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From: "manfred99 at gmx dot ch" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/32382] missed optimization in internal read
Date: Sun, 02 Sep 2007 11:53:00 -0000	[thread overview]
Message-ID: <20070902115303.31418.qmail@sourceware.org> (raw)
In-Reply-To: <bug-32382-9562@http.gcc.gnu.org/bugzilla/>



------- Comment #3 from manfred99 at gmx dot ch  2007-09-02 11:53 -------
Jerry, any news on this?

I have seen this pattern many times in legacy fortran77 code,
and the code authors seem to assume that ridiculously large loop
stop values do not compromize performance.

After all, in fortran77 you have to do something like this if you don't
know the dimension to the data to read.

Interestingly, ifort seems to have changed their mind,
as ifort 8.1 seems to loop till the end (see comp.lang.fortran 
link in BUG 32257), whereas ifort 9.0 stops at value 4, like g77.
And, as mentioned in BUG 32257, the compiler is free to choose.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32382


  parent reply	other threads:[~2007-09-02 11:53 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-17 20:29 [Bug fortran/32382] New: " manfred99 at gmx dot ch
2007-06-17 20:48 ` [Bug fortran/32382] " jvdelisle at gcc dot gnu dot org
2007-06-23  3:13 ` jvdelisle at gcc dot gnu dot org
2007-09-02 11:53 ` manfred99 at gmx dot ch [this message]
2007-09-02 16:08 ` jvdelisle at gcc dot gnu dot org
2007-10-05  9:37 ` manfred99 at gmx dot ch
2007-10-05  9:38 ` manfred99 at gmx dot ch
2009-09-13 14:30 ` jvdelisle at gcc dot gnu dot org
2010-02-13  6:17 ` jvdelisle at gcc dot gnu dot org
2010-02-14  8:29 ` jvdelisle at gcc dot gnu dot org
2010-02-14  8:33 ` jvdelisle at gcc dot gnu dot org
2010-02-14 15:02 ` hjl dot tools at gmail dot com

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