model TPASCAL

simo...@ix.netcom.com (Carl Mueller)

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

TASM: "ALIGN"ing addresses w/ model TPASCAL

I'm trying to use the ALIGN macro to align loop points on even addresses, but
with model TPASCAL, it keeps giving me the error message "ALIGN not strict
enough". I'm just doing things like:

ALIGN 4 ; dword align
@@loop:
lodsd
dec cx
jnz @@loop

Can anyone help me out? Also does this really help alot for speed?
I've tried everything I can think of.

Thanks,
Carl

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:TASM: "ALIGN"ing addresses w/ model TPASCAL

Jason Burgo

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:TASM: "ALIGN"ing addresses w/ model TPASCAL

In article: <4t3gm4$...@dfw-ixnews4.ix.netcom.com> simo...@ix.netcom.com (Carl

Quote

Mueller) writes:

>I'm trying to use the ALIGN macro to align loop points on even addresses, but
>with model TPASCAL, it keeps giving me the error message "ALIGN not strict
>enough". I'm just doing things like:

> ALIGN 4 ; dword align
>@@loop:
> lodsd
> dec cx
> jnz @@loop

I'm afraid it's pointless using this directive for code designed for BP because
the built-in linker only aligns to byte. You'll have to do it manually to your
pascal code by telling BP to generate a detailed MAP file, which you then
correlate back to the source, adding ASM padder instructions (such as nop) at
the end of each so that all the procedures, functions and methods of a unit are
a multiple of 4 bytes long. All procedures in the unit will then be dword
aligned since the code for a unit always starts on a paragraph boundary. If it's
a DPMI program then include a "{$G UnitName} in the main program to ensure the
dword aligned unit is not appended to grouped code segment.

Quote

>Can anyone help me out?

The above does work (I've done it for my low level graphics driver unit), but
it's not the easy answer you were looking for I shouldn't think.

Also does this really help alot for speed?

I don't think the above example will speed up the code for anything other than
386's, as later chips will be fetching the instructions from the primary cache,
but aligning procedure entry points will speed things up a little on all
machines.

---------------------------------------------------------------------------
| Jason Burgon - author of Graphic Vision, TV-Like GUI for 256 Colour SVGA |
| g...@jayman.demon.co.uk ftp://SimTel/msdos/turbopas/gv4svga1.zip |
| http://www.en.com/users/grendel/prog/tv_prog.html |
---------------------------------------------------------------------------

Other Threads

1. Anyone familiar with .TPASCAL model of TASM

2. "Show"ing Problems

3. "order"-ing of functions to reduce page faults

4. The keys "-"/"+"/"*"

5. Ist "modeling tool included"???

6. 3ds models and delphi "Project"

7. "Standard" Data Models

8. Component like MS "Address Bar"

9. "Address" component wanted

10. EIdProtocolReplyError "User Address required"