diff options
Diffstat (limited to 'accel')
| -rw-r--r-- | accel/tcg/translator.c | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c index b6ab9f3d33..850d82e26f 100644 --- a/accel/tcg/translator.c +++ b/accel/tcg/translator.c @@ -16,11 +16,14 @@ #include "tcg/tcg-op-common.h" #include "internal.h" -static void gen_io_start(void) +static void set_can_do_io(DisasContextBase *db, bool val) { - tcg_gen_st_i32(tcg_constant_i32(1), cpu_env, - offsetof(ArchCPU, parent_obj.can_do_io) - - offsetof(ArchCPU, env)); + if (db->saved_can_do_io != val) { + db->saved_can_do_io = val; + tcg_gen_st_i32(tcg_constant_i32(val), cpu_env, + offsetof(ArchCPU, parent_obj.can_do_io) - + offsetof(ArchCPU, env)); + } } bool translator_io_start(DisasContextBase *db) @@ -30,12 +33,8 @@ bool translator_io_start(DisasContextBase *db) if (!(cflags & CF_USE_ICOUNT)) { return false; } - if (db->num_insns == db->max_insns && (cflags & CF_LAST_IO)) { - /* Already started in translator_loop. */ - return true; - } - gen_io_start(); + set_can_do_io(db, true); /* * Ensure that this instruction will be the last in the TB. @@ -47,7 +46,7 @@ bool translator_io_start(DisasContextBase *db) return true; } -static TCGOp *gen_tb_start(uint32_t cflags) +static TCGOp *gen_tb_start(DisasContextBase *db, uint32_t cflags) { TCGv_i32 count = NULL; TCGOp *icount_start_insn = NULL; @@ -91,12 +90,9 @@ static TCGOp *gen_tb_start(uint32_t cflags) * cpu->can_do_io is cleared automatically here at the beginning of * each translation block. The cost is minimal and only paid for * -icount, plus it would be very easy to forget doing it in the - * translator. Doing it here means we don't need a gen_io_end() to - * go with gen_io_start(). + * translator. */ - tcg_gen_st_i32(tcg_constant_i32(0), cpu_env, - offsetof(ArchCPU, parent_obj.can_do_io) - - offsetof(ArchCPU, env)); + set_can_do_io(db, false); } return icount_start_insn; @@ -147,6 +143,7 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns, db->num_insns = 0; db->max_insns = *max_insns; db->singlestep_enabled = cflags & CF_SINGLE_STEP; + db->saved_can_do_io = -1; db->host_addr[0] = host_pc; db->host_addr[1] = NULL; @@ -154,7 +151,7 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns, tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ /* Start translating. */ - icount_start_insn = gen_tb_start(cflags); + icount_start_insn = gen_tb_start(db, cflags); ops->tb_start(db, cpu); tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ @@ -181,7 +178,7 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns, the next instruction. */ if (db->num_insns == db->max_insns && (cflags & CF_LAST_IO)) { /* Accept I/O on the last instruction. */ - gen_io_start(); + set_can_do_io(db, true); } ops->translate_insn(db, cpu); |