[Bug bootstrap/53278] New: [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[Bug bootstrap/53278] New: [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

             Bug #: 53278
           Summary: [4.8 regression] internal compiler error: in
                    df_uses_record, at df-scan.c:3179 when compiling
                    libgcc2.c __mulvdi3 on armv5tel-linux
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mikpe@it.uu.se


Created attachment 27343
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27343
Preprocessed source.  ICEs with -O1 and above, but not with -Os.

Attempting to bootstrap gcc-4.8-20120506 on armv5tel-linux fails with:

/mnt/scratch/objdir48/./gcc/xgcc -B/mnt/scratch/objdir48/./gcc/
-B/mnt/scratch/install48/armv5tel-unknown-linux-gnueabi/bin/
-B/mnt/scratch/install48/armv5tel-unknown-linux-gnueabi/lib/ -isystem
/mnt/scratch/install48/armv5tel-unknown-linux-gnueabi/include -isystem
/mnt/scratch/install48/armv5tel-unknown-linux-gnueabi/sys-include    -g -O2 -O2
 -g -O2 -DIN_GCC   -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes
-Wmissing-prototypes -Wold-style-definition  -isystem ./include   -fPIC
-fno-inline -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector   -fPIC
-fno-inline -I. -I. -I../.././gcc -I/mnt/scratch/gcc-4.8-20120506/libgcc
-I/mnt/scratch/gcc-4.8-20120506/libgcc/.
-I/mnt/scratch/gcc-4.8-20120506/libgcc/../gcc
-I/mnt/scratch/gcc-4.8-20120506/libgcc/../include  -DHAVE_CC_TLS  -o _mulvdi3.o
-MT _mulvdi3.o -MD -MP -MF _mulvdi3.dep -DL_mulvdi3 -c
/mnt/scratch/gcc-4.8-20120506/libgcc/libgcc2.c -fvisibility=hidden
-DHIDE_EXPORTS
/mnt/scratch/gcc-4.8-20120506/libgcc/libgcc2.c: In function '__mulvdi3':
/mnt/scratch/gcc-4.8-20120506/libgcc/libgcc2.c:397:1: internal compiler error:
in df_uses_record, at df-scan.c:3179
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
make[3]: *** [_mulvdi3.o] Error 1
make[3]: Leaving directory
`/mnt/scratch/objdir48/armv5tel-unknown-linux-gnueabi/libgcc'
make[2]: *** [all-stage1-target-libgcc] Error 2
make[2]: Leaving directory `/mnt/scratch/objdir48'
make[1]: *** [stage1-bubble] Error 2
make[1]: Leaving directory `/mnt/scratch/objdir48'
make: *** [bootstrap] Error 2

gcc-4.8-20120422 did bootstrap Ok, 4.8-20120429 failed due to breakage with the
armhf dynamic linker changes.

Configuration parameters:
/mnt/scratch/gcc-4.8-20120506/configure --prefix=/mnt/scratch/install48
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-languages=c,c++,fortran,ada
--disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --disable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
--disable-sjlj-exceptions --with-arch=armv5te --with-tune=xscale
--build=armv5tel-unknown-linux-gnueabi --disable-plugin --disable-lto
--disable-libmudflap --disable-build-poststage1-with-cxx

[Bug bootstrap/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[rearnsha at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-05-08
                 CC|                            |rsandifo at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2012-05-08 09:27:59 UTC ---
the subreg splitting pass is generating concatn in the insn stream.  The manual
says this isn't allowed.

[Bug bootstrap/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.0

[Bug rtl-optimization/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[ramana at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ramana at gcc dot gnu.org
          Component|bootstrap                   |rtl-optimization

--- Comment #2 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> 2012-05-08 14:03:37 UTC ---
Here's a reduced testcase from newlib where I hit the same issue. 

struct _reent
{
  int _errno;
};
typedef unsigned int wchar_t;
unsigned long long
_wcstoull_r(struct _reent *rptr , const wchar_t *nptr , wchar_t **endptr , int
base)
{
 register const wchar_t *s = nptr;
 register unsigned long long acc;
 register int c;
 register unsigned long long cutoff;
 register int neg = 0, any, cutlim;
 if(base < 0 
    || base == 1 
    || base > 36) {
  return(0ULL);
 }
 if ((base == 0 || base == 16) &&
     c == L'0' && (*s == L'x' || *s == L'X')) {
  c = s[1];
 }
 if (base == 0)
  base = c == L'0' ? 8 : 10;
 cutoff = (unsigned long long)(9223372036854775807LL * 2ULL + 1ULL) / (unsigned
long long)base;
 for (acc = 0, any = 0;; c = *s++) {
  if (iswdigit(c))
   break;
  if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
   any = -1;
  else {
   acc += c;
  }
 }
 if (any < 0) {
  rptr->_errno = 34;
 } else if (neg)
  acc = -acc;
}

[Bug rtl-optimization/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[ramana at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

--- Comment #3 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> 2012-05-08 14:56:18 UTC ---
The patch below appears to trigger the issue but there's a fundamental question
as to why lower-subreg generates concatns when the documentation suggests that
concat and concatn should only be used in declarations but not in the insn
stream. 


http://gcc.gnu.org/ml/gcc-patches/2012-05/msg00423.html

[Bug rtl-optimization/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[zadeck at naturalbridge dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

Kenneth Zadeck <zadeck at naturalbridge dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |zadeck at naturalbridge dot
                   |                            |com

--- Comment #4 from Kenneth Zadeck <zadeck at naturalbridge dot com> 2012-05-08 15:43:37 UTC ---
Ramana, 

I did not write this pass.  I believe that iant did.  he used concatn and
concat as a temp marker in the rtl and if all went well, these are all removed
before the pass finishes.   Obviously something is no longer going well so we
will have to look into it.  

Kenny

[Bug rtl-optimization/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

rsandifo@gcc.gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |rsandifo at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #5 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2012-05-08 18:42:47 UTC ---
My fault (again).

[Bug rtl-optimization/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

--- Comment #6 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2012-05-08 21:42:09 UTC ---
Author: rsandifo
Date: Tue May  8 21:42:03 2012
New Revision: 187299

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187299
Log:
gcc/
    PR rtl-optimization/53278
    * lower-subreg.c (decompose_multiword_subregs): Remove left-over
    speed_p code from earlier patch.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/lower-subreg.c

[Bug rtl-optimization/53278] [4.8 regression] internal compiler error: in df_uses_record, at df-scan.c:3179 when compiling libgcc2.c __mulvdi3 on armv5tel-linux

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53278

rsandifo@gcc.gnu.org <rsandifo at gcc dot gnu.org> changed:

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

--- Comment #7 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2012-05-08 21:52:36 UTC ---
Fixed.