Files
wasmtime/cranelift/codegen/src/regalloc/safepoint.rs
Nick Fitzgerald 05bf9ea3f3 Rename "Stackmap" to "StackMap"
And "stackmap" to "stack_map".

This commit is purely mechanical.
2020-08-07 10:08:44 -07:00

66 lines
2.1 KiB
Rust

use crate::cursor::{Cursor, FuncCursor};
use crate::dominator_tree::DominatorTree;
use crate::inst_predicates::is_safepoint;
use crate::ir::{Function, InstBuilder};
use crate::isa::TargetIsa;
use crate::regalloc::live_value_tracker::LiveValueTracker;
use crate::regalloc::liveness::Liveness;
use alloc::vec::Vec;
fn insert_and_encode_safepoint<'f>(
pos: &mut FuncCursor<'f>,
tracker: &LiveValueTracker,
isa: &dyn TargetIsa,
) {
// Iterate through all live values, collect only the references.
let live_ref_values = tracker
.live()
.iter()
.filter(|live_value| pos.func.dfg.value_type(live_value.value).is_ref())
.map(|live_val| live_val.value)
.collect::<Vec<_>>();
if !live_ref_values.is_empty() {
pos.ins().safepoint(&live_ref_values);
// Move cursor to the new safepoint instruction to encode it.
if let Some(inst) = pos.prev_inst() {
let ok = pos.func.update_encoding(inst, isa).is_ok();
debug_assert!(ok);
}
// Restore cursor position.
pos.next_inst();
}
}
// The emit_stack_maps() function analyzes each instruction to retrieve the liveness of
// the defs and operands by traversing a function's blocks in layout order.
pub fn emit_stack_maps(
func: &mut Function,
domtree: &DominatorTree,
liveness: &Liveness,
tracker: &mut LiveValueTracker,
isa: &dyn TargetIsa,
) {
let mut curr = func.layout.entry_block();
while let Some(block) = curr {
tracker.block_top(block, &func.dfg, liveness, &func.layout, domtree);
tracker.drop_dead_params();
let mut pos = FuncCursor::new(func);
// From the top of the block, step through the instructions.
pos.goto_top(block);
while let Some(inst) = pos.next_inst() {
if is_safepoint(&pos.func, inst) {
insert_and_encode_safepoint(&mut pos, tracker, isa);
}
// Process the instruction and get rid of dead values.
tracker.process_inst(inst, &pos.func.dfg, liveness);
tracker.drop_dead(inst);
}
curr = func.layout.next_block(block);
}
}