[Bug target/126431] New: [SH] internal compiler error: in lra_assign, at lra-assigns.cc:1691

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126431

            Bug ID: 126431
           Summary: [SH] internal compiler error: in lra_assign, at
                    lra-assigns.cc:1691
           Product: gcc
           Version: 17.0
               URL: https://buildd.debian.org/status/fetch.php?pkg=fontfor
                    ge&arch=sh4&ver=1%3A20230101%7Edfsg-8%2Bb2&stamp=17826
                    63253&raw=0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: glaubitz at debian dot org
                CC: olegendo at gcc dot gnu.org
  Target Milestone: ---
            Target: sh*-*-*

Building fontforge on Debian sh4 fails with:

/usr/lib/gcc-snapshot/bin/sh4-linux-gnu-gcc -Dfontforge_EXPORTS
-I"/home/glaubitz/fontforge/fontforge-20230101~dfsg/fontforge"
-I"/home/glaubitz/fontforge/fontforge-20230101~dfsg/inc"
-I"/home/glaubitz/fontforge/fontforge-20230101~dfsg/
build/nox/inc" -isystem /usr/include/glib-2.0 -isystem
/usr/lib/sh4-linux-gnu/glib-2.0/include -isystem /usr/include/freetype2
-isystem /usr/include/libxml2 -isystem /usr/include/readline -isystem
/usr/include/python3.14 -g -O2 -Werror=
implicit-function-declaration
-ffile-prefix-map=/home/glaubitz/fontforge/fontforge-20230101~dfsg=.
-fstack-protector-strong -Wformat -Werror=format-security -D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Wdate-time -D_FORTI
FY_SOURCE=2 -std=gnu99 -fPIC -Wall -Werror=implicit-function-declaration
-Werror=int-conversion -Wno-misleading-indentation -fdiagnostics-color=always
-MD -MT fontforge/CMakeFiles/fontforge.dir/autohint.c.o -MF
fontforge/CMakeFiles/font
forge.dir/autohint.c.o.d -o fontforge/CMakeFiles/fontforge.dir/autohint.c.o -c
'/home/glaubitz/fontforge/fontforge-20230101~dfsg/fontforge/autohint.c'
during RTL pass: reload
/home/glaubitz/fontforge/fontforge-20230101~dfsg/fontforge/autohint.c: In
function 'MergeDStemInfo':
/home/glaubitz/fontforge/fontforge-20230101~dfsg/fontforge/autohint.c:1835:1:
internal compiler error: in lra_assign, at lra-assigns.cc:1691
 1835 | }
      | ^
0x1bca449 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag*, diagnostics::kind)
        ???:0
0x1bc1215 internal_error(char const*, ...)
        ???:0
0x67b523 fancy_abort(char const*, int, char const*)
        ???:0
0xbe5d51 lra_assign(bool&)
        ???:0
0xbdfec3 lra(_IO_FILE*, int)
        ???:0
/usr/lib/gcc-snapshot/libexec/gcc/sh4-linux-gnu/17/cc1 -quiet -I
/home/glaubitz/fontforge/fontforge-20230101~dfsg/fontforge -I
/home/glaubitz/fontforge/fontforge-20230101~dfsg/inc -I
/home/glaubitz/fontforge/fontforge-20230101~dfsg/build/nox/inc -imultiarch
sh4-linux-gnu -MD fontforge/CMakeFiles/fontforge.dir/autohint.c.d -MF
fontforge/CMakeFiles/fontforge.dir/autohint.c.o.d -MT
fontforge/CMakeFiles/fontforge.dir/autohint.c.o -D fontforge_EXPORTS -D
_LARGEFILE_SOURCE -D _FILE_OFFSET_BITS=64 -D _TIME_BITS=64 -D _FORTIFY_SOURCE=2
-isystem /usr/include/glib-2.0 -isystem /usr/lib/sh4-linux-gnu/glib-2.0/include
-isystem /usr/include/freetype2 -isystem /usr/include/libxml2 -isystem
/usr/include/readline -isystem /usr/include/python3.14
/home/glaubitz/fontforge/fontforge-20230101~dfsg/fontforge/autohint.c -quiet
-dumpdir fontforge/CMakeFiles/fontforge.dir/ -dumpbase autohint.c.c
-dumpbase-ext .c -g -O2 -Werror=implicit-function-declaration -Wformat=1
-Werror=format-security -Wdate-time -Wall -Werror=implicit-function-declaration
-Werror=int-conversion -Wno-misleading-indentation -std=gnu99
-fdiagnostics-color=always
-ffile-prefix-map=/home/glaubitz/fontforge/fontforge-20230101~dfsg=.
-fstack-protector-strong -fPIC -o /tmp/cc422Bif.s
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-snapshot/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccAV3ezf.out file, please attach this to
your bugreport.

This seems to be an LRA regression as the issue does not show with reload as
verified with an LRA-enabled GCC 16 with -mlra and -mno-lra.

I'll attach the preprocessed source shortly.