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Run dead stack_store removal after stack_store to stack_load forwarding

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This commit is contained in:
bjorn3 2019-12-28 11:36:00 +01:00
parent 7d35db5319
commit c5f42aef1d
1 changed files with 42 additions and 45 deletions
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15
src/optimize/stack2reg.rs
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@ -84,10 +84,6 @@ pub(super) fn optimize_function(
continue;
}
let is_loaded = users.stack_load.is_empty().not();
let is_stored = users.stack_store.is_empty().not();
match (is_loaded, is_stored) {
(true, true) => {
for load in users.stack_load.clone().drain() {
let load_ebb = func.layout.inst_ebb(load).unwrap();
let loaded_value = func.dfg.inst_results(load)[0];
@ -119,22 +115,23 @@ pub(super) fn optimize_function(
func.dfg.detach_results(load);
func.dfg.replace(load).nop();
func.dfg.change_to_alias(loaded_value, stored_value);
users.stack_load.remove(&load);
}
}
_ => {} // FIXME implement this
}
}
}
(true, false) => println!("[{}] [BUG?] Reading uninitialized memory", name),
(false, _) => {
if users.stack_load.is_empty() {
// Never loaded; can safely remove all stores and the stack slot.
for user in users.stack_store.drain() {
println!("[{}] Remove dead stack store {} of {}", name, user, stack_slot.0);
func.dfg.replace(user).nop();
}
// FIXME make stack_slot zero sized.
}
if users.stack_store.is_empty() && users.stack_load.is_empty() {
// FIXME make stack_slot zero sized.
}
}