[Bug middle-end/80162] New: ICE on invalid code (address of register variable)

["ienkovich at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80162

            Bug ID: 80162
           Summary: ICE on invalid code (address of register variable)
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ienkovich at gcc dot gnu.org
  Target Milestone: ---

Looking at PR79990 I found that we can ICE on register variable usage even when
no CHKP is used.

Here is a possible testcase:

typedef int v8 __attribute__ ((vector_size(8)));

struct U {
  v8 a;
  v8 b;
};

register struct U u asm ("xmm0");

int *
foo (int i)
{
  return &u.a[i];
}

$ gcc-build/bin/gcc pr79990-2.c -S
pr79990-2.c:8:19: warning: call-clobbered register used for global register
variable
 register struct U u asm ("xmm0");
                   ^
pr79990-2.c: In function ‘foo’:
pr79990-2.c:13:10: internal compiler error: in expand_expr_addr_expr_1, at
expr.c:7790
   return &u.a[i];
          ^~~~~~~
0xab00d2 expand_expr_addr_expr_1
        ../../gcc/gcc/expr.c:7790
0xab04d9 expand_expr_addr_expr_1
        ../../gcc/gcc/expr.c:7828
0xab0984 expand_expr_addr_expr
        ../../gcc/gcc/expr.c:7904
0xabe143 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
        ../../gcc/gcc/expr.c:11047
0xab0df5 expand_expr_real(tree_node*, rtx_def*, machine_mode, expand_modifier,
rtx_def**, bool)
        ../../gcc/gcc/expr.c:8072
0xaa7ccd store_expr_with_bounds(tree_node*, rtx_def*, int, bool, bool,
tree_node*)
        ../../gcc/gcc/expr.c:5552
0xaa6616 expand_assignment(tree_node*, tree_node*, bool)
        ../../gcc/gcc/expr.c:5321
0x946a94 expand_gimple_stmt_1
        ../../gcc/gcc/cfgexpand.c:3641
0x946e9c expand_gimple_stmt
        ../../gcc/gcc/cfgexpand.c:3737
0x94e94d expand_gimple_basic_block
        ../../gcc/gcc/cfgexpand.c:5744
0x9503ff execute
        ../../gcc/gcc/cfgexpand.c:6357
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