Re: ARM emit jump insn

[Jeff Law <law at redhat dot com>]

On 03/09/15 17:42, Marcos DÃaz wrote:
> Hi I'm doing an investigation trying to modify the generation of
> prologues and epilogues for ARM cross compiler.
> So far I could successfully add some lines to the prologue generation,
> but Im having problems with some thing: How do you suggest is the best
> way to emit an assembler line that makes a branch (not branch with
> link) to a certain label.
> I've tried the following:
>
>      char funcname[] ="funcname"; (global)
>
>       rtx mylabel , from;
>      LABEL_NAME(mylabel) = funcname;
>          from = emit_jump_insn(gen_jump (mylabel));
>          JUMP_LABEL (from) = mylabel;
>          ++LABEL_NUSES (mylabel);
>
> But this emits a jump to an internal label (for example .L0)
>
> what I wanted to do is that those lines generate a jump to funcname:
>
> b   funcname
Two approaches.

If you want to represent the call in RTL, emit_call_insn (...).  That's 
generally the way to emit a function call.

However there are also cases where the call you're making does not 
necessarily confirm to the target ABI.  In those cases most folks have 
an insn in their backend (a define_insn) that internally performs the 
call.  If you have a named pattern fubar, you can emit an insn with that 
pattern using emit_insn (gen_fubar (arguments)))

jeff