From: Jeff Law <law@redhat.com>
To: Kugan <kugan.vivekanandarajah@linaro.org>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PR65768] Check rtx_cost when propagating constant
Date: Sat, 30 May 2015 05:47:00 -0000 [thread overview]
Message-ID: <5569429C.3050200@redhat.com> (raw)
In-Reply-To: <5568081A.4090103@linaro.org>
On 05/29/2015 12:32 AM, Kugan wrote:
>>>>
>>>> PR target/65768
>>>> * cprop.c (try_replace_reg): Check cost of constants before
>>>> propagating.
>> I should have also noted, fresh bootstrap & regression test is needed too.
>
> Thanks Jeff for the comments. I did a fresh bootstrap and regression
> testing on x86_64-linux-gnu with no new regression. I will wait for you ACK.
Can you address the 3 issues in my prior message? I'll include them
here for clarity:
--
The "const_p" variable is poorly named, though I can kindof see how you
settled on it. Maybe "check_rtx_costs" or something along those lines
would be better.
The comment for the second hunk would probably be better as:
/* If TO is a constant, check the cost of the set after propagation
to the cost of the set before the propagation. If the cost is
higher, then do not replace FROM with TO. */
You should try to produce a testcase where this change shows a code
generation improvement. Given we're checking target costs, that test
will naturally be target specific. But please do try.
So with the two nits fixed and a testcase, I think this can go forward.
--
next prev parent reply other threads:[~2015-05-30 4:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-15 7:53 Kugan
2015-04-15 9:05 ` Steven Bosscher
2015-04-15 11:18 ` Richard Biener
2015-04-17 3:19 ` Kugan
2015-05-14 5:57 ` Kugan
2015-05-28 21:52 ` Jeff Law
2015-05-28 21:55 ` Jeff Law
2015-05-29 7:46 ` Kugan
2015-05-30 5:47 ` Jeff Law [this message]
2015-06-01 2:20 ` Kugan
2015-06-02 19:16 ` Jeff Law
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