http://atnd.org/events/11551

1. Boost.Proto
Boost. #4 2011/02/26
/@fjnli id:fjnl
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2. Twitter ( ) ...
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3. http://atnd.org/events/11551
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4. http://atnd.org/events/11551
Proto
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5. http://atnd.org/events/11551
Proto
Lambda, Spirit, uBLAS
Proto
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6. Boost.Proto
4

7. Boost. #4
Proto ( )
Proto
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8. Agenda
•
• Boost.Proto
•
• +
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9. Agenda
•
• Boost.Proto
•
• +
6

10. Agenda
•
15
• Boost.Proto
5
•
• +
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11. Agenda
• Boost.Proto
• Boost.Proto
• Expression Template (ET)
• Boost.Proto
7

12. Agenda
•
• Boost.Proto
• Boost.uBLAS
• General Purpose computing on GPU (GPGPU)
• ET →
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13. • ( )
• @fjnli, id:fjnl
• → ( )
• Ariel Networks
• : GPU
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14. • ( )
• @fjnli, id:fjnl
• →
Hatena ID i
( )
• Ariel Networks
• : GPU
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15. • ( )
• @fjnli, id:fjnl
• →
Hatena ID
※
i
( )
• Ariel Networks
• : GPU
9

16. • ( )
• @fjnli, id:fjnl
• → ( )
• Ariel Networks
• : GPU
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17. .begin();
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18. Proto
• Expression Template (ET)
• a + b * c → plus<A, multiply<B, C>>
• Boost 1.37
• Headers only
12

19. Proto
• Boost.Proto
• Boost Boost.Proto :
• Boost.Spirit (Qi, Karma, Lex)
• Boost.Phoenix v3 (in the future)
• Boost.MSM.eUML (experimental, 1.44)
• Boost.Xpressive
13

20. ET
•
•
• ´ ω
• Qi Proto
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21. using
namespace proto = boost::proto;
using namespace boost::proto;
using boost::proto::argsns_::list2,
using boost::proto::exprns_::expr;
using boost::proto::exprns_::term;
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22. a[b] + (c * d)
(Syntax Tree) :
16

23. a[b] + (c * d)
(Syntax Tree) :
(+)
([]) (*)
a b c d
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24. a[b] + (c * d)
expr<tag::plus,
list2<
expr<tag::subscript,
list2<,
expr<tag::terminal, term<int>, 0>&,
expr<tag::terminal, term<int>, 0>&
>, 2
> const&,
expr<tag::multiplies,
list2<
expr<tag::terminal, term<int> 0>&,
expr<tag::terminal, term<int> 0>&
>, 2
> const&
>, 2
> const
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25. a[b] + (c * d)
expr<tag::plus,
list2<
expr<tag::subscript, expr
exprns_::
list2<,
expr<tag::terminal, term<int>, 0>&,
expr<tag::terminal, term<int>, 0>&
>, 2
> const&,
expr<tag::multiplies,
list2<
expr<tag::terminal, term<int> 0>&,
expr<tag::terminal, term<int> 0>&
>, 2
> const&
>, 2
> const
18

26. a[b] + (c * d)
expr<tag::plus,
list2< plus → +
expr<tag::subscript,
multiplies → *
list2<,
expr<tag::terminal, subscript → []
term<int>, 0>&,
expr<tag::terminal, term<int>, 0>& …
>, 2
> const&,
expr<tag::multiplies,
list2<
expr<tag::terminal, term<int> 0>&,
expr<tag::terminal, term<int> 0>&
>, 2
> const&
>, 2
> const
19

27. a[b] + (c * d)
expr<tag::plus,
list2<
expr<tag::subscript,
list2<, argsns_::listN
expr<tag::terminal, term<int>, 0>&,
expr<tag::terminal, term<int>, 0>&
>, 2
> const&,
expr<tag::multiplies,
list2<
expr<tag::terminal, term<int> 0>&,
expr<tag::terminal, term<int> 0>&
>, 2
> const&
>, 2
> const
20

28. a[b] + (c * d)
expr<tag::plus,
list2<
expr<tag::subscript, exprns_::term
list2<,
expr<tag::terminal, term<int>, 0>&,
expr<tag::terminal, term<int>, 0>&
>, 2
> const&,
expr<tag::multiplies,
list2<
expr<tag::terminal, term<int> 0>&,
expr<tag::terminal, term<int> 0>&
>, 2
> const&
>, 2
> const
21

29. a[b] + (c * d)
expr<tag::plus,
list2<
expr<tag::subscript,
list2<,
expr<tag::terminal, term<int>, 0>&,
expr<tag::terminal, term<int>, 0>&
>, 2
> const&,
expr<tag::multiplies,
list2<
expr<tag::terminal, term<int> 0>&,
expr<tag::terminal, term<int> 0>&
>, 2
> const&
>, 2
> const
22

30. :
default_context const ctx;
std::cout << eval(lit(1) + 2 + 3, ctx)
<< std::endl;
:
6
23

31. :
default_context const ctx;
std::cout << eval(lit(1) + 2 + 3, ctx)
<< std::endl;
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32. default_context → C++
null_context →
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33. + -
•x + y x-y
• int +
•→
26

34. + -
struct my_context {
template <
class Expr,
class Enable = void
> struct eval;
};
eval
my_context::eval<Expr>()(expr, ctx)
27

35. + -
struct my_context {
template <
class Expr,
class Enable = void
> struct eval;
SFINAE
};
eval
my_context::eval<Expr>()(expr, ctx)
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36. SFINAE
• SFINAE ( ?)
• Substitution Failure Is Not An Error
•
• boost::enable_if
•template <class T>
typename enable_if<is_const<T>>::type foo();
• SFINAE eval
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37. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, terminal<int>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, my_context const&)
const {
return value(e);
}
}
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38. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, terminal<int>>
>::type
> { proto :
typedef int result_type;
Expr terminal<int>
result_type true
operator ()(Expr& e, my_context const&)
const {
return value(e);
}
}
30

39. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, terminal<int>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, C++0x
my_context const&)
decltype
const {
return value(e);
}
}
31

40. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, terminal<int>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, my_context const&)
const {
return value(e);
}
}
32

41. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, terminal<int>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, my_context const&)
const {
return value(e);
}
}
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42. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, plus<_, _>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, my_context const& ctx)
const {
return proto::eval(left(e), ctx) -
proto::eval(right(e), ctx);
}
}
34

43. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, plus<_, _>>
>::type
> { _
typedef int result_type; (wildcard)
result_type
operator ()(Expr& e, my_context const& ctx)
const {
return proto::eval(left(e), ctx) -
proto::eval(right(e), ctx);
}
}
35

44. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, plus<_, _>>
>::type
> {
typedef int result_type;
left: 1
result_type
right: 2
operator ()(Expr& e, my_context const& ctx)
const {
return proto::eval(left(e), ctx) -
proto::eval(right(e), ctx);
}
}
36

45. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, plus<_, _>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, my_context const& ctx)
const {
return proto::eval(left(e), ctx) -
proto::eval(right(e), ctx);
}
}
37

46. + -
template <class Expr>
struct eval<
Expr,
typename boost::enable_if<
matches<Expr, plus<_, _>>
>::type
> {
typedef int result_type;
result_type
operator ()(Expr& e, my_context const& ctx)
const {
return proto::eval(left(e), ctx) -
proto::eval(right(e), ctx);
}
}
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47. 2
:
my_context const ctx;
std::cout << eval(lit(1) + 2 + 3, ctx)
<< std::endl;
:
-4
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48. /
• :
• proto::left, proto::right
• :
• proto::result_of::left, proto::result_of::right
• C++0x
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49. • Context
•
• Domain
•
• Extends
•
• Grammer
•
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50. :
1.User’s Guide
http://www.boost.org/doc/libs/1_46_0/doc/html/proto/
users_guide.html
2. (C++ Advent Calender JP 2010; 16 )
http://d.hatena.ne.jp/fjnl/20101222/
42

51. .end();
.begin();
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52. Proto
• ET
•
•
• (+ )
•( )
• Basic Linear Algebra Subprograms (BLAS)
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53. Boost.uBLAS
• Boost.uBLAS
• Boost.uBLAS
• Boost.uBLAS
45

54. Boost.uBLAS
• CPU, GPU
• →
• CPU GPU
• :
•
• CPU: , ATLAS, GotoBLAS, OpenCL
• GPU: , CUBLAS, OpenCL
46

55. ET →
Backend::scalar a;
Backend::vector b, x, y;
y = a * x + b;
Backend::eval<
multiply, scalar, vector>()(y, a, x);
Backend::eval<
plus, vector, vector>()(y, y, b);
47

56. (Cell, GPU )
[a * x + y]
plus<multiply<scalar, vector>, vector>
axpy<scalar, vector, vector>
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57. 49