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From Ulrich Drepper <drep...@redhat.com>
Subject Re: Is --enable-utf8 working everywhere
Date Wed, 17 Jul 2002 21:44:59 GMT
On Wed, 2002-07-17 at 14:37, Greg Hudson wrote:

> I'll try once more, having been seemingly ignored last time: What,
> precisely, is the problem with calling __error() twice?

Speed and much more importantly size.  On x86 the code sequence with
using a variable is 14 bytes shorter and no conditional jump is needed. 
Multiply this with all the places you have to perform "defensive
programming" and you'll end up with a large number.  The error handling
code also effects the non-error case since icache gets polluted with
unnecessary code.

I have never suggested to change every place where errno isn't used up
to this standard (even though this would be good).  But if you get a
patch which does it like that no argument like "that's not how we did it
so far" must outweigh the benefits.

---------------.                          ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------

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