1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136

use std::{any::TypeId, collections::HashMap, sync::Mutex};

use dyn_clone::DynClone;
use once_cell::sync::Lazy;

use crate::{backend::Cpu, primitives, Backend, Primitive, Tensor};

pub trait Eval<B, P>: DynClone + Sync + Send + 'static
where
    B: ?Sized,
    P: ?Sized,
{
    fn eval(&self, backend: &B, primitive: &P, inputs: &[Tensor], output: &Tensor);
}
dyn_clone::clone_trait_object!(<B, P> Eval<B, P> where B: ?Sized, P: ?Sized);

#[derive(Debug, Clone)]
pub struct Dispatch<B, P> {
    phantom: std::marker::PhantomData<(B, P)>,
}

impl<B, P> Eval<dyn Backend, dyn Primitive> for Dispatch<B, P>
where
    B: Backend + 'static + Sync + Send,
    P: Primitive + 'static + Sync + Send,
    Self: Eval<B, P> + 'static,
{
    #[inline]
    fn eval(
        &self,
        backend: &dyn Backend,
        primitive: &dyn Primitive,
        inputs: &[Tensor],
        output: &Tensor,
    ) {
        let backend = backend.as_any().downcast_ref::<B>().unwrap();
        let primitive = primitive.as_any().downcast_ref::<P>().unwrap();
        self.eval(backend, primitive, inputs, output);
    }
}

impl<B, P> Eval<Box<dyn Backend>, Box<dyn Primitive>> for Dispatch<B, P>
where
    B: Backend + 'static + Sync + Send,
    P: Primitive + 'static + Sync + Send,
    Self: Eval<B, P> + 'static,
{
    #[inline]
    fn eval(
        &self,
        backend: &Box<dyn Backend>,
        primitive: &Box<dyn Primitive>,
        inputs: &[Tensor],
        output: &Tensor,
    ) {
        let backend = backend.as_any().downcast_ref::<B>().unwrap();
        let primitive = primitive.as_any().downcast_ref::<P>().unwrap();
        self.eval(backend, primitive, inputs, output);
    }
}

type ErasedEval = Box<dyn Eval<dyn Backend, dyn Primitive>>;

static EVAL_DISPATCHER: Lazy<Mutex<HashMap<(TypeId, TypeId), ErasedEval>>> = Lazy::new(|| {
    let mut rules: HashMap<(TypeId, TypeId), ErasedEval> = HashMap::new();

    // creation
    _register::<Cpu, primitives::Full>(&mut rules);
    _register::<Cpu, primitives::Normal>(&mut rules);
    _register::<Cpu, primitives::Arange>(&mut rules);
    // binary
    _register::<Cpu, primitives::Add>(&mut rules);
    _register::<Cpu, primitives::Sub>(&mut rules);
    _register::<Cpu, primitives::Mul>(&mut rules);
    _register::<Cpu, primitives::Div>(&mut rules);
    _register::<Cpu, primitives::MatMul>(&mut rules);
    // unary
    _register::<Cpu, primitives::Sin>(&mut rules);
    _register::<Cpu, primitives::Cos>(&mut rules);
    _register::<Cpu, primitives::Negative>(&mut rules);
    _register::<Cpu, primitives::Square>(&mut rules);
    _register::<Cpu, primitives::Sqrt>(&mut rules);
    _register::<Cpu, primitives::Rsqrt>(&mut rules);
    _register::<Cpu, primitives::Sign>(&mut rules);
    _register::<Cpu, primitives::Abs>(&mut rules);
    _register::<Cpu, primitives::Exp>(&mut rules);
    // transform
    _register::<Cpu, primitives::Transpose>(&mut rules);
    _register::<Cpu, primitives::Reshape>(&mut rules);
    _register::<Cpu, primitives::Broadcast>(&mut rules);
    // reduce
    _register::<Cpu, primitives::ReduceSum>(&mut rules);

    Mutex::new(rules)
});

pub fn register<B, P>()
where
    B: Backend + 'static + Sync + Send,
    P: Primitive + 'static + Sync + Send,
    Dispatch<B, P>: Eval<B, P> + 'static,
{
    let mut rules = EVAL_DISPATCHER.lock().unwrap();
    _register::<B, P>(&mut rules)
}

pub fn register_custom<B, P, R>(rule: R)
where
    B: Backend + 'static + Sync + Send,
    P: Primitive + 'static + Sync + Send,
    R: Eval<B, P> + 'static + Eval<dyn Backend, dyn Primitive>,
{
    let mut rules = EVAL_DISPATCHER.lock().unwrap();
    rules.insert((TypeId::of::<B>(), TypeId::of::<P>()), Box::new(rule));
}

pub fn eval_rule(backend: &dyn Backend, primitive: &dyn Primitive) -> Option<ErasedEval> {
    let rules = EVAL_DISPATCHER.lock().unwrap();
    rules
        .get(&(backend.as_any().type_id(), primitive.as_any().type_id()))
        .cloned()
}

fn _register<B, P>(rules: &mut HashMap<(TypeId, TypeId), ErasedEval>)
where
    B: Backend + 'static + Sync + Send,
    P: Primitive + 'static + Sync + Send,
    Dispatch<B, P>: Eval<B, P> + 'static,
{
    rules.insert(
        (TypeId::of::<B>(), TypeId::of::<P>()),
        Box::new(Dispatch {
            phantom: std::marker::PhantomData::<(B, P)>,
        }),
    );
}