From: Bernd Schmidt <bschmidt@redhat.com>
To: Richard Earnshaw <Richard.Earnshaw@foss.arm.com>,
Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH][combine] PR rtl-optimization/68651 Try changing rtx from (r + r) to (r << 1) to aid recognition
Date: Tue, 15 Dec 2015 14:37:00 -0000 [thread overview]
Message-ID: <5670259E.1040209@redhat.com> (raw)
In-Reply-To: <567024C4.2080208@foss.arm.com>
On 12/15/2015 03:33 PM, Richard Earnshaw wrote:
>
> It's also possible that this would explicitly break some other
> optimization passes (such as the way in which multiplies are synthesised
> with shift/add operations).
How so? IMO such a change would make cost calculations more accurate and
should help rather than break anything.
Bernd
next prev parent reply other threads:[~2015-12-15 14:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-14 12:25 Kyrill Tkachov
2015-12-15 13:22 ` Bernd Schmidt
2015-12-15 14:22 ` Bernd Schmidt
2015-12-15 14:33 ` Richard Earnshaw
2015-12-15 14:37 ` Bernd Schmidt [this message]
2015-12-15 16:21 ` Kyrill Tkachov
2015-12-16 12:18 ` Bernd Schmidt
2015-12-16 17:00 ` Kyrill Tkachov
2015-12-16 17:28 ` Jeff Law
2015-12-17 9:46 ` Kyrill Tkachov
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