To: ao950 AT FreeNet DOT Carleton DOT CA
Cc: djgpp AT delorie DOT com
Subject: Re: register based calling
Message-ID: <19970310.083356.7495.0.fwec@juno.com>
References: <01bc2c04$dcd88540$0cb0f8ce AT pquinney>
	<5g05e4$q6d AT freenet-news DOT carleton DOT ca>
From: fwec AT juno DOT com (Mark T Logan)
Date: Mon, 10 Mar 1997 08:36:39 EST

On 10 Mar 1997 05:15:48 GMT ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
writes:
>
>"Ian Mausolus" (mausolus AT ican DOT net) writes:
>> Does anyone know how to do register based calling under DJGPP?
>> 
>> Thanx,
>> 
>> I. Mausolus
>
>Why do you want to...is it faster?
>(Maybe I should use this to make the six hundred calls to
>draw_compiled_sprite run faster in my game loops.)

It is _much_ faster.  I don't know how much faster, but is a lot quicker.
Normally when you call a function, all the parameters you pass it are
pushed onto the stack.  This is not a cheap operation.  However, Watcom
and I suspect other compilers use register passing to speed up their 
programs significantly.


||                                         Fwec AT juno DOT com
||
|| "Why can they make a potato chip in one second, but it takes us months
to
||   develop software?" - Dilbert's Boss
||