1 /* 2 * Generic intermediate code generation. 3 * 4 * Copyright (C) 2016-2017 Lluís Vilanova <vilanova@ac.upc.edu> 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or later. 7 * See the COPYING file in the top-level directory. 8 */ 9 10 #include "qemu/osdep.h" 11 #include "qemu/error-report.h" 12 #include "tcg/tcg.h" 13 #include "tcg/tcg-op.h" 14 #include "exec/exec-all.h" 15 #include "exec/gen-icount.h" 16 #include "exec/log.h" 17 #include "exec/translator.h" 18 #include "exec/plugin-gen.h" 19 #include "sysemu/replay.h" 20 21 /* Pairs with tcg_clear_temp_count. 22 To be called by #TranslatorOps.{translate_insn,tb_stop} if 23 (1) the target is sufficiently clean to support reporting, 24 (2) as and when all temporaries are known to be consumed. 25 For most targets, (2) is at the end of translate_insn. */ 26 void translator_loop_temp_check(DisasContextBase *db) 27 { 28 if (tcg_check_temp_count()) { 29 qemu_log("warning: TCG temporary leaks before " 30 TARGET_FMT_lx "\n", db->pc_next); 31 } 32 } 33 34 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest) 35 { 36 /* Suppress goto_tb if requested. */ 37 if (tb_cflags(db->tb) & CF_NO_GOTO_TB) { 38 return false; 39 } 40 41 /* Suppress goto_tb in the case of single-steping. */ 42 if (db->singlestep_enabled) { 43 return false; 44 } 45 46 /* Check for the dest on the same page as the start of the TB. */ 47 return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0; 48 } 49 50 void translator_loop(const TranslatorOps *ops, DisasContextBase *db, 51 CPUState *cpu, TranslationBlock *tb, int max_insns) 52 { 53 bool plugin_enabled; 54 55 /* Initialize DisasContext */ 56 db->tb = tb; 57 db->pc_first = tb->pc; 58 db->pc_next = db->pc_first; 59 db->is_jmp = DISAS_NEXT; 60 db->num_insns = 0; 61 db->max_insns = max_insns; 62 db->singlestep_enabled = cpu->singlestep_enabled; 63 64 ops->init_disas_context(db, cpu); 65 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 66 67 /* Reset the temp count so that we can identify leaks */ 68 tcg_clear_temp_count(); 69 70 /* Start translating. */ 71 gen_tb_start(db->tb); 72 ops->tb_start(db, cpu); 73 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 74 75 plugin_enabled = plugin_gen_tb_start(cpu, tb, 76 tb_cflags(db->tb) & CF_MEMI_ONLY); 77 78 while (true) { 79 db->num_insns++; 80 ops->insn_start(db, cpu); 81 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 82 83 if (plugin_enabled) { 84 plugin_gen_insn_start(cpu, db); 85 } 86 87 /* Disassemble one instruction. The translate_insn hook should 88 update db->pc_next and db->is_jmp to indicate what should be 89 done next -- either exiting this loop or locate the start of 90 the next instruction. */ 91 if (db->num_insns == db->max_insns 92 && (tb_cflags(db->tb) & CF_LAST_IO)) { 93 /* Accept I/O on the last instruction. */ 94 gen_io_start(); 95 ops->translate_insn(db, cpu); 96 } else { 97 /* we should only see CF_MEMI_ONLY for io_recompile */ 98 tcg_debug_assert(!(tb_cflags(db->tb) & CF_MEMI_ONLY)); 99 ops->translate_insn(db, cpu); 100 } 101 102 /* Stop translation if translate_insn so indicated. */ 103 if (db->is_jmp != DISAS_NEXT) { 104 break; 105 } 106 107 /* 108 * We can't instrument after instructions that change control 109 * flow although this only really affects post-load operations. 110 */ 111 if (plugin_enabled) { 112 plugin_gen_insn_end(); 113 } 114 115 /* Stop translation if the output buffer is full, 116 or we have executed all of the allowed instructions. */ 117 if (tcg_op_buf_full() || db->num_insns >= db->max_insns) { 118 db->is_jmp = DISAS_TOO_MANY; 119 break; 120 } 121 } 122 123 /* Emit code to exit the TB, as indicated by db->is_jmp. */ 124 ops->tb_stop(db, cpu); 125 gen_tb_end(db->tb, db->num_insns); 126 127 if (plugin_enabled) { 128 plugin_gen_tb_end(cpu); 129 } 130 131 /* The disas_log hook may use these values rather than recompute. */ 132 tb->size = db->pc_next - db->pc_first; 133 tb->icount = db->num_insns; 134 135 #ifdef DEBUG_DISAS 136 if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) 137 && qemu_log_in_addr_range(db->pc_first)) { 138 FILE *logfile = qemu_log_lock(); 139 qemu_log("----------------\n"); 140 ops->disas_log(db, cpu); 141 qemu_log("\n"); 142 qemu_log_unlock(logfile); 143 } 144 #endif 145 } 146