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>
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

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.

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