Mercurial > hg > index.cgi

view docs/manual/x218.html @ 434:052c5f335a92

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fix bug in like terms collection in expression simplification Like term collection would lose the actual "variable" part of the term if the second term collected happened to have no coefficient. This would cause the expression to take the value of the calculated coefficient which is obviously wrong. Thanks to hider <stego@satx.rr.com> for reporting the bug and providing a proper test case. Observation: this bug has been present since the first pre-release of lwtools 3.0 when the algebraic expression system was introduced. Apparently people tend not to create expressions that trigger the like terms handler. The specific conditions require the symbol to be undefined and the second operand to the addition has to have no coefficient so it's likely a fairly rare scenario. Still, it is somewhat surprising that nobody tripped on it before now.
author William Astle <lost@l-w.ca>
date Mon, 23 Jan 2017 22:58:36 -0700
parents fc166b3bbae3
children
line wrap: on
line source

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Dialects</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="LW Tool Chain"
HREF="index.html"><LINK
REL="UP"
TITLE="LWASM"
HREF="c62.html"><LINK
REL="PREVIOUS"
TITLE="LWASM"
HREF="c62.html"><LINK
REL="NEXT"
TITLE="Source Format"
HREF="x227.html"></HEAD
><BODY
CLASS="SECTION"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>LW Tool Chain</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="c62.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 3. LWASM</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="x227.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECTION"
><H1
CLASS="SECTION"
><A
NAME="AEN218"
>3.2. Dialects</A
></H1
><P
> LWASM supports all documented MC6809 instructions as defined by
Motorola.  By default, this does not include any MC6800 compatibility
instructions.  As of LWASM 4.11, those compatibility instructions can be
enabled using the <CODE
CLASS="PARAMETER"
>--6800compat</CODE
> option or the
<CODE
CLASS="PARAMETER"
>6800compat</CODE
> pragma.  It also supports all known HD6309
instructions.  While there is general agreement on the pneumonics for most
of the 6309 instructions, there is some variance with the block transfer
instructions.  TFM for all four variations seems to have gained the most
traction and, thus, this is the form that is recommended for LWASM. 
However, it also supports COPY, COPY-, IMP, EXP, TFRP, TFRM, TFRS, and TFRR. 
It further adds COPY+ as a synomym for COPY, IMPLODE for IMP, and EXPAND for
EXP.  </P
><P
>By default, LWASM accepts 6309 instructions. However, using the
<CODE
CLASS="PARAMETER"
>--6809</CODE
> parameter, you can cause it to throw errors on
6309 instructions instead.</P
><P
>The standard addressing mode specifiers are supported. These are the
hash sign ("#") for immediate mode, the less than sign ("&lt;") for forced
eight bit modes, and the greater than sign ("&gt;") for forced sixteen bit modes.</P
><P
>Additionally, LWASM supports using the asterisk ("*") to indicate
base page addressing. This should not be used in hand-written source code,
however, because it is non-standard and may or may not be present in future
versions of LWASM.</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="c62.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="x227.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>LWASM</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="c62.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Source Format</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>