From: "Emilio G. Cota" <cota@braap.org>
To: qemu-devel@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Peter Crosthwaite <crosthwaite.peter@gmail.com>,
Richard Henderson <rth@twiddle.net>,
Peter Maydell <peter.maydell@linaro.org>,
Eduardo Habkost <ehabkost@redhat.com>,
Andrzej Zaborowski <balrogg@gmail.com>,
Aurelien Jarno <aurelien@aurel32.net>,
Alexander Graf <agraf@suse.de>, Stefan Weil <sw@weilnetz.de>,
qemu-arm@nongnu.org, alex.bennee@linaro.org,
Pranith Kumar <bobby.prani+qemu@gmail.com>
Subject: [Qemu-devel] [PATCH v4 10/11] target/i386: optimize indirect branches
Date: Wed, 26 Apr 2017 23:29:23 -0400 [thread overview]
Message-ID: <1493263764-18657-11-git-send-email-cota@braap.org> (raw)
In-Reply-To: <1493263764-18657-1-git-send-email-cota@braap.org>
Speed up indirect branches by jumping to the target if it is valid.
Softmmu measurements (see later commit for user-mode numbers):
Note: baseline (i.e. speedup == 1x) is QEMU v2.9.0.
- SPECint06 (test set), x86_64-softmmu (Ubuntu 16.04 guest). Host: Intel i7-4790K @ 4.00GHz
2.4x +-+--------------------------------------------------------------------------------------------------------------+-+
| |
| cross |
2.2x +cross+jr..........................................................................+++...........................+-+
| | |
| +++ | |
2x +-+..............................................................................|..|............................+-+
| | | |
| | | |
1.8x +-+..............................................................................|####...........................+-+
| |# |# |
| **** |# |
1.6x +-+............................................................................*.|*.|#...........................+-+
| * |* |# |
| * |* |# |
1.4x +-+.......................................................................+++..*.|*.|#...........................+-+
| ++++++ #### * |*++# +++ |
| +++ | | #++# *++* # +++ | |
1.2x +-+......................###.....####....+++............|..|...........****..#.*..*..#....####...|.###.....####..+-+
| +++ **** # **** # #### ***### *++* # * * # #++# ****|# +++#++# |
| ****### +++ *++* # *++* # ++# # #### *|* |# +++ * * # * * # *** # *| *|# **** # |
1x +-++-*++*++#++***###++*++*+#++*+-*++#+****++#++***++#+-*+*++#-+****##++*++*-+#+*++*-+#++*+*++#++*-+*+#++*++*++#-++-+
| * * # * * # * * # * * # * * # * * # *|* |# *++* # * * # * * # * * # * * # * * # |
| * * # * * # * * # * * # * * # * * # *+*++# * * # * * # * * # * * # * * # * * # |
0.8x +-+--****###--***###--****##--****###-****###--***###--***###--****##--****###-****###--***###--****##--****###--+-+
astar bzip2 gcc gobmk h264ref hmmlibquantum mcf omnetpperlbench sjengxalancbmk hmean
png: http://imgur.com/DU36YFU
NB. 'cross' represents the previous commit.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
---
target/i386/translate.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/target/i386/translate.c b/target/i386/translate.c
index ea113fe..674ec96 100644
--- a/target/i386/translate.c
+++ b/target/i386/translate.c
@@ -4996,7 +4996,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
gen_push_v(s, cpu_T1);
gen_op_jmp_v(cpu_T0);
gen_bnd_jmp(s);
- gen_eob(s);
+ gen_jr(s, cpu_T0);
break;
case 3: /* lcall Ev */
gen_op_ld_v(s, ot, cpu_T1, cpu_A0);
@@ -5014,7 +5014,8 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
tcg_const_i32(dflag - 1),
tcg_const_i32(s->pc - s->cs_base));
}
- gen_eob(s);
+ tcg_gen_ld_tl(cpu_tmp4, cpu_env, offsetof(CPUX86State, eip));
+ gen_jr(s, cpu_tmp4);
break;
case 4: /* jmp Ev */
if (dflag == MO_16) {
@@ -5022,7 +5023,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
}
gen_op_jmp_v(cpu_T0);
gen_bnd_jmp(s);
- gen_eob(s);
+ gen_jr(s, cpu_T0);
break;
case 5: /* ljmp Ev */
gen_op_ld_v(s, ot, cpu_T1, cpu_A0);
@@ -5037,7 +5038,8 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
gen_op_movl_seg_T0_vm(R_CS);
gen_op_jmp_v(cpu_T1);
}
- gen_eob(s);
+ tcg_gen_ld_tl(cpu_tmp4, cpu_env, offsetof(CPUX86State, eip));
+ gen_jr(s, cpu_tmp4);
break;
case 6: /* push Ev */
gen_push_v(s, cpu_T0);
@@ -6417,7 +6419,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
/* Note that gen_pop_T0 uses a zero-extending load. */
gen_op_jmp_v(cpu_T0);
gen_bnd_jmp(s);
- gen_eob(s);
+ gen_jr(s, cpu_T0);
break;
case 0xc3: /* ret */
ot = gen_pop_T0(s);
@@ -6425,7 +6427,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
/* Note that gen_pop_T0 uses a zero-extending load. */
gen_op_jmp_v(cpu_T0);
gen_bnd_jmp(s);
- gen_eob(s);
+ gen_jr(s, cpu_T0);
break;
case 0xca: /* lret im */
val = cpu_ldsw_code(env, s->pc);
--
2.7.4
next prev parent reply other threads:[~2017-04-27 3:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-27 3:29 [Qemu-devel] [PATCH v4 00/11] TCG optimizations for 2.10 Emilio G. Cota
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 01/11] exec-all: export tb_htable_lookup Emilio G. Cota
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 02/11] tcg-runtime: add lookup_tb_ptr helper Emilio G. Cota
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 03/11] tcg: introduce goto_ptr opcode Emilio G. Cota
2017-04-27 8:09 ` Richard Henderson
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 04/11] tcg: export tcg_gen_lookup_and_goto_ptr Emilio G. Cota
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 05/11] tcg/i386: implement goto_ptr op Emilio G. Cota
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 06/11] target/arm: optimize cross-page direct jumps in softmmu Emilio G. Cota
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 07/11] target/arm: optimize indirect branches Emilio G. Cota
2017-04-27 9:36 ` Aurelien Jarno
2017-04-27 9:42 ` Richard Henderson
2017-04-27 10:15 ` Aurelien Jarno
2017-04-27 9:41 ` Alex Bennée
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 08/11] target/i386: introduce gen_jr helper to generate lookup_and_goto_ptr Emilio G. Cota
2017-04-27 8:12 ` Richard Henderson
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 09/11] target/i386: optimize cross-page direct jumps in softmmu Emilio G. Cota
2017-04-27 3:29 ` Emilio G. Cota [this message]
2017-04-27 3:29 ` [Qemu-devel] [PATCH v4 11/11] tb-hash: improve tb_jmp_cache hash function in user mode Emilio G. Cota
2017-04-27 3:32 ` [Qemu-devel] [PATCH v4 00/11] TCG optimizations for 2.10 Emilio G. Cota
2017-04-27 9:39 ` Aurelien Jarno
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