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Treat PEA operand as imm const16

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We were treating PEA's operand as an absolute address and attempting to
extend it to 24 bits.  This wasn't very successful, and was
counter-productive when the argument was actually a constant, which is
common.  Worse, if the operand appeared to reference an internal address
outside bank 0, we would output a 24-bit value, breaking 64tass and cc65.

We now treat PEA as having an immediate operand.  (It was already
classified as an "extended immediate", but the operand-address
computation was still happening.)

This will have little to no effect on projects that use OMF relocation
data, because PEA arguments are explicitly identified as symbols or
constants.

New tests were added to 20032-labels-and-symbols to exercise the code
generation failures.  A few other tests that used PEA were affected.
20152-local-variables was fixed by adding a symbolic reference, the
others remained as-is and the expected output was revised.

(issue #172)
This commit is contained in:
Andy McFadden committed 2025-07-18 13:25:29 -07:00
1 parent 859a22fe60
commit 4846a26c9a
20 files changed
+293 -101
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Asm65/OpDef.cs
+1 -1
View File
@@ -81,7 +81,7 @@ namespace Asm65 {
Implied, // OP 1
PCRel, // OP label 2 (BCC, BNE, ...)
PCRelLong, // OP label 3 (BRL)
StackAbs, // OP addr 3 (PEA)
StackAbs, // OP addr 3 (PEA), treat as imm const16
StackDPInd, // OP (dp) 2 (PEI)
StackInt, // OP 2 (BRK, COP)
StackPCRelLong, // OP label 3 (PER)
SourceGen/CodeAnalysis.cs
+1 -1
View File
@@ -962,7 +962,7 @@ namespace SourceGen {
// Merge the PBR even if we eventually want the DBR; less to fix later.
mAnattribs[offset].OperandAddress = operand | bank;
break;
case OpDef.AddressMode.StackAbs: // assume PBR
//case OpDef.AddressMode.StackAbs: // treat as imm; else assume PBR
case OpDef.AddressMode.AbsIndexXInd: // JMP (addr,X); uses program bank
mAnattribs[offset].OperandAddress = operand | bank;
break;
SourceGen/DataAnalysis.cs
+1
View File
@@ -570,6 +570,7 @@ namespace SourceGen {
} else if (op == OpDef.OpPEA_StackAbs || op == OpDef.OpPER_StackPCRelLong) {
// They might be pushing address-1 to set up an RTS. If the target address isn't
// an instruction start, check to see if the following byte is.
// (We now treat PEA as immediate, so we won't be here for that.)
if (!mAnattribs[targetOffset].IsInstructionStart &&
targetOffset + 1 < mAnattribs.Length &&
mAnattribs[targetOffset + 1].IsInstructionStart) {
SourceGen/SGTestData/20032-labels-and-symbols
BIN
View File
Binary file not shown.
SourceGen/SGTestData/20032-labels-and-symbols.dis65
+69 -2
View File
@@ -1,8 +1,8 @@
### 6502bench SourceGen dis65 v1.0 ###
{
"_ContentVersion":6,
"FileDataLength":729,
"FileDataCrc32":-1745845873,
"FileDataLength":761,
"FileDataCrc32":1509582706,
"ProjectProps":{
"CpuName":"65816",
"IncludeUndocumentedInstr":false,
@@ -146,6 +146,15 @@
"PreLabel":"",
"DisallowInward":false,
"DisallowOutward":false,
"IsRelative":false},
{
"Offset":732,
"Addr":135168,
"Length":-1024,
"PreLabel":"",
"DisallowInward":false,
"DisallowOutward":false,
"IsRelative":false}],
"TypeHints":[{
"Low":0,
@@ -252,6 +261,13 @@
"Value":4538,
"Source":"User",
"Type":"GlobalAddr",
"LabelAnno":"None"},
"733":{
"Label":"ptest",
"Value":135169,
"Source":"User",
"Type":"GlobalAddr",
"LabelAnno":"None"}},
"OperandFormats":{
@@ -1514,6 +1530,57 @@
"Label":"after",
"Part":"Low"},
"Extra":null},
"736":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null,
"Extra":null},
"739":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Symbol",
"SymbolRef":{
"Label":"ptest",
"Part":"Low"},
"Extra":null},
"748":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null,
"Extra":null},
"751":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null,
"Extra":null},
"754":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Symbol",
"SymbolRef":{
"Label":"biggie",
"Part":"Low"},
"Extra":null},
"757":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Symbol",
"SymbolRef":{
"Label":"biggie",
"Part":"Bank"},
"Extra":null}},
"LvTables":{
SourceGen/SGTestData/20152-local-variables.dis65
+115 -47
View File
@@ -1,6 +1,6 @@
### 6502bench SourceGen dis65 v1.0 ###
{
"_ContentVersion":4,
"_ContentVersion":6,
"FileDataLength":237,
"FileDataCrc32":1833028653,
"ProjectProps":{
@@ -26,7 +26,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Decimal",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":false,
@@ -43,7 +44,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"project const",
"HasWidth":false,
@@ -60,7 +62,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"project const",
"HasWidth":false,
@@ -77,7 +80,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"project addr",
"HasWidth":false,
@@ -94,7 +98,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"project addr",
"HasWidth":false,
@@ -111,7 +116,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"project addr, should clash",
"HasWidth":false,
@@ -125,11 +131,21 @@
"AddressMap":[{
"Offset":0,
"Addr":4096},
"Addr":4096,
"Length":-1024,
"PreLabel":"",
"DisallowInward":false,
"DisallowOutward":false,
"IsRelative":false},
{
"Offset":126,
"Addr":128}],
"Addr":128,
"Length":-1024,
"PreLabel":"",
"DisallowInward":false,
"DisallowOutward":false,
"IsRelative":false}],
"TypeHints":[{
"Low":0,
"High":0,
@@ -143,12 +159,14 @@
"LongComments":{
"-2147483647":{
"Text":"Edited to have duplicate labels (PROJ_ZERO, DPCODE).",
"IsFancy":false,
"BoxMode":false,
"MaxWidth":80,
"BackgroundColor":0},
"81":{
"Text":"Test name redefinition. This is mostly of interest for assemblers without redefinable variables, but also of interest to the cross-reference window.",
"IsFancy":false,
"BoxMode":false,
"MaxWidth":80,
"BackgroundColor":0}},
@@ -206,31 +224,37 @@
"SubFormat":"Symbol",
"SymbolRef":{
"Label":"CONST_ZERO",
"Part":"Low"}},
"Part":"Low"},
"Extra":null},
"24":{
"Length":2,
"Format":"NumericLE",
"SubFormat":"Decimal",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"26":{
"Length":2,
"Format":"NumericLE",
"SubFormat":"Decimal",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"136":{
"Length":2,
"Format":"NumericLE",
"SubFormat":"Ascii",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"143":{
"Length":2,
"Format":"NumericLE",
"SubFormat":"Ascii",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"155":{
"Length":3,
@@ -238,7 +262,19 @@
"SubFormat":"Symbol",
"SymbolRef":{
"Label":"STRING",
"Part":"Bank"}}},
"Part":"Bank"},
"Extra":null},
"158":{
"Length":3,
"Format":"NumericLE",
"SubFormat":"Symbol",
"SymbolRef":{
"Label":"STRING",
"Part":"Low"},
"Extra":null}},
"LvTables":{
"12":{
@@ -247,7 +283,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -264,7 +301,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -281,7 +319,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -298,7 +337,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -317,7 +357,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"clash with project symbol",
"HasWidth":true,
@@ -334,7 +375,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"clash with user label",
"HasWidth":true,
@@ -361,7 +403,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"hidden table",
"HasWidth":true,
@@ -378,7 +421,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"hidden table",
"HasWidth":true,
@@ -397,7 +441,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"not hidden",
"HasWidth":true,
@@ -414,7 +459,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"not hidden",
"HasWidth":true,
@@ -433,7 +479,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -450,7 +497,8 @@
"Length":4,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -469,7 +517,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"#1",
"HasWidth":true,
@@ -488,7 +537,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"#2",
"HasWidth":true,
@@ -507,7 +557,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"#3",
"HasWidth":true,
@@ -526,7 +577,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -545,7 +597,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -564,7 +617,8 @@
"Length":4,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -583,7 +637,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -602,7 +657,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -619,7 +675,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -636,7 +693,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -653,7 +711,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -670,7 +729,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -687,7 +747,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -706,7 +767,8 @@
"Length":4,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -725,7 +787,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"same as org",
"HasWidth":true,
@@ -744,7 +807,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -763,7 +827,8 @@
"Length":1,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -786,7 +851,8 @@
"Length":2,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -803,7 +869,8 @@
"Length":4,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
@@ -820,7 +887,8 @@
"Length":4,
"Format":"NumericLE",
"SubFormat":"Hex",
"SymbolRef":null},
"SymbolRef":null,
"Extra":null},
"Comment":"",
"HasWidth":true,
SourceGen/SGTestData/Expected/20032-labels-and-symbols_64tass.S
+15 -1
View File
@@ -34,7 +34,7 @@ start clc
lda #>start
lda #`start
pea $feed
pea start & $ffff
pea $2345
pea $0001
pea $3456
pea $0012
@@ -226,6 +226,20 @@ after ldx <after+8,y
ldy <after+9,x
pei (<after+10)
nop
jml _L21000
.here
.logical $021000
_L21000 nop
ptest pea $1001
pea $1001
pea ptest & $ffff
pea $3456
pea $0012
pea $3456
pea $0012
pea biggie & $ffff
pea biggie >> 16
rts
.here
SourceGen/SGTestData/Expected/20032-labels-and-symbols_acme.S
+2 -1
View File
@@ -23,5 +23,6 @@
!hex 656172206f6e20746865206669727374206c696e652e20205468652071756963
!hex 6b2062726f776e20666f78206a756d7073206f76657220746865206c617a7920
!hex 646f67732ea97aa959a934c230a97b56a95a34a93412eaad9f11a59fa5a0b2a1
!hex b1a2b7a3a7a4b5a5a1a6b9a700a5c0b1c1b6c2b4c3d4c4ea60
!hex b1a2b7a3a7a4b5a5a1a6b9a700a5c0b1c1b6c2b4c3d4c4ea5c001002eaf40110
!hex f40110f40110f45634f41200f45634f41200f45634f4120060
}
SourceGen/SGTestData/Expected/20032-labels-and-symbols_cc65.S
+14 -1
View File
@@ -32,7 +32,7 @@ start: clc
lda #>start
lda #^start
pea $feed
pea start & $ffff
pea $2345
pea $0001
pea $3456
pea $0012
@@ -223,5 +223,18 @@ after: ldx <after+8,y
ldy <after+9,x
pei (<after+10)
nop
jml @L21000
.org $021000
@L21000: nop
ptest: pea $1001
pea $1001
pea ptest & $ffff
pea $3456
pea $0012
pea $3456
pea $0012
pea biggie & $ffff
pea biggie >> 16
rts
SourceGen/SGTestData/Expected/20032-labels-and-symbols_merlin32.S
+14 -1
View File
@@ -29,7 +29,7 @@ start clc
lda #>start
lda #^start
pea $feed
pea start
pea $2345
pea $0001
pea $3456
pea $0012
@@ -214,5 +214,18 @@ after ldx <after+8&$ff,y
ldy <after+9&$ff,x
dfb $d4,$c4
nop
jml :L21000
org $021000
:L21000 nop
ptest pea $1001
pea $1001
pea ptest
pea $3456
pea $0012
pea $3456
pea $0012
pea biggie
pea ^biggie
rts
SourceGen/SGTestData/Expected/20062-target-adjustment_64tass.S
+1 -1
View File
@@ -4,7 +4,7 @@
.xs
nop
L1001 bit L1001
caddr pea caddr-1
caddr pea $1003
per caddr-1
lda L1001+2
lda caddr
SourceGen/SGTestData/Expected/20062-target-adjustment_acme.S
+1 -1
View File
@@ -4,7 +4,7 @@
!rs
nop
L1001 bit L1001
caddr pea caddr-1
caddr pea $1003
per caddr-1
lda L1001+2
lda caddr
SourceGen/SGTestData/Expected/20062-target-adjustment_cc65.S
+1 -1
View File
@@ -4,7 +4,7 @@
.i8
nop
L1001: bit L1001
caddr: pea caddr-1
caddr: pea $1003
per caddr-1
lda L1001+2
lda caddr
SourceGen/SGTestData/Expected/20062-target-adjustment_merlin32.S
+1 -1
View File
@@ -1,7 +1,7 @@
org $1000
nop
L1001 bit L1001
caddr pea caddr-1
caddr pea $1003
per caddr-1
lda L1001+2
lda caddr
SourceGen/SGTestData/Expected/20102-label-dp_64tass.S
+1 -1
View File
@@ -273,7 +273,7 @@ L11FC cmp @wL0086,x
_L122A sbc (L0080),y
sbc (L0080)
sbc ($80,s),y
pea L0086
pea $0086
sbc L0080,x
inc L0080,x
sbc [L0080],y
SourceGen/SGTestData/Expected/20102-label-dp_acme.S
+1 -1
View File
@@ -273,7 +273,7 @@ L11FC cmp+2 L0086,x
@L122A sbc (L0080),y
sbc (L0080)
sbc ($80,S),y
pea L0086
pea $0086
sbc+1 L0080,x
inc+1 L0080,x
sbc [L0080],y
SourceGen/SGTestData/Expected/20102-label-dp_cc65.S
+1 -1
View File
@@ -273,7 +273,7 @@ L11FC: cmp a:L0086,x
@L122A: sbc (L0080),y
sbc (L0080)
sbc ($80,S),y
pea L0086
pea $0086
sbc z:L0080,x
inc z:L0080,x
sbc [L0080],y
SourceGen/SGTestData/Expected/20102-label-dp_merlin32.S
+1 -1
View File
@@ -270,7 +270,7 @@ L11FC cmp: L0086,x
:L122A sbc (L0080),y
dfb $f2,$80
sbc ($80,S),y
pea L0086
pea $0086
sbc L0080,x
inc L0080,x
sbc [L0080],y
SourceGen/SGTestData/Source/20032-labels-and-symbols.S
+16 -2
View File
@@ -248,8 +248,22 @@ before nop
ldx <after+2&$ff,y
ldy <after+3&$ff,x
dfb $d4,$c4 ;pei (<zip+4&$ff)
after nop
jml checkpea
; Dig into PEA, using both internal and external addresses. We want to do
; this outside bank 0 to see if the bank byte creeps in.
org $021000
checkpea nop
ptest pea ptest ;don't format
pea ptest ;explicitly format as hex
pea ptest ;format as symbol
pea biggie ;don't format
pea ^biggie
pea biggie ;explicitly format as hex
pea ^biggie
pea biggie ;format as symbol (low+bank)
pea ^biggie
rts
docs/sgmanual/advanced.html
+37 -36
View File
@@ -416,18 +416,19 @@ rsrcmsg pea rsrcmsg2|-16
sta pArcRead+$06
</pre>
<p>In both cases we're referencing a 24-bit address as two 16-bit values.
Without context, the disassembler will treat the PEA instruction as two
independent 16-bit addresses, and the immediate values as constants:</p>
Without context, the disassembler will treat the PEA instruction operands
and the immediate values as constants:</p>
<pre>
.dbank $02
02/317c: f4 02 00 L2317C pea L20002 &amp; $ffff
02/317f: f4 54 32 pea L23254 &amp; $ffff
02/3182: a2 0c 20 ldx #WriteCString
02/3185: 22 00 00 e1 jsl Toolbox
02/3189: a9 00 00 L23189 lda #$0000
02/318c: 8d 78 3f sta L23F78 &amp; $ffff
02/318f: a9 03 00 lda #$0003
02/3192: 8d 7a 3f sta L23F78 &amp; $ffff +2
02/327c: f4 02 00 L2327C pea $0002
02/327f: f4 54 33 pea $3354
02/3282: a2 0c 20 ldx #WriteCString
02/3285: 22 00 00 e1 jsl Toolbox
02/3289: a9 00 01 L23289 lda #$0100
02/328c: 8d 78 40 sta L24078 & $ffff
02/328f: a9 03 00 lda #$0003
02/3292: 8d 7a 40 sta L24078 & $ffff +2
</pre>
<p>Worse yet, those <code>STA</code> instruction operands would have been
shown as hex values or incorrect labels if the DBR had been set incorrectly.
@@ -436,20 +437,20 @@ address from which the addresses were formed, and we can tell when
immediate values are addresses rather than constants. And we can do this
even without setting the DBR.</p>
<pre>
02/317c: f4 02 00 L2317C pea L23254 &gt;&gt; 16
02/317f: f4 54 32 pea L23254 &amp; $ffff
02/3182: a2 0c 20 ldx #WriteCString
02/3185: 22 00 00 e1 jsl Toolbox
02/3189: a9 00 00 L23189 lda #L30000 &amp; $ffff
02/318c: 8d 78 3f sta L23F78 &amp; $ffff
02/318f: a9 03 00 lda #L30000 &gt;&gt; 16
02/3192: 8d 7a 3f sta L23F78 &amp; $ffff +2
02/327c: f4 02 00 L2327C pea L23354 &gt;&gt; 16
02/327f: f4 54 33 pea L23354 & $ffff
02/3282: a2 0c 20 ldx #WriteCString
02/3285: 22 00 00 e1 jsl Toolbox
02/3289: a9 00 01 L23289 lda #L30100 & $ffff
02/328c: 8d 78 40 sta L24078 & $ffff
02/328f: a9 03 00 lda #L30100 &gt;&gt; 16
02/3292: 8d 7a 40 sta L24078 & $ffff +2
</pre>
<p>The absence of relocation data can be a useful signal as well. For
example, when pushing arguments for a toolbox call, the disassembler
can tell the difference between addresses and constants without needing
emulation or pattern-matching, because only the addresses get
relocated. Consider this bit of source code:</p>
relocated. Another example:</p>
<pre>
lda &lt;total_records
pha
@@ -461,25 +462,25 @@ relocated. Consider this bit of source code:</p>
</pre>
<p>Without relocation data, it becomes:</p>
<pre>
02/0aa8: a5 42 lda $42
02/0aaa: 48 pha
02/0aab: f4 02 00 pea L20002 &amp; $ffff
02/0aae: f4 03 31 pea L23103 &amp; $ffff
02/0ab1: f4 05 00 pea L20005 &amp; $ffff
02/0ab4: f4 00 00 pea L20000 &amp; $ffff
02/0ab7: a2 0b 26 ldx #Int2Dec
02/0aba: 22 00 00 e1 jsl Toolbox
02/0ba8: a5 42 lda $42
02/0baa: 48 pha
02/0bab: f4 02 00 pea $0002
02/0bae: f4 03 32 pea $3203
02/0bb1: f4 05 00 pea $0005
02/0bb4: f4 00 00 pea $0000
02/0bb7: a2 0b 26 ldx #Int2Dec
02/0bba: 22 00 00 e1 jsl Toolbox
</pre>
<p>If we treat the non-relocated operands as constants:</p>
<p>With reloc, we update the pointer but not the constants:</p>
<pre>
02/0aa8: a5 42 lda $42
02/0aaa: 48 pha
02/0aab: f4 02 00 pea L230C2 &gt;&gt; 16
02/0aae: f4 03 31 pea L23103 &amp; $ffff
02/0ab1: f4 05 00 pea $0005
02/0ab4: f4 00 00 pea $0000
02/0ab7: a2 0b 26 ldx #Int2Dec
02/0aba: 22 00 00 e1 jsl Toolbox
02/0ba8: a5 42 lda $42
02/0baa: 48 pha
02/0bab: f4 02 00 pea L231C2 >> 16
02/0bae: f4 03 32 pea L23203 & $ffff
02/0bb1: f4 05 00 pea $0005
02/0bb4: f4 00 00 pea $0000
02/0bb7: a2 0b 26 ldx #Int2Dec
02/0bba: 22 00 00 e1 jsl Toolbox
</pre>