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 /* Check for the dest on the same page as the start of the TB. */ 42 return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0; 43 } 44 45 void translator_loop(const TranslatorOps *ops, DisasContextBase *db, 46 CPUState *cpu, TranslationBlock *tb, int max_insns) 47 { 48 uint32_t cflags = tb_cflags(tb); 49 bool plugin_enabled; 50 51 /* Initialize DisasContext */ 52 db->tb = tb; 53 db->pc_first = tb->pc; 54 db->pc_next = db->pc_first; 55 db->is_jmp = DISAS_NEXT; 56 db->num_insns = 0; 57 db->max_insns = max_insns; 58 db->singlestep_enabled = cflags & CF_SINGLE_STEP; 59 60 ops->init_disas_context(db, cpu); 61 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 62 63 /* Reset the temp count so that we can identify leaks */ 64 tcg_clear_temp_count(); 65 66 /* Start translating. */ 67 gen_tb_start(db->tb); 68 ops->tb_start(db, cpu); 69 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 70 71 plugin_enabled = plugin_gen_tb_start(cpu, tb, cflags & CF_MEMI_ONLY); 72 73 while (true) { 74 db->num_insns++; 75 ops->insn_start(db, cpu); 76 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 77 78 if (plugin_enabled) { 79 plugin_gen_insn_start(cpu, db); 80 } 81 82 /* Disassemble one instruction. The translate_insn hook should 83 update db->pc_next and db->is_jmp to indicate what should be 84 done next -- either exiting this loop or locate the start of 85 the next instruction. */ 86 if (db->num_insns == db->max_insns && (cflags & CF_LAST_IO)) { 87 /* Accept I/O on the last instruction. */ 88 gen_io_start(); 89 ops->translate_insn(db, cpu); 90 } else { 91 /* we should only see CF_MEMI_ONLY for io_recompile */ 92 tcg_debug_assert(!(cflags & CF_MEMI_ONLY)); 93 ops->translate_insn(db, cpu); 94 } 95 96 /* Stop translation if translate_insn so indicated. */ 97 if (db->is_jmp != DISAS_NEXT) { 98 break; 99 } 100 101 /* 102 * We can't instrument after instructions that change control 103 * flow although this only really affects post-load operations. 104 */ 105 if (plugin_enabled) { 106 plugin_gen_insn_end(); 107 } 108 109 /* Stop translation if the output buffer is full, 110 or we have executed all of the allowed instructions. */ 111 if (tcg_op_buf_full() || db->num_insns >= db->max_insns) { 112 db->is_jmp = DISAS_TOO_MANY; 113 break; 114 } 115 } 116 117 /* Emit code to exit the TB, as indicated by db->is_jmp. */ 118 ops->tb_stop(db, cpu); 119 gen_tb_end(db->tb, db->num_insns); 120 121 if (plugin_enabled) { 122 plugin_gen_tb_end(cpu); 123 } 124 125 /* The disas_log hook may use these values rather than recompute. */ 126 tb->size = db->pc_next - db->pc_first; 127 tb->icount = db->num_insns; 128 129 #ifdef DEBUG_DISAS 130 if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) 131 && qemu_log_in_addr_range(db->pc_first)) { 132 FILE *logfile = qemu_log_lock(); 133 qemu_log("----------------\n"); 134 ops->disas_log(db, cpu); 135 qemu_log("\n"); 136 qemu_log_unlock(logfile); 137 } 138 #endif 139 } 140