[Bug tree-optimization/87126] New: ICE on valid code at -Os and above on x86_64-linux-gnu: in vn_reference_insert, at tree-ssa-sccvn.c:2698

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87126

            Bug ID: 87126
           Summary: ICE on valid code at -Os and above on
                    x86_64-linux-gnu: in vn_reference_insert, at
                    tree-ssa-sccvn.c:2698
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

This is a very recent regression. 

$ gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/9.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 9.0.0 20180827 (experimental) [trunk revision 263892] (GCC)
$
$ gcctk -O1 -c small.c
$
$ gcctk -Os -c small.c
during GIMPLE pass: fre
small.c: In function ‘f’:
small.c:16:1: internal compiler error: in vn_reference_insert, at
tree-ssa-sccvn.c:2698
16 | }
   | ^
0xe5881f vn_reference_insert
        ../../gcc-source-trunk/gcc/tree-ssa-sccvn.c:2698
0xe59d9e visit_reference_op_store
        ../../gcc-source-trunk/gcc/tree-ssa-sccvn.c:4066
0xe59d9e visit_stmt
        ../../gcc-source-trunk/gcc/tree-ssa-sccvn.c:4314
0xe5b63b process_bb
        ../../gcc-source-trunk/gcc/tree-ssa-sccvn.c:5984
0xe5d30c do_rpo_vn
        ../../gcc-source-trunk/gcc/tree-ssa-sccvn.c:6408
0xe5e21c execute
        ../../gcc-source-trunk/gcc/tree-ssa-sccvn.c:6597
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
$


----------------------


int a, *b;

void f ()
{ 
  int d = 0, e = d;
  while (a++)
    ;
  if (e)
    goto L2;
L1:
  d = e;
  b = &d;
L2:
  if (d)
    goto L1;
}