liveness.rs 15.4 KB
Newer Older
qinsoon's avatar
qinsoon committed
1 2
extern crate nalgebra;

qinsoon's avatar
qinsoon committed
3 4
use vm::CompiledFunction;
use vm::MachineCode;
5
use ast::ir::*;
qinsoon's avatar
qinsoon committed
6 7
use ast::types;
use compiler::backend;
8
use utils::vec_utils;
9
use utils::LinkedHashSet;
10 11

use std::collections::LinkedList;
qinsoon's avatar
qinsoon committed
12 13 14 15
use std::collections::{HashMap, HashSet};

use self::nalgebra::DMatrix;

16 17
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub struct Node(usize);
18
#[derive(Clone, Debug, PartialEq)]
qinsoon's avatar
qinsoon committed
19 20
pub struct NodeProperty {
    color: Option<MuID>,
21 22 23
    group: backend::RegGroup,
    temp: MuID,
    spill_cost: f32
qinsoon's avatar
qinsoon committed
24 25 26
}
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub struct Move{pub from: Node, pub to: Node}
27 28

pub struct InterferenceGraph {
qinsoon's avatar
qinsoon committed
29
    nodes: HashMap<MuID, Node>,
qinsoon's avatar
qinsoon committed
30
    nodes_property: HashMap<Node, NodeProperty>,
qinsoon's avatar
qinsoon committed
31 32 33
    
    matrix: Option<DMatrix<bool>>,
    
qinsoon's avatar
qinsoon committed
34
    moves: HashSet<Move>,
35 36 37 38
}

impl InterferenceGraph {
    fn new() -> InterferenceGraph {
qinsoon's avatar
qinsoon committed
39 40
        InterferenceGraph {
            nodes: HashMap::new(),
qinsoon's avatar
qinsoon committed
41
            nodes_property: HashMap::new(),
qinsoon's avatar
qinsoon committed
42 43 44 45 46
            matrix: None,
            moves: HashSet::new()
        }
    }
    
qinsoon's avatar
qinsoon committed
47 48 49 50
    fn new_node(&mut self, reg_id: MuID, context: &FunctionContext) -> Node {
        let entry = context.get_value(reg_id).unwrap();
        
        if !self.nodes.contains_key(&reg_id) {
qinsoon's avatar
qinsoon committed
51
            let index = self.nodes.len();
52
            let node = Node(index);
qinsoon's avatar
qinsoon committed
53 54 55 56 57 58 59 60 61 62
            
            // add the node
            self.nodes.insert(reg_id, node.clone());
            
            // add node property
            let group = {
                let ref ty = entry.ty;
                if types::is_scalar(ty) {
                    if types::is_fp(ty) {
                        backend::RegGroup::FPR
qinsoon's avatar
qinsoon committed
63 64
                    } else {
                        backend::RegGroup::GPR
qinsoon's avatar
qinsoon committed
65 66 67 68 69 70 71
                    }
                } else {
                    unimplemented!()
                }
            };
            let property = NodeProperty {
                color: None,
72 73 74
                group: group,
                temp: reg_id,
                spill_cost: 0.0f32
qinsoon's avatar
qinsoon committed
75 76
            };
            self.nodes_property.insert(node, property);
77 78 79 80 81 82 83 84 85 86
        } 
        
        
        let node = * self.nodes.get(&reg_id).unwrap();
        
        // increase node spill cost
        let property = self.nodes_property.get_mut(&node).unwrap();
        property.spill_cost += 1.0f32;
        
        node
qinsoon's avatar
qinsoon committed
87 88
    }
    
qinsoon's avatar
qinsoon committed
89
    pub fn get_node(&self, reg: MuID) -> Node {
qinsoon's avatar
qinsoon committed
90
        match self.nodes.get(&reg) {
qinsoon's avatar
qinsoon committed
91
            Some(index) => *index,
qinsoon's avatar
qinsoon committed
92
            None => panic!("do not have a node for {}", reg)
qinsoon's avatar
qinsoon committed
93 94 95
        }
    }
    
96 97 98 99 100 101 102 103
    pub fn temps(&self) -> Vec<MuID>{
        let mut ret = vec![];
        for reg in self.nodes.keys() {
            ret.push(*reg);
        }
        ret
    }
    
qinsoon's avatar
qinsoon committed
104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
    pub fn nodes(&self) -> Vec<Node> {
        let mut ret = vec![];
        for node in self.nodes.values() {
            ret.push(node.clone());
        }
        ret
    }
    
    pub fn moves(&self) -> &HashSet<Move> {
        &self.moves
    }
    
    pub fn n_nodes(&self) -> usize {
        self.nodes.len()
    }
    
qinsoon's avatar
qinsoon committed
120 121 122 123 124
    fn init_graph(&mut self) {
        let len = self.nodes.len();
        self.matrix = Some(DMatrix::from_element(len, len, false));
    }
    
qinsoon's avatar
qinsoon committed
125 126
    fn add_move(&mut self, src: Node, dst: Node) {
        self.moves.insert(Move{from: src, to: dst});
127 128
    }
    
qinsoon's avatar
qinsoon committed
129
    pub fn add_interference_edge(&mut self, from: Node, to: Node) {
qinsoon's avatar
qinsoon committed
130 131 132 133 134 135
        // only if two nodes are from the same RegGroup,
        // they may interefere
        if self.nodes_property.get(&from).unwrap().group 
           == self.nodes_property.get(&to).unwrap().group {
            self.matrix.as_mut().unwrap()[(from.0, to.0)] = true;
        }
qinsoon's avatar
qinsoon committed
136 137
    }
    
138
    pub fn color_node(&mut self, node: Node, color: MuID) {
qinsoon's avatar
qinsoon committed
139
        self.nodes_property.get_mut(&node).unwrap().color = Some(color);
qinsoon's avatar
qinsoon committed
140 141
    }
    
qinsoon's avatar
qinsoon committed
142 143 144 145
    pub fn is_colored(&self, node: Node) -> bool {
        self.nodes_property.get(&node).unwrap().color.is_some()
    }
    
146 147 148 149
    pub fn get_color_of(&self, node: Node) -> Option<MuID> {
        self.nodes_property.get(&node).unwrap().color
    }
    
qinsoon's avatar
qinsoon committed
150 151
    pub fn get_group_of(&self, node: Node) -> backend::RegGroup {
        self.nodes_property.get(&node).unwrap().group
qinsoon's avatar
qinsoon committed
152 153
    }
    
154 155 156 157 158 159 160 161
    pub fn get_temp_of(&self, node: Node) -> MuID {
        self.nodes_property.get(&node).unwrap().temp
    }
    
    pub fn get_spill_cost(&self, node: Node) -> f32 {
        self.nodes_property.get(&node).unwrap().spill_cost
    }
    
162
    fn is_same_node(&self, node1: Node, node2: Node) -> bool {
qinsoon's avatar
qinsoon committed
163
        node1 == node2
qinsoon's avatar
qinsoon committed
164 165
    }
    
qinsoon's avatar
qinsoon committed
166
    pub fn is_adj(&self, from: Node, to: Node) -> bool {
167 168
        let ref matrix = self.matrix.as_ref().unwrap();
        
169
        matrix[(from.0, to.0)] || matrix[(to.0, from.0)]
qinsoon's avatar
qinsoon committed
170 171
    }
    
172 173 174 175 176 177 178 179 180 181 182 183 184
    pub fn outedges_of(&self, node: Node) -> Vec<Node> {
        let mut ret = vec![];
        let matrix = self.matrix.as_ref().unwrap();
        
        for i in 0..self.nodes.len() {
            if matrix[(node.0, i)] {
                ret.push(Node(i));
            }
        }
        
        ret
    }
    
qinsoon's avatar
qinsoon committed
185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210
    pub fn outdegree_of(&self, node: Node) -> usize {
        let mut count = 0;
        for i in 0..self.nodes.len() {
            if self.matrix.as_ref().unwrap()[(node.0, i)] {
                count += 1;
            }
        }
        
        count
    }
    
    pub fn indegree_of(&self, node: Node) -> usize {
        let mut count = 0;
        for i in 0..self.nodes.len() {
            if self.matrix.as_ref().unwrap()[(i, node.0)] {
                count += 1;
            }
        }
        
        count
    }
    
    pub fn degree_of(&self, node: Node) -> usize {
        self.outdegree_of(node) + self.indegree_of(node)
    }
    
211 212 213 214
    pub fn print(&self) {
        println!("");
        println!("Interference Graph");

qinsoon's avatar
qinsoon committed
215 216 217 218 219
        println!("nodes:");
        for id in self.nodes.keys() {
            println!("Reg {} -> {:?}", id, self.nodes.get(&id).unwrap());
        }

220
        println!("color:");
qinsoon's avatar
qinsoon committed
221 222
        for (n, c) in self.nodes_property.iter() {
            println!("{:?} -> Color/Reg {:?}", n, c);
223 224 225
        }
        println!("moves:");
        for mov in self.moves.iter() {
qinsoon's avatar
qinsoon committed
226
            println!("Move {:?} -> {:?}", mov.from, mov.to);
227 228 229
        }
        println!("graph:");
        {
qinsoon's avatar
qinsoon committed
230 231
            let node_to_reg_id = {
                let mut ret : HashMap<Node, MuID> = HashMap::new();
232
                
qinsoon's avatar
qinsoon committed
233 234
                for reg in self.nodes.keys() {
                    ret.insert(*self.nodes.get(reg).unwrap(), *reg);
235 236 237 238 239 240 241 242 243
                }
                
                ret 
            };
            
            let matrix = self.matrix.as_ref().unwrap();
            for i in 0..matrix.ncols() {
                for j in 0..matrix.nrows() {
                    if matrix[(i, j)] {
244 245
                        let from_node = node_to_reg_id.get(&Node(i)).unwrap();
                        let to_node = node_to_reg_id.get(&Node(j)).unwrap();
246
                        
247
                        println!("Reg {} -> Reg {}", from_node, to_node);
248 249 250 251 252 253
                    }
                }
            }
        }
        println!("");
    }
qinsoon's avatar
qinsoon committed
254 255
}

qinsoon's avatar
qinsoon committed
256
pub fn is_machine_reg(reg: MuID) -> bool {
257
    if reg < RESERVED_NODE_IDS_FOR_MACHINE {
qinsoon's avatar
qinsoon committed
258 259 260
        true
    } else {
        false
261 262 263
    }
}

264
// from Tailoring Graph-coloring Register Allocation For Runtime Compilation, Figure 4
265
pub fn build_chaitin_briggs (cf: &CompiledFunction, func: &MuFunctionVersion) -> InterferenceGraph {
266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309
    let mut ig = InterferenceGraph::new();
    
    // precolor machine register nodes
    for reg in backend::all_regs().iter() {
        let reg_id = reg.extract_ssa_id().unwrap();
        let node = ig.new_node(reg_id, &func.context);
        ig.color_node(node, reg_id);
    }
    
    // Initialize and creates nodes for all the involved temps/regs
    for i in 0..cf.mc.number_of_insts() {
        for reg_id in cf.mc.get_inst_reg_defines(i) {
            let reg_id = *reg_id;
            ig.new_node(reg_id, &func.context);
        }
        
        for reg_id in cf.mc.get_inst_reg_uses(i) {
            let reg_id = *reg_id;
            ig.new_node(reg_id, &func.context);
        }
    }
    
    // all nodes has been added, we init graph (create adjacency matrix)
    ig.init_graph();    
    
    for block in cf.mc.get_all_blocks() {
        // Current_Live(B) = LiveOut(B)
        let mut current_live = LinkedHashSet::from_vec(match cf.mc.get_ir_block_liveout(block) {
            Some(liveout) => liveout.to_vec(),
            None => panic!("cannot find liveout for block {}", block)
        });
        
        let range = cf.mc.get_block_range(block);
        if range.is_none() {
            continue;
        }
        
        // for every inst I in reverse order
        for i in range.unwrap().rev() {
            let src : Option<MuID> = {
                if cf.mc.is_move(i) {
                    let src = cf.mc.get_inst_reg_uses(i);
                    let dst = cf.mc.get_inst_reg_defines(i);
                    
qinsoon's avatar
qinsoon committed
310 311 312 313
                    // src:  reg/imm/mem
                    // dest: reg/mem
                    // we dont care if src/dest is mem
                    if cf.mc.is_using_mem_op(i) {
314
                        None
qinsoon's avatar
qinsoon committed
315 316 317 318 319 320 321 322 323 324
                    } else {
                        if src.len() == 1 {
                            let node1 = ig.get_node(src[0]);
                            let node2 = ig.get_node(dst[0]);
                            ig.add_move(node1, node2);
                            
                            Some(src[0])
                        } else {
                            None
                        }
325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368
                    }
                } else {
                    None
                }
            };
            
            // for every definition D in I
            for d in cf.mc.get_inst_reg_defines(i) {
                // add an interference from D to every element E in Current_Live - {D}
                // creating nodes if necessary
                for e in current_live.iter() {
                    if src.is_none() || (src.is_some() && *e != src.unwrap()) {
                        let from = ig.get_node(*d);
                        let to = ig.get_node(*e);
                        
                        if !ig.is_same_node(from, to) && !ig.is_adj(from, to) {
                            if !ig.is_colored(from) {
                                ig.add_interference_edge(from, to);
                            }
                            if !ig.is_colored(to) {
                                ig.add_interference_edge(to, from);
                            }
                        }
                    }
                }
            }
            
            // for every definition D in I
            for d in cf.mc.get_inst_reg_defines(i) {
                // remove D from Current_Live
                current_live.remove(d);
            }
            
            // for every use U in I
            for u in cf.mc.get_inst_reg_uses(i) {
                // add U to Current_live
                current_live.insert(*u);
            }
        }
    }
    
    ig
}

369
// from tony's code src/RegAlloc/Liveness.java
370 371
// this function is no longer used
#[allow(dead_code)]
372
pub fn build (cf: &CompiledFunction, func: &MuFunctionVersion) -> InterferenceGraph {
373 374
    let mut ig = InterferenceGraph::new();
    
qinsoon's avatar
qinsoon committed
375 376 377 378 379 380
    // precolor machine register nodes
    for reg in backend::all_regs().iter() {
        let reg_id = reg.extract_ssa_id().unwrap();
        let node = ig.new_node(reg_id, &func.context);
        ig.color_node(node, reg_id);
    }
381 382 383 384 385 386 387 388 389 390 391 392 393
    
    // Liveness Analysis
    let n_insts = cf.mc.number_of_insts();
    let mut live_in : Vec<Vec<MuID>> = vec![vec![]; n_insts];
    let mut live_out : Vec<Vec<MuID>> = vec![vec![]; n_insts];
    let mut work_list : LinkedList<usize> = LinkedList::new();
    
    // Initialize 'in' sets for each node in the flow graph
    // and creates nodes for all the involved temps/regs
    for i in 0..n_insts {
        let ref mut in_set = live_in[i];
        
        for reg_id in cf.mc.get_inst_reg_defines(i) {
qinsoon's avatar
qinsoon committed
394
            let reg_id = *reg_id;
qinsoon's avatar
qinsoon committed
395
            ig.new_node(reg_id, &func.context);
396 397 398
        }
        
        for reg_id in cf.mc.get_inst_reg_uses(i) {
qinsoon's avatar
qinsoon committed
399
            let reg_id = *reg_id;
qinsoon's avatar
qinsoon committed
400
            ig.new_node(reg_id, &func.context);
qinsoon's avatar
qinsoon committed
401 402
            
            in_set.push(reg_id);
403 404 405 406 407
        }
        
        work_list.push_front(i);
    }
    
qinsoon's avatar
qinsoon committed
408 409 410 411
    // all nodes has been added, we init graph (create adjacency matrix)
    ig.init_graph();
    
    // compute liveIn and liveOut iteratively
412
    trace!("build live outs");
413 414
    while !work_list.is_empty() {
        let n = work_list.pop_front().unwrap();
415
        trace!("build liveout for #{}", n);
416
        let ref mut out_set = live_out[n];
qinsoon's avatar
qinsoon committed
417 418 419
        
        // out = union(in[succ]) for all succs
        for succ in cf.mc.get_succs(n) {
420
            trace!("add successor's livein {:?} to #{}", &live_in[*succ], n); 
421
            vec_utils::add_all(out_set, &live_in[*succ]);
qinsoon's avatar
qinsoon committed
422 423 424 425 426
        }
        
        // in = use(i.e. live_in) + (out - def) 
        let mut diff = out_set.clone();
        for def in cf.mc.get_inst_reg_defines(n) {
427
            vec_utils::remove_value(&mut diff, *def);
428 429
            trace!("removing def: {}", *def);
            trace!("diff = {:?}", diff);
qinsoon's avatar
qinsoon committed
430
        }
431
        trace!("out - def = {:?}", diff);
qinsoon's avatar
qinsoon committed
432 433 434
        
        if !diff.is_empty() {
            let ref mut in_set = live_in[n];
435
            trace!("in = (use) {:?}", in_set);
qinsoon's avatar
qinsoon committed
436
            
437
            if vec_utils::add_all(in_set, &diff) {
qinsoon's avatar
qinsoon committed
438 439 440 441 442
                for p in cf.mc.get_preds(n) {
                    work_list.push_front(*p);
                }
            }
        }
443
        trace!("in = use + (out - def) = {:?}", live_in[n]);
444 445 446 447 448 449 450 451 452
    }
    
    // debug live-outs
    if cfg!(debug_assertions) {
        trace!("check live-outs");
        for n in 0..n_insts {
            let ref mut live = live_out[n];
            trace!("#{}\t{:?}", n, live);
        }
qinsoon's avatar
qinsoon committed
453 454 455 456 457 458 459 460 461 462 463
    }
    
    // build interference graph
    for n in 0..n_insts {
        let ref mut live = live_out[n];
        
        let src : Option<MuID> = {
            if cf.mc.is_move(n) {
                let src = cf.mc.get_inst_reg_uses(n);
                let dst = cf.mc.get_inst_reg_defines(n);
                
464 465
                // src may be an immediate number
                // but dest is definitly a register
qinsoon's avatar
qinsoon committed
466 467
                debug_assert!(dst.len() == 1);
                
468
                if src.len() == 1 {
qinsoon's avatar
qinsoon committed
469 470 471
                    let node1 = ig.get_node(src[0]);
                    let node2 = ig.get_node(dst[0]);
                    ig.add_move(node1, node2);
472 473 474 475 476
                    
                    Some(src[0])
                } else {
                    None
                }
qinsoon's avatar
qinsoon committed
477 478 479 480 481 482 483 484
            } else {
                None
            }
        };
        
        for d in cf.mc.get_inst_reg_defines(n) {
            for t in live.iter() {
                if src.is_none() || (src.is_some() && *t != src.unwrap()) {
485 486
                    let from = ig.get_node(*d);
                    let to = ig.get_node(*t);
qinsoon's avatar
qinsoon committed
487 488
                    
                    if !ig.is_same_node(from, to) && !ig.is_adj(from, to) {
qinsoon's avatar
qinsoon committed
489
                        if !ig.is_colored(from) {
qinsoon's avatar
qinsoon committed
490 491
                            ig.add_interference_edge(from, to);
                        }
qinsoon's avatar
qinsoon committed
492
                        if !ig.is_colored(to) {
qinsoon's avatar
qinsoon committed
493 494 495 496 497 498 499 500
                            ig.add_interference_edge(to, from);
                        }
                    }
                }
            }
        }
        
        for d in cf.mc.get_inst_reg_defines(n) {
501
            vec_utils::remove_value(live, *d);
qinsoon's avatar
qinsoon committed
502 503 504 505 506 507 508 509
        }
        
        for u in cf.mc.get_inst_reg_uses(n) {
            live.push(*u);
        }
    }
    
    ig
510
}