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[Qemu-devel] [PATCH 10/14] i386: use inverted setcond when computing NS
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 10/14] i386: use inverted setcond when computing NS or NZ |
Date: |
Sat, 6 Oct 2012 14:30:17 +0200 |
Make gen_compute_eflags_z and gen_compute_eflags_s able to compute the
inverted condition, and use this in gen_setcc_slow_T0. We cannot do it
yet in gen_compute_eflags_c, but prepare the code for it anyway. It is
not worthwhile for PF, as usual.
shr+and+xor could be replaced by and+setcond. I'm not doing it yet.
Signed-off-by: Paolo Bonzini <address@hidden>
---
target-i386/translate.c | 51 +++++++++++++++++++++++++++++--------------------
1 file modificato, 30 inserzioni(+), 21 rimozioni(-)
diff --git a/target-i386/translate.c b/target-i386/translate.c
index daa36c1..abcd944 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -824,13 +824,16 @@ static void gen_op_update_neg_cc(void)
}
/* compute eflags.C to reg */
-static void gen_compute_eflags_c(DisasContext *s, TCGv reg)
+static void gen_compute_eflags_c(DisasContext *s, TCGv reg, bool inv)
{
if (s->cc_op != CC_OP_DYNAMIC) {
gen_op_set_cc_op(s->cc_op);
}
gen_helper_cc_compute_c(cpu_tmp2_i32, cpu_env, cpu_cc_op);
tcg_gen_extu_i32_tl(reg, cpu_tmp2_i32);
+ if (inv) {
+ tcg_gen_xori_tl(reg, reg, 1);
+ }
}
/* compute all eflags to cc_src */
@@ -857,7 +860,7 @@ static void gen_compute_eflags_p(DisasContext *s, TCGv reg)
}
/* compute eflags.S to reg */
-static void gen_compute_eflags_s(DisasContext *s, TCGv reg)
+static void gen_compute_eflags_s(DisasContext *s, TCGv reg, bool inv)
{
if (s->cc_op == CC_OP_DYNAMIC) {
gen_compute_eflags(s);
@@ -865,10 +868,13 @@ static void gen_compute_eflags_s(DisasContext *s, TCGv
reg)
if (s->cc_op == CC_OP_EFLAGS) {
tcg_gen_shri_tl(reg, cpu_cc_src, 7);
tcg_gen_andi_tl(reg, reg, 1);
+ if (inv) {
+ tcg_gen_xori_tl(reg, reg, 1);
+ }
} else {
int size = (s->cc_op - CC_OP_ADDB) & 3;
gen_ext_tl(reg, cpu_cc_dst, size, true);
- tcg_gen_setcondi_tl(TCG_COND_LT, reg, reg, 0);
+ tcg_gen_setcondi_tl(inv ? TCG_COND_GE : TCG_COND_LT, reg, reg, 0);
}
}
@@ -881,7 +887,7 @@ static void gen_compute_eflags_o(DisasContext *s, TCGv reg)
}
/* compute eflags.Z to reg */
-static void gen_compute_eflags_z(DisasContext *s, TCGv reg)
+static void gen_compute_eflags_z(DisasContext *s, TCGv reg, bool inv)
{
if (s->cc_op == CC_OP_DYNAMIC) {
gen_compute_eflags(s);
@@ -889,25 +895,28 @@ static void gen_compute_eflags_z(DisasContext *s, TCGv
reg)
if (s->cc_op == CC_OP_EFLAGS) {
tcg_gen_shri_tl(reg, cpu_cc_src, 6);
tcg_gen_andi_tl(reg, reg, 1);
+ if (inv) {
+ tcg_gen_xori_tl(reg, reg, 1);
+ }
} else {
int size = (s->cc_op - CC_OP_ADDB) & 3;
gen_ext_tl(reg, cpu_cc_dst, size, false);
- tcg_gen_setcondi_tl(TCG_COND_EQ, reg, cpu_cc_dst, 0);
+ tcg_gen_setcondi_tl(inv ? TCG_COND_NE : TCG_COND_EQ, reg, cpu_cc_dst,
0);
}
}
-static inline void gen_setcc_slow_T0(DisasContext *s, int jcc_op)
+static inline void gen_setcc_slow_T0(DisasContext *s, int jcc_op, bool inv)
{
switch(jcc_op) {
case JCC_O:
gen_compute_eflags_o(s, cpu_T[0]);
break;
case JCC_B:
- gen_compute_eflags_c(s, cpu_T[0]);
- break;
+ gen_compute_eflags_c(s, cpu_T[0], inv);
+ return;
case JCC_Z:
- gen_compute_eflags_z(s, cpu_T[0]);
- break;
+ gen_compute_eflags_z(s, cpu_T[0], inv);
+ return;
case JCC_BE:
gen_compute_eflags(s);
tcg_gen_shri_tl(cpu_T[0], cpu_cc_src, 6);
@@ -915,8 +924,8 @@ static inline void gen_setcc_slow_T0(DisasContext *s, int
jcc_op)
tcg_gen_andi_tl(cpu_T[0], cpu_T[0], 1);
break;
case JCC_S:
- gen_compute_eflags_s(s, cpu_T[0]);
- break;
+ gen_compute_eflags_s(s, cpu_T[0], inv);
+ return;
case JCC_P:
gen_compute_eflags_p(s, cpu_T[0]);
break;
@@ -938,6 +947,9 @@ static inline void gen_setcc_slow_T0(DisasContext *s, int
jcc_op)
tcg_gen_andi_tl(cpu_T[0], cpu_T[0], 1);
break;
}
+ if (inv) {
+ tcg_gen_xori_tl(cpu_T[0], cpu_T[0], 1);
+ }
}
/* return true if setcc_slow is not needed (WARNING: must be kept in
@@ -1103,7 +1115,7 @@ static inline void gen_jcc1(DisasContext *s, int b, int
l1)
break;
default:
slow_jcc:
- gen_setcc_slow_T0(s, jcc_op);
+ gen_setcc_slow_T0(s, jcc_op, false);
tcg_gen_brcondi_tl(inv ? TCG_COND_EQ : TCG_COND_NE,
cpu_T[0], 0, l1);
break;
@@ -1317,7 +1329,7 @@ static void gen_op(DisasContext *s1, int op, int ot, int
d)
}
switch(op) {
case OP_ADCL:
- gen_compute_eflags_c(s1, cpu_tmp4);
+ gen_compute_eflags_c(s1, cpu_tmp4, false);
tcg_gen_add_tl(cpu_T[0], cpu_T[0], cpu_T[1]);
tcg_gen_add_tl(cpu_T[0], cpu_T[0], cpu_tmp4);
if (d != OR_TMP0)
@@ -1332,7 +1344,7 @@ static void gen_op(DisasContext *s1, int op, int ot, int
d)
s1->cc_op = CC_OP_DYNAMIC;
break;
case OP_SBBL:
- gen_compute_eflags_c(s1, cpu_tmp4);
+ gen_compute_eflags_c(s1, cpu_tmp4, false);
tcg_gen_sub_tl(cpu_T[0], cpu_T[0], cpu_T[1]);
tcg_gen_sub_tl(cpu_T[0], cpu_T[0], cpu_tmp4);
if (d != OR_TMP0)
@@ -1406,7 +1418,7 @@ static void gen_inc(DisasContext *s1, int ot, int d, int
c)
gen_op_mov_TN_reg(ot, 0, d);
else
gen_op_ld_T0_A0(ot + s1->mem_index);
- gen_compute_eflags_c(s1, cpu_cc_src);
+ gen_compute_eflags_c(s1, cpu_cc_src, false);
if (c > 0) {
tcg_gen_addi_tl(cpu_T[0], cpu_T[0], 1);
s1->cc_op = CC_OP_INCB + ot;
@@ -2374,10 +2386,7 @@ static void gen_setcc(DisasContext *s, int b)
worth to */
inv = b & 1;
jcc_op = (b >> 1) & 7;
- gen_setcc_slow_T0(s, jcc_op);
- if (inv) {
- tcg_gen_xori_tl(cpu_T[0], cpu_T[0], 1);
- }
+ gen_setcc_slow_T0(s, jcc_op, inv);
}
}
@@ -6878,7 +6887,7 @@ static target_ulong disas_insn(DisasContext *s,
target_ulong pc_start)
case 0xd6: /* salc */
if (CODE64(s))
goto illegal_op;
- gen_compute_eflags_c(s, cpu_T[0]);
+ gen_compute_eflags_c(s, cpu_T[0], false);
tcg_gen_neg_tl(cpu_T[0], cpu_T[0]);
gen_op_mov_reg_T0(OT_BYTE, R_EAX);
break;
--
1.7.12.1
- Re: [Qemu-devel] [PATCH 06/14] i386: factor gen_op_set_cc_op/tcg_gen_discard_tl around computing flags, (continued)
- [Qemu-devel] [PATCH 09/14] i386: do not call helper to compute ZF/SF, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 08/14] i386: do not compute eflags multiple times consecutively, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 05/14] i386: move eflags computation closer to gen_op_set_cc_op, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 10/14] i386: use inverted setcond when computing NS or NZ,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 13/14] i386: optimize setbe, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 12/14] i386: change gen_setcc_slow_T0 to gen_setcc_slow, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 11/14] i386: convert gen_compute_eflags_c to TCG, Paolo Bonzini, 2012/10/06