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Re: How can I write an empty conversion instruction
- From: Daniel Jacobowitz <drow at false dot org>
- To: Steve Ellcey <sje at cup dot hp dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Fri, 6 May 2005 17:03:16 -0400
- Subject: Re: How can I write an empty conversion instruction
- References: <200505062059.NAA19579@hpsje.cup.hp.com>
On Fri, May 06, 2005 at 01:59:06PM -0700, Steve Ellcey wrote:
> My attempt:
>
> (define_insn "nop_extendsfdf"
> [(set (match_operand:DF 0 "fr_register_operand" "+f")
> (unspec:DF [(match_dup:SF 0)] UNSPEC_NOP_EXTEND))]
> ""
> ""
> [(set_attr "itanium_class" "ignore")
> (set_attr "predicable" "no")
> (set_attr "empty" "yes")])
>
> I think the match_dup may be wrong since I am using it with SF but the
> original match_operand has DF. Do I need to make this modeless? Or is
> there some other way to create an empty conversion instruction.
You might want to try this instead:
[(set (match_operand:DF 0 "fr_register_operand" "=f")
(unspec:DF [(match_operand:SF 0 "fr_register_operand" "0")] UNSPEC_NOP_EXTEND))]
--
Daniel Jacobowitz
CodeSourcery, LLC