tcg: move tcg related files into accel/tcg/ subdirectory

move cputlb.c, cpu-exec-common.c and cpu-exec.c related tcg exec
file into accel/tcg/ subdirectory.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <1496383606-18060-3-git-send-email-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 0 insertions, 683 deletions

diff --git a/cpu-exec.c b/cpu-exec.c
deleted file mode 100644
index 5b181c18ed..0000000000
--- a/cpu-exec.c
+++ /dev/null
@@ -1,683 +0,0 @@
-/*
- *  emulator main execution loop
- *
- *  Copyright (c) 2003-2005 Fabrice Bellard
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, see <http://www.gnu.org/licenses/>.
- */
-#include "qemu/osdep.h"
-#include "cpu.h"
-#include "trace-root.h"
-#include "disas/disas.h"
-#include "exec/exec-all.h"
-#include "tcg.h"
-#include "qemu/atomic.h"
-#include "sysemu/qtest.h"
-#include "qemu/timer.h"
-#include "exec/address-spaces.h"
-#include "qemu/rcu.h"
-#include "exec/tb-hash.h"
-#include "exec/log.h"
-#include "qemu/main-loop.h"
-#if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
-#include "hw/i386/apic.h"
-#endif
-#include "sysemu/cpus.h"
-#include "sysemu/replay.h"
-
-/* -icount align implementation. */
-
-typedef struct SyncClocks {
-    int64_t diff_clk;
-    int64_t last_cpu_icount;
-    int64_t realtime_clock;
-} SyncClocks;
-
-#if !defined(CONFIG_USER_ONLY)
-/* Allow the guest to have a max 3ms advance.
- * The difference between the 2 clocks could therefore
- * oscillate around 0.
- */
-#define VM_CLOCK_ADVANCE 3000000
-#define THRESHOLD_REDUCE 1.5
-#define MAX_DELAY_PRINT_RATE 2000000000LL
-#define MAX_NB_PRINTS 100
-
-static void align_clocks(SyncClocks *sc, const CPUState *cpu)
-{
-    int64_t cpu_icount;
-
-    if (!icount_align_option) {
-        return;
-    }
-
-    cpu_icount = cpu->icount_extra + cpu->icount_decr.u16.low;
-    sc->diff_clk += cpu_icount_to_ns(sc->last_cpu_icount - cpu_icount);
-    sc->last_cpu_icount = cpu_icount;
-
-    if (sc->diff_clk > VM_CLOCK_ADVANCE) {
-#ifndef _WIN32
-        struct timespec sleep_delay, rem_delay;
-        sleep_delay.tv_sec = sc->diff_clk / 1000000000LL;
-        sleep_delay.tv_nsec = sc->diff_clk % 1000000000LL;
-        if (nanosleep(&sleep_delay, &rem_delay) < 0) {
-            sc->diff_clk = rem_delay.tv_sec * 1000000000LL + rem_delay.tv_nsec;
-        } else {
-            sc->diff_clk = 0;
-        }
-#else
-        Sleep(sc->diff_clk / SCALE_MS);
-        sc->diff_clk = 0;
-#endif
-    }
-}
-
-static void print_delay(const SyncClocks *sc)
-{
-    static float threshold_delay;
-    static int64_t last_realtime_clock;
-    static int nb_prints;
-
-    if (icount_align_option &&
-        sc->realtime_clock - last_realtime_clock >= MAX_DELAY_PRINT_RATE &&
-        nb_prints < MAX_NB_PRINTS) {
-        if ((-sc->diff_clk / (float)1000000000LL > threshold_delay) ||
-            (-sc->diff_clk / (float)1000000000LL <
-             (threshold_delay - THRESHOLD_REDUCE))) {
-            threshold_delay = (-sc->diff_clk / 1000000000LL) + 1;
-            printf("Warning: The guest is now late by %.1f to %.1f seconds\n",
-                   threshold_delay - 1,
-                   threshold_delay);
-            nb_prints++;
-            last_realtime_clock = sc->realtime_clock;
-        }
-    }
-}
-
-static void init_delay_params(SyncClocks *sc,
-                              const CPUState *cpu)
-{
-    if (!icount_align_option) {
-        return;
-    }
-    sc->realtime_clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT);
-    sc->diff_clk = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - sc->realtime_clock;
-    sc->last_cpu_icount = cpu->icount_extra + cpu->icount_decr.u16.low;
-    if (sc->diff_clk < max_delay) {
-        max_delay = sc->diff_clk;
-    }
-    if (sc->diff_clk > max_advance) {
-        max_advance = sc->diff_clk;
-    }
-
-    /* Print every 2s max if the guest is late. We limit the number
-       of printed messages to NB_PRINT_MAX(currently 100) */
-    print_delay(sc);
-}
-#else
-static void align_clocks(SyncClocks *sc, const CPUState *cpu)
-{
-}
-
-static void init_delay_params(SyncClocks *sc, const CPUState *cpu)
-{
-}
-#endif /* CONFIG USER ONLY */
-
-/* Execute a TB, and fix up the CPU state afterwards if necessary */
-static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)
-{
-    CPUArchState *env = cpu->env_ptr;
-    uintptr_t ret;
-    TranslationBlock *last_tb;
-    int tb_exit;
-    uint8_t *tb_ptr = itb->tc_ptr;
-
-    qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc,
-                           "Trace %p [%d: " TARGET_FMT_lx "] %s\n",
-                           itb->tc_ptr, cpu->cpu_index, itb->pc,
-                           lookup_symbol(itb->pc));
-
-#if defined(DEBUG_DISAS)
-    if (qemu_loglevel_mask(CPU_LOG_TB_CPU)
-        && qemu_log_in_addr_range(itb->pc)) {
-        qemu_log_lock();
-#if defined(TARGET_I386)
-        log_cpu_state(cpu, CPU_DUMP_CCOP);
-#else
-        log_cpu_state(cpu, 0);
-#endif
-        qemu_log_unlock();
-    }
-#endif /* DEBUG_DISAS */
-
-    cpu->can_do_io = !use_icount;
-    ret = tcg_qemu_tb_exec(env, tb_ptr);
-    cpu->can_do_io = 1;
-    last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
-    tb_exit = ret & TB_EXIT_MASK;
-    trace_exec_tb_exit(last_tb, tb_exit);
-
-    if (tb_exit > TB_EXIT_IDX1) {
-        /* We didn't start executing this TB (eg because the instruction
-         * counter hit zero); we must restore the guest PC to the address
-         * of the start of the TB.
-         */
-        CPUClass *cc = CPU_GET_CLASS(cpu);
-        qemu_log_mask_and_addr(CPU_LOG_EXEC, last_tb->pc,
-                               "Stopped execution of TB chain before %p ["
-                               TARGET_FMT_lx "] %s\n",
-                               last_tb->tc_ptr, last_tb->pc,
-                               lookup_symbol(last_tb->pc));
-        if (cc->synchronize_from_tb) {
-            cc->synchronize_from_tb(cpu, last_tb);
-        } else {
-            assert(cc->set_pc);
-            cc->set_pc(cpu, last_tb->pc);
-        }
-    }
-    return ret;
-}
-
-#ifndef CONFIG_USER_ONLY
-/* Execute the code without caching the generated code. An interpreter
-   could be used if available. */
-static void cpu_exec_nocache(CPUState *cpu, int max_cycles,
-                             TranslationBlock *orig_tb, bool ignore_icount)
-{
-    TranslationBlock *tb;
-
-    /* Should never happen.
-       We only end up here when an existing TB is too long.  */
-    if (max_cycles > CF_COUNT_MASK)
-        max_cycles = CF_COUNT_MASK;
-
-    tb_lock();
-    tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,
-                     max_cycles | CF_NOCACHE
-                         | (ignore_icount ? CF_IGNORE_ICOUNT : 0));
-    tb->orig_tb = orig_tb;
-    tb_unlock();
-
-    /* execute the generated code */
-    trace_exec_tb_nocache(tb, tb->pc);
-    cpu_tb_exec(cpu, tb);
-
-    tb_lock();
-    tb_phys_invalidate(tb, -1);
-    tb_free(tb);
-    tb_unlock();
-}
-#endif
-
-static void cpu_exec_step(CPUState *cpu)
-{
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-    CPUArchState *env = (CPUArchState *)cpu->env_ptr;
-    TranslationBlock *tb;
-    target_ulong cs_base, pc;
-    uint32_t flags;
-
-    cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
-    if (sigsetjmp(cpu->jmp_env, 0) == 0) {
-        mmap_lock();
-        tb_lock();
-        tb = tb_gen_code(cpu, pc, cs_base, flags,
-                         1 | CF_NOCACHE | CF_IGNORE_ICOUNT);
-        tb->orig_tb = NULL;
-        tb_unlock();
-        mmap_unlock();
-
-        cc->cpu_exec_enter(cpu);
-        /* execute the generated code */
-        trace_exec_tb_nocache(tb, pc);
-        cpu_tb_exec(cpu, tb);
-        cc->cpu_exec_exit(cpu);
-
-        tb_lock();
-        tb_phys_invalidate(tb, -1);
-        tb_free(tb);
-        tb_unlock();
-    } else {
-        /* We may have exited due to another problem here, so we need
-         * to reset any tb_locks we may have taken but didn't release.
-         * The mmap_lock is dropped by tb_gen_code if it runs out of
-         * memory.
-         */
-#ifndef CONFIG_SOFTMMU
-        tcg_debug_assert(!have_mmap_lock());
-#endif
-        tb_lock_reset();
-    }
-}
-
-void cpu_exec_step_atomic(CPUState *cpu)
-{
-    start_exclusive();
-
-    /* Since we got here, we know that parallel_cpus must be true.  */
-    parallel_cpus = false;
-    cpu_exec_step(cpu);
-    parallel_cpus = true;
-
-    end_exclusive();
-}
-
-struct tb_desc {
-    target_ulong pc;
-    target_ulong cs_base;
-    CPUArchState *env;
-    tb_page_addr_t phys_page1;
-    uint32_t flags;
-};
-
-static bool tb_cmp(const void *p, const void *d)
-{
-    const TranslationBlock *tb = p;
-    const struct tb_desc *desc = d;
-
-    if (tb->pc == desc->pc &&
-        tb->page_addr[0] == desc->phys_page1 &&
-        tb->cs_base == desc->cs_base &&
-        tb->flags == desc->flags &&
-        !atomic_read(&tb->invalid)) {
-        /* check next page if needed */
-        if (tb->page_addr[1] == -1) {
-            return true;
-        } else {
-            tb_page_addr_t phys_page2;
-            target_ulong virt_page2;
-
-            virt_page2 = (desc->pc & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
-            phys_page2 = get_page_addr_code(desc->env, virt_page2);
-            if (tb->page_addr[1] == phys_page2) {
-                return true;
-            }
-        }
-    }
-    return false;
-}
-
-TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc,
-                                   target_ulong cs_base, uint32_t flags)
-{
-    tb_page_addr_t phys_pc;
-    struct tb_desc desc;
-    uint32_t h;
-
-    desc.env = (CPUArchState *)cpu->env_ptr;
-    desc.cs_base = cs_base;
-    desc.flags = flags;
-    desc.pc = pc;
-    phys_pc = get_page_addr_code(desc.env, pc);
-    desc.phys_page1 = phys_pc & TARGET_PAGE_MASK;
-    h = tb_hash_func(phys_pc, pc, flags);
-    return qht_lookup(&tcg_ctx.tb_ctx.htable, tb_cmp, &desc, h);
-}
-
-static inline TranslationBlock *tb_find(CPUState *cpu,
-                                        TranslationBlock *last_tb,
-                                        int tb_exit)
-{
-    CPUArchState *env = (CPUArchState *)cpu->env_ptr;
-    TranslationBlock *tb;
-    target_ulong cs_base, pc;
-    uint32_t flags;
-    bool have_tb_lock = false;
-
-    /* we record a subset of the CPU state. It will
-       always be the same before a given translated block
-       is executed. */
-    cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
-    tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]);
-    if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
-                 tb->flags != flags)) {
-        tb = tb_htable_lookup(cpu, pc, cs_base, flags);
-        if (!tb) {
-
-            /* mmap_lock is needed by tb_gen_code, and mmap_lock must be
-             * taken outside tb_lock. As system emulation is currently
-             * single threaded the locks are NOPs.
-             */
-            mmap_lock();
-            tb_lock();
-            have_tb_lock = true;
-
-            /* There's a chance that our desired tb has been translated while
-             * taking the locks so we check again inside the lock.
-             */
-            tb = tb_htable_lookup(cpu, pc, cs_base, flags);
-            if (!tb) {
-                /* if no translated code available, then translate it now */
-                tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
-            }
-
-            mmap_unlock();
-        }
-
-        /* We add the TB in the virtual pc hash table for the fast lookup */
-        atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb);
-    }
-#ifndef CONFIG_USER_ONLY
-    /* We don't take care of direct jumps when address mapping changes in
-     * system emulation. So it's not safe to make a direct jump to a TB
-     * spanning two pages because the mapping for the second page can change.
-     */
-    if (tb->page_addr[1] != -1) {
-        last_tb = NULL;
-    }
-#endif
-    /* See if we can patch the calling TB. */
-    if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
-        if (!have_tb_lock) {
-            tb_lock();
-            have_tb_lock = true;
-        }
-        if (!tb->invalid) {
-            tb_add_jump(last_tb, tb_exit, tb);
-        }
-    }
-    if (have_tb_lock) {
-        tb_unlock();
-    }
-    return tb;
-}
-
-static inline bool cpu_handle_halt(CPUState *cpu)
-{
-    if (cpu->halted) {
-#if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
-        if ((cpu->interrupt_request & CPU_INTERRUPT_POLL)
-            && replay_interrupt()) {
-            X86CPU *x86_cpu = X86_CPU(cpu);
-            qemu_mutex_lock_iothread();
-            apic_poll_irq(x86_cpu->apic_state);
-            cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
-            qemu_mutex_unlock_iothread();
-        }
-#endif
-        if (!cpu_has_work(cpu)) {
-            return true;
-        }
-
-        cpu->halted = 0;
-    }
-
-    return false;
-}
-
-static inline void cpu_handle_debug_exception(CPUState *cpu)
-{
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-    CPUWatchpoint *wp;
-
-    if (!cpu->watchpoint_hit) {
-        QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
-            wp->flags &= ~BP_WATCHPOINT_HIT;
-        }
-    }
-
-    cc->debug_excp_handler(cpu);
-}
-
-static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
-{
-    if (cpu->exception_index >= 0) {
-        if (cpu->exception_index >= EXCP_INTERRUPT) {
-            /* exit request from the cpu execution loop */
-            *ret = cpu->exception_index;
-            if (*ret == EXCP_DEBUG) {
-                cpu_handle_debug_exception(cpu);
-            }
-            cpu->exception_index = -1;
-            return true;
-        } else {
-#if defined(CONFIG_USER_ONLY)
-            /* if user mode only, we simulate a fake exception
-               which will be handled outside the cpu execution
-               loop */
-#if defined(TARGET_I386)
-            CPUClass *cc = CPU_GET_CLASS(cpu);
-            cc->do_interrupt(cpu);
-#endif
-            *ret = cpu->exception_index;
-            cpu->exception_index = -1;
-            return true;
-#else
-            if (replay_exception()) {
-                CPUClass *cc = CPU_GET_CLASS(cpu);
-                qemu_mutex_lock_iothread();
-                cc->do_interrupt(cpu);
-                qemu_mutex_unlock_iothread();
-                cpu->exception_index = -1;
-            } else if (!replay_has_interrupt()) {
-                /* give a chance to iothread in replay mode */
-                *ret = EXCP_INTERRUPT;
-                return true;
-            }
-#endif
-        }
-#ifndef CONFIG_USER_ONLY
-    } else if (replay_has_exception()
-               && cpu->icount_decr.u16.low + cpu->icount_extra == 0) {
-        /* try to cause an exception pending in the log */
-        cpu_exec_nocache(cpu, 1, tb_find(cpu, NULL, 0), true);
-        *ret = -1;
-        return true;
-#endif
-    }
-
-    return false;
-}
-
-static inline bool cpu_handle_interrupt(CPUState *cpu,
-                                        TranslationBlock **last_tb)
-{
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-
-    if (unlikely(atomic_read(&cpu->interrupt_request))) {
-        int interrupt_request;
-        qemu_mutex_lock_iothread();
-        interrupt_request = cpu->interrupt_request;
-        if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
-            /* Mask out external interrupts for this step. */
-            interrupt_request &= ~CPU_INTERRUPT_SSTEP_MASK;
-        }
-        if (interrupt_request & CPU_INTERRUPT_DEBUG) {
-            cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
-            cpu->exception_index = EXCP_DEBUG;
-            qemu_mutex_unlock_iothread();
-            return true;
-        }
-        if (replay_mode == REPLAY_MODE_PLAY && !replay_has_interrupt()) {
-            /* Do nothing */
-        } else if (interrupt_request & CPU_INTERRUPT_HALT) {
-            replay_interrupt();
-            cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
-            cpu->halted = 1;
-            cpu->exception_index = EXCP_HLT;
-            qemu_mutex_unlock_iothread();
-            return true;
-        }
-#if defined(TARGET_I386)
-        else if (interrupt_request & CPU_INTERRUPT_INIT) {
-            X86CPU *x86_cpu = X86_CPU(cpu);
-            CPUArchState *env = &x86_cpu->env;
-            replay_interrupt();
-            cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 0);
-            do_cpu_init(x86_cpu);
-            cpu->exception_index = EXCP_HALTED;
-            qemu_mutex_unlock_iothread();
-            return true;
-        }
-#else
-        else if (interrupt_request & CPU_INTERRUPT_RESET) {
-            replay_interrupt();
-            cpu_reset(cpu);
-            qemu_mutex_unlock_iothread();
-            return true;
-        }
-#endif
-        /* The target hook has 3 exit conditions:
-           False when the interrupt isn't processed,
-           True when it is, and we should restart on a new TB,
-           and via longjmp via cpu_loop_exit.  */
-        else {
-            if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
-                replay_interrupt();
-                *last_tb = NULL;
-            }
-            /* The target hook may have updated the 'cpu->interrupt_request';
-             * reload the 'interrupt_request' value */
-            interrupt_request = cpu->interrupt_request;
-        }
-        if (interrupt_request & CPU_INTERRUPT_EXITTB) {
-            cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB;
-            /* ensure that no TB jump will be modified as
-               the program flow was changed */
-            *last_tb = NULL;
-        }
-
-        /* If we exit via cpu_loop_exit/longjmp it is reset in cpu_exec */
-        qemu_mutex_unlock_iothread();
-    }
-
-    /* Finally, check if we need to exit to the main loop.  */
-    if (unlikely(atomic_read(&cpu->exit_request)
-        || (use_icount && cpu->icount_decr.u16.low + cpu->icount_extra == 0))) {
-        atomic_set(&cpu->exit_request, 0);
-        cpu->exception_index = EXCP_INTERRUPT;
-        return true;
-    }
-
-    return false;
-}
-
-static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
-                                    TranslationBlock **last_tb, int *tb_exit)
-{
-    uintptr_t ret;
-    int32_t insns_left;
-
-    trace_exec_tb(tb, tb->pc);
-    ret = cpu_tb_exec(cpu, tb);
-    tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
-    *tb_exit = ret & TB_EXIT_MASK;
-    if (*tb_exit != TB_EXIT_REQUESTED) {
-        *last_tb = tb;
-        return;
-    }
-
-    *last_tb = NULL;
-    insns_left = atomic_read(&cpu->icount_decr.u32);
-    atomic_set(&cpu->icount_decr.u16.high, 0);
-    if (insns_left < 0) {
-        /* Something asked us to stop executing chained TBs; just
-         * continue round the main loop. Whatever requested the exit
-         * will also have set something else (eg exit_request or
-         * interrupt_request) which we will handle next time around
-         * the loop.  But we need to ensure the zeroing of icount_decr
-         * comes before the next read of cpu->exit_request
-         * or cpu->interrupt_request.
-         */
-        smp_mb();
-        return;
-    }
-
-    /* Instruction counter expired.  */
-    assert(use_icount);
-#ifndef CONFIG_USER_ONLY
-    /* Ensure global icount has gone forward */
-    cpu_update_icount(cpu);
-    /* Refill decrementer and continue execution.  */
-    insns_left = MIN(0xffff, cpu->icount_budget);
-    cpu->icount_decr.u16.low = insns_left;
-    cpu->icount_extra = cpu->icount_budget - insns_left;
-    if (!cpu->icount_extra) {
-        /* Execute any remaining instructions, then let the main loop
-         * handle the next event.
-         */
-        if (insns_left > 0) {
-            cpu_exec_nocache(cpu, insns_left, tb, false);
-        }
-    }
-#endif
-}
-
-/* main execution loop */
-
-int cpu_exec(CPUState *cpu)
-{
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-    int ret;
-    SyncClocks sc = { 0 };
-
-    /* replay_interrupt may need current_cpu */
-    current_cpu = cpu;
-
-    if (cpu_handle_halt(cpu)) {
-        return EXCP_HALTED;
-    }
-
-    rcu_read_lock();
-
-    cc->cpu_exec_enter(cpu);
-
-    /* Calculate difference between guest clock and host clock.
-     * This delay includes the delay of the last cycle, so
-     * what we have to do is sleep until it is 0. As for the
-     * advance/delay we gain here, we try to fix it next time.
-     */
-    init_delay_params(&sc, cpu);
-
-    /* prepare setjmp context for exception handling */
-    if (sigsetjmp(cpu->jmp_env, 0) != 0) {
-#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
-        /* Some compilers wrongly smash all local variables after
-         * siglongjmp. There were bug reports for gcc 4.5.0 and clang.
-         * Reload essential local variables here for those compilers.
-         * Newer versions of gcc would complain about this code (-Wclobbered). */
-        cpu = current_cpu;
-        cc = CPU_GET_CLASS(cpu);
-#else /* buggy compiler */
-        /* Assert that the compiler does not smash local variables. */
-        g_assert(cpu == current_cpu);
-        g_assert(cc == CPU_GET_CLASS(cpu));
-#endif /* buggy compiler */
-        cpu->can_do_io = 1;
-        tb_lock_reset();
-        if (qemu_mutex_iothread_locked()) {
-            qemu_mutex_unlock_iothread();
-        }
-    }
-
-    /* if an exception is pending, we execute it here */
-    while (!cpu_handle_exception(cpu, &ret)) {
-        TranslationBlock *last_tb = NULL;
-        int tb_exit = 0;
-
-        while (!cpu_handle_interrupt(cpu, &last_tb)) {
-            TranslationBlock *tb = tb_find(cpu, last_tb, tb_exit);
-            cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit);
-            /* Try to align the host and virtual clocks
-               if the guest is in advance */
-            align_clocks(&sc, cpu);
-        }
-    }
-
-    cc->cpu_exec_exit(cpu);
-    rcu_read_unlock();
-
-    return ret;
-}