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1 /*
2  *  Host code generation
3  *
4  *  Copyright (c) 2003 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library 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 GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #include <stdarg.h>
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include <string.h>
23 #include <inttypes.h>
24 
25 #include "config.h"
26 
27 #define NO_CPU_IO_DEFS
28 #include "cpu.h"
29 #include "exec-all.h"
30 #include "disas.h"
31 #include "tcg.h"
32 #include "qemu-timer.h"
33 
34 /* code generation context */
35 TCGContext tcg_ctx;
36 
37 uint16_t gen_opc_buf[OPC_BUF_SIZE];
38 TCGArg gen_opparam_buf[OPPARAM_BUF_SIZE];
39 
40 target_ulong gen_opc_pc[OPC_BUF_SIZE];
41 uint16_t gen_opc_icount[OPC_BUF_SIZE];
42 uint8_t gen_opc_instr_start[OPC_BUF_SIZE];
43 #if defined(TARGET_I386)
44 uint8_t gen_opc_cc_op[OPC_BUF_SIZE];
45 #elif defined(TARGET_SPARC)
46 target_ulong gen_opc_npc[OPC_BUF_SIZE];
47 target_ulong gen_opc_jump_pc[2];
48 #elif defined(TARGET_MIPS) || defined(TARGET_SH4)
49 uint32_t gen_opc_hflags[OPC_BUF_SIZE];
50 #endif
51 
52 #ifdef CONFIG_MEMCHECK
53 /*
54  * Memchecker code in this module copies TB PC <-> Guest PC map to the TB
55  * descriptor after guest code has been translated in cpu_gen_init routine.
56  */
57 #include "memcheck/memcheck_api.h"
58 
59 /* Array of (tb_pc, guest_pc) pairs, big enough for all translations. This
60  * array is used to obtain guest PC address from a translated PC address.
61  * tcg_gen_code_common will fill it up when memchecker is enabled. */
62 static void* gen_opc_tpc2gpc[OPC_BUF_SIZE * 2];
63 void** gen_opc_tpc2gpc_ptr = &gen_opc_tpc2gpc[0];
64 /* Number of (tb_pc, guest_pc) pairs stored in gen_opc_tpc2gpc array. */
65 unsigned int gen_opc_tpc2gpc_pairs;
66 #endif  // CONFIG_MEMCHECK
67 
68 /* XXX: suppress that */
code_gen_max_block_size(void)69 unsigned long code_gen_max_block_size(void)
70 {
71     static unsigned long max;
72 
73     if (max == 0) {
74         max = TCG_MAX_OP_SIZE;
75 #define DEF(name, iarg, oarg, carg, flags) DEF2((iarg) + (oarg) + (carg))
76 #define DEF2(copy_size) max = (copy_size > max) ? copy_size : max;
77 #include "tcg-opc.h"
78 #undef DEF
79 #undef DEF2
80         max *= OPC_MAX_SIZE;
81     }
82 
83     return max;
84 }
85 
cpu_gen_init(void)86 void cpu_gen_init(void)
87 {
88     tcg_context_init(&tcg_ctx);
89     tcg_set_frame(&tcg_ctx, TCG_AREG0, offsetof(CPUState, temp_buf),
90                   CPU_TEMP_BUF_NLONGS * sizeof(long));
91 }
92 
93 /* return non zero if the very first instruction is invalid so that
94    the virtual CPU can trigger an exception.
95 
96    '*gen_code_size_ptr' contains the size of the generated code (host
97    code).
98 */
cpu_gen_code(CPUState * env,TranslationBlock * tb,int * gen_code_size_ptr)99 int cpu_gen_code(CPUState *env, TranslationBlock *tb, int *gen_code_size_ptr)
100 {
101     TCGContext *s = &tcg_ctx;
102     uint8_t *gen_code_buf;
103     int gen_code_size;
104 #ifdef CONFIG_PROFILER
105     int64_t ti;
106 #endif
107 
108 #ifdef CONFIG_PROFILER
109     s->tb_count1++; /* includes aborted translations because of
110                        exceptions */
111     ti = profile_getclock();
112 #endif
113     tcg_func_start(s);
114 
115     gen_intermediate_code(env, tb);
116 
117     /* generate machine code */
118     gen_code_buf = tb->tc_ptr;
119     tb->tb_next_offset[0] = 0xffff;
120     tb->tb_next_offset[1] = 0xffff;
121     s->tb_next_offset = tb->tb_next_offset;
122 #ifdef USE_DIRECT_JUMP
123     s->tb_jmp_offset = tb->tb_jmp_offset;
124     s->tb_next = NULL;
125     /* the following two entries are optional (only used for string ops) */
126     /* XXX: not used ? */
127     tb->tb_jmp_offset[2] = 0xffff;
128     tb->tb_jmp_offset[3] = 0xffff;
129 #else
130     s->tb_jmp_offset = NULL;
131     s->tb_next = tb->tb_next;
132 #endif
133 
134 #ifdef CONFIG_PROFILER
135     s->tb_count++;
136     s->interm_time += profile_getclock() - ti;
137     s->code_time -= profile_getclock();
138 #endif
139     gen_code_size = tcg_gen_code(s, gen_code_buf);
140     *gen_code_size_ptr = gen_code_size;
141 #ifdef CONFIG_PROFILER
142     s->code_time += profile_getclock();
143     s->code_in_len += tb->size;
144     s->code_out_len += gen_code_size;
145 #endif
146 
147 #ifdef CONFIG_MEMCHECK
148     /* Save translated PC -> guest PC map into TB. */
149     if (memcheck_enabled && gen_opc_tpc2gpc_pairs && is_cpu_user(env)) {
150         tb->tpc2gpc =
151                 qemu_malloc(gen_opc_tpc2gpc_pairs * 2 * sizeof(target_ulong));
152         if (tb->tpc2gpc != NULL) {
153             memcpy(tb->tpc2gpc, gen_opc_tpc2gpc_ptr,
154                    gen_opc_tpc2gpc_pairs * 2 * sizeof(target_ulong));
155             tb->tpc2gpc_pairs = gen_opc_tpc2gpc_pairs;
156         }
157     }
158 #endif  // CONFIG_MEMCHECK
159 
160 #ifdef DEBUG_DISAS
161     if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM)) {
162         qemu_log("OUT: [size=%d]\n", *gen_code_size_ptr);
163         log_disas(tb->tc_ptr, *gen_code_size_ptr);
164         qemu_log("\n");
165         qemu_log_flush();
166     }
167 #endif
168     return 0;
169 }
170 
171 /* The cpu state corresponding to 'searched_pc' is restored.
172  */
cpu_restore_state(TranslationBlock * tb,CPUState * env,unsigned long searched_pc)173 int cpu_restore_state(TranslationBlock *tb,
174                       CPUState *env, unsigned long searched_pc)
175 {
176     TCGContext *s = &tcg_ctx;
177     int j;
178     unsigned long tc_ptr;
179 #ifdef CONFIG_PROFILER
180     int64_t ti;
181 #endif
182 
183 #ifdef CONFIG_PROFILER
184     ti = profile_getclock();
185 #endif
186     tcg_func_start(s);
187 
188     gen_intermediate_code_pc(env, tb);
189 
190     if (use_icount) {
191         /* Reset the cycle counter to the start of the block.  */
192         env->icount_decr.u16.low += tb->icount;
193         /* Clear the IO flag.  */
194         env->can_do_io = 0;
195     }
196 
197     /* find opc index corresponding to search_pc */
198     tc_ptr = (unsigned long)tb->tc_ptr;
199     if (searched_pc < tc_ptr)
200         return -1;
201 
202     s->tb_next_offset = tb->tb_next_offset;
203 #ifdef USE_DIRECT_JUMP
204     s->tb_jmp_offset = tb->tb_jmp_offset;
205     s->tb_next = NULL;
206 #else
207     s->tb_jmp_offset = NULL;
208     s->tb_next = tb->tb_next;
209 #endif
210     j = tcg_gen_code_search_pc(s, (uint8_t *)tc_ptr, searched_pc - tc_ptr);
211     if (j < 0)
212         return -1;
213     /* now find start of instruction before */
214     while (gen_opc_instr_start[j] == 0)
215         j--;
216     env->icount_decr.u16.low -= gen_opc_icount[j];
217 
218     restore_state_to_opc(env, tb, j);
219 
220 #ifdef CONFIG_PROFILER
221     s->restore_time += profile_getclock() - ti;
222     s->restore_count++;
223 #endif
224     return 0;
225 }
226