2 * i386 emulator main execution loop
4 * Copyright (c) 2003 Fabrice Bellard
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include "exec-i386.h"
25 /* main execution loop */
27 /* maximum total translate dcode allocated */
28 #define CODE_GEN_BUFFER_SIZE (2048 * 1024)
29 //#define CODE_GEN_BUFFER_SIZE (128 * 1024)
30 #define CODE_GEN_MAX_SIZE 65536
31 #define CODE_GEN_ALIGN 16 /* must be >= of the size of a icache line */
33 /* threshold to flush the translated code buffer */
34 #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
36 #define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64)
37 #define CODE_GEN_HASH_BITS 15
38 #define CODE_GEN_HASH_SIZE (1 << CODE_GEN_HASH_BITS)
40 typedef struct TranslationBlock {
41 unsigned long pc; /* simulated PC corresponding to this block */
42 unsigned int flags; /* flags defining in which context the code was generated */
43 uint8_t *tc_ptr; /* pointer to the translated code */
44 struct TranslationBlock *hash_next; /* next matching block */
47 TranslationBlock tbs[CODE_GEN_MAX_BLOCKS];
48 TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE];
51 uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE];
52 uint8_t *code_gen_ptr;
55 static const char *cc_op_str[] = {
88 static void cpu_x86_dump_state(void)
91 eflags = cc_table[CC_OP].compute_all();
92 eflags |= (DF & DIRECTION_FLAG);
94 "EAX=%08x EBX=%08X ECX=%08x EDX=%08x\n"
95 "ESI=%08x EDI=%08X EBP=%08x ESP=%08x\n"
96 "CCS=%08x CCD=%08x CCO=%-8s EFL=%c%c%c%c%c%c%c\n",
97 env->regs[R_EAX], env->regs[R_EBX], env->regs[R_ECX], env->regs[R_EDX],
98 env->regs[R_ESI], env->regs[R_EDI], env->regs[R_EBP], env->regs[R_ESP],
99 env->cc_src, env->cc_dst, cc_op_str[env->cc_op],
100 eflags & DIRECTION_FLAG ? 'D' : '-',
101 eflags & CC_O ? 'O' : '-',
102 eflags & CC_S ? 'S' : '-',
103 eflags & CC_Z ? 'Z' : '-',
104 eflags & CC_A ? 'A' : '-',
105 eflags & CC_P ? 'P' : '-',
106 eflags & CC_C ? 'C' : '-'
109 fprintf(logfile, "ST0=%f ST1=%f ST2=%f ST3=%f\n",
110 (double)ST0, (double)ST1, (double)ST(2), (double)ST(3));
116 void cpu_x86_tblocks_init(void)
119 code_gen_ptr = code_gen_buffer;
123 /* flush all the translation blocks */
124 static void tb_flush(void)
128 printf("gemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
129 code_gen_ptr - code_gen_buffer,
131 (code_gen_ptr - code_gen_buffer) / nb_tbs);
134 for(i = 0;i < CODE_GEN_HASH_SIZE; i++)
136 code_gen_ptr = code_gen_buffer;
137 /* XXX: flush processor icache at this point */
140 /* find a translation block in the translation cache. If not found,
141 allocate a new one */
142 static inline TranslationBlock *tb_find_and_alloc(unsigned long pc,
145 TranslationBlock **ptb, *tb;
148 h = pc & (CODE_GEN_HASH_SIZE - 1);
154 if (tb->pc == pc && tb->flags == flags)
156 ptb = &tb->hash_next;
158 if (nb_tbs >= CODE_GEN_MAX_BLOCKS ||
159 (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE)
166 tb->hash_next = NULL;
170 int cpu_x86_exec(CPUX86State *env1)
172 int saved_T0, saved_T1, saved_A0;
173 CPUX86State *saved_env;
174 int code_gen_size, ret;
175 void (*gen_func)(void);
176 TranslationBlock *tb;
180 /* first we save global registers */
187 /* prepare setjmp context for exception handling */
188 if (setjmp(env->jmp_env) == 0) {
192 cpu_x86_dump_state();
195 /* we compute the CPU state. We assume it will not
196 change during the whole generated block. */
197 flags = env->seg_cache[R_CS].seg_32bit << GEN_FLAG_CODE32_SHIFT;
198 flags |= (((unsigned long)env->seg_cache[R_DS].base |
199 (unsigned long)env->seg_cache[R_ES].base |
200 (unsigned long)env->seg_cache[R_SS].base) != 0) <<
201 GEN_FLAG_ADDSEG_SHIFT;
202 tb = tb_find_and_alloc((unsigned long)env->pc, flags);
205 /* if no translated code available, then translate it now */
206 tc_ptr = code_gen_ptr;
207 cpu_x86_gen_code(code_gen_ptr, CODE_GEN_MAX_SIZE,
208 &code_gen_size, (uint8_t *)env->pc, flags);
210 code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));
212 /* execute the generated code */
213 gen_func = (void *)tc_ptr;
217 ret = env->exception_index;
219 /* restore global registers */
227 void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector)
229 CPUX86State *saved_env;
233 load_seg(seg_reg, selector);