bjoernager/rust
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Return use domtree.dominates in temporal_order

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This commit is contained in:
bjorn3 2019-12-30 20:52:57 +01:00
parent 7c4debdb7c
commit d6c2db2aea
1 changed files with 23 additions and 26 deletions
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19
src/optimize/stack2reg.rs
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@ -182,7 +182,7 @@ pub(super) fn optimize_function(
let store_ebb = opt_ctx.ctx.func.layout.inst_ebb(store).unwrap();
let stored_value = opt_ctx.ctx.func.dfg.inst_args(store)[0];
let stored_type = opt_ctx.ctx.func.dfg.value_type(stored_value);
if stored_type == loaded_type && store_ebb == load_ebb {
if stored_type == loaded_type {
println!("Store to load forward {} -> {}", store, load);
users.change_load_to_alias(&mut opt_ctx.ctx.func, load, stored_value);
}
@ -379,19 +379,17 @@ enum TemporalOrder {
fn temporal_order(ctx: &Context, src: Inst, dest: Inst) -> TemporalOrder {
debug_assert_ne!(src, dest);
if ctx.domtree.dominates(src, dest, &ctx.func.layout) {
return TemporalOrder::DefinitivelyBefore;
} else if ctx.domtree.dominates(src, dest, &ctx.func.layout) {
return TemporalOrder::NeverBefore;
}
let src_ebb = ctx.func.layout.inst_ebb(src).unwrap();
let dest_ebb = ctx.func.layout.inst_ebb(dest).unwrap();
if src_ebb == dest_ebb {
use std::cmp::Ordering::*;
match ctx.func.layout.cmp(src, dest) {
Less => TemporalOrder::DefinitivelyBefore,
Equal => unreachable!(),
Greater => TemporalOrder::MaybeBefore, // FIXME use dominator to check for loops
}
} else {
// FIXME O(stack_load count * ebb count)
// FIXME reuse memory allocations
// FIXME return DefinitivelyBefore is src dominates dest
let mut visited = EntitySet::new();
let mut todo = EntitySet::new();
todo.insert(dest_ebb);
@ -408,5 +406,4 @@ fn temporal_order(ctx: &Context, src: Inst, dest: Inst) -> TemporalOrder {
}
}
TemporalOrder::NeverBefore
}
}