[Bug rtl-optimization/63491] Ice in LRA with simple vector test case on power

["bergner at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63491

--- Comment #8 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Vladimir Makarov from comment #7)
> I tried again the test on gcc rev. 221324 (Mar 10) with the mentioned
> options and I've failed to reproduce the crash.

Maybe a configure option thing?  Maybe --disable-bootstrap which I have been
using?  I just tried using the same revision you did (221324) and I still see
the same error:


Target: powerpc64-linux
Configured with: /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/configure
--target=powerpc64-linux --host=powerpc64-linux --build=powerpc64-linux
--enable-threads=posix --enable-shared --enable-__cxa_atexit
--enable-languages=c,c++ --enable-secureplt --enable-checking=yes
--with-gmp=/home/bergner/tools/meissner
--with-mpfr=/home/bergner/tools/meissner
--with-mpc=/home/bergner/tools/meissner --with-long-double-128
--enable-decimal-float --disable-bootstrap --disable-alsa
--prefix=/home/bergner/gcc/install/gcc-fsf-mainline-vlad-lra-r221324
Thread model: posix
gcc version 5.0.0 20150310 (experimental) [trunk revision 221324] (GCC) 


[bergner@makalu-lp1 LRA]$
/home/bergner/gcc/build/gcc-fsf-mainline-vlad-lra-r221324/gcc/xgcc
-B/home/bergner/gcc/build/gcc-fsf-mainline-vlad-lra-r221324/gcc -O1 -m64
-mcpu=power8 -mlra -S pr63491.i pr63491.i: In function ‘foo’:
pr63491.i:14:1: internal compiler error: in check_and_process_move, at
lra-constraints.c:1171
 }
 ^
0x1099c933 check_and_process_move
    /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/gcc/lra-constraints.c:1168
0x109a5313 curr_insn_transform
    /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/gcc/lra-constraints.c:3464
0x109a9b93 lra_constraints(bool)
    /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/gcc/lra-constraints.c:4452
0x10989da3 lra(_IO_FILE*)
    /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/gcc/lra.c:2301
0x1090cb97 do_reload
    /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/gcc/ira.c:5418
0x1090d22f execute
    /home/bergner/gcc/gcc-fsf-mainline-vlad-lra/gcc/ira.c:5589
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
>From gcc-bugs-return-480025-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Tue Mar 10 21:52:33 2015
Return-Path: <gcc-bugs-return-480025-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Delivered-To: listarch-gcc-bugs@gcc.gnu.org
Received: (qmail 60112 invoked by alias); 10 Mar 2015 21:52:32 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Delivered-To: mailing list gcc-bugs@gcc.gnu.org
Received: (qmail 60040 invoked by uid 48); 10 Mar 2015 21:52:29 -0000
From: "boger at us dot ibm.com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug go/64999] s390x libgo test failure in TestMemoryProfiler
Date: Tue, 10 Mar 2015 21:52:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: go
X-Bugzilla-Version: 5.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: boger at us dot ibm.com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: ian at airs dot com
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-64999-4-JMJk8kB9Uk@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-64999-4@http.gcc.gnu.org/bugzilla/>
References: <bug-64999-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-03/txt/msg01169.txt.bz2
Content-length: 2014

https://gcc.gnu.org/bugzilla/show_bug.cgi?idd999

--- Comment #50 from boger at us dot ibm.com ---
(In reply to Ian Lance Taylor from comment #49)
> libbacktrace returns the line number that you actually care about: the line
> number of the call instruction.  There is no question that that is correct.
>
> You say that it is a problem if the PC does not match the line number, but
> to me that sounds like a conceptual problem.  What is the actual problem?
>
> The pprof.go code expects to get the PC after the call instruction, and
> tries to turn it into the PC of the call instruction.  I think we can all
> agree that pprof.go should in fact see the PC after the call instruction.
> The simple way to do that is for callback in libgo/runtime/go-callers.c to
> increment pc before storing it in loc->pc.  Apparently there is some problem
> with that but I do not know what that problem is.
>
> The additional argument I mentioned would be for the function types
> backtrace_fulL_callback and backtrace_simple_callback defined in
> libbacktrace/backtrace.h.  The additional argument would be, essentially,
> the value of ip_before_insn in libbacktrace/backtrace.c and
> libbacktrace/simple.c.  The argument would tell you whether the PC follows a
> call instruction, or whether it is the correct PC for a signal frame
> instruction

OK.

I didn't realize that backtrace_full is expected to return an array of Location
structures which contain the PC for the instruction following the call but the
line number for the call.  When I saw there was a single structure containing a
PC and lineno, I assumed that it was intended to hold information for a single
location, i.e., a PC and the lineno that corresponded to it.

I will go back and try this again as you suggested.  I had tried several
variations and hit different errors and when I saw how the line number and PC
were out of sync that steered me down the wrong path.  Now that I understand
what it really should be I think it should probably work.