From: Richard Henderson <rth@twiddle.net>
To: Aurelien Jarno <aurelien@aurel32.net>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 2/7] tcg: Optimize add2 + sub2
Date: Mon, 01 Oct 2012 11:41:19 -0700 [thread overview]
Message-ID: <5069E3CF.6080606@twiddle.net> (raw)
In-Reply-To: <20121001174644.GA4623@ohm.aurel32.net>
On 2012-10-01 10:46, Aurelien Jarno wrote:
> For the first add2 that seemed to have work correctly, this patch
> optimized 0.2% of them. I am not sure it worth it as is.
You're probably right.
> I think optimizing add2, and in general all *2 ops is a good idea, but
> we should be able to do more agressive optimization. Maybe, a bit like
> Blue was suggesting, add2 should always be followed by a nop, so we can
> do more optimizations?
Adding an extra nop sounds like a better idea than add2_part[12]. And
it's probably easier than adding mov2 opcodes -- one little assert inside
the optimizer and we're golden.
r~
next prev parent reply other threads:[~2012-10-01 18:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-27 17:19 [Qemu-devel] [PATCH 0/7] Double-word tcg/optimize improvements Richard Henderson
2012-09-27 17:19 ` [Qemu-devel] [PATCH 1/7] tcg: Split out swap_commutative as a subroutine Richard Henderson
2012-09-27 21:45 ` Aurelien Jarno
2012-09-27 17:19 ` [Qemu-devel] [PATCH 2/7] tcg: Optimize add2 + sub2 Richard Henderson
2012-09-27 23:20 ` Aurelien Jarno
2012-09-27 23:28 ` Richard Henderson
2012-10-01 17:46 ` Aurelien Jarno
2012-10-01 18:41 ` Richard Henderson [this message]
2012-09-30 7:04 ` Blue Swirl
2012-10-01 18:36 ` Richard Henderson
2012-09-27 17:19 ` [Qemu-devel] [PATCH 3/7] tcg: Swap commutative double-word comparisons Richard Henderson
2012-09-27 23:22 ` Aurelien Jarno
2012-09-27 17:19 ` [Qemu-devel] [PATCH 4/7] tcg: Optimize double-word comparisons against zero Richard Henderson
2012-10-01 18:43 ` Aurelien Jarno
2012-10-01 18:47 ` Richard Henderson
2012-09-27 17:19 ` [Qemu-devel] [PATCH 5/7] tcg: Split out subroutines from do_constant_folding_cond Richard Henderson
2012-10-01 18:46 ` Aurelien Jarno
2012-09-27 17:19 ` [Qemu-devel] [PATCH 6/7] tcg: Tidy brcond optimization Richard Henderson
2012-10-01 18:48 ` Aurelien Jarno
2012-09-27 17:19 ` [Qemu-devel] [PATCH 7/7] tcg: Do constant folding on double-word comparisons Richard Henderson
2012-10-01 18:50 ` Aurelien Jarno
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