#ifndef HALIDE_INLINE_REDUCTIONS_H
#define HALIDE_INLINE_REDUCTIONS_H
#include "IR.h"
#include "RDom.h"
#include "Tuple.h"
/** \file
* Defines some inline reductions: sum, product, minimum, maximum.
*/
namespace Halide {
/** An inline reduction. This is suitable for convolution-type
* operations - the reduction will be computed in the innermost loop
* that it is used in. The argument may contain free or implicit
* variables, and must refer to some reduction domain. The free
* variables are still free in the return value, but the reduction
* domain is captured - the result expression does not refer to a
* reduction domain and can be used in a pure function definition.
*
* An example using \ref sum :
*
\code
Func f, g;
Var x;
RDom r(0, 10);
f(x) = x*x;
g(x) = sum(f(x + r));
\endcode
*
* Here g computes some blur of x, but g is still a pure function. The
* sum is being computed by an anonymous reduction function that is
* scheduled innermost within g.
*/
//@{
EXPORT Expr sum(Expr, const std::string &s = "sum");
EXPORT Expr product(Expr, const std::string &s = "product");
EXPORT Expr maximum(Expr, const std::string &s = "maximum");
EXPORT Expr minimum(Expr, const std::string &s = "minimum");
//@}
/** Variants of the inline reduction in which the RDom is stated
* explicitly. The expression can refer to multiple RDoms, and only
* the inner one is captured by the reduction. This allows you to
* write expressions like:
\code
RDom r1(0, 10), r2(0, 10), r3(0, 10);
Expr e = minimum(r1, product(r2, sum(r3, r1 + r2 + r3)));
\endcode
*/
// @{
EXPORT Expr sum(RDom, Expr, const std::string &s = "sum");
EXPORT Expr product(RDom, Expr, const std::string &s = "product");
EXPORT Expr maximum(RDom, Expr, const std::string &s = "maximum");
EXPORT Expr minimum(RDom, Expr, const std::string &s = "minimum");
// @}
/** Returns an Expr or Tuple representing the coordinates of the point
* in the RDom which minimizes or maximizes the expression. The
* expression must refer to some RDom. Also returns the extreme value
* of the expression as the last element of the tuple. */
// @{
EXPORT Tuple argmax(Expr, const std::string &s = "argmax");
EXPORT Tuple argmin(Expr, const std::string &s = "argmin");
EXPORT Tuple argmax(RDom, Expr, const std::string &s = "argmax");
EXPORT Tuple argmin(RDom, Expr, const std::string &s = "argmin");
// @}
}
#endif