[Bug target/127256] libjxl build ICEs in simplify_gen_subreg_concatn, at lower-subreg.cc:744

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127256

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
1117              if (t != CONST0_RTX (word_mode))
1118                emit_move_insn (t,
1119                                simplify_gen_subreg_concatn (word_mode,
src,
1120                                                             orig_mode,
1121                                                             i *
UNITS_PER_WORD));

(subreg:TI (reg:VNx4SI 665) 0)

and we want offset 0 and 8 here.

The "simple move" is originally

(insn 350 348 2096 29 (set (concatn:TI [
                (reg:DI 1542 [ MEM <uint128_t> [(char *
{ref-all})scratch_space_8(D) + 4096B] ])
                (reg:DI 1543 [ MEM <uint128_t> [(char *
{ref-all})scratch_space_8(D) + 4096B]+8 ])
            ])
        (subreg:TI (reg:VNx4SI 665) 0))
"/home/abuild/rpmbuild/BUILD/libjxl-0.12.0-build/libjxl-0.12.0/lib/jxl/dct_block-inl.h":90:22
discrim 32769 110 {*movti_aarch64}
     (expr_list:REG_DEAD (reg:VNx4SI 665)
        (nil)))