Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Remove the OperandConstraint::Stack variant #185

Merged
merged 2 commits into from
Aug 30, 2024
Merged

Remove the OperandConstraint::Stack variant #185

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
aa994ad
Remove the OperandConstraint::Stack variant
elliottt Aug 30, 2024
09f5c9c
Embiggen BUNDLE_MAX_SPILL_WEIGHT
elliottt Aug 30, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 5 additions & 8 deletions doc/DESIGN.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -648,14 +648,11 @@ other):

```plain

___Unknown_____
| | |
| | |
| ____Any(rc) |
|/ | |
Stack(rc) FixedReg(reg)
\ /
Conflict
Any(rc)
/ \
FixedReg(reg) FixedStack(reg)
\ /
Conflict
```

Once we have the Requirement for a bundle, we can decide what to do.
Expand Down
11 changes: 0 additions & 11 deletions src/checker.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -649,17 +649,6 @@ impl CheckerState {
}
return Err(CheckerError::AllocationIsNotReg { inst, op, alloc });
}
OperandConstraint::Stack => {
if alloc.kind() != AllocationKind::Stack {
// Accept pregs that represent a fixed stack slot.
if let Some(preg) = alloc.as_reg() {
if checker.machine_env.fixed_stack_slots.contains(&preg) {
return Ok(());
}
}
return Err(CheckerError::AllocationIsNotStack { inst, op, alloc });
}
}
OperandConstraint::FixedReg(preg) => {
if alloc != Allocation::reg(preg) {
return Err(CheckerError::AllocationIsNotFixedReg { inst, op, alloc });
Expand Down
4 changes: 1 addition & 3 deletions src/ion/data_structures.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -216,14 +216,12 @@ impl LiveBundle {
minimal: bool,
fixed: bool,
fixed_def: bool,
stack: bool,
) {
debug_assert!(spill_weight <= BUNDLE_MAX_SPILL_WEIGHT);
self.spill_weight_and_props = spill_weight
| (if minimal { 1 << 31 } else { 0 })
| (if fixed { 1 << 30 } else { 0 })
| (if fixed_def { 1 << 29 } else { 0 })
| (if stack { 1 << 28 } else { 0 });
| (if fixed_def { 1 << 29 } else { 0 });
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Since we get bit 28 back here can we update BUNDLE_MAX_SPILL_WEIGHT as well (so the saturation point moves a little further out, leading to maybe slightly better alloc in deeply nested loops)?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Great idea!

}

#[inline(always)]
Expand Down
4 changes: 0 additions & 4 deletions src/ion/liveranges.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -805,10 +805,6 @@ impl<'a, F: Function> Env<'a, F> {
first_reg_slot.get_or_insert(u.slot);
}
}
// Maybe this could be supported in this future...
OperandConstraint::Stack => panic!(
"multiple uses of vreg with a Stack constraint are not supported"
),
}
}

Expand Down
9 changes: 1 addition & 8 deletions src/ion/merge.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -263,7 +263,6 @@ impl<'a, F: Function> Env<'a, F> {

let mut fixed = false;
let mut fixed_def = false;
let mut stack = false;
for entry in &self.bundles[bundle].ranges {
for u in &self.ranges[entry.index].uses {
if let OperandConstraint::FixedReg(_) = u.operand.constraint() {
Expand All @@ -272,10 +271,7 @@ impl<'a, F: Function> Env<'a, F> {
fixed_def = true;
}
}
if let OperandConstraint::Stack = u.operand.constraint() {
stack = true;
}
if fixed && stack && fixed_def {
if fixed && fixed_def {
break;
}
}
Expand All @@ -286,9 +282,6 @@ impl<'a, F: Function> Env<'a, F> {
if fixed_def {
self.bundles[bundle].set_cached_fixed_def();
}
if stack {
self.bundles[bundle].set_cached_stack();
}

// Create a spillslot for this bundle.
let reg = self.vreg(vreg);
Expand Down
15 changes: 1 addition & 14 deletions src/ion/process.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -265,7 +265,6 @@ impl<'a, F: Function> Env<'a, F> {
let minimal;
let mut fixed = false;
let mut fixed_def = false;
let mut stack = false;
let bundledata = &self.bundles[bundle];
let first_range = bundledata.ranges[0].index;
let first_range_data = &self.ranges[first_range];
Expand All @@ -286,12 +285,7 @@ impl<'a, F: Function> Env<'a, F> {
trace!(" -> is fixed def");
fixed_def = true;
}
}
if let OperandConstraint::Stack = u.operand.constraint() {
trace!(" -> stack operand at {:?}: {:?}", u.pos, u.operand);
stack = true;
}
if stack && fixed {

break;
}
}
Expand Down Expand Up @@ -343,7 +337,6 @@ impl<'a, F: Function> Env<'a, F> {
minimal,
fixed,
fixed_def,
stack,
);
}

Expand Down Expand Up @@ -1056,12 +1049,6 @@ impl<'a, F: Function> Env<'a, F> {
let fixed_preg = match req {
Requirement::FixedReg(preg) | Requirement::FixedStack(preg) => Some(preg),
Requirement::Register => None,
Requirement::Stack => {
// If we must be on the stack, mark our spillset
// as required immediately.
self.spillsets[self.bundles[bundle].spillset].required = true;
return Ok(());
}

Requirement::Any => {
self.spilled_bundles.push(bundle);
Expand Down
11 changes: 2 additions & 9 deletions src/ion/requirement.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,6 @@ pub enum Requirement {
FixedReg(PReg),
FixedStack(PReg),
Register,
Stack,
Any,
}
impl Requirement {
Expand All @@ -70,15 +69,10 @@ impl Requirement {
match (self, other) {
(other, Requirement::Any) | (Requirement::Any, other) => Ok(other),
(Requirement::Register, Requirement::Register) => Ok(self),
(Requirement::Stack, Requirement::Stack) => Ok(self),
(Requirement::Register, Requirement::FixedReg(preg))
| (Requirement::FixedReg(preg), Requirement::Register) => {
Ok(Requirement::FixedReg(preg))
}
(Requirement::Stack, Requirement::FixedStack(preg))
| (Requirement::FixedStack(preg), Requirement::Stack) => {
Ok(Requirement::FixedStack(preg))
}
(Requirement::FixedReg(a), Requirement::FixedReg(b)) if a == b => Ok(self),
(Requirement::FixedStack(a), Requirement::FixedStack(b)) if a == b => Ok(self),
_ => Err(RequirementConflict),
Expand All @@ -88,7 +82,7 @@ impl Requirement {
#[inline(always)]
pub fn is_stack(self) -> bool {
match self {
Requirement::Stack | Requirement::FixedStack(..) => true,
Requirement::FixedStack(..) => true,
Requirement::Register | Requirement::FixedReg(..) => false,
Requirement::Any => false,
}
Expand All @@ -98,7 +92,7 @@ impl Requirement {
pub fn is_reg(self) -> bool {
match self {
Requirement::Register | Requirement::FixedReg(..) => true,
Requirement::Stack | Requirement::FixedStack(..) => false,
Requirement::FixedStack(..) => false,
Requirement::Any => false,
}
}
Expand All @@ -116,7 +110,6 @@ impl<'a, F: Function> Env<'a, F> {
}
}
OperandConstraint::Reg | OperandConstraint::Reuse(_) => Requirement::Register,
OperandConstraint::Stack => Requirement::Stack,
OperandConstraint::Any => Requirement::Any,
}
}
Expand Down
5 changes: 0 additions & 5 deletions src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -447,8 +447,6 @@ pub enum OperandConstraint {
Any,
/// Operand must be in a register. Register is read-only for Uses.
Reg,
/// Operand must be on the stack.
Stack,
/// Operand must be in a fixed register.
FixedReg(PReg),
/// On defs only: reuse a use's register.
Expand All @@ -460,7 +458,6 @@ impl core::fmt::Display for OperandConstraint {
match self {
Self::Any => write!(f, "any"),
Self::Reg => write!(f, "reg"),
Self::Stack => write!(f, "stack"),
Self::FixedReg(preg) => write!(f, "fixed({})", preg),
Self::Reuse(idx) => write!(f, "reuse({})", idx),
}
Expand Down Expand Up @@ -556,7 +553,6 @@ impl Operand {
let constraint_field = match constraint {
OperandConstraint::Any => 0,
OperandConstraint::Reg => 1,
OperandConstraint::Stack => 2,
OperandConstraint::FixedReg(preg) => {
debug_assert_eq!(preg.class(), vreg.class());
0b1000000 | preg.hw_enc() as u32
Expand Down Expand Up @@ -829,7 +825,6 @@ impl Operand {
match constraint_field {
0 => OperandConstraint::Any,
1 => OperandConstraint::Reg,
2 => OperandConstraint::Stack,
_ => unreachable!(),
}
}
Expand Down
Loading