From: Ian Lance Taylor <iant@google.com>
To: "Aparna Jain \(apjain\)" <apjain@cisco.com>
Cc: <gcc-help@gcc.gnu.org>
Subject: Re: problem with -funit-at-a-time
Date: Sat, 08 Mar 2008 02:10:00 -0000 [thread overview]
Message-ID: <m3bq5qezk6.fsf@google.com> (raw)
In-Reply-To: <FAC3B22F34BE4145A159CF4E0D3A9A5305EC9977@xmb-blr-413.apac.cisco.com> (Aparna Jain's message of "Thu\, 6 Mar 2008 15\:56\:01 +0530")
"Aparna Jain (apjain)" <apjain@cisco.com> writes:
> The code generated by 3.4.5 is no more assumes the first function of a C
> file as the starting Address of the compiled code. I think this is
> because of -funit-at-a-time which is enabled by default by O2 option.
...
> I used -fno-unit-at-a-time , and it was fine. But just concerned about
> the throughput of the code generated. Is there any other way to deal
> with this problem ?
If you need the output to be in the same order as the input, then in
gcc 3.4.5 -fno-unit-at-a-time is the right approach. In gcc 4.2 and
later, you can instead use -fno-toplevel-reorder, which retains the
ordering while also giving you the performance benefits of
-funit-at-a-time.
Ian
prev parent reply other threads:[~2008-03-08 2:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-06 10:27 Aparna Jain (apjain)
2008-03-08 2:10 ` Ian Lance Taylor [this message]
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