From: Georg-Johann Lay <avr@gjlay.de>
To: Ian Lance Taylor <iant@google.com>
Cc: gcc-help@gcc.gnu.org
Subject: Re: Reload pass ignores constraints. Why?
Date: Fri, 17 Apr 2009 15:34:00 -0000 [thread overview]
Message-ID: <49E8B05D.1080007@gjlay.de> (raw)
In-Reply-To: <m3zlehu5u5.fsf@google.com>
Ian Lance Taylor schrieb:
> Georg-Johann Lay <avr@gjlay.de> writes:
>
>> iii) Expand into MOV+LSHIFTRT and allow the resulting const in
>> *movsi_insn:
>> CSE et. al. will reconstruct the original constant and
>> replace MOV+LSHIFTRT with a single SET:
>> Bad: expanding was in vain and we Goto i)
>
> I think this is the option you should use. You should use
> TARGET_RTX_COSTS to make the constants which may not be immediate
> operands expensive. Then CSE will not reconstruct them.
Jepp, that works.
Thanks a lot!
Georg-Johann
prev parent reply other threads:[~2009-04-17 15:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-14 9:35 Georg-Johann Lay
2009-04-14 14:43 ` Ian Lance Taylor
2009-04-14 18:12 ` Georg-Johann Lay
2009-04-14 20:54 ` Ian Lance Taylor
2009-04-15 12:00 ` Georg-Johann Lay
2009-04-15 14:28 ` Ian Lance Taylor
2009-04-15 16:55 ` Georg-Johann Lay
2009-04-15 18:31 ` Ian Lance Taylor
2009-04-17 15:34 ` Georg-Johann Lay [this message]
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