Public Types
enum class	OpInfo { DEAD , READ , WRITE , READ_WRITE , LIVE }

Public Member Functions
bool	can_overlay (const LiveRangeInfo &other) const

OpInfo &	deparser ()

const OpInfo &	deparser () const

std::vector< LiveRange >	disjoint_ranges () const

OpInfo &	parser ()

const OpInfo &	parser () const

OpInfo &	stage (int i)

const OpInfo &	stage (int i) const

const safe_vector< OpInfo > &	vec () const

Static Public Member Functions
static std::vector< LiveRange >	merge_invalid_ranges (const std::vector< LiveRange > &ranges)

static void	set_num_table_stages (int stage)

Member Function Documentation

◆ can_overlay()

bool PHV::LiveRangeInfo::can_overlay ( const LiveRangeInfo & other ) const

Returns: true when this and other can be overlaid, defined as: (1) For any stage s, at least one of OpInfo at s of this or other is dead. (2) Except for the write-after-read case that: For example P 0 1 2 3 4 D A W L L R D D D B D D D W L L R A and B can be overlaid because the Write at stage 2 of B actually happens after the Read of A at stage 2, i.e., for write, we require Dead in the next stage, instead of the corresponding stage. Note that, we cannot overlay in this case: P 0 1 2 3 4 D A W L L R D D D B D D W RW L L R TODO: we do not need to use this function during PHV allocation because AllocSlices already have the presice live range info already. This function is kept here for future overlay analysis before PHV allocation.

std::vector< LiveRange > PHV::LiveRangeInfo::disjoint_ranges ( ) const

Returns: a vector of disjoint live ranges. For example P 0 1 2 3 4 ... D Foo W R D W L L L R Foo.disjoint_ranges() = [(-1W, 0R), (2W, 12R)] // if tofino stage of parse is -1, mau stages starts from 0 and deparser is device::max_stage(). Uninitialized reads, that are not caught by parser implicit init or when auto-init-metadata are not enabled, will have a short live range [xR, xR]. These short live ranges should be treated as overlayable to any other live ranges. contract: for every paired def and use, all stages in between are marked as LIVE. NOTE: Even if IDs of units seem to be using the same schema as min-stage-based StageAndAccess, they are not. The previous StageAndAccess use max_min_stage + 1 as deparser, which was very error-prone because dependency graph can be changed.

std::vector< LiveRange > PHV::LiveRangeInfo::merge_invalid_ranges ( const std::vector< LiveRange > & ranges )

static

Returns: a new vector of live ranges that consecutive invalid live ranges will be merged into one. For example, {(1R, 1R), (2R, 2R), (5R, 5R), (6W, 10R)} => {(1R, 5R), (6W, 10R)} {(1R, 1W), (2W, 2W), (3W, 3W)} => {(1R, 1W), (2W, 3W)} premise: ranges must be disjoint and sorted in increasing order of LiveRange. a compiler BUG will be thrown if not satisfied.

static void PHV::LiveRangeInfo::set_num_table_stages ( int stage )

inlinestatic

Record the number of table stages in use

Minimum size is Device::numStages()

const safe_vector< OpInfo > & PHV::LiveRangeInfo::vec ( ) const

inline