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FastIntegerDivide.h
Go to the documentation of this file.
#ifndef HALIDE_FAST_INTEGER_DIVIDE_H
#define HALIDE_FAST_INTEGER_DIVIDE_H
#include "Buffer.h"
#include "Expr.h"
namespace Halide {
/** Integer division by small values can be done exactly as multiplies
* and shifts. This function does integer division for numerators of
* various integer types (8, 16, 32 bit signed and unsigned)
* numerators and uint8 denominators. The type of the result is the
* type of the numerator. The unsigned version is faster than the
* signed version, so cast the numerator to an unsigned int if you
* know it's positive.
*
* If your divisor is compile-time constant, Halide performs a
* slightly better optimization automatically, so there's no need to
* use this function (but it won't hurt).
*
* This function vectorizes well on arm, and well on x86 for 16 and 8
* bit vectors. For 32-bit vectors on x86 you're better off using
* native integer division.
*
* Also, this routine treats division by zero as division by
* 256. I.e. it interprets the uint8 divisor as a number from 1 to 256
* inclusive.
*/
Expr fast_integer_divide(const Expr &numerator, const Expr &denominator);
/** A variant of the above which rounds towards zero instead of rounding towards
* negative infinity. */
Expr fast_integer_divide_round_to_zero(const Expr &numerator, const Expr &denominator);
/** Use the fast integer division tables to implement a modulo
* operation via the Euclidean identity: a%b = a - (a/b)*b
*/
Expr fast_integer_modulo(const Expr &numerator, const Expr &denominator);
} // namespace Halide
#endif
Buffer.h
Expr.h
Base classes for Halide expressions (Halide::Expr) and statements (Halide::Internal::Stmt).
Halide
This file defines the class FunctionDAG, which is our representation of a Halide pipeline,...
Definition AbstractGenerator.h:19
Halide::fast_integer_modulo
Expr fast_integer_modulo(const Expr &numerator, const Expr &denominator)
Use the fast integer division tables to implement a modulo operation via the Euclidean identity: ab =...
Halide::fast_integer_divide
Expr fast_integer_divide(const Expr &numerator, const Expr &denominator)
Integer division by small values can be done exactly as multiplies and shifts.
Halide::fast_integer_divide_round_to_zero
Expr fast_integer_divide_round_to_zero(const Expr &numerator, const Expr &denominator)
A variant of the above which rounds towards zero instead of rounding towards negative infinity.
Halide::Expr
A fragment of Halide syntax.
Definition Expr.h:258