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Improved the compiler documentation, a little bit.

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This commit is contained in:
Greg King
2015-05-26 11:23:54 -04:00
parent bbb6f89731
commit b49fd26d16
2 changed files with 33 additions and 33 deletions
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doc/cc65.sgml
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@@ -3,7 +3,7 @@
<article>
<title>cc65 Users Guide
<author><url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">
<date>2015-04-21
<date>2015-05-26
<abstract>
cc65 is a C compiler for 6502 targets. It supports several 6502 based home
@@ -558,10 +558,10 @@ and the one defined by the ISO standard:
be passed as parameters by value. However, struct assignment *is*
possible.
<p>
<item> Most of the C library is available only with the fastcall calling
convention (<ref id="extension-fastcall" name="see below">). It means
that you must not mix pointers to those functions with pointers to
user-written, cdecl functions.
<item> Most of the C library is available with only the fastcall calling
convention (<ref id="extension-fastcall" name="see below">). It means
that you must not mix pointers to those functions with pointers to
user-written, cdecl functions (the calling conventions are incompatible).
<p>
<item> The <tt/volatile/ keyword doesn't have an effect. This is not as bad
as it sounds, since the 6502 has so few registers that it isn't
@@ -600,30 +600,30 @@ This cc65 version has some extensions to the ISO C standard.
<p>
<label id="extension-fastcall">
<item> The normal calling convention -- for non-variadic functions -- is
named "fastcall". The syntax for a function declaration that
<em/explicitly/ uses fastcall is
<item> The normal calling convention -- for non-variadic functions -- is
named "fastcall". The syntax for a function declaration that
<em/explicitly/ uses fastcall is
<tscreen><verb>
&lt;return type&gt; fastcall &lt;function name&gt; (&lt;parameter list&gt;)
</verb></tscreen>
or
<tscreen><verb>
&lt;return type&gt; __fastcall__ &lt;function name&gt; (&lt;parameter list&gt;)
</verb></tscreen>
An example would be
<tscreen><verb>
void __fastcall__ f (unsigned char c)
</verb></tscreen>
The first form of the fastcall keyword is in the user namespace and can
therefore be disabled with the <tt><ref id="option--standard"
<tscreen><verb>
&lt;return type&gt; fastcall &lt;function name&gt; (&lt;parameter list&gt;)
</verb></tscreen>
or
<tscreen><verb>
&lt;return type&gt; __fastcall__ &lt;function name&gt; (&lt;parameter list&gt;)
</verb></tscreen>
An example is
<tscreen><verb>
void __fastcall__ f (unsigned char c)
</verb></tscreen>
The first form of the fastcall keyword is in the user namespace and can
therefore be disabled with the <tt><ref id="option--standard"
name="--standard"></tt> command line option.
For functions that are <tt/fastcall/, the rightmost parameter is not
pushed on the stack but left in the primary register when the function
is called. That significantly reduces the cost of calling functions.
<newline><newline>
<p>
For functions that are <tt/fastcall/, the rightmost parameter is not
pushed on the stack but left in the primary register when the function
is called. That significantly reduces the cost of calling those functions.
<newline><newline>
<p>
<item> There is another calling convention named "cdecl". Variadic functions
(their prototypes have an ellipsis &lsqb;<tt/.../&rsqb;) always use that
@@ -636,14 +636,14 @@ This cc65 version has some extensions to the ISO C standard.
<tscreen><verb>
&lt;return type&gt; __cdecl__ &lt;function name&gt; (&lt;parameter list&gt;)
</verb></tscreen>
An example would be
An example is
<tscreen><verb>
int * __cdecl__ f (unsigned char c)
int* __cdecl__ f (unsigned char c)
</verb></tscreen>
The first form of the cdecl keyword is in the user namespace;
and therefore, can be disabled with the <tt><ref id="option--standard"
name="--standard"></tt> command-line option.
and therefore, can be disabled with the <tt/<ref id="option--standard"
name="--standard">/ command-line option.
For functions that are <tt/cdecl/, the rightmost parameter is pushed
onto the stack before the function is called. That increases the cost
@@ -701,7 +701,7 @@ This cc65 version has some extensions to the ISO C standard.
</verb></tscreen>
Since the variable is of type <tt/void/ you may not use it as is.
However, taking the address of the variable results in a <tt/void */
However, taking the address of the variable results in a <tt/void*/
which may be passed to any function expecting a pointer.
See the <url url="geos.html" name="GEOS library document"> for examples