[Bug target/79451] New: [7 Regression] ICE in expand_expr_real_2, at expr.c:9021 w/ -O3 -floop-nest-optimize

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79451

            Bug ID: 79451
           Summary: [7 Regression] ICE in expand_expr_real_2, at
                    expr.c:9021 w/ -O3 -floop-nest-optimize
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: powerpc-e500v2-linux-gnuspe

7.0.0-alpha20170205 snapshot ICEs when compiling the following snippet w/ -O3
(or -Ofast) -floop-nest-optimize:

int dx;

void
bm (unsigned int ms)
{
  int fe = dx;
  unsigned int *gd = &ms;

  for (ms = 0; ms < 1; ++ms)
    gd = &dx;
  while (fe < 1)
    {
      *gd /= dx;
      *gd -= fe & 1;
      ++fe;
    }
}

% powerpc-e500v2-linux-gnuspe-gcc-7.0.0-alpha20170205 -O3 -floop-nest-optimize
-w -c kfzgpxfl.c
kfzgpxfl.c: In function 'bm':
kfzgpxfl.c:4:1: internal compiler error: in expand_expr_real_2, at expr.c:9021
 bm (unsigned int ms)
 ^~
0x312b1745f2d expand_expr_real_2(separate_ops*, rtx_def*, machine_mode,
expand_modifier)
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/expr.c:9021
0x312b1730b60 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/expr.c:9730
0x312b173c1fd expand_expr
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/expr.h:276
0x312b173c1fd expand_operands(tree_node*, tree_node*, rtx_def*, rtx_def**,
rtx_def**, expand_modifier)
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/expr.c:7672
0x312b174427a expand_expr_real_2(separate_ops*, rtx_def*, machine_mode,
expand_modifier)
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/expr.c:9521
0x312b15f5f61 expand_gimple_stmt_1
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/cfgexpand.c:3677
0x312b15f5f61 expand_gimple_stmt
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/cfgexpand.c:3737
0x312b15f7d8b expand_gimple_basic_block
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/cfgexpand.c:5744
0x312b15fe48f execute
       
/var/tmp/portage/cross-powerpc-e500v2-linux-gnuspe/gcc-7.0.0_alpha20170205/work/gcc-7-20170205/gcc/cfgexpand.c:6357

It may be similar to PR71012, but I cannot reproduce that one w/ the current
7.0 snapshot.