ActionData::MeterALU Class Reference

#include <action_format.h>

Inheritance diagram for ActionData::MeterALU:

Public Member Functions
	MeterALU (cstring au, le_bitrange r)
void	dbprint (std::ostream &out) const override
bool	equiv_value (const Parameter *, bool check_cond=true) const override
bool	from_p4_program () const override
const Parameter *	get_extended_param (uint32_t extension, const Parameter *) const override
bool	is_next_bit_of_param (const Parameter *, bool) const override
cstring	name () const override
bool	only_one_overlap_solution () const override
const Parameter *	overlap (const Parameter *ad, bool only_one_overlap_solution, le_bitrange *my_overlap, le_bitrange *ad_overlap) const override
le_bitrange	range () const
int	size () const override
const Parameter *	split (int lo, int hi) const override
Public Member Functions inherited from ActionData::Parameter
virtual bool	can_merge (const Parameter *param) const
bool	can_overlap_ranges (le_bitrange my_range, le_bitrange ad_range, le_bitrange &overlap, le_bitrange *my_overlap, le_bitrange *ad_overlap) const
cstring	cond_name () const
bool	equiv_cond (const Parameter *p) const
template<typename T >
bool	is () const
bool	is_cond_type (ModConditionally_t type) const
virtual bool	is_subset_of (const Parameter *param) const
virtual const Parameter *	merge (const Parameter *param) const
void	set_cond (const Parameter *p)
void	set_cond (ModConditionally_t ct, cstring n)
template<typename T >
const T *	to () const
Public Member Functions inherited from P4::IHasDbPrint
void	print () const

Additional Inherited Members
Protected Attributes inherited from ActionData::Parameter
cstring	_cond_name
ModConditionally_t	_cond_type = NONE

Detailed Description

As in the name, this represents data that comes from the Meter/Stateful ALU directly, not meter color. LPF, WRED, and StatefulAlu operations directly write to the home row action bus when activated, and differ in meter color.

Similar to Meter Color, the position of the actual parameter is fixed in hardware on where the output will be appearing. However, because nothing besides the Meter ALU output is on that particular row, and is never packed with anything else, no padding is necessary.

See also

attached_output.cpp and create_meter_alu_RamSection for more details

Member Function Documentation

dbprint()

void ActionData::MeterALU::dbprint ( std::ostream & out ) const

inlineoverridevirtual

Implements ActionData::Parameter.

equiv_value()

bool ActionData::MeterALU::equiv_value ( const Parameter * ad, bool check_cond = true ) const

overridevirtual

Implements ActionData::Parameter.

from_p4_program()

bool ActionData::MeterALU::from_p4_program ( ) const

inlineoverridevirtual

Implements ActionData::Parameter.

get_extended_param()

const Parameter * ActionData::MeterALU::get_extended_param ( uint32_t extension, const Parameter *  ) const

overridevirtual

Implements ActionData::Parameter.

is_next_bit_of_param()

bool ActionData::MeterALU::is_next_bit_of_param ( const Parameter * ad, bool  ) const

overridevirtual

Implements ActionData::Parameter.

name()

cstring ActionData::MeterALU::name ( ) const

inlineoverridevirtual

Implements ActionData::Parameter.

only_one_overlap_solution()

bool ActionData::MeterALU::only_one_overlap_solution ( ) const

inlineoverridevirtual

Implements ActionData::Parameter.

overlap()

const Parameter * ActionData::MeterALU::overlap ( const Parameter * ad, bool only_one_overlap_solution, le_bitrange * my_overlap, le_bitrange * ad_overlap ) const

overridevirtual

Each action in a table is mutually exclusive, thus random externs that are used in different actions can share the same bits in the immediate, as these bits will be mutually exclusive. Random externs used in the same actions can not overlap, in order to guarantee that each random bit is unique.

Previously checked before this pass is run, a random extern can only be used once per action, as the infrastucture cannot tell what bits are supposed to be shared, vs. what bits will be different.

Bits that are not headed directly to an ALU operation can be overlaid:

action a1() { f1 = random1.get(); f2 = random2.get(); }

where f1 and f2 are two 4 bit fields in different 8 bit containers. In this case, because the random numbers output byte by byte, each random number impact is actually 8 bits. But because each of these operands only use 4 bits, each random number can overlap with each other.

Because these bits can always overlap, just return the max size position

Implements ActionData::Parameter.

size()

int ActionData::MeterALU::size ( ) const

inlineoverridevirtual

Implements ActionData::Parameter.

split()

const Parameter * ActionData::MeterALU::split ( int lo, int hi ) const

overridevirtual

Implements ActionData::Parameter.