[Bug target/74563] [6/7 regression] Classic MIPS16 (non-MIPS16e) function return broken

["law at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74563

--- Comment #8 from Jeffrey A. Law <law at redhat dot com> ---
So AFAICT this pattern:

(define_insn "*<optab>"
  [(any_return)]
  ""
  {
    operands[0] = gen_rtx_REG (Pmode, RETURN_ADDR_REGNUM);
    return mips_output_jump (operands, 0, -1, false);
  }
  [(set_attr "type"     "jump")
   (set_attr "mode"     "none")])


Is used for shrink-wrapping -- in particular it may be used while the return
pointer is still sitting in $31.


The _internal pattern:

(define_insn "<optab>_internal"
  [(any_return)
   (use (match_operand 0 "pmode_register_operand" ""))]
  ""
  {
    operands[0] = gen_rtx_REG (Pmode, RETURN_ADDR_REGNUM);
    return mips_output_jump (operands, 0, -1, false);
  }
  [(set_attr "type"     "jump")
   (set_attr "mode"     "none")])

Is used directly by mips.c which should be passing in the right
RETURN_ADDR_REGNUM.

So like you, I think the solution is to just remove the offending line.  I'm
going to spin one more test.  But I think we're converging on the solution.