[Bug c++/13712] Executable runs 25% slower than when compiled with INTEL compiler

["william dot crocker at analog dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From william dot crocker at analog dot com  2004-01-22 19:42 -------
Subject: Re:  Executable runs 25% slower than when compiled with INTEL compiler


> From dberlin@gcc.gnu.org Fri Jan 16 17:54:53 2004
> Date: 16 Jan 2004 22:54:51 -0000
> From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
> To: william.crocker@analog.com
> Subject: [Bug c++/13712] Executable runs 25% slower than when compiled with INTEL compiler
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> ------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-16 22:54 -------
> We need a testcase?

I can probably put together a test case but I don't think you
are going to like it. (I tried to make a small test case, but it
did not demonstrate the problem.)

My app is 750K LOC.
gprof shows that a single 2K line function accounts
for most (if not all) of the 25% difference in execution speed.
This function is primarily floating point operations
with a little control logic.

I can try to carve this function out
and see if it demonstrates the problem.

Would that be satisfactory ?

Bill

> 
> -- 
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>              Status|UNCONFIRMED                 |WAITING
>            Keywords|                            |pessimizes-code
> 
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13712
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13712