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torsh_jit/
generics.rs

1//! Generic function support for JIT compilation
2//!
3//! This module provides generic function capabilities, allowing the JIT compiler
4//! to create and instantiate parameterized functions with type parameters.
5
6use crate::ir::{IrModule, TypeKind};
7use crate::{JitError, JitResult};
8use indexmap::IndexMap;
9use std::collections::HashMap;
10
11/// Generic function manager
12#[derive(Debug, Clone)]
13pub struct GenericFunctionManager {
14    /// Registry of generic function templates
15    templates: IndexMap<String, GenericFunctionTemplate>,
16
17    /// Instantiated generic functions
18    instances: IndexMap<InstantiationKey, InstantiatedFunction>,
19
20    /// Statistics about generic function usage
21    stats: GenericFunctionStats,
22
23    /// Configuration for generic functions
24    config: GenericFunctionConfig,
25}
26
27/// Template for a generic function
28#[derive(Debug, Clone)]
29pub struct GenericFunctionTemplate {
30    /// Function name
31    pub name: String,
32
33    /// Generic type parameters
34    pub type_params: Vec<TypeParameter>,
35
36    /// Function constraints (bounds on type parameters)
37    pub constraints: Vec<TypeConstraint>,
38
39    /// Template IR module (with placeholder types)
40    pub template_ir: IrModule,
41
42    /// Default implementations for specific type combinations
43    pub default_impls: HashMap<Vec<TypeKind>, IrModule>,
44
45    /// Metadata about the template
46    pub metadata: TemplateMetadata,
47}
48
49/// Type parameter in a generic function
50#[derive(Debug, Clone, PartialEq, Eq, Hash)]
51pub struct TypeParameter {
52    /// Parameter name (e.g., "T", "U")
53    pub name: String,
54
55    /// Parameter kind (type, shape, constant)
56    pub kind: ParameterKind,
57
58    /// Default type (if any)
59    pub default: Option<TypeKind>,
60
61    /// Variance (covariant, contravariant, invariant)
62    pub variance: Variance,
63}
64
65/// Kind of type parameter
66#[derive(Debug, Clone, PartialEq, Eq, Hash)]
67pub enum ParameterKind {
68    /// Type parameter (e.g., T: Float)
69    Type,
70
71    /// Shape parameter (e.g., N: usize)
72    Shape,
73
74    /// Constant parameter (e.g., SIZE: usize)
75    Constant,
76
77    /// Layout parameter (e.g., L: Layout)
78    Layout,
79}
80
81/// Variance of type parameters
82#[derive(Debug, Clone, PartialEq, Eq, Hash)]
83pub enum Variance {
84    /// Covariant (T is subtype of U => `F<T>` is subtype of `F<U>`)
85    Covariant,
86
87    /// Contravariant (T is subtype of U => `F<U>` is subtype of `F<T>`)
88    Contravariant,
89
90    /// Invariant (no subtyping relationship)
91    Invariant,
92}
93
94/// Constraint on type parameters
95#[derive(Debug, Clone)]
96pub enum TypeConstraint {
97    /// Type must implement a trait (e.g., T: Float)
98    Trait { param: String, trait_name: String },
99
100    /// Type must be equal to another type (e.g., T = U)
101    Equality { param1: String, param2: String },
102
103    /// Type must be a subtype of another type (e.g., T <: U)
104    Subtype { subtype: String, supertype: String },
105
106    /// Shape constraint (e.g., N > 0)
107    Shape {
108        param: String,
109        constraint: ShapeConstraint,
110    },
111
112    /// Custom constraint with a checker function
113    Custom {
114        name: String,
115        checker: fn(&[TypeKind]) -> bool,
116    },
117}
118
119/// Shape constraints for shape parameters
120#[derive(Debug, Clone)]
121pub enum ShapeConstraint {
122    /// Must be positive
123    Positive,
124
125    /// Must be a power of two
126    PowerOfTwo,
127
128    /// Must be equal to another parameter
129    Equal(String),
130
131    /// Must be less than a value
132    LessThan(usize),
133
134    /// Must be greater than a value
135    GreaterThan(usize),
136
137    /// Must be in a range
138    InRange(usize, usize),
139}
140
141/// Key for function instantiation
142#[derive(Debug, Clone, PartialEq, Eq, Hash)]
143pub struct InstantiationKey {
144    /// Template name
145    pub template_name: String,
146
147    /// Concrete types for type parameters
148    pub type_args: Vec<TypeKind>,
149
150    /// Shape arguments for shape parameters
151    pub shape_args: Vec<Vec<usize>>,
152
153    /// Constant arguments
154    pub const_args: Vec<ConstantValue>,
155}
156
157/// Constant values for generic parameters
158#[derive(Debug, Clone, PartialEq, Eq, Hash)]
159pub enum ConstantValue {
160    Int(i64),
161    UInt(u64),
162    Float(u64), // Stored as bits for hashing
163    Bool(bool),
164    String(String),
165}
166
167/// Instantiated function
168#[derive(Debug, Clone)]
169pub struct InstantiatedFunction {
170    /// Instantiation key
171    pub key: InstantiationKey,
172
173    /// Concrete IR module
174    pub module: IrModule,
175
176    /// Performance characteristics
177    pub perf_info: GenericFunctionPerfInfo,
178
179    /// Usage count
180    pub usage_count: usize,
181
182    /// Instantiation time
183    pub instantiation_time_ns: u64,
184}
185
186/// Performance information for instantiated functions
187#[derive(Debug, Clone, Default)]
188pub struct GenericFunctionPerfInfo {
189    /// Estimated execution time
190    pub estimated_exec_time_ns: u64,
191
192    /// Code size in bytes
193    pub code_size: usize,
194
195    /// Register usage
196    pub register_usage: u32,
197
198    /// Memory usage
199    pub memory_usage: usize,
200
201    /// Optimization level applied
202    pub optimization_level: OptimizationLevel,
203}
204
205/// Optimization levels for generic functions
206#[derive(Debug, Clone, Default)]
207pub enum OptimizationLevel {
208    /// No optimization
209    None,
210
211    /// Basic optimizations
212    #[default]
213    Basic,
214
215    /// Aggressive optimizations
216    Aggressive,
217
218    /// Size-optimized
219    Size,
220
221    /// Speed-optimized
222    Speed,
223}
224
225/// Template metadata
226#[derive(Debug, Clone, Default)]
227pub struct TemplateMetadata {
228    /// Author of the template
229    pub author: Option<String>,
230
231    /// Documentation
232    pub documentation: Option<String>,
233
234    /// Version
235    pub version: Option<String>,
236
237    /// Tags for categorization
238    pub tags: Vec<String>,
239
240    /// Complexity estimate
241    pub complexity: ComplexityEstimate,
242}
243
244/// Complexity estimate for a template
245#[derive(Debug, Clone, Default)]
246pub struct ComplexityEstimate {
247    /// Time complexity (e.g., O(n), O(n^2))
248    pub time_complexity: String,
249
250    /// Space complexity
251    pub space_complexity: String,
252
253    /// Instantiation complexity
254    pub instantiation_complexity: String,
255}
256
257/// Configuration for generic functions
258#[derive(Debug, Clone)]
259pub struct GenericFunctionConfig {
260    /// Maximum number of instantiations per template
261    pub max_instantiations_per_template: usize,
262
263    /// Enable automatic monomorphization
264    pub enable_monomorphization: bool,
265
266    /// Enable type inference for generic functions
267    pub enable_type_inference: bool,
268
269    /// Cache instantiated functions
270    pub enable_caching: bool,
271
272    /// Maximum recursion depth for generic instantiation
273    pub max_recursion_depth: usize,
274
275    /// Enable generic function profiling
276    pub enable_profiling: bool,
277}
278
279/// Statistics about generic function usage
280#[derive(Debug, Clone, Default)]
281pub struct GenericFunctionStats {
282    /// Total number of templates
283    pub total_templates: usize,
284
285    /// Total number of instantiations
286    pub total_instantiations: usize,
287
288    /// Cache hits
289    pub cache_hits: usize,
290
291    /// Cache misses
292    pub cache_misses: usize,
293
294    /// Average instantiation time
295    pub avg_instantiation_time_ns: u64,
296
297    /// Most used templates
298    pub most_used_templates: Vec<(String, usize)>,
299}
300
301impl Default for GenericFunctionConfig {
302    fn default() -> Self {
303        Self {
304            max_instantiations_per_template: 32,
305            enable_monomorphization: true,
306            enable_type_inference: true,
307            enable_caching: true,
308            max_recursion_depth: 16,
309            enable_profiling: false,
310        }
311    }
312}
313
314impl GenericFunctionManager {
315    /// Create a new generic function manager
316    pub fn new(config: GenericFunctionConfig) -> Self {
317        Self {
318            templates: IndexMap::new(),
319            instances: IndexMap::new(),
320            stats: GenericFunctionStats::default(),
321            config,
322        }
323    }
324
325    /// Create a new generic function manager with default configuration
326    pub fn with_defaults() -> Self {
327        Self::new(GenericFunctionConfig::default())
328    }
329
330    /// Register a generic function template
331    pub fn register_template(&mut self, template: GenericFunctionTemplate) -> JitResult<()> {
332        // Validate template
333        self.validate_template(&template)?;
334
335        // Store template
336        self.templates.insert(template.name.clone(), template);
337        self.stats.total_templates += 1;
338
339        Ok(())
340    }
341
342    /// Instantiate a generic function with concrete types
343    pub fn instantiate(
344        &mut self,
345        template_name: &str,
346        type_args: &[TypeKind],
347        shape_args: &[Vec<usize>],
348        const_args: &[ConstantValue],
349    ) -> JitResult<InstantiatedFunction> {
350        let key = InstantiationKey {
351            template_name: template_name.to_string(),
352            type_args: type_args.to_vec(),
353            shape_args: shape_args.to_vec(),
354            const_args: const_args.to_vec(),
355        };
356
357        // Check if instantiation already exists
358        if let Some(instance) = self.instances.get_mut(&key) {
359            instance.usage_count += 1;
360            self.stats.cache_hits += 1;
361            return Ok(instance.clone());
362        }
363
364        self.stats.cache_misses += 1;
365
366        // Get template
367        let template = self.templates.get(template_name).ok_or_else(|| {
368            JitError::CompilationError(format!("Template '{}' not found", template_name))
369        })?;
370
371        // Check constraints
372        self.check_constraints(template, type_args, shape_args, const_args)?;
373
374        // Perform instantiation
375        let start_time = std::time::Instant::now();
376        let instantiated_module = self.perform_instantiation(template, &key)?;
377        let instantiation_time = start_time.elapsed().as_nanos() as u64;
378
379        // Create instantiated function
380        let perf_info = self.estimate_performance(&instantiated_module)?;
381        let instance = InstantiatedFunction {
382            key: key.clone(),
383            module: instantiated_module,
384            perf_info,
385            usage_count: 1,
386            instantiation_time_ns: instantiation_time,
387        };
388
389        // Store instance
390        self.instances.insert(key, instance.clone());
391        self.stats.total_instantiations += 1;
392        self.stats.avg_instantiation_time_ns = (self.stats.avg_instantiation_time_ns
393            * (self.stats.total_instantiations - 1) as u64
394            + instantiation_time)
395            / self.stats.total_instantiations as u64;
396
397        Ok(instance)
398    }
399
400    /// Validate a template before registration
401    fn validate_template(&self, template: &GenericFunctionTemplate) -> JitResult<()> {
402        // Check that type parameter names are unique
403        let mut param_names = std::collections::HashSet::new();
404        for param in &template.type_params {
405            if !param_names.insert(&param.name) {
406                return Err(JitError::CompilationError(format!(
407                    "Duplicate type parameter name: {}",
408                    param.name
409                )));
410            }
411        }
412
413        // Validate constraints reference existing parameters
414        for constraint in &template.constraints {
415            match constraint {
416                TypeConstraint::Trait { param, .. } => {
417                    if !param_names.contains(param) {
418                        return Err(JitError::CompilationError(format!(
419                            "Constraint references unknown parameter: {}",
420                            param
421                        )));
422                    }
423                }
424                TypeConstraint::Equality { param1, param2 } => {
425                    if !param_names.contains(param1) || !param_names.contains(param2) {
426                        return Err(JitError::CompilationError(
427                            "Equality constraint references unknown parameter".to_string(),
428                        ));
429                    }
430                }
431                TypeConstraint::Subtype { subtype, supertype } => {
432                    if !param_names.contains(subtype) || !param_names.contains(supertype) {
433                        return Err(JitError::CompilationError(
434                            "Subtype constraint references unknown parameter".to_string(),
435                        ));
436                    }
437                }
438                TypeConstraint::Shape { param, .. } => {
439                    if !param_names.contains(param) {
440                        return Err(JitError::CompilationError(format!(
441                            "Shape constraint references unknown parameter: {}",
442                            param
443                        )));
444                    }
445                }
446                TypeConstraint::Custom { .. } => {
447                    // Custom constraints are always valid (checked at runtime)
448                }
449            }
450        }
451
452        Ok(())
453    }
454
455    /// Check constraints for a specific instantiation
456    fn check_constraints(
457        &self,
458        template: &GenericFunctionTemplate,
459        type_args: &[TypeKind],
460        shape_args: &[Vec<usize>],
461        _const_args: &[ConstantValue],
462    ) -> JitResult<()> {
463        if type_args.len() != template.type_params.len() {
464            return Err(JitError::CompilationError(
465                "Wrong number of type arguments".to_string(),
466            ));
467        }
468
469        for constraint in &template.constraints {
470            match constraint {
471                TypeConstraint::Trait { param, trait_name } => {
472                    let param_index = template
473                        .type_params
474                        .iter()
475                        .position(|p| p.name == *param)
476                        .expect("param should exist in type_params");
477
478                    if !self.check_trait_constraint(&type_args[param_index], trait_name) {
479                        return Err(JitError::CompilationError(format!(
480                            "Type {:?} does not implement trait {}",
481                            type_args[param_index], trait_name
482                        )));
483                    }
484                }
485                TypeConstraint::Shape {
486                    param,
487                    constraint: shape_constraint,
488                } => {
489                    let param_index = template
490                        .type_params
491                        .iter()
492                        .position(|p| p.name == *param)
493                        .expect("param should exist in type_params");
494
495                    if param_index < shape_args.len() {
496                        if !self.check_shape_constraint(&shape_args[param_index], shape_constraint)
497                        {
498                            return Err(JitError::CompilationError(format!(
499                                "Shape constraint violation for parameter {}",
500                                param
501                            )));
502                        }
503                    }
504                }
505                TypeConstraint::Custom { checker, .. } => {
506                    if !checker(type_args) {
507                        return Err(JitError::CompilationError(
508                            "Custom constraint violation".to_string(),
509                        ));
510                    }
511                }
512                TypeConstraint::Equality { param1, param2 } => {
513                    // Find the types for both parameters
514                    let type1 = self.find_type_for_param(template, param1, type_args)?;
515                    let type2 = self.find_type_for_param(template, param2, type_args)?;
516
517                    if type1 != type2 {
518                        return Err(JitError::CompilationError(format!(
519                            "Type equality constraint violated: {} != {}",
520                            param1, param2
521                        )));
522                    }
523                }
524                TypeConstraint::Subtype { subtype, supertype } => {
525                    // Find the types for both parameters
526                    let sub_type = self.find_type_for_param(template, subtype, type_args)?;
527                    let super_type = self.find_type_for_param(template, supertype, type_args)?;
528
529                    if !self.is_subtype(&sub_type, &super_type) {
530                        return Err(JitError::CompilationError(format!(
531                            "Subtype constraint violated: {} is not a subtype of {}",
532                            subtype, supertype
533                        )));
534                    }
535                }
536            }
537        }
538
539        Ok(())
540    }
541
542    /// Find the type for a given parameter name
543    fn find_type_for_param(
544        &self,
545        template: &GenericFunctionTemplate,
546        param_name: &str,
547        type_args: &[TypeKind],
548    ) -> JitResult<TypeKind> {
549        for (i, param) in template.type_params.iter().enumerate() {
550            if param.name == param_name {
551                return Ok(type_args[i].clone());
552            }
553        }
554        Err(JitError::CompilationError(format!(
555            "Type parameter '{}' not found",
556            param_name
557        )))
558    }
559
560    /// Check if one type is a subtype of another
561    fn is_subtype(&self, sub: &TypeKind, sup: &TypeKind) -> bool {
562        // Simple subtype rules
563        match (sub, sup) {
564            // Same types are subtypes
565            (a, b) if a == b => true,
566            // Integer promotion: smaller signed -> larger signed
567            (TypeKind::I8, TypeKind::I16 | TypeKind::I32 | TypeKind::I64) => true,
568            (TypeKind::I16, TypeKind::I32 | TypeKind::I64) => true,
569            (TypeKind::I32, TypeKind::I64) => true,
570            // Unsigned integer promotion
571            (TypeKind::U8, TypeKind::U16 | TypeKind::U32 | TypeKind::U64) => true,
572            (TypeKind::U16, TypeKind::U32 | TypeKind::U64) => true,
573            (TypeKind::U32, TypeKind::U64) => true,
574            // Float promotion
575            (TypeKind::F16, TypeKind::F32 | TypeKind::F64) => true,
576            (TypeKind::F32, TypeKind::F64) => true,
577            // Complex promotion
578            (TypeKind::C64, TypeKind::C128) => true,
579            _ => false,
580        }
581    }
582
583    /// Check if a type satisfies a trait constraint
584    fn check_trait_constraint(&self, type_kind: &TypeKind, trait_name: &str) -> bool {
585        match trait_name {
586            "Float" => matches!(type_kind, TypeKind::F16 | TypeKind::F32 | TypeKind::F64),
587            "Integer" => matches!(
588                type_kind,
589                TypeKind::I8
590                    | TypeKind::I16
591                    | TypeKind::I32
592                    | TypeKind::I64
593                    | TypeKind::U8
594                    | TypeKind::U16
595                    | TypeKind::U32
596                    | TypeKind::U64
597            ),
598            "Numeric" => matches!(
599                type_kind,
600                TypeKind::I8
601                    | TypeKind::I16
602                    | TypeKind::I32
603                    | TypeKind::I64
604                    | TypeKind::U8
605                    | TypeKind::U16
606                    | TypeKind::U32
607                    | TypeKind::U64
608                    | TypeKind::F16
609                    | TypeKind::F32
610                    | TypeKind::F64
611            ),
612            "Complex" => matches!(type_kind, TypeKind::C64 | TypeKind::C128),
613            _ => false, // Unknown trait
614        }
615    }
616
617    /// Check if a shape satisfies a shape constraint
618    fn check_shape_constraint(&self, shape: &[usize], constraint: &ShapeConstraint) -> bool {
619        match constraint {
620            ShapeConstraint::Positive => shape.iter().all(|&dim| dim > 0),
621            ShapeConstraint::PowerOfTwo => shape.iter().all(|&dim| dim.is_power_of_two()),
622            ShapeConstraint::LessThan(limit) => shape.iter().all(|&dim| dim < *limit),
623            ShapeConstraint::GreaterThan(limit) => shape.iter().all(|&dim| dim > *limit),
624            ShapeConstraint::InRange(min, max) => {
625                shape.iter().all(|&dim| dim >= *min && dim <= *max)
626            }
627            ShapeConstraint::Equal(_param_name) => {
628                // For Equal constraint, we'd need to compare against another shape parameter
629                // For now, assume it's satisfied if the shape is valid
630                // A full implementation would look up the other parameter's value
631                !shape.is_empty()
632            }
633        }
634    }
635
636    /// Perform the actual instantiation of a template
637    fn perform_instantiation(
638        &self,
639        template: &GenericFunctionTemplate,
640        key: &InstantiationKey,
641    ) -> JitResult<IrModule> {
642        // Start with the template IR
643        let mut instantiated = template.template_ir.clone();
644        instantiated.name = format!("{}_{}", template.name, self.generate_mangled_name(key));
645
646        // Replace type parameters with concrete types
647        self.substitute_types(&mut instantiated, template, key)?;
648
649        // Apply generic-specific optimizations
650        self.optimize_instantiated_function(&mut instantiated)?;
651
652        Ok(instantiated)
653    }
654
655    /// Generate a mangled name for the instantiation
656    fn generate_mangled_name(&self, key: &InstantiationKey) -> String {
657        use std::collections::hash_map::DefaultHasher;
658        use std::hash::{Hash, Hasher};
659
660        let mut hasher = DefaultHasher::new();
661        key.hash(&mut hasher);
662        format!("{:x}", hasher.finish())
663    }
664
665    /// Substitute type parameters with concrete types
666    fn substitute_types(
667        &self,
668        module: &mut IrModule,
669        template: &GenericFunctionTemplate,
670        key: &InstantiationKey,
671    ) -> JitResult<()> {
672        // Create type substitution map
673        let mut type_map = HashMap::new();
674        for (param, type_arg) in template.type_params.iter().zip(key.type_args.iter()) {
675            type_map.insert(param.name.clone(), type_arg.clone());
676        }
677
678        // Substitute types in all values
679        for (_val_id, val_def) in module.values.iter_mut() {
680            // Update the type of the value if it references a type parameter
681            self.substitute_ir_type(&mut val_def.ty, &type_map)?;
682        }
683
684        // Substitute types in all instructions
685        for (_block_id, block) in module.blocks.iter_mut() {
686            for instruction in &mut block.instructions {
687                // Update instruction result type if present
688                if let Some(result) = instruction.result {
689                    if let Some(val_def) = module.values.get_mut(&result) {
690                        self.substitute_ir_type(&mut val_def.ty, &type_map)?;
691                    }
692                }
693            }
694        }
695
696        Ok(())
697    }
698
699    /// Substitute a single IR type
700    fn substitute_ir_type(
701        &self,
702        _ir_type: &mut crate::ir::IrType,
703        _type_map: &HashMap<String, TypeKind>,
704    ) -> JitResult<()> {
705        // In a full implementation, this would:
706        // 1. Check if the IR type references a type parameter
707        // 2. Look up the concrete type in type_map
708        // 3. Replace the type parameter with the concrete type
709
710        // This is a simplified placeholder as the actual implementation
711        // depends on the structure of IrType and how type parameters are represented
712        Ok(())
713    }
714
715    /// Apply optimizations specific to instantiated generic functions
716    fn optimize_instantiated_function(&self, module: &mut IrModule) -> JitResult<()> {
717        // Apply optimizations that benefit from concrete type information
718
719        // 1. Dead code elimination for unused branches
720        self.eliminate_dead_code_in_generics(module)?;
721
722        // 2. Constant folding with known type information
723        self.fold_constants_with_type_info(module)?;
724
725        // 3. Inlining small generic functions
726        self.inline_small_functions(module)?;
727
728        // 4. Type-specific optimizations
729        self.apply_type_specific_optimizations(module)?;
730
731        Ok(())
732    }
733
734    /// Eliminate dead code that becomes unreachable after instantiation
735    fn eliminate_dead_code_in_generics(&self, module: &mut IrModule) -> JitResult<()> {
736        use std::collections::HashSet;
737
738        // Track reachable blocks
739        let mut reachable = HashSet::new();
740        let mut worklist = vec![module.entry_block];
741
742        while let Some(block_id) = worklist.pop() {
743            if reachable.insert(block_id) {
744                // Add successor blocks to worklist
745                if let Some(_block) = module.blocks.get(&block_id) {
746                    // In a full implementation, we would analyze control flow
747                    // to find successor blocks and add them to the worklist
748                    // For now, we just mark the entry block as reachable
749                }
750            }
751        }
752
753        // Remove unreachable blocks
754        module
755            .blocks
756            .retain(|block_id, _| reachable.contains(block_id));
757
758        Ok(())
759    }
760
761    /// Fold constants using type-specific knowledge
762    fn fold_constants_with_type_info(&self, module: &mut IrModule) -> JitResult<()> {
763        use crate::ir::IrOpcode;
764
765        // Identify constant operations that can be folded
766        for (_block_id, block) in module.blocks.iter_mut() {
767            let mut folded_instructions = Vec::new();
768
769            for instruction in &block.instructions {
770                // Check if instruction operates on constants
771                match instruction.opcode {
772                    IrOpcode::Add | IrOpcode::Sub | IrOpcode::Mul | IrOpcode::Div => {
773                        // Would check if operands are constants and fold
774                        folded_instructions.push(instruction.clone());
775                    }
776                    _ => {
777                        folded_instructions.push(instruction.clone());
778                    }
779                }
780            }
781
782            // block.instructions = folded_instructions;
783        }
784
785        Ok(())
786    }
787
788    /// Inline small functions that are only called once
789    fn inline_small_functions(&self, _module: &mut IrModule) -> JitResult<()> {
790        // Track function call sites and inline small functions
791        // This is a simplified placeholder
792        Ok(())
793    }
794
795    /// Apply optimizations specific to the instantiated types
796    fn apply_type_specific_optimizations(&self, module: &mut IrModule) -> JitResult<()> {
797        use crate::ir::{IrOpcode, ValueKind};
798
799        // Apply optimizations based on the concrete types
800        for (_val_id, val_def) in &module.values {
801            match &val_def.kind {
802                ValueKind::Constant { .. } => {
803                    // Constant values can enable additional optimizations
804                }
805                _ => {}
806            }
807        }
808
809        // Type-specific optimizations:
810        // - For float types: enable fast-math optimizations
811        // - For integer types: use shift instead of multiply/divide by powers of 2
812        // - For complex types: optimize conjugate operations
813
814        for (_block_id, block) in module.blocks.iter_mut() {
815            for instruction in &mut block.instructions {
816                match instruction.opcode {
817                    IrOpcode::Mul => {
818                        // Could optimize to shift for integer power-of-2
819                    }
820                    IrOpcode::Div => {
821                        // Could optimize to shift for integer power-of-2
822                    }
823                    _ => {}
824                }
825            }
826        }
827
828        Ok(())
829    }
830
831    /// Estimate performance characteristics of an instantiated function
832    fn estimate_performance(&self, module: &IrModule) -> JitResult<GenericFunctionPerfInfo> {
833        let mut perf_info = GenericFunctionPerfInfo::default();
834
835        // Simple heuristics for performance estimation
836        let mut instruction_count = 0;
837        for (_, block) in &module.blocks {
838            instruction_count += block.instructions.len();
839        }
840
841        perf_info.estimated_exec_time_ns = instruction_count as u64 * 10; // ~10ns per instruction
842        perf_info.code_size = instruction_count * 4; // ~4 bytes per instruction
843        perf_info.register_usage = (instruction_count / 4).min(32) as u32; // Estimate register pressure
844        perf_info.memory_usage = instruction_count * 8; // Estimate memory usage
845
846        Ok(perf_info)
847    }
848
849    /// Get statistics about generic function usage
850    pub fn stats(&self) -> &GenericFunctionStats {
851        &self.stats
852    }
853
854    /// List all registered templates
855    pub fn list_templates(&self) -> Vec<&str> {
856        self.templates.keys().map(|s| s.as_str()).collect()
857    }
858
859    /// Get template by name
860    pub fn get_template(&self, name: &str) -> Option<&GenericFunctionTemplate> {
861        self.templates.get(name)
862    }
863
864    /// Clear all instantiations (for memory management)
865    pub fn clear_instances(&mut self) {
866        self.instances.clear();
867        self.stats.total_instantiations = 0;
868        self.stats.cache_hits = 0;
869        self.stats.cache_misses = 0;
870    }
871
872    /// Get the number of instantiations for a template
873    pub fn instantiation_count(&self, template_name: &str) -> usize {
874        self.instances
875            .keys()
876            .filter(|k| k.template_name == template_name)
877            .count()
878    }
879}
880
881/// Helper function to create a simple type parameter
882pub fn create_type_param(name: &str, kind: ParameterKind) -> TypeParameter {
883    TypeParameter {
884        name: name.to_string(),
885        kind,
886        default: None,
887        variance: Variance::Invariant,
888    }
889}
890
891/// Helper function to create a trait constraint
892pub fn trait_constraint(param: &str, trait_name: &str) -> TypeConstraint {
893    TypeConstraint::Trait {
894        param: param.to_string(),
895        trait_name: trait_name.to_string(),
896    }
897}
898
899/// Helper function to create a shape constraint
900pub fn shape_constraint(param: &str, constraint: ShapeConstraint) -> TypeConstraint {
901    TypeConstraint::Shape {
902        param: param.to_string(),
903        constraint,
904    }
905}
906
907#[cfg(test)]
908mod tests {
909    use super::*;
910
911    #[test]
912    fn test_generic_function_manager_creation() {
913        let manager = GenericFunctionManager::with_defaults();
914        assert_eq!(manager.templates.len(), 0);
915        assert_eq!(manager.instances.len(), 0);
916    }
917
918    #[test]
919    fn test_type_parameter_creation() {
920        let param = create_type_param("T", ParameterKind::Type);
921        assert_eq!(param.name, "T");
922        assert_eq!(param.kind, ParameterKind::Type);
923        assert_eq!(param.variance, Variance::Invariant);
924    }
925
926    #[test]
927    fn test_trait_constraint_creation() {
928        let constraint = trait_constraint("T", "Float");
929        match constraint {
930            TypeConstraint::Trait { param, trait_name } => {
931                assert_eq!(param, "T");
932                assert_eq!(trait_name, "Float");
933            }
934            _ => panic!("Expected trait constraint"),
935        }
936    }
937
938    #[test]
939    fn test_trait_constraint_checking() {
940        let manager = GenericFunctionManager::with_defaults();
941
942        // Float types should satisfy Float trait
943        assert!(manager.check_trait_constraint(&TypeKind::F32, "Float"));
944        assert!(manager.check_trait_constraint(&TypeKind::F64, "Float"));
945
946        // Integer types should not satisfy Float trait
947        assert!(!manager.check_trait_constraint(&TypeKind::I32, "Float"));
948
949        // Integer types should satisfy Integer trait
950        assert!(manager.check_trait_constraint(&TypeKind::I32, "Integer"));
951        assert!(manager.check_trait_constraint(&TypeKind::U64, "Integer"));
952    }
953
954    #[test]
955    fn test_shape_constraint_checking() {
956        let manager = GenericFunctionManager::with_defaults();
957
958        let positive_shape = vec![2, 4, 8];
959        let zero_shape = vec![0, 4, 8];
960        let power_of_two_shape = vec![2, 4, 8];
961        let non_power_of_two_shape = vec![3, 5, 7];
962
963        assert!(manager.check_shape_constraint(&positive_shape, &ShapeConstraint::Positive));
964        assert!(!manager.check_shape_constraint(&zero_shape, &ShapeConstraint::Positive));
965
966        assert!(manager.check_shape_constraint(&power_of_two_shape, &ShapeConstraint::PowerOfTwo));
967        assert!(
968            !manager.check_shape_constraint(&non_power_of_two_shape, &ShapeConstraint::PowerOfTwo)
969        );
970    }
971}