[Bug c/112509] New: GCC: 14: internal compiler error: in verify_range, at value-range.cc:1132

[Bug c/112509] New: GCC: 14: internal compiler error: in verify_range, at value-range.cc:1132

[141242068 at smail dot nju.edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112509

            Bug ID: 112509
           Summary: GCC: 14: internal compiler error: in verify_range, at
                    value-range.cc:1132
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: 141242068 at smail dot nju.edu.cn
  Target Milestone: ---

Compiler Explorer: https://gcc.godbolt.org/z/151vEnafj

When compiling this program with `gcc-14 -O2 -fno-tree-vrp -fno-tree-fre
-fno-tree-forwprop`, gcc crashes:

```
struct S {
  unsigned j : 3;
};
int k, l, m_1 = {0};
void f(int l, struct S x) {
  unsigned int k_1;
  while (m_1 % 8) switch (x.j) {
    case 1:
    case 3:
    case 4:
    case 6:
    case 2:
    case 5: l = m_1;
    case 7:
    case 0: k_1 = 0;
    default: break;
    }
}
void foo(struct S x) { f(l, x); }
```

The crash output:
```
during GIMPLE pass: dom
<source>: In function 'f':
<source>:5:6: internal compiler error: in verify_range, at value-range.cc:1132
    5 | void f(int l, struct S x) {
      |      ^
0x238b06e internal_error(char const*, ...)
        ???:0
0xa1125c fancy_abort(char const*, int, char const*)
        ???:0
0x148ea37 irange::set(tree_node*, generic_wide_int<wide_int_storage> const&,
generic_wide_int<wide_int_storage> const&, value_range_kind)
        ???:0
0x144ca1f find_case_label_range(gswitch*, irange const*)
        ???:0
0x139e1ef hybrid_jt_simplifier::simplify(gimple*, gimple*, basic_block_def*,
jt_state*)
        ???:0
0x139d525 jump_threader::simplify_control_stmt_condition(edge_def*, gimple*)
        ???:0
0x139db5a jump_threader::thread_through_normal_block(vec<jump_thread_edge*,
va_heap, vl_ptr>*, edge_def*, bitmap_head*)
        ???:0
0x139fa66 jump_threader::thread_across_edge(edge_def*)
        ???:0
0x139fc5a jump_threader::thread_outgoing_edges(basic_block_def*)
        ???:0
0x126f828 dom_opt_dom_walker::after_dom_children(basic_block_def*)
        ???:0
0x1ed3f2f dom_walker::walk(basic_block_def*)
        ???:0
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1
```

[Bug tree-optimization/112509] GCC: 14: internal compiler error: in verify_range, at value-range.cc:1132

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112509

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-11-13
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |ice-checking,
                   |                            |ice-on-valid-code
     Ever confirmed|0                           |1
          Component|c                           |tree-optimization
                 CC|                            |amacleod at redhat dot com

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  Somehow lb and ub are "swapped".

[Bug tree-optimization/112509] GCC: 14: internal compiler error: in verify_range, at value-range.cc:1132

[amacleod at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112509

--- Comment #2 from Andrew Macleod <amacleod at redhat dot com> ---
the original switch is an unsigned value with precision of 3 bits, so 0..7 just
fits.

It gets translated to an int index during gimplification, but the case labels
are still precision 3 values. 

find_case_label_ranges in tree-vrp.cc does the following:

     tree label = gimple_switch_label (switch_stmt, i);
      tree case_high
        = CASE_HIGH (label) ? CASE_HIGH (label) : CASE_LOW (label);
      wide_int wlow = wi::to_wide (CASE_LOW (label));
      wide_int whigh = wi::to_wide (case_high);
      int_range_max label_range (type,
                                 wide_int::from (wlow, prec, sign),
                                 wide_int::from (whigh, prec, sign));

 CASE_HIGH is indeed 6, but when we to the to_wide call, it is sign extended to
produce:
(gdb) p whigh.dump ()
[0xfffffffffffffffe], precision = 3

but then when we do wide_int::from() in the signed int precision 32 of the new
switch type, we get -2 for the high value.

Whats suppose to happen here?  seems odd to me that the case labels are a
different precision than the switch itself..  but then we would also lose the
fact that there is only 3 bits of precision in the switch.

Should the low and high values be cast from the original case precision/type to
the new perhaps?

something like this seems to work:
 tree
 find_case_label_range (gswitch *switch_stmt, const irange *range_of_op)
@@ -900,9 +901,9 @@ find_case_label_range (gswitch *switch_stmt, const irange
*range_of_op)
        = CASE_HIGH (label) ? CASE_HIGH (label) : CASE_LOW (label);
       wide_int wlow = wi::to_wide (CASE_LOW (label));
       wide_int whigh = wi::to_wide (case_high);
-      int_range_max label_range (type,
-                                wide_int::from (wlow, prec, sign),
-                                wide_int::from (whigh, prec, sign));
+      int_range_max label_range (TREE_TYPE (case_high), wlow, whigh);
+      range_cast (label_range, type);
+      label_range.dump(stderr);

[Bug tree-optimization/112509] [14 Regression] internal compiler error: in verify_range, at value-range.cc:1132

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112509

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0
            Summary|GCC: 14: internal compiler  |[14 Regression] internal
                   |error: in verify_range, at  |compiler error: in
                   |value-range.cc:1132         |verify_range, at
                   |                            |value-range.cc:1132
           Keywords|                            |needs-bisection

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This looks to be a GCC 14 regression.

[Bug tree-optimization/112509] [14 Regression] internal compiler error: in verify_range, at value-range.cc:1132

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112509

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

https://gcc.gnu.org/g:8f331be42991aa4d58ac770faf993accfcce882b

commit r14-5449-g8f331be42991aa4d58ac770faf993accfcce882b
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Mon Nov 13 09:58:10 2023 -0500

    Use case label type to create case range.

    Create a range from the label type, and cast it to the required type.

            PR tree-optimization/112509
            gcc/
            * tree-vrp.cc (find_case_label_range): Create range from case
labels.

            gcc/testsuite/
            * gcc.dg/pr112509.c: New.

[Bug tree-optimization/112509] [14 Regression] internal compiler error: in verify_range, at value-range.cc:1132

[amacleod at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112509

Andrew Macleod <amacleod at redhat dot com> changed:

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

--- Comment #5 from Andrew Macleod <amacleod at redhat dot com> ---
fixed.