i_slint_compiler/llr/optim_passes/
inline_expressions.rs

1// Copyright © SixtyFPS GmbH <info@slint.dev>
2// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
3
4//! Inline properties that are simple enough to be inlined
5//!
6//! If an expression does a single property access or less, it can be inlined
7//! in the calling expression
8
9use crate::expression_tree::{BuiltinFunction, ImageReference};
10use crate::llr::{CompilationUnit, EvaluationContext, Expression};
11
12const PROPERTY_ACCESS_COST: isize = 1000;
13const ALLOC_COST: isize = 700;
14const ARRAY_INDEX_COST: isize = 500;
15/// The threshold from which we consider an expression to be worth inlining.
16/// less than two allocations. (since property access usually cost one allocation)
17const INLINE_THRESHOLD: isize = ALLOC_COST * 2 - 10;
18/// 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
19const INLINE_SINGLE_THRESHOLD: isize = ALLOC_COST * 10;
20
21// The cost of an expression.
22fn expression_cost(exp: &Expression, ctx: &EvaluationContext) -> isize {
23    let mut cost = match exp {
24        Expression::StringLiteral(_) => ALLOC_COST,
25        Expression::NumberLiteral(_) => 0,
26        Expression::BoolLiteral(_) => 0,
27        Expression::PropertyReference(_) => PROPERTY_ACCESS_COST,
28        Expression::FunctionParameterReference { .. } => return isize::MAX,
29        Expression::StoreLocalVariable { .. } => 0,
30        Expression::ReadLocalVariable { .. } => 1,
31        Expression::StructFieldAccess { .. } => 1,
32        Expression::ArrayIndex { .. } => ARRAY_INDEX_COST,
33        Expression::Cast { .. } => 0,
34        Expression::CodeBlock(_) => 0,
35        Expression::BuiltinFunctionCall { function, .. } => builtin_function_cost(function),
36        Expression::CallBackCall { callback, .. } => callback_cost(callback, ctx),
37        Expression::FunctionCall { function, .. } => callback_cost(function, ctx),
38        Expression::ItemMemberFunctionCall { function } => callback_cost(function, ctx),
39        Expression::ExtraBuiltinFunctionCall { .. } => return isize::MAX,
40        Expression::PropertyAssignment { .. } => return isize::MAX,
41        Expression::ModelDataAssignment { .. } => return isize::MAX,
42        Expression::ArrayIndexAssignment { .. } => return isize::MAX,
43        Expression::BinaryExpression { .. } => 1,
44        Expression::UnaryOp { .. } => 1,
45        // Avoid inlining calls to load the image from the cache, as in the worst case the image isn't cached
46        // and repeated calls will load the image over and over again. It's better to keep the image cached in the
47        // `property<image>` of the `Image` element, with the exception of embedded textures.
48        Expression::ImageReference {
49            resource_ref: ImageReference::EmbeddedTexture { .. }, ..
50        } => 1,
51        Expression::ImageReference { .. } => return isize::MAX,
52        Expression::Condition { condition, true_expr, false_expr } => {
53            return expression_cost(condition, ctx)
54                .saturating_add(
55                    expression_cost(true_expr, ctx).max(expression_cost(false_expr, ctx)),
56                )
57                .saturating_add(10);
58        }
59        // Never inline an array because it is a model and when shared it needs to keep its identity
60        // (cf #5249)  (otherwise it would be `ALLOC_COST`)
61        Expression::Array { .. } => return isize::MAX,
62        Expression::Struct { .. } => 1,
63        Expression::EasingCurve(_) => 1,
64        Expression::LinearGradient { .. } => ALLOC_COST,
65        Expression::RadialGradient { .. } => ALLOC_COST,
66        Expression::EnumerationValue(_) => 0,
67        Expression::LayoutCacheAccess { .. } => PROPERTY_ACCESS_COST,
68        Expression::BoxLayoutFunction { .. } => return isize::MAX,
69        Expression::ComputeDialogLayoutCells { .. } => return isize::MAX,
70        Expression::MinMax { .. } => 10,
71        Expression::EmptyComponentFactory => 10,
72        Expression::TranslationReference { .. } => PROPERTY_ACCESS_COST + 2 * ALLOC_COST,
73    };
74
75    exp.visit(|e| cost = cost.saturating_add(expression_cost(e, ctx)));
76
77    cost
78}
79
80fn callback_cost(_callback: &crate::llr::PropertyReference, _ctx: &EvaluationContext) -> isize {
81    // TODO: lookup the callback and find out what it does
82    isize::MAX
83}
84
85fn builtin_function_cost(function: &BuiltinFunction) -> isize {
86    match function {
87        BuiltinFunction::GetWindowScaleFactor => PROPERTY_ACCESS_COST,
88        BuiltinFunction::GetWindowDefaultFontSize => PROPERTY_ACCESS_COST,
89        BuiltinFunction::AnimationTick => PROPERTY_ACCESS_COST,
90        BuiltinFunction::Debug => isize::MAX,
91        BuiltinFunction::Mod => 10,
92        BuiltinFunction::Round => 10,
93        BuiltinFunction::Ceil => 10,
94        BuiltinFunction::Floor => 10,
95        BuiltinFunction::Abs => 10,
96        BuiltinFunction::Sqrt => 10,
97        BuiltinFunction::Cos => 10,
98        BuiltinFunction::Sin => 10,
99        BuiltinFunction::Tan => 10,
100        BuiltinFunction::ACos => 10,
101        BuiltinFunction::ASin => 10,
102        BuiltinFunction::ATan => 10,
103        BuiltinFunction::ATan2 => 10,
104        BuiltinFunction::Log => 10,
105        BuiltinFunction::Ln => 10,
106        BuiltinFunction::Pow => 10,
107        BuiltinFunction::Exp => 10,
108        BuiltinFunction::ToFixed => ALLOC_COST,
109        BuiltinFunction::ToPrecision => ALLOC_COST,
110        BuiltinFunction::SetFocusItem | BuiltinFunction::ClearFocusItem => isize::MAX,
111        BuiltinFunction::ShowPopupWindow
112        | BuiltinFunction::ClosePopupWindow
113        | BuiltinFunction::ShowPopupMenu => isize::MAX,
114        BuiltinFunction::SetSelectionOffsets => isize::MAX,
115        BuiltinFunction::ItemFontMetrics => PROPERTY_ACCESS_COST,
116        BuiltinFunction::StringToFloat => 50,
117        BuiltinFunction::StringIsFloat => 50,
118        BuiltinFunction::StringIsEmpty => 50,
119        BuiltinFunction::StringCharacterCount => 50,
120        BuiltinFunction::StringToLowercase => ALLOC_COST,
121        BuiltinFunction::StringToUppercase => ALLOC_COST,
122        BuiltinFunction::ColorRgbaStruct => 50,
123        BuiltinFunction::ColorHsvaStruct => 50,
124        BuiltinFunction::ColorBrighter => 50,
125        BuiltinFunction::ColorDarker => 50,
126        BuiltinFunction::ColorTransparentize => 50,
127        BuiltinFunction::ColorMix => 50,
128        BuiltinFunction::ColorWithAlpha => 50,
129        BuiltinFunction::ImageSize => 50,
130        BuiltinFunction::ArrayLength => 50,
131        BuiltinFunction::Rgb => 50,
132        BuiltinFunction::Hsv => 50,
133        BuiltinFunction::ImplicitLayoutInfo(_) => isize::MAX,
134        BuiltinFunction::ItemAbsolutePosition => isize::MAX,
135        BuiltinFunction::RegisterCustomFontByPath => isize::MAX,
136        BuiltinFunction::RegisterCustomFontByMemory => isize::MAX,
137        BuiltinFunction::RegisterBitmapFont => isize::MAX,
138        BuiltinFunction::ColorScheme => PROPERTY_ACCESS_COST,
139        BuiltinFunction::SupportsNativeMenuBar => 10,
140        BuiltinFunction::SetupNativeMenuBar => isize::MAX,
141        BuiltinFunction::MonthDayCount => isize::MAX,
142        BuiltinFunction::MonthOffset => isize::MAX,
143        BuiltinFunction::FormatDate => isize::MAX,
144        BuiltinFunction::DateNow => isize::MAX,
145        BuiltinFunction::ValidDate => isize::MAX,
146        BuiltinFunction::ParseDate => isize::MAX,
147        BuiltinFunction::SetTextInputFocused => PROPERTY_ACCESS_COST,
148        BuiltinFunction::TextInputFocused => PROPERTY_ACCESS_COST,
149        BuiltinFunction::Translate => 2 * ALLOC_COST + PROPERTY_ACCESS_COST,
150        BuiltinFunction::Use24HourFormat => 2 * ALLOC_COST + PROPERTY_ACCESS_COST,
151        BuiltinFunction::UpdateTimers => 10,
152        BuiltinFunction::DetectOperatingSystem => 10,
153    }
154}
155
156pub fn inline_simple_expressions(root: &CompilationUnit) {
157    root.for_each_expression(&mut |e, ctx| {
158        inline_simple_expressions_in_expression(&mut e.borrow_mut(), ctx)
159    })
160}
161
162fn inline_simple_expressions_in_expression(expr: &mut Expression, ctx: &EvaluationContext) {
163    if let Expression::PropertyReference(prop) = expr {
164        let prop_info = ctx.property_info(prop);
165        if prop_info.analysis.as_ref().is_some_and(|a| !a.is_set && !a.is_set_externally) {
166            if let Some((binding, map)) = prop_info.binding {
167                if binding.animation.is_none()
168                    // State info binding are special and the binding cannot be inlined or used.
169                    && !binding.is_state_info
170                {
171                    let mapped_ctx = map.map_context(ctx);
172                    let cost = expression_cost(&binding.expression.borrow(), &mapped_ctx);
173                    let use_count = binding.use_count.get();
174                    debug_assert!(
175                        use_count > 0,
176                        "We use a property and its count is zero: {}",
177                        crate::llr::pretty_print::DisplayPropertyRef(prop, ctx)
178                    );
179                    if cost <= INLINE_THRESHOLD
180                        || (use_count == 1 && cost <= INLINE_SINGLE_THRESHOLD)
181                    {
182                        // Perform inlining
183                        *expr = binding.expression.borrow().clone();
184                        map.map_expression(expr);
185                        // adjust use count
186                        binding.use_count.set(use_count - 1);
187                        if let Some(prop_decl) = prop_info.property_decl {
188                            prop_decl.use_count.set(prop_decl.use_count.get() - 1);
189                        }
190                        adjust_use_count(expr, ctx, 1);
191                        if use_count == 1 {
192                            adjust_use_count(&binding.expression.borrow(), &mapped_ctx, -1);
193                            binding.expression.replace(Expression::CodeBlock(vec![]));
194                        }
195                    }
196                }
197            } else if let Some(prop_decl) = prop_info.property_decl {
198                if let Some(e) = Expression::default_value_for_type(&prop_decl.ty) {
199                    prop_decl.use_count.set(prop_decl.use_count.get() - 1);
200                    *expr = e;
201                }
202            }
203        }
204    };
205
206    expr.visit_mut(|e| inline_simple_expressions_in_expression(e, ctx));
207}
208
209fn adjust_use_count(expr: &Expression, ctx: &EvaluationContext, adjust: isize) {
210    expr.visit_property_references(ctx, &mut |p, ctx| {
211        let prop_info = ctx.property_info(p);
212        if let Some(property_decl) = prop_info.property_decl {
213            property_decl
214                .use_count
215                .set(property_decl.use_count.get().checked_add_signed(adjust).unwrap());
216        }
217        if let Some((binding, _)) = prop_info.binding {
218            let use_count = binding.use_count.get().checked_add_signed(adjust).unwrap();
219            binding.use_count.set(use_count);
220        }
221    });
222}
i_slint_compiler/llr/optim_passes/inline_expressions.rs

i_slint_compiler/llr/optim_passes/
inline_expressions.rs
