сб, 14 сент. 2024 г. в 13:00, Georg-Johann Lay <a...@gjlay.de>:
>
> This uses new rtx code copysign instead of an unspec.
> It also allows const_double as 2nd operand because gcc
> does not optimize code like
>
> __builtin_copysignf (x, -1.0f);
>
> Ok for trunk?
Ok. Please apply.
Denis.
>
> Johann
>
> --
>
> AVR: Use rtx code copysign.
>
> gcc/
> * config/avr/avr.md (UNSPEC_COPYSIGN): Remove define_enum.
> (copysignsf3): Use copysign instead of UNSPEC_COPYSIGN.
> Allow const_double for operand 2.
>
> diff --git a/gcc/config/avr/avr.md b/gcc/config/avr/avr.md
> index 429f537b7d4..2abf3c38d83 100644
> --- a/gcc/config/avr/avr.md
> +++ b/gcc/config/avr/avr.md
> @@ -87,7 +87,6 @@ (define_c_enum "unspec"
> UNSPEC_FMUL
> UNSPEC_FMULS
> UNSPEC_FMULSU
> - UNSPEC_COPYSIGN
> UNSPEC_INSERT_BITS
> UNSPEC_ROUND
> ])
> @@ -9272,12 +9271,18 @@ (define_insn "*ffssihi2.libgcc"
> ;; Copysign
>
> (define_insn "copysignsf3"
> - [(set (match_operand:SF 0 "register_operand" "=r")
> - (unspec:SF [(match_operand:SF 1 "register_operand" "0")
> - (match_operand:SF 2 "register_operand" "r")]
> - UNSPEC_COPYSIGN))]
> + [(set (match_operand:SF 0 "register_operand" "=r")
> + (copysign:SF (match_operand:SF 1 "register_operand" "0")
> + (match_operand:SF 2 "nonmemory_operand" "rF")))]
> ""
> - "bst %D2,7\;bld %D0,7"
> + {
> + if (const_double_operand (operands[2], SFmode))
> + {
> + rtx xmsb = simplify_gen_subreg (QImode, operands[2], SFmode, 3);
> + return INTVAL (xmsb) < 0 ? "set\;bld %D0,7" : "clt\;bld %D0,7";
> + }
> + return "bst %D2,7\;bld %D0,7";
> + }
> [(set_attr "length" "2")])
