From: "Andrew Crabtree" <andrewc AT rosemail DOT rose DOT hp DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: special registers in ASM
Date: Wed, 11 Feb 1998 13:19:32 -0800
Organization: Hewlett Packard
Lines: 23
Message-ID: <6bt4l8$kn9$1@rosenews.rose.hp.com>
References: <01bd371c$3b3ff0a0$b1fcffc2 AT fsl22 DOT novo DOT dk>
NNTP-Posting-Host: ros51675cra.rose.hp.com
Mime-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk


Flemming Stig Larsen wrote in message
<01bd371c$3b3ff0a0$b1fcffc2 AT fsl22 DOT novo DOT dk>...
>I'm going to translate a loop written in C to ASM, but I need more than 8
>individual 32-bit registers to do it properly
Wait for the Merced chip.  128 GP Regs. ;)

> I'm only familar with
>the 6 standarts(EAX-EDX,ESI,EDI)
You can also use EBP if you omit the frame pointer.

> Then I read about some special registers in the 386+ ex. DR2, TR5,
>CR3. My questions are, can I  use them right away?, are they 32bit?,
>what are the syntax to use them in DJGPP's AT&T inline-assembler?

Did you read the instruction timing for them?  THe debug registers are 10x
slower than regular registers
(also 10x slower than a push or a pop instruction), and CR3 is 20x slower.
This is on a Pentium.  Also,
you can't do anything with them, just move to and from.  Rewrite your code
to be more register efficient
or just push/pop.