RE: [avr-gcc-list] Odd prologue for ATmega256x in WinAVR20080407

[Weddington, Eric]

> -----Original Message-----
> From: 
> address@hidden 
> [mailto:address@hidden
> org] On Behalf Of Jeff Barlow
> Sent: Thursday, April 10, 2008 9:10 AM
> To: address@hidden
> Subject: Re: [avr-gcc-list] Odd prologue for ATmega256x in 
> WinAVR20080407
> 
> Stu Bell <address@hidden>  wrote:
> 
> >What does the double "rcall ." do?
> 
> It just adjusts the stack pointer prior to loading it as the
> local frame pointer. It's a fairly cute optimization actually.
> 

Hi Stu,

Don't feel bad. When I first saw this, I thought the same thing: "Huh?,
What's this?" After some quick double checking in the instruction set
manual, it finally made sense. I agree with Jeff, it's quite a trick
optimization. Thanks go to Anatoly Sokolov. ;-)