[Bug target/125746] [16/17 Regression] ICE in gen_rtx_SUBREG, at emit-rtl.cc:1043 since r16-718

[dimitar at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125746

--- Comment #4 from Dimitar Dimitrov <dimitar at gcc dot gnu.org> ---
Created attachment 64747
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64747&action=edit
Fix I'm testing as of 20260615

I was wrong - decode_reg_name_and_count seems to be working correctly.  The
register mode is validated during expand:
  make_decl_rtl()
    -> targetm.hard_regno_mode_ok()

Drea, I believe this particular PR is a distinct target-specific issue.  Thanks
for the pointers.

I'm now testing the attached fix.