T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Skip ghost instructions when coloring.

Browse Source 
Ghost instructions don't have an encoding, and don't appear in the
output. The values they define do not need to be assigned to registers,
so they can be skipped.
This commit is contained in:
Jakob Stoklund Olesen
2017-06-22 09:31:32 -07:00
parent 03a856f4da
commit d079dead9a
1 changed files with 16 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
lib/cretonne/src/regalloc/coloring.rs
View File

@@ -31,18 +31,18 @@
//! defined by the instruction and only consider the colors of other values that are live at the
//! instruction.
use entity_map::EntityMap;
use dominator_tree::DominatorTree;
use entity_map::EntityMap;
use ir::{Ebb, Inst, Value, Function, Cursor, ValueLoc, DataFlowGraph, ValueLocations};
use ir::{InstBuilder, Signature, ArgumentType, ArgumentLoc};
use isa::{TargetIsa, Encoding, EncInfo, OperandConstraint, ConstraintKind};
use isa::{RegUnit, RegClass, RegInfo, regs_overlap};
use isa::{TargetIsa, EncInfo, RecipeConstraints, OperandConstraint, ConstraintKind};
use regalloc::RegDiversions;
use regalloc::affinity::Affinity;
use regalloc::allocatable_set::AllocatableSet;
use regalloc::live_value_tracker::{LiveValue, LiveValueTracker};
use regalloc::liveness::Liveness;
use regalloc::solver::Solver;
use regalloc::RegDiversions;
use topo_order::TopoOrder;
@@ -138,19 +138,18 @@ impl<'a> Context<'a> {
let mut pos = Cursor::new(&mut func.layout);
pos.goto_top(ebb);
while let Some(inst) = pos.next_inst() {
let encoding = func.encodings[inst];
assert!(encoding.is_legal(), "Illegal: {}", func.dfg[inst].opcode());
self.visit_inst(inst,
encoding,
&mut pos,
&mut func.dfg,
tracker,
&mut regs,
&mut func.locations,
&func.signature);
tracker.drop_dead(inst);
if let Some(constraints) = self.encinfo.operand_constraints(func.encodings[inst]) {
self.visit_inst(inst,
constraints,
&mut pos,
&mut func.dfg,
tracker,
&mut regs,
&mut func.locations,
&func.signature);
tracker.drop_dead(inst);
}
}
}
/// Visit the `ebb` header.
@@ -304,21 +303,14 @@ impl<'a> Context<'a> {
/// or killed values from the set.
fn visit_inst(&mut self,
inst: Inst,
encoding: Encoding,
constraints: &RecipeConstraints,
pos: &mut Cursor,
dfg: &mut DataFlowGraph,
tracker: &mut LiveValueTracker,
regs: &mut AllocatableSet,
locations: &mut ValueLocations,
func_signature: &Signature) {
dbg!("Coloring [{}] {}",
self.encinfo.display(encoding),
dfg.display_inst(inst));
// Get the operand constraints for `inst` that we are trying to satisfy.
let constraints = self.encinfo
.operand_constraints(encoding)
.expect("Missing instruction encoding");
dbg!("Coloring {}", dfg.display_inst(inst));
// Program the solver with register constraints for the input side.
self.solver.reset(regs);