https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121198
--- Comment #4 from Georg-Johann Lay <gjl at gcc dot gnu.org> ---
(In reply to Stefan Schulze Frielinghaus from comment #3)
> Since we already select via a filter the hard register, we could set the
> class to ALL_REGS. Could you give the following a try:
>
> diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
> index 83f8fda3b52..18298e14586 100644
> --- a/gcc/lra-constraints.cc
> +++ b/gcc/lra-constraints.cc
> @@ -2551,7 +2551,7 @@ process_alt_operands (int only_alternative)
> {
> int regno = decode_hard_reg_constraint (p);
> gcc_assert (regno >= 0);
> - cl = REGNO_REG_CLASS (regno);
> + cl = ALL_REGS;
> CLEAR_HARD_REG_SET (hard_reg_constraint);
> SET_HARD_REG_BIT (hard_reg_constraint, regno);
> cl_filter = &hard_reg_constraint;
>
> It works for me in a cross compiler.
Thank you for looking into this. It works (I had to apply the patch by hand due
to rejects).
Though I used GENERAL_REGS, since as far as I no, HRC doesn't support fixed
regs.
It works in inline asm and for the bswap insn in avr.md. Great! :-)
