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Lynx support #3

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5e4aa72
lynx feature
LLeny Apr 17, 2026
3fefc87
gitignore
LLeny Apr 18, 2026
68a492a
Lynx memory model
LLeny Apr 18, 2026
b2c7776
Make use of the bank keyword for Lynx "file" loading
LLeny Apr 18, 2026
f35d830
Lynx bank org declaration
LLeny Apr 20, 2026
8e09bfa
Lynx: disable "jsr Call{}"
LLeny Apr 23, 2026
d10fb83
Disable bank check for lynx
LLeny Apr 26, 2026
2581d56
Enable var_const for Lynx
LLeny Apr 26, 2026
4e864b4
Lynx disable default const on charptr
LLeny May 3, 2026
5b62b0e
Enable alignment on Lynx
LLeny May 5, 2026
a12ae45
Cargo.toml, remove mistakenly pushed default atarilynx feature
LLeny May 5, 2026
8137cb2
65c02 jmp->bra opt, moved AsmLine distance calc to own function.
LLeny May 5, 2026
d625c38
Add 65c02 STZ
LLeny May 6, 2026
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1 change: 1 addition & 0 deletions .gitignore
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Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
target/
3 changes: 3 additions & 0 deletions Cargo.toml
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Expand Up @@ -21,5 +21,8 @@ regex = "1"
itertools = "0.13.0"

[features]
default = []
65C02 = []
atari2600 = []
atari7800 = []
atarilynx = [ "65C02" ]
181 changes: 117 additions & 64 deletions src/assemble.rs
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Expand Up @@ -32,6 +32,8 @@ pub enum AsmMnemonic {
STA,
STX,
STY,
#[cfg(feature = "65C02")]
STZ,
TAX,
TAY,
TXA,
Expand Down Expand Up @@ -63,6 +65,8 @@ pub enum AsmMnemonic {
DEX,
DEY,
JMP,
#[cfg(feature = "65C02")]
BRA,
JSR,
RTS,
RTI,
Expand Down Expand Up @@ -236,15 +240,114 @@ impl AssemblyCode {
Ok(s)
}

pub fn optimize(&mut self) -> u32 {
pub(crate) fn distance(&self, inst: &AsmInstruction, position: usize) -> i32 {
let mut bytes_above = 0;
let mut bytes_below = 0;
let mut index_above = position;
let mut index_below = position + 1;
let mut reached_above = false;
let above;
let mut notfound = 0;
loop {
if !reached_above {
match &self.code[index_above] {
AsmLine::Label(l) => {
debug!("Iter above: {:?}", l);
if *l == inst.dasm_operand {
above = true;
break;
}
}
AsmLine::Inline(_, s) => {
bytes_above += s;
}
AsmLine::Instruction(k) => {
debug!("Iter above: {:?}", k);
bytes_above += k.nb_bytes;
}
_ => (),
}
}
match self.code.get(index_below) {
Some(AsmLine::Label(l)) => {
debug!("Iter below: {:?}", l);
if *l == inst.dasm_operand {
above = false;
break;
}
}
Some(AsmLine::Inline(_, s)) => {
bytes_below += s;
}
Some(AsmLine::Instruction(k)) => {
debug!("Iter below: {:?}", k);
bytes_below += k.nb_bytes;
}
None => notfound |= 2,
_ => (),
}
if index_above == 0 {
reached_above = true;
notfound |= 1;
} else {
index_above -= 1;
}
index_below += 1;
if notfound == 3 {
error!("Label {} not found", inst.dasm_operand);
unreachable!()
};
}
// Ok, now we have the distance in bytes
if above { bytes_above as i32 } else { -(bytes_below as i32) }
}


#[cfg(feature = "65C02")]
fn optimize_jmp_bra(&mut self) {
let to_replace: Vec<usize> = self
.code
.iter()
.enumerate()
.filter_map(|(pos, line)| {
if let AsmLine::Instruction(jmp) = line {
if jmp.mnemonic == AsmMnemonic::JMP
&& !jmp.protected
&& (-127..=128).contains(&self.distance(jmp, pos))
{
Some(pos)
} else {
None
}
} else {
None
}
})
.collect();

for pos in to_replace {
if let AsmLine::Instruction(jmp) = &self.code[pos] {
self.code[pos] = AsmLine::Instruction(AsmInstruction {
mnemonic: AsmMnemonic::BRA,
dasm_operand: jmp.dasm_operand.clone(),
cycles: 3,
cycles_alt: Some(4),
nb_bytes: 2,
protected: false,
});
}
}
}

fn general_6502_optimizations(&mut self) -> u32 {
let mut removed_instructions = 0u32;
let mut accumulator = None;
let mut x_register = None;
let mut y_register = None;
let mut flags = FlagsState::Unknown;
let mut iter = itertools::multipeek(self.code.iter_mut());
let mut first = iter.next();
let mut flags = FlagsState::Unknown;


loop {
match &first {
None => return removed_instructions,
Expand Down Expand Up @@ -785,6 +888,15 @@ impl AssemblyCode {
}
}

pub fn optimize(&mut self) -> u32 {
let removed_instructions = self.general_6502_optimizations();

#[cfg(feature = "65C02")]
self.optimize_jmp_bra();

removed_instructions
}

pub fn check_branches(&mut self) -> u32 {
// Loop until there is no problematic branch instruction
let mut restart = true;
Expand All @@ -810,69 +922,10 @@ impl AssemblyCode {
| AsmMnemonic::BPL
| AsmMnemonic::BCS
| AsmMnemonic::BCC => {
// Ok, let's try to find the label above and under and try to count the bytes
let mut bytes_above = 0;
let mut bytes_below = 0;
let mut index_above = position;
let mut index_below = position + 1;
let mut reached_above = false;
let above;
let mut notfound = 0;
loop {
if !reached_above {
match &self.code[index_above] {
AsmLine::Label(l) => {
debug!("Iter above: {:?}", l);
if *l == inst.dasm_operand {
above = true;
break;
}
}
AsmLine::Inline(_, s) => {
bytes_above += s;
}
AsmLine::Instruction(k) => {
debug!("Iter above: {:?}", k);
bytes_above += k.nb_bytes;
}
_ => (),
}
}
match self.code.get(index_below) {
Some(AsmLine::Label(l)) => {
debug!("Iter below: {:?}", l);
if *l == inst.dasm_operand {
above = false;
break;
}
}
Some(AsmLine::Inline(_, s)) => {
bytes_below += s;
}
Some(AsmLine::Instruction(k)) => {
debug!("Iter below: {:?}", k);
bytes_below += k.nb_bytes;
}
None => notfound |= 2,
_ => (),
}
if index_above == 0 {
reached_above = true;
notfound |= 1;
} else {
index_above -= 1;
}
index_below += 1;
if notfound == 3 {
error!("Label {} not found", inst.dasm_operand);
unreachable!()
};
}
// Ok, now we have the distance in bytes
let distance = if above { bytes_above } else { bytes_below };
let distance = self.distance(inst, position);
//error!("distance = {:?}", distance);
//if above {unreachable!();}
if distance > 127 {
if !(-127..=128).contains(&distance) {
// OK. We have a problem here
// This branch should be changed for a jump
repair = true;
Expand Down
5 changes: 4 additions & 1 deletion src/cc6502.pest
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Expand Up @@ -27,16 +27,19 @@ decl = { enclosed_decl
| func_vec_decl
| func_decl
| included_assembler
| bank_org_decl
}
enclosed_decl = { bank ~ "{" ~ decl+ ~ "}" }
var_decl = { var_type ~ global_id ~ ("," ~ global_id)* ~ ";"+ }
var_type = ${ ((var_const | superchip | ramchip | ramplus | bank | aligned | display | frequency | reversed | scattered | holeydma | noholeydma | screencode | nopagecross) ~ WHITESPACE+ )* ~ (var_sign ~ WHITESPACE+)? ~ var_simple_type ~ WHITESPACE+ }
var_type = ${ ((var_const | superchip | zp | ramchip | ramplus | bank | aligned | display | frequency | reversed | scattered | holeydma | noholeydma | screencode | nopagecross) ~ WHITESPACE+ )* ~ (var_sign ~ WHITESPACE+)? ~ var_simple_type ~ WHITESPACE+ }
local_var_decl = { local_var_decl_const | local_var_decl_mut }
local_var_decl_const = { "const" ~ var_type ~ global_id ~ ("," ~ global_id)* ~ ";" }
local_var_decl_mut = { local_var_type ~ local_id ~ ("," ~ local_id)* ~ ";" }
local_var_type = ${ (var_sign ~ WHITESPACE+)? ~ var_simple_type ~ WHITESPACE+ }
bank_org_decl = { bank ~ "org" ~ int ~ ";" }
var_const = { "const" }
superchip = { "superchip" }
zp = { "zp" }
ramchip = { "ramchip" }
ramplus = { "ramplus" }
display = { "display" }
Expand Down
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