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use dynasmrt::x64::Assembler;
use dynasmrt::{DynasmApi, DynasmLabelApi};
use super::*;
use super::analysis::{BoundsAnalysis, AbstractInterpreter, NoAnalysis};
use common::Count;
use peephole;
use rts;
pub trait JitCompilable {
fn with_peephole<F, R>(&self, k: F) -> R
where F: FnOnce(&peephole::Program) -> R;
fn jit_compile(&self, checked: bool) -> Program {
self.with_peephole(|ast| compile(ast, checked))
}
}
dynasm!(asm
; .alias pointer, r12
; .alias mem_start, r13
; .alias mem_limit, r14
; .alias rts, r15
);
pub fn compile(program: &peephole::Program, checked: bool) -> Program {
if checked {
let mut compiler = Compiler::<AbstractInterpreter>::new(program, true);
compiler.compile(program);
compiler.into_program()
} else {
let mut compiler = Compiler::<NoAnalysis>::new(program, false);
compiler.compile(program);
compiler.into_program()
}
}
struct Compiler<B: BoundsAnalysis> {
asm: Assembler,
start: dynasmrt::AssemblyOffset,
checked: bool,
interpreter: B,
}
impl<B: BoundsAnalysis> Compiler<B> {
fn new(program: &peephole::Program, checked: bool) -> Self {
let asm = Assembler::new().expect("Could not create assembler");
let start = asm.offset();
let mut result = Compiler {
asm: asm,
start: start,
checked: checked,
interpreter: B::new(program),
};
result.emit_prologue();
result
}
fn into_program(mut self) -> Program {
self.emit_epilogue();
Program {
code: self.asm.finalize().unwrap(),
start: self.start,
}
}
fn emit_prologue(&mut self) {
dynasm!(self.asm
; push r12
; push r13
; push r14
; push r15
; mov pointer, rcx
; mov mem_start, rcx
; mov mem_limit, rcx
; add mem_limit, rdx
; mov rts, r8
);
}
fn emit_epilogue(&mut self) {
dynasm!(self.asm
; mov rax, rts::OKAY as i32
; jmp ->finish
; ->underflow:
; mov rax, rts::UNDERFLOW as i32
; jmp ->finish
; ->overflow:
; mov rax, rts::OVERFLOW as i32
; ->finish:
; pop r15
; pop r14
; pop r13
; pop r12
; ret
);
}
fn compile(&mut self, program: &[peephole::Statement]) {
for stm in program {
self.compile_statement(stm);
}
}
fn compile_statement(&mut self, stm: &peephole::Statement) {
use peephole::Statement::*;
use common::Instruction::*;
match *stm {
Instr(Right(count)) => {
let proved = self.interpreter.move_right(count);
dynasm!(self.asm
;; self.load_pos_offset(count, proved)
; add pointer, rax
);
}
Instr(Left(count)) => {
let proved = self.interpreter.move_left(count);
dynasm!(self.asm
;; self.load_neg_offset(count, proved)
; sub pointer, rax
);
}
Instr(Add(count)) => {
dynasm!(self.asm
; add [pointer], BYTE count as i8
);
}
Instr(In) => {
dynasm!(self.asm
;; self.rts_call(rts::RtsState::read as _)
; mov [pointer], al
);
}
Instr(Out) => {
dynasm!(self.asm
; xor rdx, rdx
; mov dl, [pointer]
;; self.rts_call(rts::RtsState::write as _)
);
}
Instr(SetZero) => {
dynasm!(self.asm
; mov BYTE [pointer], 0
)
}
Instr(FindZeroRight(skip)) => {
self.interpreter.reset_right();
dynasm!(self.asm
; jmp >end_loop
; begin_loop:
;; self.load_pos_offset(skip, false)
; add pointer, rax
; end_loop:
; cmp BYTE [pointer], 0
; jnz <begin_loop
)
}
Instr(FindZeroLeft(skip)) => {
self.interpreter.reset_left();
dynasm!(self.asm
; jmp >end_loop
; begin_loop:
;; self.load_neg_offset(skip, false)
; sub pointer, rax
; end_loop:
; cmp BYTE [pointer], 0
; jnz <begin_loop
)
}
Instr(OffsetAddRight(offset)) => {
let proved = self.interpreter.check_right(offset);
dynasm!(self.asm
; cmp BYTE [pointer], 0
; jz >skip
;; self.load_pos_offset(offset, proved)
; mov cl, BYTE [pointer]
; mov BYTE [pointer], 0
; add BYTE [pointer + rax], cl
; skip:
);
}
Instr(OffsetAddLeft(offset)) => {
let proved = self.interpreter.check_left(offset);
dynasm!(self.asm
; cmp BYTE [pointer], 0
; jz >skip
;; self.load_neg_offset(offset, proved)
; mov cl, BYTE [pointer]
; mov BYTE [pointer], 0
; neg rax
; add BYTE [pointer + rax], cl
; skip:
);
}
Instr(JumpZero(_)) | Instr(JumpNotZero(_)) =>
panic!("unexpected jump instruction"),
Loop(ref body) => {
let begin_label = self.asm.new_dynamic_label();
let end_label = self.asm.new_dynamic_label();
self.interpreter.enter_loop(body);
dynasm!(self.asm
; jmp =>end_label
; =>begin_label
;; self.compile(body)
; =>end_label
; cmp BYTE [pointer], 0
; jnz =>begin_label
);
self.interpreter.leave_loop();
}
}
}
fn rts_call(&mut self, fun: i64) {
dynasm!(self.asm
; mov rax, QWORD fun
; mov rcx, rts
; sub rsp, BYTE 0x28
; call rax
; add rsp, BYTE 0x28
);
}
#[inline]
fn load_constant(&mut self, count: Count) {
if count as i32 as Count == count {
dynasm!(self.asm
; mov rax, DWORD count as i32
);
} else {
dynasm!(self.asm
; mov rax, QWORD count as i64
);
}
}
#[inline]
fn load_pos_offset(&mut self, offset: Count, proved: bool) {
self.load_constant(offset);
if self.checked && !proved {
dynasm!(self.asm
; mov rcx, mem_limit
; sub rcx, pointer
; cmp rcx, rax
; jle ->overflow
);
}
}
#[inline]
fn load_neg_offset(&mut self, offset: Count, proved: bool) {
self.load_constant(offset);
if self.checked && !proved {
dynasm!(self.asm
; mov rcx, pointer
; sub rcx, mem_start
; cmp rcx, rax
; jl ->underflow
);
}
}
}
impl JitCompilable for peephole::Program {
fn with_peephole<F, R>(&self, k: F) -> R
where F: FnOnce(&peephole::Program) -> R
{
k(self)
}
}
impl<T: peephole::PeepholeCompilable + ?Sized> JitCompilable for T {
fn with_peephole<F, R>(&self, k: F) -> R
where F: FnOnce(&peephole::Program) -> R
{
k(&self.peephole_compile())
}
}