Class ov::MemorySolver

class MemorySolver

Helps to solve issue of optimal memory allocation only for particular execution order.

It works with abstract data description where

• Node is index in execution order

• Edge is Box object with size and start-finish indexes (live time)

Example:

Mem(offset) | |____| Box {4, 5} | |_____________| Box {2, 6} | |____| Box {3, 4} | |____| Box {2, 3} | |____| Box {6, 7} |_____________________________________ 1 2 3 4 5 6 7 8 9 ExecOrder

Boxes which has an ExecOrder-axis intersection should have no Mem-axis intersections. The goal is to define a minimal required memory blob to store all boxes with such constraints and specify all corresponding position on Mem axis(through offset field).

NOTE! Exec order is predefined.

Public Functions

inline int64_t solve()

Solve memory location with maximal reuse.

Returns

Size of common memory blob required for storing all

inline int64_t get_offset(int id) const

Provides calculated offset for specified box id

inline int64_t max_depth()

Additional info. Max sum of box sizes required for any time stamp.

inline int64_t max_top_depth()

Additional info. Max num of boxes required for any time stamp.

Public Static Functions

static inline int normalize_boxes(std::vector<Box> &boxes)

Performes inplace normalization of the input boxes.

Returns

lifespan of all boxes

struct Box

Representation of edge (size and live time)

Public Members

int start

Execution order index of first use. The data will be produced here.

int finish

The execution order index of last use. After that data will be released. -1 is a reserved value for “till to end”. The data will be alive to very end of execution.

int64_t size

Size of data. In abstract unit of measure (byte, simd, cache line, …)

int64_t id

Box identifier, unique for each box. Will be used to querying calculated offset.