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Re: RFA: Process '*' in '@'-output-template alternatives
On Wed, Sep 19, 2012 at 2:06 PM, Joern Rennecke <amylaar@spamcop.net> wrote:
> Quoting Richard Guenther <richard.guenther@gmail.com>:
>
>
>> I think that needs to be documented somewhere in the internals manual,
>
>
> I suppose it should logically go to the current end of the Output Statement
> node in md.texi . Line 668 in revision 191429, just before the Predicates
> node.
Yes.
>> possibly with an example.
>
>
> AFAICT the existing examples are pieces of real machine descriptions.
> One possibility would be the movsi_insn from the arc-4_4-20090909-branch:
>
> (define_insn "*movsi_insn"
> [(set (match_operand:SI 0 "move_dest_operand" "=Rcq,Rcq#q,w, w,w, w,???w,
> ?w, w,Rcq#q, w,Rcq, S,Us<,RcqRck,!*x,r,m,???m,VUsc")
> (match_operand:SI 1 "move_src_operand" "
> cL,cP,Rcq#q,cL,I,Crr,?Rac,Cpc,Clb,?Cal,?Cal,T,Rcq,RcqRck,Us>,Usd,m,c,?Rac,C32"))]
> "register_operand (operands[0], SImode)
> || register_operand (operands[1], SImode)
> || (CONSTANT_P (operands[1])
> /* Don't use a LIMM that we could load with a single insn - we loose
> delay-slot filling opportunities. */
> && !satisfies_constraint_I (operands[1])
> && satisfies_constraint_Usc (operands[0]))"
> "@
> mov%? %0,%1%&
> mov%? %0,%1%&
> mov%? %0,%1%&
> mov%? %0,%1
> mov%? %0,%1
> ror %0,((%1*2+1) & 0x3f)
> mov%? %0,%1
> add %0,%S1
> * return arc_get_unalign () ? \"add %0,pcl,%1-.+2\" : \"add
> %0,pcl,%1-.\";
> mov%? %0,%S1%&
> mov%? %0,%S1
> ld%? %0,%1%&
> st%? %1,%0%&
> * return arc_short_long (insn, \"push%? %1%&\", \"st%U0 %1,%0%&\");
> * return arc_short_long (insn, \"pop%? %0%&\", \"ld%U1 %0,%1%&\");
> ld%? %0,%1%&
> ld%U1%V1 %0,%1
> st%U0%V0 %1,%0
> st%U0%V0 %1,%0
> st%U0%V0 %S1,%0"
> [(set_attr "type"
> "move,move,move,move,move,two_cycle_core,move,binary,binary,move,move,load,store,store,load,load,load,store,store,store")
> (set_attr "iscompact"
> "maybe,maybe,maybe,false,false,false,false,false,false,maybe_limm,false,true,true,true,true,true,false,false,false,false")
> ; Use default length for iscompact to mark length varying. But set
> length
> ; of Crr to 4.
> (set_attr "length" "*,*,*,4,4,4,4,8,8,*,8,*,*,*,*,*,*,*,*,8")
> (set_attr "cond"
> "canuse,canuse_limm,canuse,canuse,canuse_limm,canuse_limm,canuse,nocond,nocond,canuse,canuse,nocond,nocond,nocond,nocond,nocond,nocond,nocond,nocond,nocond")])
>
> Although the number of different concepts combined here might a bit
> distract from the point. Also, it'll need steering commitee approval
> to put this code, which was previously contributed under the GPL (on the
> branch) into GFDL documentation.
>
> Or should I make up a reduced/synthetic example for a simpler - but
> probably pointless as an actual output template - example?
Something smaller (but pointless) woudl be nice.
Richard.