diff options
Diffstat (limited to 'target-i386')
| -rw-r--r-- | target-i386/translate.c | 48 |
1 files changed, 39 insertions, 9 deletions
diff --git a/target-i386/translate.c b/target-i386/translate.c index 71104fb..a767b50 100644 --- a/target-i386/translate.c +++ b/target-i386/translate.c @@ -174,14 +174,48 @@ enum { OR_A0, /* temporary register used when doing address evaluation */ }; +enum { + USES_CC_DST = 1, + USES_CC_SRC = 2, +}; + +/* Bit set if the global variable is live after setting CC_OP to X. */ +static const uint8_t cc_op_live[CC_OP_NB] = { + [CC_OP_DYNAMIC] = USES_CC_DST | USES_CC_SRC, + [CC_OP_EFLAGS] = USES_CC_SRC, + [CC_OP_MULB ... CC_OP_MULQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_ADDB ... CC_OP_ADDQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_ADCB ... CC_OP_ADCQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_SUBB ... CC_OP_SUBQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_SBBB ... CC_OP_SBBQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_LOGICB ... CC_OP_LOGICQ] = USES_CC_DST, + [CC_OP_INCB ... CC_OP_INCQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_DECB ... CC_OP_DECQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_SHLB ... CC_OP_SHLQ] = USES_CC_DST | USES_CC_SRC, + [CC_OP_SARB ... CC_OP_SARQ] = USES_CC_DST | USES_CC_SRC, +}; + static void set_cc_op(DisasContext *s, CCOp op) { - if (s->cc_op != op) { - s->cc_op = op; - /* The DYNAMIC setting is translator only, and should never be - stored. Thus we always consider it clean. */ - s->cc_op_dirty = (op != CC_OP_DYNAMIC); + int dead; + + if (s->cc_op == op) { + return; + } + + /* Discard CC computation that will no longer be used. */ + dead = cc_op_live[s->cc_op] & ~cc_op_live[op]; + if (dead & USES_CC_DST) { + tcg_gen_discard_tl(cpu_cc_dst); } + if (dead & USES_CC_SRC) { + tcg_gen_discard_tl(cpu_cc_src); + } + + s->cc_op = op; + /* The DYNAMIC setting is translator only, and should never be + stored. Thus we always consider it clean. */ + s->cc_op_dirty = (op != CC_OP_DYNAMIC); } static void gen_update_cc_op(DisasContext *s) @@ -809,7 +843,6 @@ static inline void gen_movs(DisasContext *s, int ot) static void gen_op_update1_cc(void) { - tcg_gen_discard_tl(cpu_cc_src); tcg_gen_mov_tl(cpu_cc_dst, cpu_T[0]); } @@ -827,7 +860,6 @@ static inline void gen_op_cmpl_T0_T1_cc(void) static inline void gen_op_testl_T0_T1_cc(void) { - tcg_gen_discard_tl(cpu_cc_src); tcg_gen_and_tl(cpu_cc_dst, cpu_T[0], cpu_T[1]); } @@ -853,7 +885,6 @@ static void gen_compute_eflags(DisasContext *s) } gen_update_cc_op(s); gen_helper_cc_compute_all(cpu_tmp2_i32, cpu_env, cpu_cc_op); - tcg_gen_discard_tl(cpu_cc_dst); set_cc_op(s, CC_OP_EFLAGS); tcg_gen_extu_i32_tl(cpu_cc_src, cpu_tmp2_i32); } @@ -6640,7 +6671,6 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, gen_op_mov_reg_T0(ot, reg); tcg_gen_movi_tl(cpu_cc_dst, 1); gen_set_label(label1); - tcg_gen_discard_tl(cpu_cc_src); set_cc_op(s, CC_OP_LOGICB + ot); } tcg_temp_free(t0); |