Date: Thu, 22 Feb 2001 13:19:26 +0100 (CET) From: Alexander Leidinger <Alexander@Leidinger.net> To: cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/share/mk sys.mk Message-ID: <200102221219.f1MCJSF08422@Magelan.Leidinger.net> In-Reply-To: <20010221114805.A96924@dragon.nuxi.com>
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On 21 Feb, David O'Brien wrote:
>> BTW, may be -mcpu=${MACHINE_CPU} can be added to the default CFLAGS now?
>
> I am nervous about this on the Alpha unless very well tested. We all
> know that an ev4 system as the ev4 cannot handled ev56-only instructions.
> [note the release building box and package cluster are ev56 machines]
> According to the GCC manual for 3.0 (in development), -mcpu on the Alpha
> includes the functionality of -march:
[Quoting the docs]
Reading "man gcc" on my -current (gcc 2.95.3) I interpret this as:
- -mcpu does the _instruction scheduling_ for the specified CPU
- -march _uses instructions_ of the specified CPU
So using -mcpu may slow down a program on a different CPU, but it didn't
uses instructions for the specified CPU.
Is this a bug in the 2.95.3 manual (I think not) or does the behavior
change in gcc 3.0 (that would be bad, is this a fixed decission)?
Bye,
Alexander.
--
0 and 1. Now what could be so hard about that?
http://www.Leidinger.net Alexander @ Leidinger.net
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