BFN::IdentifyPovMergeTargets Class Reference

Identify POV bits that can be merged. More...

Inheritance diagram for BFN::IdentifyPovMergeTargets:

Public Member Functions
	IdentifyPovMergeTargets (const PhvInfo &phv, const CollectParserInfo &parser_info, const HeaderValidityAnalysis &hva, ordered_map< const PHV::Field *, const PHV::Field * > &merge_pov)

Protected Member Functions
void	end_apply () override
Visitor::profile_t	init_apply (const IR::Node *root) override
bool	preorder (const IR::BFN::Extract *e) override

Protected Attributes
const HeaderValidityAnalysis &	hva
ordered_map< const PHV::Field *, const PHV::Field * > &	merge_pov
const CollectParserInfo &	parser_info
const PhvInfo &	phv
ordered_map< const PHV::Field *, std::set< const IR::BFN::ParserState * > >	pov_states
std::set< const PHV::Field * >	pov_zero_writes
ordered_map< const IR::BFN::ParserState *, ordered_set< const PHV::Field * > >	state_povs

Detailed Description

Identify POV bits that can be merged.

Two POV bits can be merged if the headers are always extracted together, and if their validity remains in sync in MAU (always invalidated/validated together). The extractions can occur in the same state or in consecutive states.

FIXME: Handle headers that are not extracted but which are made valid in MAU.