ref: 6ad5bd232504801b1b6b911c918677a7aff2c698
parent: 2a97535e75be78ca1e7ec47587849a7e0d82fb86
author: Antonio Niño Díaz <antonio_nd@outlook.com>
date: Sat Feb 24 10:43:55 EST 2018
Add flag to rgbasm to disable LD->LDH optimization 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>
--- a/docs/rgbasm.1.html
+++ b/docs/rgbasm.1.html
@@ -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 @@
<dd class="It-tag">Add an include path.</dd>
<dt class="It-tag"> </dt>
<dd class="It-tag"> </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"> </dt>
+ <dd class="It-tag"> </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 @@
<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 — it must first
be run through <a class="Xr" title="Xr">rgblink(1)</a> and
@@ -138,7 +149,7 @@
<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>
--- a/docs/rgbasm.5.html
+++ b/docs/rgbasm.5.html
@@ -125,7 +125,10 @@
<b class="Sy" title="Sy">LDH [$FF00+n8],A</b> and
<b class="Sy" title="Sy">LDH A,[$FF00+n8]</b> syntax instead. This forces
the assembler to emit the correct instruction and the linker to check if
- the value is in the correct range.</dd>
+ the value is in the correct range. This optimization can be disabled by
+ passing the <b class="Fl" title="Fl">-L</b> flag to
+ <b class="Sy" title="Sy">rgbasm</b> as explained in
+ <a class="Xr" title="Xr">rgbasm(1)</a>.</dd>
</dl>
<div class="Pp"></div>
A section is usually defined as a floating one, but the code can restrict where
@@ -1462,7 +1465,7 @@
<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 27, 2018</td>
+ <td class="foot-date">February 24, 2018</td>
<td class="foot-os">RGBDS Manual</td>
</tr>
</table>
--- a/docs/rgbds.7.html
+++ b/docs/rgbds.7.html
@@ -26,9 +26,13 @@
<h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
To get a working ROM image from a single assembly source file:
<div class="Pp"></div>
-<div class="D1">$ rgbasm -o bar.o foo.asm</div>
-<div class="D1">$ rgblink -o baz.gb bar.o</div>
-<div class="D1">$ rgbfix -v -p 0 baz.gb</div>
+<div class="Bd" style="margin-left: 5.00ex;">
+<pre class="Li">
+$ rgbasm -o bar.o foo.asm
+$ rgblink -o baz.gb bar.o
+$ rgbfix -v -p 0 baz.gb
+</pre>
+</div>
<h1 class="Sh" title="Sh" id="SEE_ALSO"><a class="selflink" href="#SEE_ALSO">SEE
ALSO</a></h1>
<a class="Xr" title="Xr">rgbasm(1)</a>, <a class="Xr" title="Xr">rgbfix(1)</a>,
@@ -58,7 +62,7 @@
</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>
--- a/include/asm/main.h
+++ b/include/asm/main.h
@@ -15,12 +15,13 @@
#include "extern/stdnoreturn.h"
struct sOptions {- char gbgfx[4];
char binary[2];
+ char gbgfx[4];
+ bool exportall;
int32_t fillchar;
- bool verbose;
bool haltnop;
- bool exportall;
+ bool optimizeloads;
+ bool verbose;
bool warnings; /* True to enable warnings, false to disable them. */
};
--- a/src/asm/asmy.y
+++ b/src/asm/asmy.y
@@ -1728,7 +1728,8 @@
}
| T_Z80_LD op_mem_ind comma T_MODE_A
{- if ((!rpn_isReloc(&$2)) && ($2.nVal >= 0xFF00)) {+ if (CurrentOptions.optimizeloads &&
+ (!rpn_isReloc(&$2)) && ($2.nVal >= 0xFF00)) {out_AbsByte(0xE0);
out_AbsByte($2.nVal & 0xFF);
} else {@@ -1781,7 +1782,8 @@
| T_Z80_LD reg_r comma op_mem_ind
{ if ($2 == REG_A) {- if ((!rpn_isReloc(&$4)) && ($4.nVal >= 0xFF00)) {+ if (CurrentOptions.optimizeloads &&
+ (!rpn_isReloc(&$4)) && ($4.nVal >= 0xFF00)) {out_AbsByte(0xF0);
out_AbsByte($4.nVal & 0xFF);
} else {--- a/src/asm/main.c
+++ b/src/asm/main.c
@@ -282,7 +282,7 @@
static void print_usage(void)
{printf(
-"usage: rgbasm [-EhVvw] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"
+"usage: rgbasm [-EhLVvw] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"
" [-M dependfile] [-o outfile] [-p pad_value] file.asm\n");
exit(1);
}
@@ -316,10 +316,11 @@
DefaultOptions.gbgfx[3] = '3';
DefaultOptions.binary[0] = '0';
DefaultOptions.binary[1] = '1';
+ DefaultOptions.exportall = false;
DefaultOptions.fillchar = 0;
- DefaultOptions.verbose = false;
+ DefaultOptions.optimizeloads = true;
DefaultOptions.haltnop = true;
- DefaultOptions.exportall = false;
+ DefaultOptions.verbose = false;
DefaultOptions.warnings = true;
opt_SetCurrentOptions(&DefaultOptions);
@@ -326,7 +327,7 @@
newopt = CurrentOptions;
- while ((ch = getopt(argc, argv, "b:D:g:hi:M:o:p:EVvw")) != -1) {+ while ((ch = getopt(argc, argv, "b:D:Eg:hi:LM:o:p:Vvw")) != -1) { switch (ch) {case 'b':
if (strlen(optarg) == 2) {@@ -357,6 +358,9 @@
break;
case 'i':
fstk_AddIncludePath(optarg);
+ break;
+ case 'L':
+ newopt.optimizeloads = false;
break;
case 'M':
dependfile = fopen(optarg, "w");
--- a/src/asm/rgbasm.1
+++ b/src/asm/rgbasm.1
@@ -5,7 +5,7 @@
.\"
.\" SPDX-License-Identifier: MIT
.\"
-.Dd January 26, 2018
+.Dd February 24, 2018
.Dt RGBASM 1
.Os RGBDS Manual
.Sh NAME
@@ -13,7 +13,7 @@
.Nd Game Boy assembler
.Sh SYNOPSIS
.Nm rgbasm
-.Op Fl EhVvw
+.Op Fl EhLVvw
.Op Fl b Ar chars
.Op Fl D Ar name Ns Op = Ns Ar value
.Op Fl g Ar chars
@@ -55,6 +55,12 @@
option disables this behavior.
.It Fl i Ar path
Add an include path.
+.It Fl L
+Disable the optimization that turns loads of the form
+.Sy LD [$FF00+n8],A
+into the opcode
+.Sy LDH [$FF00+n8],A
+in order to have full control of the result in the final ROM.
.It Fl M Ar dependfile
.Xr make 1
@@ -75,7 +81,9 @@
.Sh EXAMPLES
Assembling a basic source file is simple:
.Pp
-.D1 $ rgbasm -o bar.o foo.asm
+.Bd -literal -offset indent
+$ rgbasm -o bar.o foo.asm
+.Ed
.Pp
The resulting object file is not yet a usable ROM image \(em it must first be
run through
--- a/src/asm/rgbasm.5
+++ b/src/asm/rgbasm.5
@@ -5,7 +5,7 @@
.\"
.\" SPDX-License-Identifier: MIT
.\"
-.Dd January 27, 2018
+.Dd February 24, 2018
.Dt RGBASM 5
.Os RGBDS Manual
.Sh NAME
@@ -110,7 +110,13 @@
.Sy LDH A,[$FF00+n8]
syntax instead.
This forces the assembler to emit the correct instruction and the linker to
-check if the value is in the correct range.
+check if the value is in the correct range. This optimization can be disabled
+by passing the
+.Fl L
+flag to
+.Sy rgbasm
+as explained in
+.Xr rgbasm 1 .
.El
.Pp
A section is usually defined as a floating one, but the code can restrict where
--- a/src/rgbds.7
+++ b/src/rgbds.7
@@ -5,7 +5,7 @@
.\"
.\" SPDX-License-Identifier: MIT
.\"
-.Dd January 26, 2018
+.Dd February 24, 2018
.Dt RGBDS 7
.Os RGBDS Manual
.Sh NAME
@@ -14,9 +14,11 @@
.Sh EXAMPLES
To get a working ROM image from a single assembly source file:
.Pp
-.D1 $ rgbasm \-o bar.o foo.asm
-.D1 $ rgblink \-o baz.gb bar.o
-.D1 $ rgbfix \-v \-p 0 baz.gb
+.Bd -literal -offset indent
+$ rgbasm \-o bar.o foo.asm
+$ rgblink \-o baz.gb bar.o
+$ rgbfix \-v \-p 0 baz.gb
+.Ed
.Sh SEE ALSO
.Xr rgbasm 1 ,
.Xr rgbfix 1 ,