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* [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap
@ 2012-01-24 22:36 matt at use dot net
  2012-01-24 22:40 ` [Bug middle-end/51986] " matt at use dot net
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: matt at use dot net @ 2012-01-24 22:36 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51986

             Bug #: 51986
           Summary: [4.7 regression] uninitialized variable warning
                    regression prevents bootstrap
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: matt@use.net


This just started in the last few days:

/tmp/gcc-obj/./prev-gcc/g++ -B/tmp/gcc-obj/./prev-gcc/
-B/home/matt/x86_64-unknown-linux-gnu/bin/ -nostdinc++
-B/tmp/gcc-obj/prev-x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs
-B/tmp/gcc-obj/prev-x86_64-unknown-linux-gnu/libstdc++-v3/libsupc++/.libs
-I/tmp/gcc-obj/prev-x86_64-unknown-linux-gnu/libstdc++-v3/include/x86_64-unknown-linux-gnu
-I/tmp/gcc-obj/prev-x86_64-unknown-linux-gnu/libstdc++-v3/include
-I/home/matt/src/gcc-4.7.0/libstdc++-v3/libsupc++
-L/tmp/gcc-obj/prev-x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs
-L/tmp/gcc-obj/prev-x86_64-unknown-linux-gnu/libstdc++-v3/libsupc++/.libs -c  
-g -O2 -flto=jobserver -frandom-seed=1 -O2 -finline-functions -funswitch-loops
-fpredictive-commoning -fgcse-after-reload -ftree-vectorize -ffast-math
-floop-interchange -floop-strip-mine -floop-block -ftree-loop-distribution
-ftree-loop-distribute-patterns -ftree-loop-im -ftree-loop-ivcanon -fivopts
-fweb -DIN_GCC   -fno-exceptions -fno-rtti -W -Wall -Wno-narrowing
-Wwrite-strings -Wcast-qual -Wmissing-format-attribute -pedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common 
-DHAVE_CONFIG_H -I. -I. -I/home/matt/src/gcc-4.7.0/gcc
-I/home/matt/src/gcc-4.7.0/gcc/. -I/home/matt/src/gcc-4.7.0/gcc/../include
-I/home/matt/src/gcc-4.7.0/gcc/../libcpp/include 
-I/home/matt/src/gcc-4.7.0/gcc/../libdecnumber
-I/home/matt/src/gcc-4.7.0/gcc/../libdecnumber/bid -I../libdecnumber   
/home/matt/src/gcc-4.7.0/gcc/sched-deps.c -o sched-deps.o
/home/matt/src/gcc-4.7.0/gcc/sched-deps.c: In function
‘sched_get_condition_with_rev(rtx_def const*, bool*)’:

/home/matt/src/gcc-4.7.0/gcc/sched-deps.c:599:33: error: ‘tmp’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]

Verified that it is a false positive, as
sched_get_condition_with_rev_uncached() always sets the contents of the bool in
question (if it isn't NULL, and it isn't in this case).

Can be reduced to -O2 -finline-functions, which probably isn't getting tested
much since using the bootstrap-O3 config has been broken for months now.

Pre-processed sources are attached.


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug middle-end/51986] [4.7 regression] uninitialized variable warning regression prevents bootstrap
  2012-01-24 22:36 [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap matt at use dot net
@ 2012-01-24 22:40 ` matt at use dot net
  2012-01-25 10:57 ` rguenth at gcc dot gnu.org
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: matt at use dot net @ 2012-01-24 22:40 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51986

--- Comment #1 from Matt Hargett <matt at use dot net> 2012-01-24 22:31:05 UTC ---
Created attachment 26448
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26448
pre-processed source of the file that triggers the regression


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug middle-end/51986] [4.7 regression] uninitialized variable warning regression prevents bootstrap
  2012-01-24 22:36 [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap matt at use dot net
  2012-01-24 22:40 ` [Bug middle-end/51986] " matt at use dot net
@ 2012-01-25 10:57 ` rguenth at gcc dot gnu.org
  2012-01-25 14:46 ` jakub at gcc dot gnu.org
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-25 10:57 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51986

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.7.0


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug middle-end/51986] [4.7 regression] uninitialized variable warning regression prevents bootstrap
  2012-01-24 22:36 [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap matt at use dot net
  2012-01-24 22:40 ` [Bug middle-end/51986] " matt at use dot net
  2012-01-25 10:57 ` rguenth at gcc dot gnu.org
@ 2012-01-25 14:46 ` jakub at gcc dot gnu.org
  2012-01-25 20:35 ` jakub at gcc dot gnu.org
  2012-01-25 21:15 ` jakub at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-01-25 14:46 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51986

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-01-25
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-25 14:33:39 UTC ---
Created attachment 26463
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26463
gcc47-pr51986.patch

I think it isn't a false positive, at least from compiler's POV.
The compiler can't know that PATTERN (insn) is always non-NULL.

I think it is always non-NULL, thus I'm proposing just removing the IMHO
unneeded check, if it was actually needed (but then it would need to be
scheduler internal, I think most of RTL code assumes everywhere that an insn
has non-NULL PATTERN and PATTERN shouldn't be used on non-insns like notes or
barriers), we'd want to swap the pat == 0 check with initialization of *rev.


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug middle-end/51986] [4.7 regression] uninitialized variable warning regression prevents bootstrap
  2012-01-24 22:36 [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap matt at use dot net
                   ` (2 preceding siblings ...)
  2012-01-25 14:46 ` jakub at gcc dot gnu.org
@ 2012-01-25 20:35 ` jakub at gcc dot gnu.org
  2012-01-25 21:15 ` jakub at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-01-25 20:35 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51986

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-25 20:22:59 UTC ---
Author: jakub
Date: Wed Jan 25 20:22:53 2012
New Revision: 183536

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183536
Log:
    PR middle-end/51986
    * sched-deps.c (sched_get_condition_with_rev_uncached): Don't test
    for pat == 0.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/sched-deps.c


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug middle-end/51986] [4.7 regression] uninitialized variable warning regression prevents bootstrap
  2012-01-24 22:36 [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap matt at use dot net
                   ` (3 preceding siblings ...)
  2012-01-25 20:35 ` jakub at gcc dot gnu.org
@ 2012-01-25 21:15 ` jakub at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-01-25 21:15 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51986

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-25 20:25:03 UTC ---
Fixed.


^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-01-25 20:25 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-01-24 22:36 [Bug middle-end/51986] New: [4.7 regression] uninitialized variable warning regression prevents bootstrap matt at use dot net
2012-01-24 22:40 ` [Bug middle-end/51986] " matt at use dot net
2012-01-25 10:57 ` rguenth at gcc dot gnu.org
2012-01-25 14:46 ` jakub at gcc dot gnu.org
2012-01-25 20:35 ` jakub at gcc dot gnu.org
2012-01-25 21:15 ` jakub at gcc dot gnu.org

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