https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109676
Bug ID: 109676
Summary: [13/14 regression] ICE in simplify_subreg, at
simplify-rtx.cc:7426 when building firefox with -O2
-march=alderlake -g
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Target Milestone: ---
Originally reported downstream in Gentoo at https://bugs.gentoo.org/905262.
Unfortunately, the original reproducer is too big even compressed, so it's at
http://dev.gentoo.org/~sam/bugs/gcc/gcc-firefox-alderlake-x86/Unified_cpp_dom_fetch1.ii.xz.
I'm working on a reduction now.
```
$ g++-13 -march=alderlake -O2 -g -c Unified_cpp_dom_fetch1.ii
[...]
during RTL pass: vartrack
Unified_cpp_dom_fetch1.ii: In static member function ‘static
mozilla::Maybe<mozilla::dom::ParentToParentStream>
IPC::ParamTraits<mozilla::dom::ParentToParentStream>::Read(IPC::MessageReader*)’:
Unified_cpp_dom_fetch1.ii:183311:1: internal compiler error: in
simplify_subreg, at simplify-rtx.cc:7426
183311 | }
| ^
0xb99b70 simplify_context::simplify_subreg(machine_mode, rtx_def*,
machine_mode, poly_int<1u, unsigned long>)
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/simplify-rtx.cc:7426
0x1f4e111 simplify_context::simplify_gen_subreg(machine_mode, rtx_def*,
machine_mode, poly_int<1u, unsigned long>)
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/simplify-rtx.cc:7715
0x20c4a01 simplify_gen_subreg(machine_mode, rtx_def*, machine_mode,
poly_int<1u, unsigned long>)
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/rtl.h:3535
0x20c4a01 vt_expand_loc_callback
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:8524
0x208b8b1 cselib_expand_value_rtx_1
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1953
0x20c3b4b vt_expand_var_loc_chain
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1836
0x20c459b vt_expand_loc_callback
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:8583
0x208b4ec cselib_expand_value_rtx_1
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1988
0x20c3b4b vt_expand_var_loc_chain
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1836
0x20c459b vt_expand_loc_callback
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:8583
0x20c3b4b vt_expand_var_loc_chain
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1836
0x20c459b vt_expand_loc_callback
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:8583
0x208b4ec cselib_expand_value_rtx_1
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1988
0x20c3b4b vt_expand_var_loc_chain
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/cselib.cc:1836
0x20c2f94 vt_expand_1pvar
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:8696
0x20c2f94 emit_note_insn_var_location(variable**, emit_note_data*)
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:8750
0x20804fc void hash_table<variable_hasher, false,
xcallocator>::traverse_noresize<emit_note_data*,
&(emit_note_insn_var_location(variable**, emit_note_data*))>(emit_note_data*)
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/hash-table.h:1173
0x20804fc void hash_table<variable_hasher, false,
xcallocator>::traverse<emit_note_data*,
&(emit_note_insn_var_location(variable**, emit_note_data*))>(emit_note_data*)
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/hash-table.h:1194
0x20804fc emit_notes_for_changes
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:9110
0x207e49d emit_notes_in_bb
/usr/src/debug/sys-devel/gcc-13.1.0-r1/gcc-13.1.0/gcc/var-tracking.cc:9544
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://bugs.gentoo.org/> for instructions.
```
