fails to cross-compile for sparc64

[wbx]

Hi,

in buildroot we have stress-ng package with version 0.04.16 and it fails
to cross-compile for sparc64 with following gcc ICE:
stress-vecmath.c: In function ‘stress_vecmath’:
stress-vecmath.c:48:4: internal compiler error: in emit_library_call_value_1, at calls.c:3779
  a *= s; \
    ^
stress-vecmath.c:114:4: note: in expansion of macro ‘OPS’
    OPS(a64, b64, c64, s64);
    ^
Please submit a full bug report,
with preprocessed source if appropriate.

Latest 0.06.01 fails, too.
Any idea? GCC 4.9.3 is used.

best regards
 Waldemar

[John Paul Adrian Glaubitz (glaubitz)]

Created attachment 38445
Pre-processed source for stress-vecmath.c

Hi!

When building stress-ng on powerpc-linux-gnuspe, an internal compiler error occurs when compiling stress-vecmath.c:

cc -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall -Wextra -DVERSION="0.06.01" -O2 -DHAVE_APPARMOR -DHAVE_KEYUTILS_H -DHAVE_XATTR_H -DHAVE_LIB_BSD -DHAVE_LIB_Z -DHAVE_LIB_CRYPT -DHAVE_LIB_RT -DHAVE_LIB_PTHREAD -DHAVE_FLOAT_DECIMAL -DHAVE_SECCOMP_H -DHAVE_LIB_AIO -DHAVE_SYS_CAP_H -c -o stress-vecmath.o stress-vecmath.c
stress-vecmath.c: In function 'stress_vecmath':
stress-vecmath.c:49:4: internal compiler error: in expand_expr_real_2, at expr.c:9348
  a ^= c; \
    ^
stress-vecmath.c:114:4: note: in expansion of macro 'OPS'
    OPS(a64, b64, c64, s64);
    ^
0x103166eb expand_expr_real_2(separate_ops*, rtx_def*, machine_mode, expand_modifier)
 ../../src/gcc/expr.c:9348
0x1021f24b expand_gimple_stmt_1
 ../../src/gcc/cfgexpand.c:3462
0x1021f24b expand_gimple_stmt
 ../../src/gcc/cfgexpand.c:3522
0x10222ed3 expand_gimple_basic_block
 ../../src/gcc/cfgexpand.c:5534
0x10224f33 execute
 ../../src/gcc/cfgexpand.c:6152
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-5/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccRHm88P.out file, please attach this to your bugreport.

This has been failing for quite some time. However, it seems it does not seem to be related to gcc directly as both the last successful build [1] and the last unsuccessful build [2] used both the same revision of gcc-4.9.2: r218987.

Attaching the pre-processed source from the last build with gcc-5.

Adrian

> [1] https://buildd.debian.org/status/fetch.php?pkg=stress-ng&arch=powerpcspe&ver=0.03.12-1&stamp=1422673290
> [2] https://buildd.debian.org/status/fetch.php?pkg=stress-ng&arch=powerpcspe&ver=0.03.13-1&stamp=1422840779

[Colin Ian King (colin-king)]

This also happens on other architectures too:

https://buildd.debian.org/status/fetch.php?pkg=stress-ng&arch=powerpcspe&ver=0.06.01-1&stamp=1462574245

[Colin Ian King (colin-king)]

There has been an upstream bug against gcc filed against this issue:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71012

[Colin Ian King (colin-king)]

Do you mind adding the failure you are seeing to the upstream bug report as this seems to occur on more than one architecture.

[Colin Ian King (colin-king)]

For the moment, I've added an auto-detect workaround in the build phase of stress-ng. Attached is a patch. Do you mind trying this out?

Thanks

[Colin Ian King (colin-king)]

Ignore the above fix, it's not correct. I've pushed a more generic solution to the stress-ng git repository, the fix is the following commit:

http://kernel.ubuntu.com/git/cking/stress-ng.git/commit/?id=9b5a3aaffdd613f03c10ebe3550b89193e9993ef

[wbx (k-mail-n)]

Hi Colin,

thanks for the quick fix. Buildroot package was updated to latest release, which builds now.

thx
 Waldemar

[Colin Ian King (colin-king)]

Fixes in stress-ng 0.06.01

[Pinskia (pinskia)]

https://buildd.debian.org/status/fetch.php?pkg=stress-ng&arch=powerpcspe&ver=0.06.01-1&stamp=1462574245

[Asolokha (asolokha)]

I can reproduce it w/ gcc 5.4.0, but cannot w/ 7.0.0-alpha20170205 snapshot.

[John Paul Adrian Glaubitz (glaubitz)]

(In reply to Arseny Solokha from comment #2)
> I can reproduce it w/ gcc 5.4.0, but cannot w/ 7.0.0-alpha20170205 snapshot.

We also haven't seen it in Debian since last May, see:

> https://buildd.debian.org/status/logs.php?pkg=stress-ng&arch=powerpcspe

stress-ng has been building fine ever since.

[Asolokha (asolokha)]

int mw;

int
j3 (int cn)
{
  const int l7 = 0;
  int wz;

  for (wz = l7; wz < l7 + 3; ++wz)
    while (mw != 0)
      {
        cn ^= -(wz == l7);
        ++mw;
      }

  return cn;
}

actually leads to ICE w/ -O2 (-O3, -Ofast) -ftree-vectorize all the way from gcc-8.0.0-alpha20170507 snapshot down to 4.9:

% powerpc-e500v2-linux-gnuspe-gcc-8.0.0-alpha20170507 -O2 -ftree-vectorize -c ndknofut.c
ndknofut.c: In function 'j3':
ndknofut.c:12:12: internal compiler error: in expand_expr_real_2, at expr.c:9069
         cn ^= -(wz == l7);
         ~~~^~~~~~~~~~~~~~
0x8a1b2a expand_expr_real_2(separate_ops*, rtx_def*, machine_mode, expand_modifier)
 /var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-8.0.0_alpha20170507/work/gcc-8-20170507/gcc/expr.c:9069
0x74e4de expand_gimple_stmt_1
 /var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-8.0.0_alpha20170507/work/gcc-8-20170507/gcc/cfgexpand.c:3676
0x74e4de expand_gimple_stmt
 /var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-8.0.0_alpha20170507/work/gcc-8-20170507/gcc/cfgexpand.c:3737
0x7510e7 expand_gimple_basic_block
 /var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-8.0.0_alpha20170507/work/gcc-8-20170507/gcc/cfgexpand.c:5744
0x7576df execute
 /var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-8.0.0_alpha20170507/work/gcc-8-20170507/gcc/cfgexpand.c:6357

[Segher-8 (segher-8)]

The powerpcspe backend has been deprecated in GCC 8 and removed during GCC 9 development. See corresponding mailing list threads[1,2,3] for details.

[1] https://gcc.gnu.org/legacy-ml/gcc/2018-04/msg00102.html
[2] https://gcc.gnu.org/legacy-ml/gcc-patches/2018-12/msg00123.html
[3] https://gcc.gnu.org/pipermail/gcc/2020-May/232342.html