Re: [PATCH] combine: distribute_notes again (PR69567, PR64682)

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Sat, Feb 6, 2016 at 4:51 PM, Segher Boessenkool
<segher@kernel.crashing.org> wrote:
> On Sat, Feb 06, 2016 at 09:54:25AM -0800, H.J. Lu wrote:
>> On Thu, Feb 4, 2016 at 3:28 PM, Segher Boessenkool
>> <segher@kernel.crashing.org> wrote:
>> > On Tue, Feb 02, 2016 at 11:32:08AM +0000, Segher Boessenkool wrote:
>> >> As it happens the patch I did over a year ago for PR64682 isn't quite
>> >> correct.  This is PR69567.  This fixes it.
>> >>
>> >> Tested on the separate testcases; also did bootstrap + testsuite on
>> >> powerpc64-linux and x86_64-linux.  I'll commit this tomorrow or so if
>> >> no one sees something wrong with it.
>> >>
>> >>
>> >> 2016-02-02  Segher Boessenkool  <segher@kernel.crashing.org>
>> >>
>> >>       PR rtl-optimization/64682
>> >>       PR rtl-optimization/69567
>> >>       * combine.c (distribute_notes) <REG_DEAD>: Place the death note
>> >>       before I2 only if the register is both used and set in I2.
>> >
>> > Committed to mainline and 5 now.
>> >
>>
>> This caused:
>>
>> FAIL: gcc.c-torture/execute/pr64682.c   -O2  execution test
>> FAIL: gcc.c-torture/execute/pr64682.c   -O2 -flto
>> -fno-use-linker-plugin -flto-partition=none  execution test
>> FAIL: gcc.c-torture/execute/pr64682.c   -O2 -flto -fuse-linker-plugin
>> -fno-fat-lto-objects  execution test
>> FAIL: gcc.c-torture/execute/pr64682.c   -O3 -fomit-frame-pointer  execution test
>> FAIL: gcc.c-torture/execute/pr64682.c   -O3 -fomit-frame-pointer
>> -funroll-all-loops -finline-functions  execution test
>> FAIL: gcc.c-torture/execute/pr64682.c   -O3 -fomit-frame-pointer
>> -funroll-loops  execution test
>> FAIL: gcc.c-torture/execute/pr64682.c   -O3 -g  execution test
>>
>> on x86 on GCC 5 branch.  Trunk is OK.  Did you miss a backport from
>> trunk?
>
> I tested it on x86_64-linux.  What does "x86" mean, exactly?
>
> Note -O2 and -O3 do not exhibit the fail condition on trunk on the 64682
> testcase (but -O1 does).
>

By x86, I mean ia32, x86-64 and x32:

https://gcc.gnu.org/ml/gcc-testresults/2016-02/msg00475.html
https://gcc.gnu.org/ml/gcc-testresults/2016-02/msg00645.html
https://gcc.gnu.org/ml/gcc-testresults/2016-02/msg00503.html

It only happens on gcc-5-branch, not on trunk:

/export/build/gnu/gcc-5/build-x86_64-linux/gcc/
/export/gnu/import/git/sources/gcc-release/gcc/testsuite/gcc.c-torture/execute/pr64682.c
-fno-diagnostics-show-caret -fdiagnostics-color=never -O2 -w -lm -o
./pr64682.exe
[hjl@gnu-skl-1 testsuite]$ gdb ./pr64682.exe
GNU gdb (GDB) Fedora 7.10.1-30.fc23
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
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For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./pr64682.exe...(no debugging symbols found)...done.
(gdb) r
Starting program:
/export/build/gnu/gcc-5/build-x86_64-linux/gcc/testsuite/pr64682.exe
Missing separate debuginfos, use: dnf debuginfo-install
glibc-2.22-7.0.fc23.x86_64

Program received signal SIGABRT, Aborted.
0x00007ffff774c3b8 in raise () from /lib64/libc.so.6
(gdb) bt
#0  0x00007ffff774c3b8 in raise () from /lib64/libc.so.6
#1  0x00007ffff774dfba in abort () from /lib64/libc.so.6
#2  0x00000000004005dd in foo ()
#3  0x00000000004004b6 in main ()
(gdb)


-- 
H.J.