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-common.h" 12 #include "qemu/error-report.h" 13 #include "cpu.h" 14 #include "tcg/tcg.h" 15 #include "tcg/tcg-op.h" 16 #include "exec/exec-all.h" 17 #include "exec/gen-icount.h" 18 #include "exec/log.h" 19 #include "exec/translator.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 void translator_loop(const TranslatorOps *ops, DisasContextBase *db, 35 CPUState *cpu, TranslationBlock *tb, int max_insns) 36 { 37 int bp_insn = 0; 38 39 /* Initialize DisasContext */ 40 db->tb = tb; 41 db->pc_first = tb->pc; 42 db->pc_next = db->pc_first; 43 db->is_jmp = DISAS_NEXT; 44 db->num_insns = 0; 45 db->max_insns = max_insns; 46 db->singlestep_enabled = cpu->singlestep_enabled; 47 48 ops->init_disas_context(db, cpu); 49 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 50 51 /* Reset the temp count so that we can identify leaks */ 52 tcg_clear_temp_count(); 53 54 /* Start translating. */ 55 gen_tb_start(db->tb); 56 ops->tb_start(db, cpu); 57 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 58 59 while (true) { 60 db->num_insns++; 61 ops->insn_start(db, cpu); 62 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 63 64 /* Pass breakpoint hits to target for further processing */ 65 if (!db->singlestep_enabled 66 && unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) { 67 CPUBreakpoint *bp; 68 QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) { 69 if (bp->pc == db->pc_next) { 70 if (ops->breakpoint_check(db, cpu, bp)) { 71 bp_insn = 1; 72 break; 73 } 74 } 75 } 76 /* The breakpoint_check hook may use DISAS_TOO_MANY to indicate 77 that only one more instruction is to be executed. Otherwise 78 it should use DISAS_NORETURN when generating an exception, 79 but may use a DISAS_TARGET_* value for Something Else. */ 80 if (db->is_jmp > DISAS_TOO_MANY) { 81 break; 82 } 83 } 84 85 /* Disassemble one instruction. The translate_insn hook should 86 update db->pc_next and db->is_jmp to indicate what should be 87 done next -- either exiting this loop or locate the start of 88 the next instruction. */ 89 if (db->num_insns == db->max_insns 90 && (tb_cflags(db->tb) & CF_LAST_IO)) { 91 /* Accept I/O on the last instruction. */ 92 gen_io_start(); 93 ops->translate_insn(db, cpu); 94 gen_io_end(); 95 } else { 96 ops->translate_insn(db, cpu); 97 } 98 99 /* Stop translation if translate_insn so indicated. */ 100 if (db->is_jmp != DISAS_NEXT) { 101 break; 102 } 103 104 /* Stop translation if the output buffer is full, 105 or we have executed all of the allowed instructions. */ 106 if (tcg_op_buf_full() || db->num_insns >= db->max_insns) { 107 db->is_jmp = DISAS_TOO_MANY; 108 break; 109 } 110 } 111 112 /* Emit code to exit the TB, as indicated by db->is_jmp. */ 113 ops->tb_stop(db, cpu); 114 gen_tb_end(db->tb, db->num_insns - bp_insn); 115 116 /* The disas_log hook may use these values rather than recompute. */ 117 db->tb->size = db->pc_next - db->pc_first; 118 db->tb->icount = db->num_insns; 119 120 #ifdef DEBUG_DISAS 121 if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) 122 && qemu_log_in_addr_range(db->pc_first)) { 123 qemu_log_lock(); 124 qemu_log("----------------\n"); 125 ops->disas_log(db, cpu); 126 qemu_log("\n"); 127 qemu_log_unlock(); 128 } 129 #endif 130 } 131