slint/internal/compiler/llr/optim_passes/inline_expressions.rs
2025-05-06 13:06:27 +02:00

222 lines
11 KiB
Rust

// Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
//! Inline properties that are simple enough to be inlined
//!
//! If an expression does a single property access or less, it can be inlined
//! in the calling expression
use crate::expression_tree::{BuiltinFunction, ImageReference};
use crate::llr::{CompilationUnit, EvaluationContext, Expression};
const PROPERTY_ACCESS_COST: isize = 1000;
const ALLOC_COST: isize = 700;
const ARRAY_INDEX_COST: isize = 500;
/// The threshold from which we consider an expression to be worth inlining.
/// less than two allocations. (since property access usually cost one allocation)
const INLINE_THRESHOLD: isize = ALLOC_COST * 2 - 10;
/// Property that are used only once should almost always be inlined unless it is really expensive to compute and we want to cache the result
const INLINE_SINGLE_THRESHOLD: isize = ALLOC_COST * 10;
// The cost of an expression.
fn expression_cost(exp: &Expression, ctx: &EvaluationContext) -> isize {
let mut cost = match exp {
Expression::StringLiteral(_) => ALLOC_COST,
Expression::NumberLiteral(_) => 0,
Expression::BoolLiteral(_) => 0,
Expression::PropertyReference(_) => PROPERTY_ACCESS_COST,
Expression::FunctionParameterReference { .. } => return isize::MAX,
Expression::StoreLocalVariable { .. } => 0,
Expression::ReadLocalVariable { .. } => 1,
Expression::StructFieldAccess { .. } => 1,
Expression::ArrayIndex { .. } => ARRAY_INDEX_COST,
Expression::Cast { .. } => 0,
Expression::CodeBlock(_) => 0,
Expression::BuiltinFunctionCall { function, .. } => builtin_function_cost(function),
Expression::CallBackCall { callback, .. } => callback_cost(callback, ctx),
Expression::FunctionCall { function, .. } => callback_cost(function, ctx),
Expression::ItemMemberFunctionCall { function } => callback_cost(function, ctx),
Expression::ExtraBuiltinFunctionCall { .. } => return isize::MAX,
Expression::PropertyAssignment { .. } => return isize::MAX,
Expression::ModelDataAssignment { .. } => return isize::MAX,
Expression::ArrayIndexAssignment { .. } => return isize::MAX,
Expression::BinaryExpression { .. } => 1,
Expression::UnaryOp { .. } => 1,
// Avoid inlining calls to load the image from the cache, as in the worst case the image isn't cached
// and repeated calls will load the image over and over again. It's better to keep the image cached in the
// `property<image>` of the `Image` element, with the exception of embedded textures.
Expression::ImageReference {
resource_ref: ImageReference::EmbeddedTexture { .. }, ..
} => 1,
Expression::ImageReference { .. } => return isize::MAX,
Expression::Condition { condition, true_expr, false_expr } => {
return expression_cost(condition, ctx)
.saturating_add(
expression_cost(true_expr, ctx).max(expression_cost(false_expr, ctx)),
)
.saturating_add(10);
}
// Never inline an array because it is a model and when shared it needs to keep its identity
// (cf #5249) (otherwise it would be `ALLOC_COST`)
Expression::Array { .. } => return isize::MAX,
Expression::Struct { .. } => 1,
Expression::EasingCurve(_) => 1,
Expression::LinearGradient { .. } => ALLOC_COST,
Expression::RadialGradient { .. } => ALLOC_COST,
Expression::EnumerationValue(_) => 0,
Expression::LayoutCacheAccess { .. } => PROPERTY_ACCESS_COST,
Expression::BoxLayoutFunction { .. } => return isize::MAX,
Expression::ComputeDialogLayoutCells { .. } => return isize::MAX,
Expression::MinMax { .. } => 10,
Expression::EmptyComponentFactory => 10,
Expression::TranslationReference { .. } => PROPERTY_ACCESS_COST + 2 * ALLOC_COST,
};
exp.visit(|e| cost = cost.saturating_add(expression_cost(e, ctx)));
cost
}
fn callback_cost(_callback: &crate::llr::PropertyReference, _ctx: &EvaluationContext) -> isize {
// TODO: lookup the callback and find out what it does
isize::MAX
}
fn builtin_function_cost(function: &BuiltinFunction) -> isize {
match function {
BuiltinFunction::GetWindowScaleFactor => PROPERTY_ACCESS_COST,
BuiltinFunction::GetWindowDefaultFontSize => PROPERTY_ACCESS_COST,
BuiltinFunction::AnimationTick => PROPERTY_ACCESS_COST,
BuiltinFunction::Debug => isize::MAX,
BuiltinFunction::Mod => 10,
BuiltinFunction::Round => 10,
BuiltinFunction::Ceil => 10,
BuiltinFunction::Floor => 10,
BuiltinFunction::Abs => 10,
BuiltinFunction::Sqrt => 10,
BuiltinFunction::Cos => 10,
BuiltinFunction::Sin => 10,
BuiltinFunction::Tan => 10,
BuiltinFunction::ACos => 10,
BuiltinFunction::ASin => 10,
BuiltinFunction::ATan => 10,
BuiltinFunction::ATan2 => 10,
BuiltinFunction::Log => 10,
BuiltinFunction::Ln => 10,
BuiltinFunction::Pow => 10,
BuiltinFunction::Exp => 10,
BuiltinFunction::ToFixed => ALLOC_COST,
BuiltinFunction::ToPrecision => ALLOC_COST,
BuiltinFunction::SetFocusItem | BuiltinFunction::ClearFocusItem => isize::MAX,
BuiltinFunction::ShowPopupWindow
| BuiltinFunction::ClosePopupWindow
| BuiltinFunction::ShowPopupMenu => isize::MAX,
BuiltinFunction::SetSelectionOffsets => isize::MAX,
BuiltinFunction::ItemFontMetrics => PROPERTY_ACCESS_COST,
BuiltinFunction::StringToFloat => 50,
BuiltinFunction::StringIsFloat => 50,
BuiltinFunction::StringIsEmpty => 50,
BuiltinFunction::StringCharacterCount => 50,
BuiltinFunction::StringToLowercase => ALLOC_COST,
BuiltinFunction::StringToUppercase => ALLOC_COST,
BuiltinFunction::ColorRgbaStruct => 50,
BuiltinFunction::ColorHsvaStruct => 50,
BuiltinFunction::ColorBrighter => 50,
BuiltinFunction::ColorDarker => 50,
BuiltinFunction::ColorTransparentize => 50,
BuiltinFunction::ColorMix => 50,
BuiltinFunction::ColorWithAlpha => 50,
BuiltinFunction::ImageSize => 50,
BuiltinFunction::ArrayLength => 50,
BuiltinFunction::Rgb => 50,
BuiltinFunction::Hsv => 50,
BuiltinFunction::ImplicitLayoutInfo(_) => isize::MAX,
BuiltinFunction::ItemAbsolutePosition => isize::MAX,
BuiltinFunction::RegisterCustomFontByPath => isize::MAX,
BuiltinFunction::RegisterCustomFontByMemory => isize::MAX,
BuiltinFunction::RegisterBitmapFont => isize::MAX,
BuiltinFunction::ColorScheme => PROPERTY_ACCESS_COST,
BuiltinFunction::SupportsNativeMenuBar => 10,
BuiltinFunction::SetupNativeMenuBar => isize::MAX,
BuiltinFunction::MonthDayCount => isize::MAX,
BuiltinFunction::MonthOffset => isize::MAX,
BuiltinFunction::FormatDate => isize::MAX,
BuiltinFunction::DateNow => isize::MAX,
BuiltinFunction::ValidDate => isize::MAX,
BuiltinFunction::ParseDate => isize::MAX,
BuiltinFunction::SetTextInputFocused => PROPERTY_ACCESS_COST,
BuiltinFunction::TextInputFocused => PROPERTY_ACCESS_COST,
BuiltinFunction::Translate => 2 * ALLOC_COST + PROPERTY_ACCESS_COST,
BuiltinFunction::Use24HourFormat => 2 * ALLOC_COST + PROPERTY_ACCESS_COST,
BuiltinFunction::UpdateTimers => 10,
BuiltinFunction::DetectOperatingSystem => 10,
}
}
pub fn inline_simple_expressions(root: &CompilationUnit) {
root.for_each_expression(&mut |e, ctx| {
inline_simple_expressions_in_expression(&mut e.borrow_mut(), ctx)
})
}
fn inline_simple_expressions_in_expression(expr: &mut Expression, ctx: &EvaluationContext) {
if let Expression::PropertyReference(prop) = expr {
let prop_info = ctx.property_info(prop);
if prop_info.analysis.as_ref().is_some_and(|a| !a.is_set && !a.is_set_externally) {
if let Some((binding, map)) = prop_info.binding {
if binding.animation.is_none()
// State info binding are special and the binding cannot be inlined or used.
&& !binding.is_state_info
{
let mapped_ctx = map.map_context(ctx);
let cost = expression_cost(&binding.expression.borrow(), &mapped_ctx);
let use_count = binding.use_count.get();
debug_assert!(
use_count > 0,
"We use a property and its count is zero: {}",
crate::llr::pretty_print::DisplayPropertyRef(prop, ctx)
);
if cost <= INLINE_THRESHOLD
|| (use_count == 1 && cost <= INLINE_SINGLE_THRESHOLD)
{
// Perform inlining
*expr = binding.expression.borrow().clone();
map.map_expression(expr);
// adjust use count
binding.use_count.set(use_count - 1);
if let Some(prop_decl) = prop_info.property_decl {
prop_decl.use_count.set(prop_decl.use_count.get() - 1);
}
adjust_use_count(expr, ctx, 1);
if use_count == 1 {
adjust_use_count(&binding.expression.borrow(), &mapped_ctx, -1);
binding.expression.replace(Expression::CodeBlock(vec![]));
}
}
}
} else if let Some(prop_decl) = prop_info.property_decl {
if let Some(e) = Expression::default_value_for_type(&prop_decl.ty) {
prop_decl.use_count.set(prop_decl.use_count.get() - 1);
*expr = e;
}
}
}
};
expr.visit_mut(|e| inline_simple_expressions_in_expression(e, ctx));
}
fn adjust_use_count(expr: &Expression, ctx: &EvaluationContext, adjust: isize) {
expr.visit_property_references(ctx, &mut |p, ctx| {
let prop_info = ctx.property_info(p);
if let Some(property_decl) = prop_info.property_decl {
property_decl
.use_count
.set(property_decl.use_count.get().checked_add_signed(adjust).unwrap());
}
if let Some((binding, _)) = prop_info.binding {
let use_count = binding.use_count.get().checked_add_signed(adjust).unwrap();
binding.use_count.set(use_count);
}
});
}