add rest of basic mov instructions

This commit is contained in:
2026-06-12 21:53:22 -04:00
parent 397176759d
commit 715a50b1fa
6 changed files with 109 additions and 36 deletions
+51 -18
View File
@@ -28,7 +28,7 @@ impl Code {
if src.requires_rex() || dst.requires_rex() { if src.requires_rex() || dst.requires_rex() {
self.bytes.push(rex(width, src, 0, dst)); self.bytes.push(rex(width, src, 0, dst));
} }
self.bytes.push(0x88 | width.gt8() as u8); self.bytes.push(0x88 | width.not8());
self.bytes.push(modrm_regs(src, dst)); self.bytes.push(modrm_regs(src, dst));
} }
RegImmMem::Imm(src) => { RegImmMem::Imm(src) => {
@@ -49,15 +49,42 @@ impl Code {
if dst.requires_rex() { if dst.requires_rex() {
self.bytes.push(rex(dst.width(), 0, 0, dst)); self.bytes.push(rex(dst.width(), 0, 0, dst));
} }
let opcode = 0xb0 | ((dst.width().gt8() as u8) << 3); self.bytes.push(0xb0 | (dst.not8() << 3) | dst.base());
self.bytes.push(opcode | dst.base());
self.imm(src, dst.width()); self.imm(src, dst.width());
} }
} }
RegImmMem::Mem(src) => todo!(), RegImmMem::Mem(src) => {
if src.width != dst.width() {
return Err("register & memory sizes don't match".into());
}
if dst.high() && src.reg.gt8() {
return Err("registers incompatible (REX)".into());
}
self.prefix32(&src)?;
self.prefix16(dst);
if dst.requires_rex() | src.reg.gt8() {
self.bytes.push(rex(dst.width(), dst, 0, src.reg));
}
self.bytes.push(0x8a | dst.not8());
self.modrm_regdisp(dst, src);
}
}, },
RegMem::Mem(dst) => match src { RegMem::Mem(dst) => match src {
RegImmMem::Reg(src) => todo!(), RegImmMem::Reg(src) => {
if src.width() != dst.width {
return Err("register & memory sizes don't match".into());
}
if src.high() && dst.reg.gt8() {
return Err("registers incompatible (REX)".into());
}
self.prefix32(&dst)?;
self.prefix16(src);
if src.requires_rex() | dst.reg.gt8() {
self.bytes.push(rex(src.width(), src, 0, dst.reg));
}
self.bytes.push(0x88 | src.not8());
self.modrm_regdisp(src, dst);
}
RegImmMem::Imm(src) => { RegImmMem::Imm(src) => {
let encode_width = dst.width.min(Width::B32); let encode_width = dst.width.min(Width::B32);
let src_width = if dst.width == Width::B64 { let src_width = if dst.width == Width::B64 {
@@ -71,17 +98,13 @@ impl Code {
if src_width > dst.width { if src_width > dst.width {
return Err("source cannot fit in destination".into()); return Err("source cannot fit in destination".into());
} }
match dst.reg.width() { self.prefix32(&dst)?;
Width::B8 | Width::B16 => return Err("invalid register width".into()),
Width::B32 => self.bytes.push(0x67),
Width::B64 => (),
}
self.prefix16(encode_width); self.prefix16(encode_width);
if dst.reg.requires_mem_rex() || dst.width == Width::B64 { if dst.reg.requires_mem_rex() || dst.width == Width::B64 {
self.bytes.push(rex(dst.width, 0, 0, dst.reg)); self.bytes.push(rex(dst.width, 0, 0, dst.reg));
} }
self.bytes.push(0xc6 | (encode_width != Width::B8) as u8); self.bytes.push(0xc6 | encode_width.not8());
self.modrm_regdisp(dst.reg, dst.disp); self.modrm_regdisp(None, dst);
self.imm(src, encode_width); self.imm(src, encode_width);
} }
RegImmMem::Mem(_) => return Err("cannot move memory to memory".into()), RegImmMem::Mem(_) => return Err("cannot move memory to memory".into()),
@@ -170,23 +193,33 @@ impl Code {
} }
} }
fn modrm_regdisp(&mut self, reg: Reg, disp: i32) { fn prefix32(&mut self, mem: &Mem) -> Result<(), CompilerMsg> {
match mem.reg.width() {
Width::B8 | Width::B16 => return Err("invalid register width".into()),
Width::B32 => self.bytes.push(0x67),
Width::B64 => (),
}
Ok(())
}
fn modrm_regdisp(&mut self, reg: impl Into<Option<Reg>>, mem: Mem) {
const I8_MIN: i32 = i8::MIN as i32; const I8_MIN: i32 = i8::MIN as i32;
const I8_MAX: i32 = i8::MAX as i32; const I8_MAX: i32 = i8::MAX as i32;
let mod_ = match disp { let mod_ = match mem.disp {
0 => 0b00, 0 => 0b00,
I8_MIN..=I8_MAX => 0b01, I8_MIN..=I8_MAX => 0b01,
_ => 0b10, _ => 0b10,
}; };
self.bytes.push(modrm(mod_, 0, reg.base())); let r = reg.into().map(|r| Reg::base(&r)).unwrap_or(0);
if reg.base() == rsp.base() { self.bytes.push(modrm(mod_, r, mem.reg.base()));
if mem.reg.base() == rsp.base() {
// SIB // SIB
self.bytes.push(0x24); self.bytes.push(0x24);
} }
match mod_ { match mod_ {
0b00 => (), 0b00 => (),
0b01 => self.bytes.push(disp as u8), 0b01 => self.bytes.push(mem.disp as u8),
0b10 => self.bytes.extend(disp.to_le_bytes()), 0b10 => self.bytes.extend(mem.disp.to_le_bytes()),
_ => unreachable!(), _ => unreachable!(),
} }
} }
+10 -2
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@@ -51,6 +51,14 @@ impl Reg {
self.width self.width
} }
pub fn not8(&self) -> u8 {
self.width.not8()
}
pub fn high(&self) -> bool {
self.high
}
/// if self has 64 bit width, changes width to 32 bit /// if self has 64 bit width, changes width to 32 bit
pub fn lower64(&self) -> Self { pub fn lower64(&self) -> Self {
let mut new = *self; let mut new = *self;
@@ -101,8 +109,8 @@ impl Width {
} }
/// greater than 8 bits /// greater than 8 bits
pub const fn gt8(&self) -> bool { pub const fn not8(&self) -> u8 {
!matches!(self, Self::B8) !matches!(self, Self::B8) as u8
} }
} }
+46 -16
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@@ -34,26 +34,53 @@ const WIDTHS: &[Width] = &[Width::B8, Width::B16, Width::B32, Width::B64];
#[test] #[test]
fn mov() { fn mov() {
let c = &mut TestCtx::new(); let c = &mut TestCtx::new("mov");
for &r1 in Reg::IMPORTANT { for dst in regs() {
for &r2 in Reg::IMPORTANT { for src in regs() {
eq(c, format!("mov {r1}, {r2}"), |c| c.mov(r1, r2)); eq(c, format!("mov {dst}, {src}"), |c| c.mov(dst, src));
} }
} }
for &r1 in Reg::IMPORTANT { for dst in regs() {
for &imm in IMMS { for src in mems() {
eq(c, format!("mov {r1}, {imm}"), |c| c.mov(r1, imm)); eq(c, format!("mov {dst}, {src}"), |c| c.mov(dst, src));
} }
} }
for &reg in Reg::IMPORTANT { for dst in regs() {
for &disp in DISPS { for src in imms() {
for &imm in IMMS { eq(c, format!("mov {dst}, {src}"), |c| c.mov(dst, src));
}
}
for dst in mems() {
for src in regs() {
eq(c, format!("mov {dst}, {src}"), |c| c.mov(dst, src));
}
}
for dst in mems() {
for src in imms() {
eq(c, format!("mov {dst}, {src}"), |c| c.mov(dst, src));
}
}
}
fn imms() -> impl Iterator<Item = i128> {
IMMS.iter().cloned()
}
fn regs() -> impl Iterator<Item = Reg> {
Reg::IMPORTANT.iter().cloned()
}
fn mems() -> impl Iterator<Item = Mem> {
gen move {
for &reg in Reg::IMPORTANT {
for &disp in DISPS {
for &width in WIDTHS { for &width in WIDTHS {
let mem = mem(reg, disp, width); yield mem(reg, disp, width);
eq(c, format!("mov {mem}, {imm}"), |c| c.mov(mem, imm));
} }
} }
} }
@@ -61,6 +88,7 @@ fn mov() {
} }
struct TestCtx { struct TestCtx {
path: String,
code: Code, code: Code,
cache: HashMap<String, Result<Vec<u8>, String>>, cache: HashMap<String, Result<Vec<u8>, String>>,
changed: bool, changed: bool,
@@ -145,15 +173,17 @@ fn write(path: &str, binary: &[u8]) {
file.sync_all().expect("Failed to sync file"); file.sync_all().expect("Failed to sync file");
} }
const CACHE_PATH: &str = "test/nasm_test_cache"; const CACHE_PATH: &str = "test/nasm_cache";
impl TestCtx { impl TestCtx {
fn new() -> Self { fn new(name: &str) -> Self {
let cache = match std::fs::read(CACHE_PATH) { let path = CACHE_PATH.to_string() + "/" + name;
let cache = match std::fs::read(&path) {
Ok(bytes) => bitcode::decode(&bytes).unwrap_or_default(), Ok(bytes) => bitcode::decode(&bytes).unwrap_or_default(),
Err(_) => Default::default(), Err(_) => Default::default(),
}; };
Self { Self {
path,
code: Default::default(), code: Default::default(),
cache, cache,
changed: Default::default(), changed: Default::default(),
@@ -164,7 +194,7 @@ impl TestCtx {
impl Drop for TestCtx { impl Drop for TestCtx {
fn drop(&mut self) { fn drop(&mut self) {
if self.changed { if self.changed {
write(CACHE_PATH, &bitcode::encode(&self.cache)); write(&self.path, &bitcode::encode(&self.cache));
} }
} }
} }
+2
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@@ -1,3 +1,5 @@
#![feature(gen_blocks)]
use crate::{io::CompilerOutput, parser_ir::parse_program}; use crate::{io::CompilerOutput, parser_ir::parse_program};
mod arch; mod arch;
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