http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42505
Jeffrey A. Law changed:
What|Removed |Added
Status|NEW |RESOLVED
CC|
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42505
Richard Guenther changed:
What|Removed |Added
Known to work||4.6.0
Target Milestone|4.4.6
--- Comment #12 from sandra at gcc dot gnu dot org 2010-07-10 18:43 ---
Subject: Bug 42505
Author: sandra
Date: Sat Jul 10 18:43:29 2010
New Revision: 162043
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=162043
Log:
2010-07-10 Sandra Loosemore
PR middle-end/42505
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42505
Jakub Jelinek changed:
What|Removed |Added
Target Milestone|4.4.5 |4.4.6
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42505
--- Comment #13 from Sandra Loosemore
2010-10-01 15:01:08 UTC ---
I think this bug is fixed now.
--
jakub at gcc dot gnu dot org changed:
What|Removed |Added
Target Milestone|4.4.4 |4.4.5
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42505
--- Comment #4 from sandra at codesourcery dot com 2010-06-04 00:09 ---
I've been looking at this problem today. Here's the stupid part coming out of
ivopts:
:
# ivtmp.7_21 = PHI <0(2), ivtmp.7_20(4)>
# ivtmp.10_22 = PHI
count_25 = (int) ivtmp.10_22;
if (count_25 != 0)
got
--- Comment #5 from steven at gcc dot gnu dot org 2010-06-04 07:45 ---
AFAIU, you can't randomly change signed to unsigned, due to different overflow
semantics, which is why IVOPTS doesn't make this change itself. Imagine you
enter the loop with count = 0, and with a second counter hidde
--- Comment #6 from rguenth at gcc dot gnu dot org 2010-06-04 09:08 ---
If the result of the conversion is only used in an exit equality test against a
constant it can be dropped. This could also happen in a following
forwprop run which is our single tree-combiner (though that currently
--- Comment #7 from sandra at codesourcery dot com 2010-06-05 20:41 ---
OK, I'm testing a hack to rewrite_use_compare to make it know that it doesn't
have to introduce a temporary just to compare against constant zero. I'm also
doing a little tuning of the costs model for -Os, using CSi
--- Comment #8 from sandra at codesourcery dot com 2010-06-10 13:01 ---
I was barking up the wrong tree with my last idea -- the signed/unsigned
conversion business was a red herring. Here's what I now believe is the
problem: the costs computation is underestimating the register pressur
--- Comment #9 from sandra at codesourcery dot com 2010-06-12 07:42 ---
I now have a specific theory of what is going on here. There are two problems:
(1) estimate_reg_pressure_cost is not accounting for the function call in the
loop body. In this case it ought to use call_used_regs i
--- Comment #10 from sandra at codesourcery dot com 2010-06-19 12:56
---
Patch posted here:
http://gcc.gnu.org/ml/gcc-patches/2010-06/msg01920.html
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42505
--- Comment #11 from sandra at gcc dot gnu dot org 2010-07-05 17:41 ---
Subject: Bug 42505
Author: sandra
Date: Mon Jul 5 17:40:57 2010
New Revision: 161844
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=161844
Log:
2010-07-05 Sandra Loosemore
PR middle-end/42505
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