SliceExtracts Struct Reference

Inheritance diagram for SliceExtracts:

Public Member Functions
	SliceExtracts (const PhvInfo &phv, const ClotInfo &clot, const CollectParserInfo &parser_info, const MapFieldToParserStates &field_to_states)
template<class Extract >
const Extract *	make_slice (const IR::BFN::Extract *extract, int le_low_idx, int width, int extract_base, std::optional< PHV::Container > cont=std::nullopt)
bool	preorder (IR::BFN::ParserState *state) override
std::vector< const IR::BFN::Extract * >	slice_extract (const IR::BFN::Extract *extract)

Public Attributes
const ClotInfo &	clot
const PhvInfo &	phv
const ParserQuery	pq
const IR::BFN::ParserState *	state = nullptr

Detailed Description

Slices each extract into multiple extracts that each write into a single PHV container or CLOT. This prepares for the subsequent state-splitting pass, where we may need to allocate the sliced extracts into different states (this is the case when field straddles the input-buffer boundary).

Member Function Documentation

make_slice()

template<class Extract >

const Extract * SliceExtracts::make_slice ( const IR::BFN::Extract * extract, int le_low_idx, int width, int extract_base, std::optional< PHV::Container > cont = std::nullopt )

inline

Rewrites an extract so that it extracts exactly the slice specified by le_low_idx and width, and marks the extract with the given extract type.

Parameters

extract	extract to be rewritten.
le_low_idx	the little-endian index for the low end of the slice.
width	the width of the slice, in bits.
extract_base	The low index of the extract destination ignoring slicing. For example, for extract inbuf bit[112..175] to ig_md.f[95:32], assume ig_md.f[95:64] and ig_md.f[63:32] are allocated to two 32-bit container. Two make_slice will be called. For the first make_slice, le_low_idx is 32, width is 32 and extract_base is 32. For the second make_slice, le_low_idx is 64, width is 32 and extract_base is 32.

slice_extract()

std::vector< const IR::BFN::Extract * > SliceExtracts::slice_extract ( const IR::BFN::Extract * extract )

inline

Breaks up an Extract into a series of Extracts according to the extracted field's PHV and CLOT allocation.