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codegen: Emit Intel syntax
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AT&T syntax is really awful I'm sorry
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@mrkajetanp
mrkajetanp committed Aug 12, 2024
1 parent 327b18c commit 2ec83f1
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Showing 2 changed files with 32 additions and 29 deletions.
59 changes: 31 additions & 28 deletions src/codegen.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@ impl Program {
pub fn emit(&self) -> String {
let mut result = String::new();

result.push_str(&format!(".intel_syntax noprefix\n\n"));
result.push_str(&self.body.emit());
result.push_str(".section .note.GNU-stack,\"\",@progbits\n");
result.push_str(&format!(".globl {}\n", self.body.name));
Expand Down Expand Up @@ -89,8 +90,9 @@ impl Function {
let mut result = String::new();

result.push_str(&format!("{}:\n", self.name));
result.push_str(&format!("\t{}\n", "pushq %rbp"));
result.push_str(&format!("\t{}\n", "movq %rsp, %rbp"));
// Emit function prologue
result.push_str(&format!("\t{}\n", "push rbp"));
result.push_str(&format!("\t{}\n", "mov rbp, rsp"));
for instr in &self.instructions {
result.push_str(&instr.emit());
}
Expand Down Expand Up @@ -301,20 +303,20 @@ impl Instruction {
let mut result = String::new();
// TODO: slightly awkward, to be fixed at some point
// format_instr will wrap whatever the match returns in \t and \n
result.push_str(&format!("{}\n", "movq %rbp, %rsp"));
result.push_str(&format_instr("popq %rbp"));
result.push_str(&format!("{}\n", "mov rsp, rbp"));
result.push_str(&format_instr("pop rbp"));
result.push_str(&format!("\t{}", "ret"));
result
}
Self::Mov(src, dst) => format!("movl {}, {}", src.emit_4b(), dst.emit_4b()),
Self::Mov(src, dst) => format!("mov {}, {}", dst.emit_4b(), src.emit_4b()),
Self::Unary(operator, operand) => format!("{} {}", operator.emit(), operand.emit_4b()),
Self::Binary(operator, op1, op2) => {
format!("{} {}, {}", operator.emit(), op1.emit_4b(), op2.emit_4b())
format!("{} {}, {}", operator.emit(), op2.emit_4b(), op1.emit_4b())
}
Self::Idiv(operand) => format!("idivl {}", operand.emit_4b()),
Self::Idiv(operand) => format!("idiv {}", operand.emit_4b()),
Self::Cdq => format!("cdq"),
Self::AllocateStack(val) => format!("subq ${}, %rsp", val),
Self::Cmp(a, b) => format!("cmpl {}, {}", a.emit_4b(), b.emit_4b()),
Self::AllocateStack(val) => format!("sub rsp, {}", val),
Self::Cmp(a, b) => format!("cmp {}, {}", b.emit_4b(), a.emit_4b()),
Self::Jmp(label) => format!("jmp .L{}", label),
Self::JmpCC(cc, label) => format!("j{} .L{}", cc.emit(), label),
Self::SetCC(cc, operand) => format!("set{} {}", cc.emit(), operand.emit_1b()),
Expand All @@ -327,7 +329,7 @@ impl fmt::Display for Instruction {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let result = match self {
Self::Ret => format!("<epilogue>"),
Self::Mov(src, dst) => format!("mov {}, {}", src, dst),
Self::Mov(src, dst) => format!("mov {}, {}", dst, src),
Self::Unary(operator, operand) => format!("{} {}", operator, operand),
Self::Binary(operator, op1, op2) => format!("{} {}, {}", operator, op1, op2),
Self::Idiv(operand) => format!("div {}", operand),
Expand Down Expand Up @@ -364,9 +366,9 @@ impl BinaryOperator {

pub fn emit(&self) -> String {
match self {
&BinaryOperator::Add => "addl",
&BinaryOperator::Sub => "subl",
&BinaryOperator::Mult => "imull",
&BinaryOperator::Add => "add",
&BinaryOperator::Sub => "sub",
&BinaryOperator::Mult => "imul",
}
.to_owned()
}
Expand Down Expand Up @@ -401,8 +403,8 @@ impl UnaryOperator {

pub fn emit(&self) -> String {
match self {
Self::Neg => "negl",
Self::Not => "notl",
Self::Neg => "neg",
Self::Not => "not",
}
.to_owned()
}
Expand All @@ -411,8 +413,8 @@ impl UnaryOperator {
impl fmt::Display for UnaryOperator {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let result = match self {
&UnaryOperator::Neg => "neg",
&UnaryOperator::Not => "not",
UnaryOperator::Neg => "neg",
UnaryOperator::Not => "not",
};
write!(f, "{}", result)
}
Expand Down Expand Up @@ -465,15 +467,16 @@ impl Operand {
pub fn emit_4b(&self) -> String {
match self {
Self::Reg(reg) => reg.emit_4b(),
Self::Immediate(val) => format!("${}", val),
Self::Stack(val) => format!("{}(%rbp)", val),
Self::Immediate(val) => format!("{}", val),
Self::Stack(val) => format!("DWORD PTR [rbp{}]", val),
Self::Pseudo(_) => panic!("Fatal error: Pseudo-operand in emit stage"),
}
}

pub fn emit_1b(&self) -> String {
match self {
Self::Reg(reg) => reg.emit_1b(),
Self::Stack(val) => format!("BYTE PTR [rbp{}]", val),
_ => self.emit_4b(),
}
}
Expand All @@ -484,7 +487,7 @@ impl fmt::Display for Operand {
let result = match self {
Self::Reg(reg) => format!("{}", reg),
Self::Immediate(val) => format!("{}", val),
Self::Stack(val) => format!("{}(stack)", val),
Self::Stack(val) => format!("[rbp{}]", val),
Self::Pseudo(name) => format!("<{}>", name),
};
write!(f, "{}", result)
Expand All @@ -503,19 +506,19 @@ pub enum Register {
impl Register {
pub fn emit_4b(&self) -> String {
match self {
Self::AX => format!("%eax"),
Self::DX => format!("%edx"),
Self::R10 => format!("%r10d"),
Self::R11 => format!("%r11d"),
Self::AX => format!("eax"),
Self::DX => format!("edx"),
Self::R10 => format!("r10d"),
Self::R11 => format!("r11d"),
}
}

pub fn emit_1b(&self) -> String {
match self {
Self::AX => format!("%al"),
Self::DX => format!("%dl"),
Self::R10 => format!("%r10b"),
Self::R11 => format!("%r11b"),
Self::AX => format!("al"),
Self::DX => format!("dl"),
Self::R10 => format!("r10b"),
Self::R11 => format!("r11b"),
}
}
}
Expand Down
2 changes: 1 addition & 1 deletion src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -146,7 +146,7 @@ impl Driver {

fn assemble(&self, path: &str) {
let _ = Command::new("gcc")
.args([path, "-o", &self.name])
.args([path, "-masm=intel", "-o", &self.name])
.status()
.expect("Failed to run the assembler");
}
Expand Down

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