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[Bug fortran/38199] missed optimization: I/O performance
- From: "pault at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 21 Nov 2008 13:54:05 -0000
- Subject: [Bug fortran/38199] missed optimization: I/O performance
- References: <bug-38199-9562@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #6 from pault at gcc dot gnu dot org 2008-11-21 13:54 -------
I do not believe that it is a regression, so I have removed that from the
summary.
The profiling that you have done tells a story - I think that it is fairly
clear where the problem lies; not in making a spurious copy as I first thought
but rather in looking for an end of record, or some such foolishness.
I had a brief look in the library to try to understand why so much time is
spent in next_char, mem_read and memcpy and cannot immediately see what is
happening. Jerry knows the terrain better than me.
Cheers
Paul
--
pault at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|[4.4 regression] I/O |missed optimization: I/O
|performance |performance
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38199