PHV::ActionPackingValidatorInterface Class Reference

#include <action_packing_validator_interface.h>

Inheritance diagram for PHV::ActionPackingValidatorInterface:

Classes
struct	Result

Public Member Functions
virtual Result	can_pack (const ordered_set< const SuperCluster::SliceList * > &slice_lists, const ordered_set< const SuperCluster::SliceList * > &can_be_further_split={}, const bool loose_mode=false) const =0

Detailed Description

PackingValidator is an interface type of classes that have a can_pack function to verify whether the packing will violate any constraint.

Member Function Documentation

can_pack()

virtual Result PHV::ActionPackingValidatorInterface::can_pack ( const ordered_set< const SuperCluster::SliceList * > & slice_lists, const ordered_set< const SuperCluster::SliceList * > & can_be_further_split = {}, const bool loose_mode = false ) const

pure virtual

can_pack returns Result with code::OK if slice_lists can be allocated to containers without being further split, and allocation will not violate action PHV constraints. If can_be_split_further is not empty, this function will further check that when slice_lists are allocated to containers without further split, can can_be_split_further be split and allocated successfully, by checking whether slices in the same byte (must be packed in one container) will violate any action phv constraint. contract: both slice_lists and can_be_split_further must contain fine-sliced PHV::Fieldslices, that any operation will only read or write one PHV::FieldSlice. All Slicelists in a super cluster satisfy this constraint. contract: no overlapping slice between slice_lists and can_be_further_split. when loose_mode is true, instructions are allowed to overwrite bytes of destination container that has unwritten fields slices. Although it usually means that the action cannot be be synthesized because live bits will be corrupted. However, because dest can be split further later to avoid corruption, it is sometimes useful to use loose_mode so that caller can solve the problem in a divide-and-conquer way.

Implemented in PHV::legacy::ActionPackingValidator, and PHV::v2::ActionPackingValidator.