJ_BYTE(0)) { goto m0; } mask >>= 1;
31 { 76 if (BR86_IS_BCJ_BYTE(1)) { goto m1; } mask >>= 1;
32 *state = (d > 2 ? 0 : mask >> (unsigned)d); 77 if (BR86_IS_BCJ_BYTE(2)) { goto m2; } mask = 0;
33 return pos; 78 if (BR86_IS_BCJ_BYTE(3)) { goto a3; }
34 }
35 if (d > 2)
36 mask = 0;
37 else
38 {
39 mask >>= (unsigned)d;
40 if (mask != 0 && (mask > 4 || mask == 3 || Test86MSByte(p[(size_t)(mask >> 1) + 1])))
41 {
42 mask = (mask >> 1) | 4;
43 pos++;
44 continue;
45 }
46 }
47 } 79 }
80 goto main_loop;
48 81
49 if (Test86MSByte(p[4])) 82 m0: p--;
83 m1: p--;
84 m2: p--;
85 if (mask == 0)
86 goto a3;
87 if (p > lim)
88 goto fin_p;
89
90 // if (((0x17u >> mask) & 1) == 0)
91 if (mask > 4 || mask == 3)
92 {
93 mask >>= 1;
94 continue; // goto cont;
95 }
96 mask >>= 1;
97 if (BR86_NEED_CONV_FOR_MS_BYTE(p[mask]))
98 continue; // goto cont;
99 // if (!BR86_NEED_CONV_FOR_MS_BYTE(p[3])) continue; // goto cont;
50 { 100 {
51 UInt32 v = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]); 101 UInt32 v = GetUi32(p);
52 UInt32 cur = ip + (UInt32)pos; 102 UInt32 c;
53 pos += 5; 103 v += (1 << 24); if (v & 0xfe000000) continue; // goto cont;
54 if (encoding) 104 c = BR_PC_GET;
55 v += cur; 105 BR_CONVERT_VAL(v, c)
56 else
57 v -= cur;
58 if (mask != 0)
59 { 106 {
60 unsigned sh = (mask & 6) << 2; 107 mask <<= 3;
61 if (Test86MSByte((Byte)(v >> sh))) 108 if (BR86_NEED_CONV_FOR_MS_BYTE(v >> mask))
62 { 109 {
63 v ^= (((UInt32)0x100 << sh) - 1); 110 v ^= (((UInt32)0x100 << mask) - 1);
64 if (encoding) 111 #ifdef MY_CPU_X86
65 v += cur; 112 // for X86 : we can recalculate (c) to reduce register pressure
66 else 113 c = BR_PC_GET;
67 v -= cur; 114 #endif
115 BR_CONVERT_VAL(v, c)
68 } 116 }
69 mask = 0; 117 mask = 0;
70 } 118 }
71 p[1] = (Byte)v; 119 // v = (v & ((1 << 24) - 1)) - (v & (1 << 24));
72 p[2] = (Byte)(v >> 8); 120 v &= (1 << 25) - 1; v -= (1 << 24);
73 p[3] = (Byte)(v >> 16); 121 SetUi32(p, v)
74 p[4] = (Byte)(0 - ((v >> 24) & 1)); 122 p += 4;
123 goto main_loop;
75 } 124 }
76 else 125
126 main_loop:
127 if (p >= lim)
128 goto fin;
129 for (;;)
77 { 130 {
78 mask = (mask >> 1) | 4; 131 BR86_PREPARE_BCJ_SCAN
79 pos++; 132 p += 4;
133 if (BR86_IS_BCJ_BYTE(0)) { goto a0; }
134 if (BR86_IS_BCJ_BYTE(1)) { goto a1; }
135 if (BR86_IS_BCJ_BYTE(2)) { goto a2; }
136 if (BR86_IS_BCJ_BYTE(3)) { goto a3; }
137 if (p >= lim)
138 goto fin;
139 }
140
141 a0: p--;
142 a1: p--;
143 a2: p--;
144 a3:
145 if (p > lim)
146 goto fin_p;
147 // if (!BR86_NEED_CONV_FOR_MS_BYTE(p[3])) continue; // goto cont;
148 {
149 UInt32 v = GetUi32(p);
150 UInt32 c;
151 v += (1 << 24); if (v & 0xfe000000) continue; // goto cont;
152 c = BR_PC_GET;
153 BR_CONVERT_VAL(v, c)
154 // v = (v & ((1 << 24) - 1)) - (v & (1 << 24));
155 v &= (1 << 25) - 1; v -= (1 << 24);
156 SetUi32(p, v)
157 p += 4;
158 goto main_loop;
80 } 159 }
81 } 160 }
161
162fin_p:
163 p--;
164fin:
165 // the following processing for tail is optional and can be commented
166 /*
167 lim += 4;
168 for (; p < lim; p++, mask >>= 1)
169 if ((*p & 0xfe) == 0xe8)
170 break;
171 */
172 *state = (UInt32)mask;
173 return p;
174 }
82} 175}
176
177
178#define Z7_BRANCH_CONV_ST_FUNC_IMP(name, m, encoding) \
179Z7_NO_INLINE \
180Z7_ATTRIB_NO_VECTOR \
181Byte *m(name)(Byte *data, SizeT size, UInt32 pc, UInt32 *state) \
182 { return Z7_BRANCH_CONV_ST(name)(data, size, pc, state, encoding); }
183
184Z7_BRANCH_CONV_ST_FUNC_IMP(X86, Z7_BRANCH_CONV_ST_DEC, 0)
185#ifndef Z7_EXTRACT_ONLY
186Z7_BRANCH_CONV_ST_FUNC_IMP(X86, Z7_BRANCH_CONV_ST_ENC, 1)
187#endif
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