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[Qemu-devel] [PATCH 09/14] i386: do not call helper to compute ZF/SF
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 09/14] i386: do not call helper to compute ZF/SF |
Date: |
Sat, 6 Oct 2012 14:30:16 +0200 |
ZF, SF and PF can always be computed from CC_DST except in the
CC_OP_EFLAGS case (and CC_OP_DYNAMIC, which just resolves to CC_OP_EFLAGS
in gen_compute_eflags). Use setcond to compute ZF and SF.
We could also use a table lookup to compute PF.
Signed-off-by: Paolo Bonzini <address@hidden>
---
target-i386/translate.c | 28 ++++++++++++++++++++++------
1 file modificato, 22 inserzioni(+), 6 rimozioni(-)
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 09512c3..daa36c1 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -859,9 +859,17 @@ 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)
{
- gen_compute_eflags(s);
- tcg_gen_shri_tl(reg, cpu_cc_src, 7);
- tcg_gen_andi_tl(reg, reg, 1);
+ if (s->cc_op == CC_OP_DYNAMIC) {
+ gen_compute_eflags(s);
+ }
+ if (s->cc_op == CC_OP_EFLAGS) {
+ tcg_gen_shri_tl(reg, cpu_cc_src, 7);
+ tcg_gen_andi_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);
+ }
}
/* compute eflags.O to reg */
@@ -875,9 +883,17 @@ 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)
{
- gen_compute_eflags(s);
- tcg_gen_shri_tl(reg, cpu_cc_src, 6);
- tcg_gen_andi_tl(reg, reg, 1);
+ if (s->cc_op == CC_OP_DYNAMIC) {
+ gen_compute_eflags(s);
+ }
+ if (s->cc_op == CC_OP_EFLAGS) {
+ tcg_gen_shri_tl(reg, cpu_cc_src, 6);
+ tcg_gen_andi_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);
+ }
}
static inline void gen_setcc_slow_T0(DisasContext *s, int jcc_op)
--
1.7.12.1
- [Qemu-devel] [PATCH 04/14] i386: drop cc_op argument of gen_jcc1, (continued)
- [Qemu-devel] [PATCH 04/14] i386: drop cc_op argument of gen_jcc1, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 02/14] i386: introduce gen_ext_tl, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 07/14] i386: add helper functions to get other flags, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 06/14] i386: factor gen_op_set_cc_op/tcg_gen_discard_tl around computing flags, Paolo Bonzini, 2012/10/06
- [Qemu-devel] [PATCH 09/14] i386: do not call helper to compute ZF/SF,
Paolo Bonzini <=
- [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, 2012/10/06