gbdev/rgbds
1
0
Fork 0
mirror of https://github.com/gbdev/rgbds.git synced 2025-11-24 20:12:07 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add flag to rgbasm to disable LD->LDH optimization

Browse Source 
rgbasm tries to optimize any loads from/to $FF00-$FFFF and generate
LDH 2-byte opcodes instead of regular LD 3-byte opcodes. This is a bit
inconsistent as it only works for constant values. If a load is trying
to access a label in a HRAM floating section, or a section found in a
different object file, this optimization doesn't work.

This means that a simple refactor or code could allow rgbasm to perform
the optimzation or prevent it from doing so. For certain projects, like
disassemblies, this is a problem.

This patch adds flag -L to rgbasm to disable the optimization, and
doesn't change the behaviour of any other existing code.

Signed-off-by: Antonio Niño Díaz <antonio_nd@outlook.com>
This commit is contained in:
Antonio Niño Díaz
2018-02-24 15:43:55 +00:00
parent 2a97535e75
commit 6ad5bd2325
9 changed files with 70 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
docs/rgbasm.1.html
View File

@@ -27,7 +27,7 @@
<table class="Nm">
<tr>
<td><b class="Nm" title="Nm">rgbasm</b></td>
<td>[<span class="Op"><b class="Fl" title="Fl">-EhVvw</b></span>]
<td>[<span class="Op"><b class="Fl" title="Fl">-EhLVvw</b></span>]
[<span class="Op"><b class="Fl" title="Fl">-b</b>
<var class="Ar" title="Ar">chars</var></span>]
[<span class="Op"><b class="Fl" title="Fl">-D</b>
@@ -89,6 +89,13 @@ The <b class="Nm" title="Nm">rgbasm</b> program creates an object file from an
<dd class="It-tag">Add an include path.</dd>
<dt class="It-tag">&#x00A0;</dt>
<dd class="It-tag">&#x00A0;</dd>
<dt class="It-tag"><a class="selflink" href="#L"><b class="Fl" title="Fl" id="L">-L</b></a></dt>
<dd class="It-tag">Disable the optimization that turns loads of the form
<b class="Sy" title="Sy">LD [$FF00+n8],A</b> into the opcode
<b class="Sy" title="Sy">LDH [$FF00+n8],A</b> in order to have full
control of the result in the final ROM.</dd>
<dt class="It-tag">&#x00A0;</dt>
<dd class="It-tag">&#x00A0;</dd>
<dt class="It-tag"><a class="selflink" href="#M"><b class="Fl" title="Fl" id="M">-M</b></a>
<var class="Ar" title="Ar">dependfile</var></dt>
<dd class="It-tag">Print <a class="Xr" title="Xr">make(1)</a> dependencies to
@@ -120,7 +127,11 @@ The <b class="Nm" title="Nm">rgbasm</b> program creates an object file from an
<h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
Assembling a basic source file is simple:
<div class="Pp"></div>
<div class="D1">$ rgbasm -o bar.o foo.asm</div>
<div class="Bd" style="margin-left: 5.00ex;">
<pre class="Li">
$ rgbasm -o bar.o foo.asm
</pre>
</div>
<div class="Pp"></div>
The resulting object file is not yet a usable ROM image &#x2014; it must first
be run through <a class="Xr" title="Xr">rgblink(1)</a> and
@@ -138,7 +149,7 @@ The resulting object file is not yet a usable ROM image &#x2014; it must first
<a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.</div>
<table class="foot">
<tr>
<td class="foot-date">January 26, 2018</td>
<td class="foot-date">February 24, 2018</td>
<td class="foot-os">RGBDS Manual</td>
</tr>
</table>