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* [Bug tree-optimization/16220] New: Jump pessimization
@ 2004-06-26 17:39 falk at debian dot org
2004-06-26 19:13 ` [Bug tree-optimization/16220] [3.5 Regression] " pinskia at gcc dot gnu dot org
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: falk at debian dot org @ 2004-06-26 17:39 UTC (permalink / raw)
To: gcc-bugs
long ticks(long val, long high, long prev) {
return high + ((long) (val < prev) << 32);
}
gcc 3.3 produces this nice branch-free code:
cmplt a0,a2,v0
sll v0,0x20,t1
addq a1,t1,v0
whereas mainline introduces a branch and pointless constants:
cmplt a0,a2,a2
clr v0
beq a2,L14
lda t0,1
sll t0,0x20,v0
L14: addq v0,a1,v0
ret
--
Summary: Jump pessimization
Product: gcc
Version: 3.5.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: falk at debian dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: alphaev68-unknown-linux-gnu
GCC host triplet: alphaev68-unknown-linux-gnu
GCC target triplet: alphaev68-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [3.5 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
@ 2004-06-26 19:13 ` pinskia at gcc dot gnu dot org
2004-06-26 19:51 ` pinskia at gcc dot gnu dot org
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-06-26 19:13 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |3.5.0
Known to work| |3.3
Summary|Jump pessimization |[3.5 Regression] Jump
| |pessimization
Target Milestone|--- |3.5.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [3.5 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
2004-06-26 19:13 ` [Bug tree-optimization/16220] [3.5 Regression] " pinskia at gcc dot gnu dot org
@ 2004-06-26 19:51 ` pinskia at gcc dot gnu dot org
2004-07-17 22:52 ` pinskia at gcc dot gnu dot org
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-06-26 19:51 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-06-26 19:46 -------
Confirmed, the problem comes the fact PHI-OPT not being able to optimize this and something
converting (a<b) to (a<b)?0:1 where the 1 is overflowed.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2004-06-26 19:46:23
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [3.5 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
2004-06-26 19:13 ` [Bug tree-optimization/16220] [3.5 Regression] " pinskia at gcc dot gnu dot org
2004-06-26 19:51 ` pinskia at gcc dot gnu dot org
@ 2004-07-17 22:52 ` pinskia at gcc dot gnu dot org
2004-09-30 18:06 ` [Bug tree-optimization/16220] [4.0 " pinskia at gcc dot gnu dot org
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-07-17 22:52 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-07-17 22:52 -------
Actually what has happened now is that (long) (val < prev) << 32 is changed into a < b ? 1 <<32 : 0. :(
So what needs to happen is PHI-OPT needs to detect this situational.
--
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2004-06-26 19:46:23 |2004-07-17 22:52:49
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [4.0 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
` (2 preceding siblings ...)
2004-07-17 22:52 ` pinskia at gcc dot gnu dot org
@ 2004-09-30 18:06 ` pinskia at gcc dot gnu dot org
2004-12-20 14:01 ` pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-09-30 18:06 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-09-30 18:06 -------
Roger I almost think this was caused by:
2004-05-20 Roger Sayle <roger@eyesopen.com>
PR middle-end/3074
* fold-const.c (strip_compound_expr): Delete function.
(count_cond): Delete function.
(fold_binary_op_with_conditional_arg): Only perform transformations
"a + (b?c:d) -> b ? a+c : a+d" and "(b?c:d) + a -> b ? c+a : d+a"
when a is constant. This greatly simplifies this routine.
but I could be wrong.
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |roger at eyesopen dot com
Known to fail|4.0 |4.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [4.0 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
` (3 preceding siblings ...)
2004-09-30 18:06 ` [Bug tree-optimization/16220] [4.0 " pinskia at gcc dot gnu dot org
@ 2004-12-20 14:01 ` pinskia at gcc dot gnu dot org
2005-01-04 19:25 ` pinskia at gcc dot gnu dot org
2005-01-10 1:05 ` pinskia at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-12-20 14:01 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |minor
GCC build triplet|alphaev68-unknown-linux-gnu |
GCC host triplet|alphaev68-unknown-linux-gnu |
GCC target triplet|alphaev68-unknown-linux-gnu |alpha*-*-*
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [4.0 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
` (4 preceding siblings ...)
2004-12-20 14:01 ` pinskia at gcc dot gnu dot org
@ 2005-01-04 19:25 ` pinskia at gcc dot gnu dot org
2005-01-10 1:05 ` pinskia at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-01-04 19:25 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-01-04 19:25 -------
Patch here: <http://gcc.gnu.org/ml/gcc-patches/2005-01/msg00210.html>.
--
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |patch
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/16220] [4.0 Regression] Jump pessimization
2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
` (5 preceding siblings ...)
2005-01-04 19:25 ` pinskia at gcc dot gnu dot org
@ 2005-01-10 1:05 ` pinskia at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-01-10 1:05 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-01-10 01:05 -------
Fixed by:
2005-01-08 Roger Sayle <roger@eyesopen.com>
* ifcvt.c (find_if_case_1): Reinstate 2005-01-04 change, now that
the latent bug in rtl_delete_block has been resolved.
aka
2005-01-04 Roger Sayle <roger@eyesopen.com>
* ifcvt.c (find_if_case_1): Avoid creating an empty forwarder block,
if deleting the then-block allows the test-block to fallthru to the
else-block.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16220
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2005-01-10 1:05 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2004-06-26 17:39 [Bug tree-optimization/16220] New: Jump pessimization falk at debian dot org
2004-06-26 19:13 ` [Bug tree-optimization/16220] [3.5 Regression] " pinskia at gcc dot gnu dot org
2004-06-26 19:51 ` pinskia at gcc dot gnu dot org
2004-07-17 22:52 ` pinskia at gcc dot gnu dot org
2004-09-30 18:06 ` [Bug tree-optimization/16220] [4.0 " pinskia at gcc dot gnu dot org
2004-12-20 14:01 ` pinskia at gcc dot gnu dot org
2005-01-04 19:25 ` pinskia at gcc dot gnu dot org
2005-01-10 1:05 ` pinskia at gcc dot gnu dot org
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