[Bug target/112623] New: [14 Regression] ICE: in emit_move_insn, at expr.cc:4249 with -O -mavx512vl -mavx512fp16 on vector conversion

["zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112623

            Bug ID: 112623
           Summary: [14 Regression] ICE: in emit_move_insn, at
                    expr.cc:4249 with -O -mavx512vl -mavx512fp16 on vector
                    conversion
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          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 56643
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56643&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -mavx512vl -mavx512fp16 testcase.c 
during RTL pass: expand
testcase.c: In function 'foo':
testcase.c:7:10: internal compiler error: in emit_move_insn, at expr.cc:4249
    7 |   return __builtin_convertvector (f, BF);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0x7583d8 emit_move_insn(rtx_def*, rtx_def*)
        /repo/gcc-trunk/gcc/expr.cc:4249
0xf591f9 expand_value_return
        /repo/gcc-trunk/gcc/cfgexpand.cc:3739
0xf63364 expand_return
        /repo/gcc-trunk/gcc/cfgexpand.cc:3811
0xf63364 expand_gimple_stmt_1
        /repo/gcc-trunk/gcc/cfgexpand.cc:3918
0xf63364 expand_gimple_stmt
        /repo/gcc-trunk/gcc/cfgexpand.cc:4044
0xf694ae expand_gimple_basic_block
        /repo/gcc-trunk/gcc/cfgexpand.cc:6100
0xf6b187 execute
        /repo/gcc-trunk/gcc/cfgexpand.cc:6835
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-r14-5593-20231119062640-g78d132d73ec-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/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-r14-5593-20231119062640-g78d132d73ec-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.0 20231119 (experimental) (GCC)