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* [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer
@ 2014-09-29 4:20 andi-gcc at firstfloor dot org
2014-09-29 4:26 ` [Bug middle-end/63404] " andi-gcc at firstfloor dot org
` (13 more replies)
0 siblings, 14 replies; 15+ messages in thread
From: andi-gcc at firstfloor dot org @ 2014-09-29 4:20 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Bug ID: 63404
Summary: gcc 5 miscompiles linux block layer
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: andi-gcc at firstfloor dot org
When I boot a current Linux mainline kernel compiled with mainline gcc
and the section fix patch applied I always get a crash at boot in the block
layer.
gcc version 5.0.0 20140926 (experimental) (GCC)
1.318801] EXT4-fs (sda1): write access will be enabled during recovery
[ 1.367592] ------------[ cut here ]------------
[ 1.369061] kernel BUG at /home/andi/lsrc/linux/block/blk-flush2.c:80!
[ 1.370910] invalid opcode: 0000 [#1] SMP
I narrowed it down to one function. When only the function is compiled with gcc
4.9 the kernel boots.
Attach is a test case with only the function.
It doesn't quite run by itself yet, so the code has to be examined.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug middle-end/63404] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
@ 2014-09-29 4:26 ` andi-gcc at firstfloor dot org
2014-09-29 4:57 ` [Bug target/63404] " andi-gcc at firstfloor dot org
` (12 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: andi-gcc at firstfloor dot org @ 2014-09-29 4:26 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #1 from Andi Kleen <andi-gcc at firstfloor dot org> ---
Created attachment 33607
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33607&action=edit
not quite yet runnable test case
In the real execution blk_flush_complete_seq always ends up in the default case
in the switch and crashes.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
2014-09-29 4:26 ` [Bug middle-end/63404] " andi-gcc at firstfloor dot org
@ 2014-09-29 4:57 ` andi-gcc at firstfloor dot org
2014-09-29 8:29 ` [Bug target/63404] [5 Regression] " trippels at gcc dot gnu.org
` (11 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: andi-gcc at firstfloor dot org @ 2014-09-29 4:57 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Andi Kleen <andi-gcc at firstfloor dot org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|middle-end |target
--- Comment #2 from Andi Kleen <andi-gcc at firstfloor dot org> ---
The switch is miscompiled and destroys the flags register in the middle of a
comparison:
.LVL2:
.loc 1 49 0
cmpl $2, %eax #, seq
je .L5 #,
shrb $2, %r12b #, D.32130 <-------- BAD1
andl $1, %r12d #, D.32130 <-------- BAD2
jbe .L24 #,
cmpl $4, %eax #, seq
je .L7 #,
cmpl $8, %eax #, seq
jne .L4 #,
gcc 4.9 creates the same code except for BAD1/BAD2. These two
JBE relies on CF/ZF being preserved, but SHR can overwrite ZF/CF,
which breaks the JBE after the CMP
So somehow the backend lost track of these two flag bits.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
2014-09-29 4:26 ` [Bug middle-end/63404] " andi-gcc at firstfloor dot org
2014-09-29 4:57 ` [Bug target/63404] " andi-gcc at firstfloor dot org
@ 2014-09-29 8:29 ` trippels at gcc dot gnu.org
2014-09-29 10:49 ` jiwang at gcc dot gnu.org
` (10 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: trippels at gcc dot gnu.org @ 2014-09-29 8:29 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Priority|P3 |P1
Status|UNCONFIRMED |NEW
Keywords| |wrong-code
Last reconfirmed| |2014-09-29
CC| |jiwang at gcc dot gnu.org,
| |trippels at gcc dot gnu.org
Ever confirmed|0 |1
Summary|gcc 5 miscompiles linux |[5 Regression] gcc 5
|block layer |miscompiles linux block
| |layer
Target Milestone|--- |5.0
--- Comment #3 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Started with r215563.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (2 preceding siblings ...)
2014-09-29 8:29 ` [Bug target/63404] [5 Regression] " trippels at gcc dot gnu.org
@ 2014-09-29 10:49 ` jiwang at gcc dot gnu.org
2014-09-29 11:14 ` jiwang at gcc dot gnu.org
` (9 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: jiwang at gcc dot gnu.org @ 2014-09-29 10:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #4 from Jiong Wang <jiwang at gcc dot gnu.org> ---
sorry for causing the trouble.
the reason might be the "flag" is an implified register while it's not take
into account in current shrink-wrap reg read/write analysis.
I will revert my patch temperarily if I couldn't find a proper fix today.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (3 preceding siblings ...)
2014-09-29 10:49 ` jiwang at gcc dot gnu.org
@ 2014-09-29 11:14 ` jiwang at gcc dot gnu.org
2014-09-29 18:46 ` pthaugen at gcc dot gnu.org
` (8 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: jiwang at gcc dot gnu.org @ 2014-09-29 11:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #5 from Jiong Wang <jiwang at gcc dot gnu.org> ---
we need to check the following
else if (GET_CODE == CLOBBER
|| GET_CODE (x) == USE
|| GET_CODE (x) == ASM_INPUT)
I will post the fix after pass x86 bootstrap and regression
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (4 preceding siblings ...)
2014-09-29 11:14 ` jiwang at gcc dot gnu.org
@ 2014-09-29 18:46 ` pthaugen at gcc dot gnu.org
2014-09-29 18:48 ` jiwang at gcc dot gnu.org
` (7 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: pthaugen at gcc dot gnu.org @ 2014-09-29 18:46 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Pat Haugen <pthaugen at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |pthaugen at gcc dot gnu.org
--- Comment #6 from Pat Haugen <pthaugen at gcc dot gnu.org> ---
(In reply to Jiong Wang from comment #5)
> we need to check the following
>
> else if (GET_CODE == CLOBBER
> || GET_CODE (x) == USE
> || GET_CODE (x) == ASM_INPUT)
>
> I will post the fix after pass x86 bootstrap and regression
r215563 also introduced a miscompare on PowerPC for cpu2000 benchmark 254.gap.
Applying your patch proposed on the gcc-patches ml for this bug fixes the
issue.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (5 preceding siblings ...)
2014-09-29 18:46 ` pthaugen at gcc dot gnu.org
@ 2014-09-29 18:48 ` jiwang at gcc dot gnu.org
2014-09-29 18:50 ` jiwang at gcc dot gnu.org
` (6 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: jiwang at gcc dot gnu.org @ 2014-09-29 18:48 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #7 from Jiong Wang <jiwang at gcc dot gnu.org> ---
(In reply to Pat Haugen from comment #6)
> (In reply to Jiong Wang from comment #5)
> > we need to check the following
> >
>
> r215563 also introduced a miscompare on PowerPC for cpu2000 benchmark
> 254.gap. Applying your patch proposed on the gcc-patches ml for this bug
> fixes the issue.
thanks for reporting this, sorry for causing trouble.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (6 preceding siblings ...)
2014-09-29 18:48 ` jiwang at gcc dot gnu.org
@ 2014-09-29 18:50 ` jiwang at gcc dot gnu.org
2014-09-29 21:03 ` dominiq at lps dot ens.fr
` (5 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: jiwang at gcc dot gnu.org @ 2014-09-29 18:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #8 from Jiong Wang <jiwang at gcc dot gnu.org> ---
(In reply to Pat Haugen from comment #6)
> (In reply to Jiong Wang from comment #5)
> > we need to check the following
> >
> > else if (GET_CODE == CLOBBER
> > || GET_CODE (x) == USE
> > || GET_CODE (x) == ASM_INPUT)
> >
> > I will post the fix after pass x86 bootstrap and regression
>
> r215563 also introduced a miscompare on PowerPC for cpu2000 benchmark
> 254.gap. Applying your patch proposed on the gcc-patches ml for this bug
> fixes the issue.
and I am curious about whether there are any performance change since this insn
sink change.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (7 preceding siblings ...)
2014-09-29 18:50 ` jiwang at gcc dot gnu.org
@ 2014-09-29 21:03 ` dominiq at lps dot ens.fr
2014-10-01 20:45 ` pthaugen at gcc dot gnu.org
` (4 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: dominiq at lps dot ens.fr @ 2014-09-29 21:03 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #9 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
For the record the test gfortran.dg/typebound_operator_3.f03 also failed with
-O1 and -m64 (see https://gcc.gnu.org/ml/gcc-regression/2014-09/msg00226.html).
This is fixed by the patch at
https://gcc.gnu.org/ml/gcc-patches/2014-09/msg02568.html.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (8 preceding siblings ...)
2014-09-29 21:03 ` dominiq at lps dot ens.fr
@ 2014-10-01 20:45 ` pthaugen at gcc dot gnu.org
2014-10-08 4:42 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: pthaugen at gcc dot gnu.org @ 2014-10-01 20:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #10 from Pat Haugen <pthaugen at gcc dot gnu.org> ---
(In reply to Jiong Wang from comment #8)
> and I am curious about whether there are any performance change since this
> insn sink change.
I built/ran cpu2000 and didn't see any difference outside the noise range. The
number of shrink-wrapped procedures over the entire benchmark suite build went
from 558 to 567.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (9 preceding siblings ...)
2014-10-01 20:45 ` pthaugen at gcc dot gnu.org
@ 2014-10-08 4:42 ` pinskia at gcc dot gnu.org
2014-10-10 15:56 ` rth at gcc dot gnu.org
` (2 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: pinskia at gcc dot gnu.org @ 2014-10-08 4:42 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |sasha.levin at oracle dot com
--- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 63481 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (10 preceding siblings ...)
2014-10-08 4:42 ` pinskia at gcc dot gnu.org
@ 2014-10-10 15:56 ` rth at gcc dot gnu.org
2014-10-17 12:14 ` trippels at gcc dot gnu.org
2014-11-07 15:55 ` jiwang at gcc dot gnu.org
13 siblings, 0 replies; 15+ messages in thread
From: rth at gcc dot gnu.org @ 2014-10-10 15:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
--- Comment #12 from Richard Henderson <rth at gcc dot gnu.org> ---
Author: rth
Date: Fri Oct 10 15:56:07 2014
New Revision: 216096
URL: https://gcc.gnu.org/viewcvs?rev=216096&root=gcc&view=rev
Log:
PR target/63404
* shrink-wrap.c (move_insn_for_shrink_wrap): Don't use single_set.
Restrict the set of expressions we're willing to move.
Modified:
trunk/gcc/ChangeLog
trunk/gcc/shrink-wrap.c
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (11 preceding siblings ...)
2014-10-10 15:56 ` rth at gcc dot gnu.org
@ 2014-10-17 12:14 ` trippels at gcc dot gnu.org
2014-11-07 15:55 ` jiwang at gcc dot gnu.org
13 siblings, 0 replies; 15+ messages in thread
From: trippels at gcc dot gnu.org @ 2014-10-17 12:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #13 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 15+ messages in thread
* [Bug target/63404] [5 Regression] gcc 5 miscompiles linux block layer
2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
` (12 preceding siblings ...)
2014-10-17 12:14 ` trippels at gcc dot gnu.org
@ 2014-11-07 15:55 ` jiwang at gcc dot gnu.org
13 siblings, 0 replies; 15+ messages in thread
From: jiwang at gcc dot gnu.org @ 2014-11-07 15:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63404
Jiong Wang <jiwang at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |schwab@linux-m68k.org
--- Comment #14 from Jiong Wang <jiwang at gcc dot gnu.org> ---
*** Bug 63463 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2014-11-07 15:55 UTC | newest]
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2014-09-29 4:20 [Bug middle-end/63404] New: gcc 5 miscompiles linux block layer andi-gcc at firstfloor dot org
2014-09-29 4:26 ` [Bug middle-end/63404] " andi-gcc at firstfloor dot org
2014-09-29 4:57 ` [Bug target/63404] " andi-gcc at firstfloor dot org
2014-09-29 8:29 ` [Bug target/63404] [5 Regression] " trippels at gcc dot gnu.org
2014-09-29 10:49 ` jiwang at gcc dot gnu.org
2014-09-29 11:14 ` jiwang at gcc dot gnu.org
2014-09-29 18:46 ` pthaugen at gcc dot gnu.org
2014-09-29 18:48 ` jiwang at gcc dot gnu.org
2014-09-29 18:50 ` jiwang at gcc dot gnu.org
2014-09-29 21:03 ` dominiq at lps dot ens.fr
2014-10-01 20:45 ` pthaugen at gcc dot gnu.org
2014-10-08 4:42 ` pinskia at gcc dot gnu.org
2014-10-10 15:56 ` rth at gcc dot gnu.org
2014-10-17 12:14 ` trippels at gcc dot gnu.org
2014-11-07 15:55 ` jiwang at gcc dot gnu.org
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