83571028d9
Collect the data structures that hang around between function compilations. Provide a main entry point to the register allocator passes.
58 lines
1.9 KiB
Rust
58 lines
1.9 KiB
Rust
//! Register allocator context.
|
|
//!
|
|
//! The `Context` struct contains data structures that should be preserved across invocations of
|
|
//! the register allocator algorithm. This doesn't preserve any data between functions, but it
|
|
//! avoids allocating data structures independently for each function begin compiled.
|
|
|
|
use dominator_tree::DominatorTree;
|
|
use ir::Function;
|
|
use regalloc::coloring::Coloring;
|
|
use regalloc::live_value_tracker::LiveValueTracker;
|
|
use regalloc::liveness::Liveness;
|
|
use isa::TargetIsa;
|
|
use cfg::ControlFlowGraph;
|
|
|
|
/// Persistent memory allocations for register allocation.
|
|
pub struct Context {
|
|
liveness: Liveness,
|
|
tracker: LiveValueTracker,
|
|
coloring: Coloring,
|
|
}
|
|
|
|
impl Context {
|
|
/// Create a new context for register allocation.
|
|
///
|
|
/// This context should be reused for multiple functions in order to avoid repeated memory
|
|
/// allocations.
|
|
pub fn new() -> Context {
|
|
Context {
|
|
liveness: Liveness::new(),
|
|
tracker: LiveValueTracker::new(),
|
|
coloring: Coloring::new(),
|
|
}
|
|
}
|
|
|
|
/// Allocate registers in `func`.
|
|
///
|
|
/// After register allocation, all values in `func` have been assigned to a register or stack
|
|
/// location that is consistent with instruction encoding constraints.
|
|
pub fn run(&mut self,
|
|
isa: &TargetIsa,
|
|
func: &mut Function,
|
|
cfg: &ControlFlowGraph,
|
|
domtree: &DominatorTree) {
|
|
// `Liveness` and `Coloring` are self-clearing.
|
|
// Tracker state (dominator live sets) is actually reused between the spilling and coloring
|
|
// phases.
|
|
self.tracker.clear();
|
|
|
|
// First pass: Liveness analysis.
|
|
self.liveness.compute(isa, func, cfg);
|
|
|
|
// TODO: Second pass: Spilling.
|
|
|
|
// Third pass: Reload and coloring.
|
|
self.coloring.run(isa, func, domtree, &mut self.liveness, &mut self.tracker);
|
|
}
|
|
}
|