Files
regalloc2/src/ion/fast_alloc.rs
2023-04-12 03:49:50 +02:00

312 lines
9.3 KiB
Rust

use alloc::vec;
use alloc::vec::Vec;
use smallvec::{smallvec, SmallVec};
use std::convert::TryFrom;
use crate::{
cfg::CFGInfo, Allocation, Block, Edit, Function, Inst, MachineEnv, Operand, OperandConstraint,
OperandKind, OperandPos, Output, PReg, ProgPoint, RegAllocError, RegClass, SpillSlot, VReg,
};
#[derive(Default, Clone, Copy)]
struct VRegData {
pub preg: Option<PReg>,
pub slot_idx: Option<u32>,
pub reftype: bool,
}
#[derive(Default, Clone, Copy)]
struct PRegData {
pub vreg: Option<u32>,
pub stack_pseudo: bool,
}
#[derive(Default, Clone, Copy)]
struct BlockData {
pub allocated: bool,
}
struct FastAllocState<'a, F: Function> {
pub vregs: Vec<VRegData>,
pub pregs: Vec<PRegData>,
pub blocks: Vec<BlockData>,
pub preorder: Vec<Block>,
pub reg_order_int: Vec<PReg>,
pub reg_order_float: Vec<PReg>,
pub cur_stack_slot_idx: u32,
pub reftype_vregs_in_pregs_count: u32,
pub stack_slot_count_int: u8,
pub stack_slot_count_float: u8,
pub allocs: Vec<Allocation>,
pub inst_alloc_offsets: Vec<u32>,
pub edits: Vec<(ProgPoint, Edit)>,
pub safepoint_slots: Vec<(ProgPoint, Allocation)>,
pub func: &'a F,
pub mach_env: &'a MachineEnv,
pub cfg: &'a CFGInfo,
}
impl<'a, F: Function> FastAllocState<'a, F> {
pub fn init(func: &'a F, mach_env: &'a MachineEnv, cfg: &'a CFGInfo) -> Self {
let vregs = {
let mut vregs = Vec::with_capacity(func.num_vregs());
vregs.resize(func.num_vregs(), VRegData::default());
for vreg in func.reftype_vregs() {
vregs[vreg.vreg()].reftype = true;
}
vregs
};
let pregs = {
let mut pregs = Vec::with_capacity(PReg::NUM_INDEX);
pregs.resize(PReg::NUM_INDEX, PRegData::default());
for preg in &mach_env.fixed_stack_slots {
pregs[preg.index()].stack_pseudo = true;
}
pregs
};
let blocks = {
let mut blocks = Vec::with_capacity(func.num_blocks());
blocks.resize(func.num_blocks(), BlockData::default());
blocks
};
let reg_order_int = {
let class = RegClass::Int as usize;
let amount = mach_env.preferred_regs_by_class[class].len()
+ mach_env.non_preferred_regs_by_class[class].len();
let mut reg_order = Vec::with_capacity(amount);
reg_order.extend_from_slice(&mach_env.preferred_regs_by_class[class]);
reg_order.extend_from_slice(&mach_env.non_preferred_regs_by_class[class]);
reg_order
};
let reg_order_float = {
let class = RegClass::Float as usize;
let amount = mach_env.preferred_regs_by_class[class].len()
+ mach_env.non_preferred_regs_by_class[class].len();
let mut reg_order = Vec::with_capacity(amount);
reg_order.extend_from_slice(&mach_env.preferred_regs_by_class[class]);
reg_order.extend_from_slice(&mach_env.non_preferred_regs_by_class[class]);
reg_order
};
let mut inst_alloc_offsets = Vec::with_capacity(func.num_insts());
inst_alloc_offsets.resize(func.num_insts(), 0);
Self {
vregs,
pregs,
blocks,
preorder: Self::calc_preorder(func),
reg_order_int,
reg_order_float,
cur_stack_slot_idx: 0,
reftype_vregs_in_pregs_count: 0,
stack_slot_count_int: u8::try_from(func.spillslot_size(RegClass::Int))
.expect("that's a big integer"),
stack_slot_count_float: u8::try_from(func.spillslot_size(RegClass::Float))
.expect("that's a big float"),
allocs: Vec::new(),
inst_alloc_offsets,
edits: Vec::new(),
safepoint_slots: Vec::new(),
func,
mach_env,
cfg,
}
}
pub fn get_or_alloc_stack_slot(&mut self, vreg: VReg) -> u32 {
if let Some(idx) = self.vregs[vreg.vreg()].slot_idx {
return idx;
}
self.alloc_stack_slot(vreg)
}
pub fn alloc_stack_slot(&mut self, vreg: VReg) -> u32 {
let data = &mut self.vregs[vreg.vreg()];
if data.slot_idx.is_some() {
panic!("Trying to allocate already allocated stack slot");
}
let size = if vreg.class() == RegClass::Int {
self.stack_slot_count_int
} else {
self.stack_slot_count_float
};
let idx = self.cur_stack_slot_idx;
self.cur_stack_slot_idx += size as u32;
data.slot_idx = Some(idx);
idx
}
pub fn move_to_preg(&mut self, vreg: VReg, preg: PReg, pos: ProgPoint) {
if let Some(vreg) = &self.pregs[preg.index()].vreg {
let vdata = &mut self.vregs[*vreg as usize];
debug_assert!(vdata.preg.is_some());
debug_assert_eq!(vdata.preg.unwrap(), preg);
vdata.preg = None;
}
if let Some(preg) = &self.vregs[vreg.vreg()].preg {
// TODO: allow multiple pregs for a single vreg?
let pdata = &mut self.pregs[preg.index()];
debug_assert!(pdata.vreg.is_some());
debug_assert_eq!(pdata.vreg.unwrap(), vreg.vreg() as u32);
pdata.vreg = None;
}
let vdata = &mut self.vregs[vreg.vreg()];
let pdata = &mut self.pregs[preg.index()];
if vdata.slot_idx.is_none() {
panic!("Trying to move from vreg that has no stack slot to preg");
}
self.edits.push((
pos,
Edit::Move {
from: Allocation::stack(SpillSlot::new(vdata.slot_idx.unwrap() as usize)),
to: Allocation::reg(preg),
},
));
vdata.preg = Some(preg);
pdata.vreg = Some(vreg.vreg() as u32);
if vdata.reftype {
self.reftype_vregs_in_pregs_count += 1;
}
}
pub fn move_to_stack(&mut self, preg: PReg, vreg: VReg, pos: ProgPoint) {
let vdata = &mut self.vregs[vreg.vreg()];
let pdata = &mut self.pregs[preg.index()];
if pdata.vreg.is_none() || vdata.preg.is_none() {
panic!("Trying to move from unallocated preg/vreg to stack");
}
debug_assert_eq!(vdata.preg.unwrap(), preg);
debug_assert_eq!(pdata.vreg.unwrap(), vreg.vreg() as u32);
if vdata.slot_idx.is_none() {
panic!("Trying to move to vreg without stack slot");
}
self.edits.push((
pos,
Edit::Move {
from: Allocation::reg(preg),
to: Allocation::stack(SpillSlot::new(vdata.slot_idx.unwrap() as usize)),
},
));
}
pub fn clear_preg(&mut self, preg: PReg) {
let pdata = &mut self.pregs[preg.index()];
if let Some(vreg) = pdata.vreg {
let vdata = &mut self.vregs[vreg as usize];
debug_assert_eq!(vdata.preg.unwrap(), preg);
vdata.preg = None;
pdata.vreg = None;
if vdata.reftype {
self.reftype_vregs_in_pregs_count -= 1;
}
}
}
pub fn clear_vreg_from_reg(&mut self, vreg: VReg) {
let vdata = &mut self.vregs[vreg.vreg()];
if let Some(preg) = vdata.preg {
debug_assert_eq!(self.pregs[preg.index()].vreg.unwrap(), vreg.vreg() as u32);
self.pregs[preg.index()].vreg = None;
vdata.preg = None;
if vdata.reftype {
self.reftype_vregs_in_pregs_count -= 1;
}
}
}
fn calc_preorder(func: &F) -> Vec<Block> {
let entry = func.entry_block();
let mut ret = vec![entry];
struct State<'a> {
block: Block,
succs: &'a [Block],
next_succ: usize,
}
let mut stack: SmallVec<[State; 64]> = smallvec![];
stack.push(State {
block: entry,
succs: func.block_succs(entry),
next_succ: 0,
});
while let Some(ref mut state) = stack.last_mut() {
if state.next_succ >= state.succs.len() {
stack.pop();
continue;
}
let block = state.succs[state.next_succ];
let succs = func.block_succs(block);
ret.push(block);
state.next_succ += 1;
if state.next_succ >= state.succs.len() {
stack.pop();
}
if !succs.is_empty() {
stack.push(State {
block,
succs: func.block_succs(block),
next_succ: 0,
});
}
}
ret
}
}
pub fn run<F: Function>(
func: &F,
mach_env: &MachineEnv,
cfg: CFGInfo,
) -> Result<Output, RegAllocError> {
if func.multi_spillslot_named_by_last_slot() {
panic!("MultiSpillslotIndexPos not supported");
}
let mut state = FastAllocState::init(func, mach_env, &cfg);
todo!("")
}
fn setup_entry_params<'a, F: Function>(
state: &mut FastAllocState<'a, F>,
) -> Result<(), RegAllocError> {
// we need to set the vreg location for the initial block parameters and copy them to the stack
let entry = state.func.entry_block();
todo!("")
}