[Bug debug/104557] New: [12 Regression] ICE: in simplify_subreg, at simplify-rtx.cc:7324 with -O -g

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104557

            Bug ID: 104557
           Summary: [12 Regression] ICE: in simplify_subreg, at
                    simplify-rtx.cc:7324 with -O -g
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 52449
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52449&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -g testcase.c
testcase.c: In function 'bar':
testcase.c:7:1: warning: AVX vector return without AVX enabled changes the ABI
[-Wpsabi]
    7 | {
      | ^
during RTL pass: vartrack
testcase.c:12:1: internal compiler error: in simplify_subreg, at
simplify-rtx.cc:7324
   12 | }
      | ^
0x782476 simplify_context::simplify_subreg(machine_mode, rtx_def*,
machine_mode, poly_int<1u, unsigned long>)
        /repo/gcc-trunk/gcc/simplify-rtx.cc:7324
0x13771d9 simplify_context::simplify_gen_subreg(machine_mode, rtx_def*,
machine_mode, poly_int<1u, unsigned long>)
        /repo/gcc-trunk/gcc/simplify-rtx.cc:7602
0x16ac5b3 simplify_gen_subreg(machine_mode, rtx_def*, machine_mode,
poly_int<1u, unsigned long>)
        /repo/gcc-trunk/gcc/rtl.h:3534
0x16ac5b3 vt_expand_loc_callback
        /repo/gcc-trunk/gcc/var-tracking.cc:8524
0xec90e1 cselib_expand_value_rtx_1
        /repo/gcc-trunk/gcc/cselib.cc:1848
0xeca75e cselib_expand_value_rtx_cb(rtx_def*, bitmap_head*, int, rtx_def*
(*)(rtx_def*, bitmap_head*, int, void*), void*)
        /repo/gcc-trunk/gcc/cselib.cc:1731
0x16ac149 vt_expand_var_loc_chain
        /repo/gcc-trunk/gcc/var-tracking.cc:8420
0x16ac759 vt_expand_loc_callback
        /repo/gcc-trunk/gcc/var-tracking.cc:8583
0xec93b0 cselib_expand_value_rtx_1
        /repo/gcc-trunk/gcc/cselib.cc:1883
0xeca75e cselib_expand_value_rtx_cb(rtx_def*, bitmap_head*, int, rtx_def*
(*)(rtx_def*, bitmap_head*, int, void*), void*)
        /repo/gcc-trunk/gcc/cselib.cc:1731
0x16ac149 vt_expand_var_loc_chain
        /repo/gcc-trunk/gcc/var-tracking.cc:8420
0x16ac759 vt_expand_loc_callback
        /repo/gcc-trunk/gcc/var-tracking.cc:8583
0xeca75e cselib_expand_value_rtx_cb(rtx_def*, bitmap_head*, int, rtx_def*
(*)(rtx_def*, bitmap_head*, int, void*), void*)
        /repo/gcc-trunk/gcc/cselib.cc:1731
0x16ac570 vt_expand_loc_callback
        /repo/gcc-trunk/gcc/var-tracking.cc:8517
0xec90e1 cselib_expand_value_rtx_1
        /repo/gcc-trunk/gcc/cselib.cc:1848
0xec9506 cselib_expand_value_rtx_1
        /repo/gcc-trunk/gcc/cselib.cc:1938
0xeca75e cselib_expand_value_rtx_cb(rtx_def*, bitmap_head*, int, rtx_def*
(*)(rtx_def*, bitmap_head*, int, void*), void*)
        /repo/gcc-trunk/gcc/cselib.cc:1731
0x16ac149 vt_expand_var_loc_chain
        /repo/gcc-trunk/gcc/var-tracking.cc:8420
0x16ac759 vt_expand_loc_callback
        /repo/gcc-trunk/gcc/var-tracking.cc:8583
0xec93b0 cselib_expand_value_rtx_1
        /repo/gcc-trunk/gcc/cselib.cc:1883
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.

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-7249-20220215180935-g8e84b2b37a5-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r12-7249-20220215180935-g8e84b2b37a5-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.1 20220215 (experimental) (GCC)