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Outline combine_stack_addr_with_load_store and remove unused stack_load insts

This commit is contained in:
bjorn3 2019-12-27 15:02:10 +01:00
parent b6642e5cd8
commit 73961709d6
1 changed files with 48 additions and 30 deletions
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78
src/optimize/stack2reg.rs
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@ -10,36 +10,7 @@ pub(super) fn optimize_function(
clif_comments: &mut crate::pretty_clif::CommentWriter,
name: String, // FIXME remove
) {
// Turn load and store into stack_load and stack_store when possible.
let mut cursor = FuncCursor::new(func);
while let Some(_ebb) = cursor.next_ebb() {
while let Some(inst) = cursor.next_inst() {
match cursor.func.dfg[inst] {
InstructionData::Load { opcode: Opcode::Load, arg: addr, flags: _, offset } => {
if cursor.func.dfg.ctrl_typevar(inst) == types::I128 || cursor.func.dfg.ctrl_typevar(inst).is_vector() {
continue; // WORKAROUD: stack_load.i128 not yet implemented
}
if let Some((stack_slot, stack_addr_offset)) = try_get_stack_slot_and_offset_for_addr(cursor.func, addr) {
if let Some(combined_offset) = offset.try_add_i64(stack_addr_offset.into()) {
let ty = cursor.func.dfg.ctrl_typevar(inst);
cursor.func.dfg.replace(inst).stack_load(ty, stack_slot, combined_offset);
}
}
}
InstructionData::Store { opcode: Opcode::Store, args: [value, addr], flags: _, offset } => {
if cursor.func.dfg.ctrl_typevar(inst) == types::I128 || cursor.func.dfg.ctrl_typevar(inst).is_vector() {
continue; // WORKAROUND: stack_store.i128 not yet implemented
}
if let Some((stack_slot, stack_addr_offset)) = try_get_stack_slot_and_offset_for_addr(cursor.func, addr) {
if let Some(combined_offset) = offset.try_add_i64(stack_addr_offset.into()) {
cursor.func.dfg.replace(inst).stack_store(value, stack_slot, combined_offset);
}
}
}
_ => {}
}
}
}
combine_stack_addr_with_load_store(func);
// Record all stack_addr, stack_load and stack_store instructions. Also record all stack_addr
// and stack_load insts whose result is used.
@ -112,6 +83,20 @@ pub(super) fn optimize_function(
}
}
for inst in used_stack_load_insts.keys().filter(|&inst| used_stack_load_insts[inst]) {
assert!(stack_load_insts[inst]);
}
// Replace all unused stack_load instructions with nop.
for inst in stack_load_insts.keys() {
if stack_load_insts[inst] && !used_stack_load_insts[inst] {
func.dfg.detach_results(inst);
func.dfg.replace(inst).nop();
stack_load_insts[inst] = false;
}
}
//println!("stack_addr (after): [{}]", bool_secondary_map_to_string(&stack_addr_insts));
let mut stack_slot_usage_map: SecondaryMap<StackSlot, HashSet<Inst>> = SecondaryMap::new();
@ -203,6 +188,39 @@ pub(super) fn optimize_function(
}
}
fn combine_stack_addr_with_load_store(func: &mut Function) {
// Turn load and store into stack_load and stack_store when possible.
let mut cursor = FuncCursor::new(func);
while let Some(_ebb) = cursor.next_ebb() {
while let Some(inst) = cursor.next_inst() {
match cursor.func.dfg[inst] {
InstructionData::Load { opcode: Opcode::Load, arg: addr, flags: _, offset } => {
if cursor.func.dfg.ctrl_typevar(inst) == types::I128 || cursor.func.dfg.ctrl_typevar(inst).is_vector() {
continue; // WORKAROUD: stack_load.i128 not yet implemented
}
if let Some((stack_slot, stack_addr_offset)) = try_get_stack_slot_and_offset_for_addr(cursor.func, addr) {
if let Some(combined_offset) = offset.try_add_i64(stack_addr_offset.into()) {
let ty = cursor.func.dfg.ctrl_typevar(inst);
cursor.func.dfg.replace(inst).stack_load(ty, stack_slot, combined_offset);
}
}
}
InstructionData::Store { opcode: Opcode::Store, args: [value, addr], flags: _, offset } => {
if cursor.func.dfg.ctrl_typevar(inst) == types::I128 || cursor.func.dfg.ctrl_typevar(inst).is_vector() {
continue; // WORKAROUND: stack_store.i128 not yet implemented
}
if let Some((stack_slot, stack_addr_offset)) = try_get_stack_slot_and_offset_for_addr(cursor.func, addr) {
if let Some(combined_offset) = offset.try_add_i64(stack_addr_offset.into()) {
cursor.func.dfg.replace(inst).stack_store(value, stack_slot, combined_offset);
}
}
}
_ => {}
}
}
}
}
fn try_get_stack_slot_and_offset_for_addr(func: &Function, addr: Value) -> Option<(StackSlot, Offset32)> {
if let ValueDef::Result(addr_inst, 0) = func.dfg.value_def(addr) {
if let InstructionData::StackLoad {