[Bug target/106586] riscv32 still broke with zba_zbb_zbc_zbs, ICE in do_SUBST in C++ code

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106586

--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
There is still some missing sign extend of the const_int.
(insn 17 16 18 4 (set (reg:SI 77)
        (mem/u/c:SI (lo_sum:SI (reg/f:SI 78)
                (symbol_ref/u:SI ("*.LC0") [flags 0x82])) [0  S4 A32]))
"t89.c":5:16 140 {*movsi_internal}
     (expr_list:REG_DEAD (reg/f:SI 78)
        (expr_list:REG_EQUAL (const_int 2147483648 [0x80000000])
            (nil))))


Notice the REG_EQUAL.

I think the issue is inside riscv_build_integer_1.

Specifically this:
      alt_cost = 1 + riscv_build_integer_1 (alt_codes, value - low_part, mode);