Re: [PATCH 4 of 7] x86/paravirt: selectively save/restore regs aroundpvops calls

[Jeremy Fitzhardinge]

Rusty Russell wrote:
> On Thursday 29 January 2009 09:05:04 Jeremy Fitzhardinge wrote:
>   
> > +#define PV_SAVE_REGS(set)			\
> > +	COND_PUSH(set, CLBR_RAX, rax);		\
> > +	COND_PUSH(set, CLBR_RCX, rcx);		\
> > +	COND_PUSH(set, CLBR_RDX, rdx);		\
> > +	COND_PUSH(set, CLBR_RSI, rsi);		\
> > +	COND_PUSH(set, CLBR_RDI, rdi);		\
> > +	COND_PUSH(set, CLBR_R8, r8);		\
> > +	COND_PUSH(set, CLBR_R9, r9);		\
> > +	COND_PUSH(set, CLBR_R10, r10);		\
> > +	COND_PUSH(set, CLBR_R11, r11)
> >     
>
> It's kind of messy.  Can we do something clever here with token pasting?
>   

I tried a few things, but no.  Passing in just RAX, and then pasting 
CLBR_##reg works, and the assembler accepts %RAX - but - the asm code 
also #defines RAX <some stack offset>, so the assembler ends up seeing 
%48.  I considered renaming all the CLBR_ defines to CLBR_rax, but that 
looks unhappy too.  So I stayed with this.

   J
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