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
|
.. meta::
:description: MIGraphX internal matchers
:keywords: MIGraphX, code base, contribution, developing, matchers
Matchers
========
Introduction
------------
The matchers provide a way to compose several predicates together. A matcher such as ``m(m1, m2)`` first checks a match for ``m`` followed by a match for ``m1`` and ``m2`` subsequently.
The most commonly used matcher is the ``name`` matcher. It matches the instruction with the operator equal to the name specified::
auto match_sum = name("sum");
The above matcher finds ``sum`` operators. To find ``sum`` operators with the output ``standard_shape``, use:
auto match_sum = name("sum")(standard_shape());
Arguments
---------
To match arguments in the instructions, match each argument using the ``arg`` matcher::
auto match_sum = name("sum")(arg(0)(name("@literal"), arg(1)(name("@literal"))));
The above matcher matches a ``sum`` operator with two arguments that are literals. Note that the ``args`` matcher eliminates the need to write ``arg(0)`` and ``arg(1)`` everytime::
auto match_sum = name("sum")(args(name("@literal"), name("@literal")));
Binding
-------
To reference other instructions encountered while traversing through the instructions, use ``.bind``::
auto match_sum = name("sum")(args(
name("@literal").bind("one"),
name("@literal").bind("two")
)).bind("sum");
This associates the instruction to a name that can be read from the ``matcher_result`` when it matches.
Finding matches
---------------
To use the matchers to find instructions, write a callback object that contains the matcher and an ``apply`` function that takes the ``matcher_result`` when the match is found::
struct match_find_sum
{
auto matcher() const { return name("sum"); }
void apply(program& p, matcher_result r) const
{
// Do something with the result
}
};
find_matches(prog, match_find_sum{});
Creating matchers
-----------------
The macros ``MIGRAPH_BASIC_MATCHER`` and ``MIGRAPH_PRED_MATCHER`` help in the creation of the matchers. Here is how you can create a matcher for shapes that are broadcasted::
MIGRAPH_PRED_MATCHER(broadcasted_shape, instruction_ref ins)
{
return ins->get_shape().broadcasted();
}
For parameters to the predicate, use ``make_basic_pred_matcher`` to create the matcher. Here is how you can create a matcher to check the number of dimensions of the shape::
inline auto number_of_dims(std::size_t n)
{
return make_basic_pred_matcher([=](instruction_ref ins) {
return ins->get_shape().lens().size() == n;
});
}
|
