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::SliceIndexAssignment { .. } => return isize::MAX,
44        Expression::BinaryExpression { .. } => 1,
45        Expression::UnaryOp { .. } => 1,
46        // Avoid inlining calls to load the image from the cache, as in the worst case the image isn't cached
47        // and repeated calls will load the image over and over again. It's better to keep the image cached in the
48        // `property<image>` of the `Image` element, with the exception of embedded textures.
49        Expression::ImageReference {
50            resource_ref: ImageReference::EmbeddedTexture { .. }, ..
51        } => 1,
52        Expression::ImageReference { .. } => return isize::MAX,
53        Expression::Condition { condition, true_expr, false_expr } => {
54            return expression_cost(condition, ctx)
55                .saturating_add(
56                    expression_cost(true_expr, ctx).max(expression_cost(false_expr, ctx)),
57                )
58                .saturating_add(10);
59        }
60        // Never inline an array because it is a model and when shared it needs to keep its identity
61        // (cf #5249)  (otherwise it would be `ALLOC_COST`)
62        Expression::Array { .. } => return isize::MAX,
63        Expression::Struct { .. } => 1,
64        Expression::EasingCurve(_) => 1,
65        Expression::LinearGradient { .. } => ALLOC_COST,
66        Expression::RadialGradient { .. } => ALLOC_COST,
67        Expression::ConicGradient { .. } => ALLOC_COST,
68        Expression::EnumerationValue(_) => 0,
69        Expression::LayoutCacheAccess { .. } => PROPERTY_ACCESS_COST,
70        Expression::WithLayoutItemInfo { .. } => return isize::MAX,
71        Expression::WithGridInputData { .. } => return isize::MAX,
72        Expression::MinMax { .. } => 10,
73        Expression::EmptyComponentFactory => 10,
74        Expression::TranslationReference { .. } => PROPERTY_ACCESS_COST + 2 * ALLOC_COST,
75    };
76
77    exp.visit(|e| cost = cost.saturating_add(expression_cost(e, ctx)));
78
79    cost
80}
81
82fn callback_cost(_callback: &crate::llr::MemberReference, _ctx: &EvaluationContext) -> isize {
83    // TODO: lookup the callback and find out what it does
84    isize::MAX
85}
86
87fn builtin_function_cost(function: &BuiltinFunction) -> isize {
88    match function {
89        BuiltinFunction::GetWindowScaleFactor => PROPERTY_ACCESS_COST,
90        BuiltinFunction::GetWindowDefaultFontSize => PROPERTY_ACCESS_COST,
91        BuiltinFunction::AnimationTick => PROPERTY_ACCESS_COST,
92        BuiltinFunction::Debug => isize::MAX,
93        BuiltinFunction::Mod => 10,
94        BuiltinFunction::Round => 10,
95        BuiltinFunction::Ceil => 10,
96        BuiltinFunction::Floor => 10,
97        BuiltinFunction::Abs => 10,
98        BuiltinFunction::Sqrt => 10,
99        BuiltinFunction::Cos => 10,
100        BuiltinFunction::Sin => 10,
101        BuiltinFunction::Tan => 10,
102        BuiltinFunction::ACos => 10,
103        BuiltinFunction::ASin => 10,
104        BuiltinFunction::ATan => 10,
105        BuiltinFunction::ATan2 => 10,
106        BuiltinFunction::Log => 10,
107        BuiltinFunction::Ln => 10,
108        BuiltinFunction::Pow => 10,
109        BuiltinFunction::Exp => 10,
110        BuiltinFunction::ToFixed => ALLOC_COST,
111        BuiltinFunction::ToPrecision => ALLOC_COST,
112        BuiltinFunction::SetFocusItem | BuiltinFunction::ClearFocusItem => isize::MAX,
113        BuiltinFunction::ShowPopupWindow
114        | BuiltinFunction::ClosePopupWindow
115        | BuiltinFunction::ShowPopupMenu
116        | BuiltinFunction::ShowPopupMenuInternal => isize::MAX,
117        BuiltinFunction::SetSelectionOffsets => isize::MAX,
118        BuiltinFunction::ItemFontMetrics => PROPERTY_ACCESS_COST,
119        BuiltinFunction::StringToFloat => 50,
120        BuiltinFunction::StringIsFloat => 50,
121        BuiltinFunction::StringIsEmpty => 50,
122        BuiltinFunction::StringCharacterCount => 50,
123        BuiltinFunction::StringToLowercase => ALLOC_COST,
124        BuiltinFunction::StringToUppercase => ALLOC_COST,
125        BuiltinFunction::ColorRgbaStruct => 50,
126        BuiltinFunction::ColorHsvaStruct => 50,
127        BuiltinFunction::ColorOklchStruct => 50,
128        BuiltinFunction::ColorBrighter => 50,
129        BuiltinFunction::ColorDarker => 50,
130        BuiltinFunction::ColorTransparentize => 50,
131        BuiltinFunction::ColorMix => 50,
132        BuiltinFunction::ColorWithAlpha => 50,
133        BuiltinFunction::ImageSize => 50,
134        BuiltinFunction::ArrayLength => 50,
135        BuiltinFunction::Rgb => 50,
136        BuiltinFunction::Hsv => 50,
137        BuiltinFunction::Oklch => 50,
138        BuiltinFunction::ImplicitLayoutInfo(_) => isize::MAX,
139        BuiltinFunction::ItemAbsolutePosition => isize::MAX,
140        BuiltinFunction::RegisterCustomFontByPath => isize::MAX,
141        BuiltinFunction::RegisterCustomFontByMemory => isize::MAX,
142        BuiltinFunction::RegisterBitmapFont => isize::MAX,
143        BuiltinFunction::ColorScheme => PROPERTY_ACCESS_COST,
144        BuiltinFunction::SupportsNativeMenuBar => 10,
145        BuiltinFunction::SetupMenuBar => isize::MAX,
146        BuiltinFunction::MonthDayCount => isize::MAX,
147        BuiltinFunction::MonthOffset => isize::MAX,
148        BuiltinFunction::FormatDate => isize::MAX,
149        BuiltinFunction::DateNow => isize::MAX,
150        BuiltinFunction::ValidDate => isize::MAX,
151        BuiltinFunction::ParseDate => isize::MAX,
152        BuiltinFunction::SetTextInputFocused => PROPERTY_ACCESS_COST,
153        BuiltinFunction::TextInputFocused => PROPERTY_ACCESS_COST,
154        BuiltinFunction::Translate => 2 * ALLOC_COST + PROPERTY_ACCESS_COST,
155        BuiltinFunction::Use24HourFormat => 2 * ALLOC_COST + PROPERTY_ACCESS_COST,
156        BuiltinFunction::UpdateTimers => 10,
157        BuiltinFunction::DetectOperatingSystem => 10,
158        BuiltinFunction::StartTimer => 10,
159        BuiltinFunction::StopTimer => 10,
160        BuiltinFunction::RestartTimer => 10,
161        BuiltinFunction::ParseMarkdown | BuiltinFunction::EscapeMarkdown => isize::MAX,
162    }
163}
164
165pub fn inline_simple_expressions(root: &CompilationUnit) {
166    root.for_each_expression(&mut |e, ctx| {
167        inline_simple_expressions_in_expression(&mut e.borrow_mut(), ctx)
168    })
169}
170
171fn inline_simple_expressions_in_expression(expr: &mut Expression, ctx: &EvaluationContext) {
172    if let Expression::PropertyReference(prop) = expr {
173        let prop_info = ctx.property_info(prop);
174        if prop_info.analysis.as_ref().is_some_and(|a| !a.is_set && !a.is_set_externally) {
175            if let Some((binding, map)) = prop_info.binding {
176                if binding.animation.is_none()
177                    // State info binding are special and the binding cannot be inlined or used.
178                    && !binding.is_state_info
179                {
180                    let mapped_ctx = map.map_context(ctx);
181                    let cost = expression_cost(&binding.expression.borrow(), &mapped_ctx);
182                    let use_count = binding.use_count.get();
183                    debug_assert!(
184                        use_count > 0,
185                        "We use a property and its count is zero: {}",
186                        crate::llr::pretty_print::DisplayPropertyRef(prop, ctx)
187                    );
188                    if cost <= INLINE_THRESHOLD
189                        || (use_count == 1 && cost <= INLINE_SINGLE_THRESHOLD)
190                    {
191                        // Perform inlining
192                        *expr = binding.expression.borrow().clone();
193                        map.map_expression(expr);
194                        // adjust use count
195                        binding.use_count.set(use_count - 1);
196                        if let Some(use_count) = prop_info.use_count {
197                            use_count.set(use_count.get() - 1);
198                        }
199                        adjust_use_count(expr, ctx, 1);
200                        if use_count == 1 {
201                            adjust_use_count(&binding.expression.borrow(), &mapped_ctx, -1);
202                            binding.expression.replace(Expression::CodeBlock(Vec::new()));
203                        }
204                    }
205                }
206            } else if let Some(use_count) = prop_info.use_count
207                && let Some(e) = Expression::default_value_for_type(&prop_info.ty)
208            {
209                use_count.set(use_count.get() - 1);
210                *expr = e;
211            }
212        }
213    };
214
215    expr.visit_mut(|e| inline_simple_expressions_in_expression(e, ctx));
216}
217
218fn adjust_use_count(expr: &Expression, ctx: &EvaluationContext, adjust: isize) {
219    expr.visit_property_references(ctx, &mut |p, ctx| {
220        let prop_info = ctx.property_info(p);
221        if let Some(use_count) = prop_info.use_count {
222            use_count.set(use_count.get().checked_add_signed(adjust).unwrap());
223        }
224        if let Some((binding, _)) = prop_info.binding {
225            let use_count = binding.use_count.get().checked_add_signed(adjust).unwrap();
226            binding.use_count.set(use_count);
227        }
228    });
229}
i_slint_compiler/llr/optim_passes/inline_expressions.rs

i_slint_compiler/llr/optim_passes/
inline_expressions.rs
