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Re: [patch, libfortran] [4.7/4.8/4.9 Regression] PR38199 missed optimization: I/O performance
- From: Steven Bosscher <stevenb dot gcc at gmail dot com>
- To: Jerry DeLisle <jvdelisle at charter dot net>
- Cc: gfortran <fortran at gcc dot gnu dot org>, gcc patches <gcc-patches at gcc dot gnu dot org>
- Date: Sat, 8 Mar 2014 13:58:24 +0100
- Subject: Re: [patch, libfortran] [4.7/4.8/4.9 Regression] PR38199 missed optimization: I/O performance
- Authentication-results: sourceware.org; auth=none
- References: <531ABAF8 dot 2070604 at charter dot net>
On Sat, Mar 8, 2014 at 7:38 AM, Jerry DeLisle wrote:
> The speedup is accomplished by simply skipping over spaces without calling
> next_read, then backing up one character and letting the existing execution path
> proceed, preserving all the end of record code needed in next_char.
>
> I also remove some unneeded error checks.
Would it be enough to make them "unlikely" instead?
- if (length < 0)
+ if (unlikely(length < 0))
Ciao!
Steven