[Bug c/97709] New: powerpc: ICE when building glibc with latest gcc

[Bug c/97709] New: powerpc: ICE when building glibc with latest gcc

[msc at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97709

            Bug ID: 97709
           Summary: powerpc: ICE when building glibc with latest gcc
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: msc at linux dot ibm.com
  Target Milestone: ---

Created attachment 49499
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49499&action=edit
Pre-processed source with the issue

This was first observed when upgrading GCC on Advance Toolchain, but I was also
able to reproduce this with upstream GCC (commit 93e79ed391b9c636f0). 

Trying to build glibc with latest GCC causes an internal compiler error:

vfprintf-internal.c: In function ‘__vfprintf_internal’:
vfprintf-internal.c:1320:1: error: SSA_NAME_OCCURS_IN_ABNORMAL_PHI should be
set
for SSA_NAME: _1972 in statement:
prec_413(ab) = PHI <_1972(36)>
PHI argument
_1972
for PHI node
prec_413(ab) = PHI <_1972(36)>
during GIMPLE pass: slp
vfprintf-internal.c:1320:1: internal compiler error: verify_ssa failed
0x10dfa0d3 verify_ssa(bool, bool)
        /home/mscastanho/src/gcc/gcc/tree-ssa.c:1208
0x1099fc1f execute_function_todo
        /home/mscastanho/src/gcc/gcc/passes.c:2046
0x109a088b do_per_function
        /home/mscastanho/src/gcc/gcc/passes.c:1687
0x109a0aaf execute_todo
        /home/mscastanho/src/gcc/gcc/passes.c:2093
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.



Preprocessed source generated with -save-temps is attached to the bug. The
issue only happens if I use -mcpu=power9 or -mcpu=power10. -mcpu=power8 seems
to be OK.

Cmdline used:
~/usr/bin/gcc -m64 ./stdio-common/vfprintf-internal.i -c -std=gnu11
-fgnu89-inline  -g -O3 -mcpu=power9 -Wall



NOTE: The original Advance Toolchain build used a slightly older GCC (commit
943cc2a1b70f), and the error message I saw was a bit different (although still
somewhat related):

Unable to coalesce ssa_names 219 and 1972 which are marked as MUST COALESCE.   
                                                                               
                                                                               
             prec_219(ab) and  _1972                         
during RTL pass: expand
vfprintf-internal.c: In function ‘__vfprintf_internal’:
vfprintf-internal.c:148:25: internal compiler error: SSA corruption             
  148 | # define vfprintf       __vfprintf_internal                             
      |                         ^~~~~~~~~~~~~~~~~~~                             
vfprintf-internal.c:1320:1: note: in expansion of macro ‘vfprintf’              
 1320 | vfprintf (FILE *s, const CHAR_T *format, va_list ap, unsigned int
mode_flags)
      | ^~~~~~~~                                                                
0x109e7dc7 fail_abnormal_edge_coalesce                         
       
/home/mscastanho/AT/broken-gcc-p910/build/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources/gcc/gcc/tree-ssa-coalesce.c:1003 
0x109e7dc7 coalesce_partitions   
       
/home/mscastanho/AT/broken-gcc-p910/build/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources/gcc/gcc/tree-ssa-coalesce.c:1425
0x109e7dc7 coalesce_ssa_name(_var_map*)
       
/home/mscastanho/AT/broken-gcc-p910/build/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources/gcc/gcc/tree-ssa-coalesce.c:1755
0x1097f8bb remove_ssa_form
       
/home/mscastanho/AT/broken-gcc-p910/build/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources/gcc/gcc/tree-outof-ssa.c:1065
0x1097f8bb rewrite_out_of_ssa(ssaexpand*)
       
/home/mscastanho/AT/broken-gcc-p910/build/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources/gcc/gcc/tree-outof-ssa.c:1323
0x1035f04b execute
       
/home/mscastanho/AT/broken-gcc-p910/build/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources/gcc/gcc/cfgexpand.c:6378

[Bug tree-optimization/97709] powerpc: ICE when building glibc with latest gcc

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97709

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
            Version|unknown                     |11.0
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |ASSIGNED
             Target|                            |powerpc
   Last reconfirmed|                            |2020-11-04

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will try to have a look.

[Bug tree-optimization/97709] powerpc: ICE when building glibc with latest gcc

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97709

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|powerpc                     |powerpc64le

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
The testcase suggests powerpc64le where I can reproduce the issue.  Reducing.

[Bug tree-optimization/97709] powerpc: ICE when building glibc with latest gcc

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97709

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Reduced testcase:

int a;
struct b {
  int c;
  int d;
}; 
void k (struct b);
struct b 
e() 
{
  void *f[] = {&&g, &&h, &&i, &&j};
  int d, c;
j:
  goto *a;
g:
  d = 0;
h:
  c = 1;
  goto *a;
i: 
  {
    struct b b = {c, d};
    k(b);
  }
}

[Bug tree-optimization/97709] powerpc: ICE when building glibc with latest gcc

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97709

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:1e9f339d946b8296e3785bec77e03d71b487d689

commit r11-4718-g1e9f339d946b8296e3785bec77e03d71b487d689
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Nov 4 11:20:17 2020 +0100

    tree-optimization/97709 - set abnormal flag when vectorizing live lanes

    This properly sets the abnormal flag when vectorizing live lanes
    when the original scalar was live across an abnormal edge.

    2020-11-04  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/97709
            * tree-vect-loop.c (vectorizable_live_operation): Set
            SSA_NAME_OCCURS_IN_ABNORMAL_PHI when necessary.

            * gcc.dg/vect/bb-slp-pr97709.c: New testcase.

[Bug tree-optimization/97709] powerpc: ICE when building glibc with latest gcc

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97709

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

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

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.