From: Richard Henderson <rth@twiddle.net>
To: Aurelien Jarno <aurelien@aurel32.net>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 05/13] tcg: rework liveness analysis
Date: Thu, 27 Sep 2012 11:54:05 -0700 [thread overview]
Message-ID: <5064A0CD.1070701@twiddle.net> (raw)
In-Reply-To: <1348766113-18373-6-git-send-email-aurelien@aurel32.net>
On 09/27/2012 10:15 AM, Aurelien Jarno wrote:
> Rework the liveness analysis by tracking temps that need to go back to
> memory in addition to dead temps tracking. This allows to mark output
> arguments as "need sync", and to synchronize them back to memory as soon
> as they are not written anymore. This way even arguments mapping to
> globals can be marked as "dead", avoiding moves to a new register when
> input and outputs are aliased.
>
> In addition it means that registers are freed as soon as temps are not
> used anymore, instead of waiting for a basic block end or an op with side
> effects. This reduces register spilling especially on CPUs with few
> registers, and spread the mov over all the TB, increasing the
> performances on in-order CPUs.
>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
> tcg/tcg.c | 64 +++++++++++++++++++++++++++++++++++--------------------------
> 1 file changed, 37 insertions(+), 27 deletions(-)
Reviewed-by: Richard Henderson <rth@twiddle.net>
r~
next prev parent reply other threads:[~2012-09-27 18:54 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-27 17:15 [Qemu-devel] [PATCH 00/13] tcg: rework liveness analysis and register allocator Aurelien Jarno
2012-09-27 17:15 ` [Qemu-devel] [PATCH 01/13] tcg: add temp_dead() Aurelien Jarno
2012-09-27 18:19 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 02/13] tcg: add tcg_reg_sync() Aurelien Jarno
2012-09-27 18:24 ` Richard Henderson
2012-09-27 20:00 ` Aurelien Jarno
2012-09-27 17:15 ` [Qemu-devel] [PATCH 03/13] tcg: add temp_sync() Aurelien Jarno
2012-09-27 18:30 ` Richard Henderson
2012-09-27 20:02 ` Aurelien Jarno
2012-09-27 17:15 ` [Qemu-devel] [PATCH 04/13] tcg: sync output arguments on liveness request Aurelien Jarno
2012-09-27 18:39 ` Richard Henderson
2012-09-27 20:05 ` Aurelien Jarno
2012-09-27 20:10 ` Richard Henderson
2012-09-27 20:25 ` Aurelien Jarno
2012-09-27 17:15 ` [Qemu-devel] [PATCH 05/13] tcg: rework liveness analysis Aurelien Jarno
2012-09-27 18:54 ` Richard Henderson [this message]
2012-09-27 17:15 ` [Qemu-devel] [PATCH 06/13] tcg: improve tcg_reg_alloc_movi() Aurelien Jarno
2012-09-27 18:55 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 07/13] tcg: rewrite tcg_reg_alloc_mov() Aurelien Jarno
2012-09-27 19:09 ` Richard Henderson
2012-09-27 20:17 ` Aurelien Jarno
2012-09-27 22:18 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 08/13] tcg: always mark dead input arguments as dead Aurelien Jarno
2012-09-27 19:10 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 09/13] tcg: start with local temps in TEMP_VAL_MEM state Aurelien Jarno
2012-09-27 19:10 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 10/13] tcg: don't explicitely save globals and temps Aurelien Jarno
2012-09-27 19:13 ` Richard Henderson
2012-09-27 20:23 ` Aurelien Jarno
2012-09-27 17:15 ` [Qemu-devel] [PATCH 11/13] tcg: sync globals for pure helpers instead of saving them Aurelien Jarno
2012-09-27 19:39 ` Richard Henderson
2012-09-27 20:34 ` Aurelien Jarno
2012-09-27 22:02 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 12/13] tcg: fix some op flags Aurelien Jarno
2012-09-27 19:44 ` Richard Henderson
2012-09-27 17:15 ` [Qemu-devel] [PATCH 13/13] tcg: rework TCG ops flags Aurelien Jarno
2012-09-27 19:56 ` Richard Henderson
2012-09-27 20:37 ` Aurelien Jarno
2012-09-27 22:00 ` Richard Henderson
2012-09-27 23:08 ` Aurelien Jarno
2012-09-27 23:11 ` Richard Henderson
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