decaf : a deparser optimization of copy assigned fields More...

Collaboration diagram for DeparserCopyOpt:

Classes
struct	Assign

class	AssignChain

struct	CollectHeaderValidity

class	CollectWeakFields

class	ComputeValuesAtDeparser

class	CreateConstants

class	DeparserCopyOpt
	Top level PassManager. More...

struct	FieldGroup

class	RewriteDeparser

class	RewriteWeakFieldWrites

class	SynthesizePovEncoder

struct	Value

struct	VersionMap

Detailed Description

decaf : a deparser optimization of copy assigned fields

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

SPDX-License-Identifier: Apache-2.0

author: zhao ma

The observation is that there is a high degree of data movement in many common data-plane program patterns (e.g. tunneling, label switching), i.e. a large number of fields participate in copy assignment only. These are the fields whose final value is that of another such copied only field.

Based on this observation, we devise an optimization to resolve data copies directly in the deparser rather than using the MAU to move the data, costing normal PHV containers.

Consider the program below:

 action a1() { modify_field(data.a, data.b); }
 action a2() { modify_field(data.a, 0x0800); }
 action a3() { modify_field(data.a, data.c); }
 table t1 {
     reads { data.m : exact; }
     actions { a1; a2; a3; nop; }
 }
 action a4() { modify_field(data.b, data.a); }
 action a5() { modify_field(data.b, 0x0866); }
 table t2 {
     reads { data.k : exact; }
     actions { a4; a5; nop; }
 }
 control ingress {
     apply(t1);
     apply(t2);
 }

The possible values for each field (and reaching action sequence) are:

 data.a : v0: 0x0800:   t1.a2 -> *
          v1: data.b:   t1.a1 -> *
          v2: data.c:   t1.a3 -> *
          v3: data.a:  t1.nop -> *
 data.b : v0: 0x0800:  t1.a2 -> t2.a4
          v1: 0x0866:      * -> t2.a5
          v2: data.a: t1.nop -> t2.a4
          v3: data.c:  t1.a3 -> t2.a4
          v4: data.b:  t1.a1 -> t2.nop
 data.c : data.c (read-only)

Let's assign a bit to each action, and another bit to each version for a field's final value. The function between the action bits and version bits can be represented as a truth table.

 a1  a2  a3  a4  a5 | a_v0 a_v1 a_v2 a_v3  b_v0 b_v1 b_v2 b_v3 b_v4
 -------------------------------------------------------------------
 1   0   0   0   0  | 0    1    0    0     0    0    0    0    1
 0   1   0   0   0  | 1    0    0    0     0    0    0    0    1
 0   0   1   0   0  | 0    1    0    1     0    0    0    0    1
 0   1   0   1   0  | 1    0    0    0     1    0    0    0    0
 0   0   0   0   1  | 0    0    0    1     0    1    0    0    0
   ...
   ...

Conveniently, the truth table can be implemented in Tofino as a match action table (using static entries). The version bits are wired to the FD as POV bits for the deparser to disambiguate which version to use for each field to reconstruct final packet, and with each version allocated to its own FD entry. Finally, all versions of value can be parsed into tagalong containers.

TODO

Tagalong containers, though abundant, are not unlimited. In addition, other resources also need to be managed. The list below is all resources need to be managed in the order of scarcity (most scarce to least). We need to make sure we don't over-fit any of these. Given a list of fields that can be decaf'd, we need to establish a partial order between any two fields such that one requires less resource than the other.

tagalong PHV space (2k bits, half of normal PHV)
POV bits (128 bits per gress)
Parser constant extract (each state has 4xB, 2xH, 2xW constant extract bandwidth)
Table resources (logical ID, memory)
FD entries (abundant)

Class Documentation

◆ Assign

struct Assign

Public Member Functions
	Assign (const IR::MAU::Instruction instr, const PHV::Field dst, const IR::Constant *src)

	Assign (const IR::MAU::Instruction instr, const PHV::Field dst, const PHV::Field *src)

std::string	print () const

Public Attributes
const PHV::Field *	dst

const IR::MAU::Instruction *	instr = nullptr

const Value *	src

◆ AssignChain

class AssignChain

Inheritance diagram for AssignChain:

[legend]

Public Member Functions
bool	contains (const IR::MAU::Instruction *instr) const

void	push_front (const Assign *assign)

◆ CollectHeaderValidity

struct CollectHeaderValidity

Inheritance diagram for CollectHeaderValidity:

[legend]

Public Member Functions
	CollectHeaderValidity (const PhvInfo &phv)

void	dbprint (std::ostream &out) const

void	end_apply () override

const IR::Expression *	get_valid_bit_expr (const PHV::Field *f) const

bool	preorder (const IR::BFN::Emit *emit) override

bool	preorder (const IR::MAU::Instruction *instr) override

Public Member Functions inherited from P4::Inspector
const IR::Node *	apply_visitor (const IR::Node , const char name=0) override

profile_t	init_apply (const IR::Node *root) override

virtual void	loop_revisit (const IR::Node *)

virtual void	postorder (const IR::Node *)

virtual bool	preorder (const IR::Node *)

virtual void	revisit (const IR::Node *)

void	revisit_visited ()

bool	visit_in_progress (const IR::Node *n) const

void	visitAgain () const override

void	visitOnce () const override

Public Member Functions inherited from P4::Visitor
virtual bool	check_global (cstring)

virtual void	clear_globals ()

virtual Visitor *	clone () const

virtual ControlFlowVisitor *	controlFlowVisitor ()

virtual void	end_apply (const IR::Node *root)

virtual void	erase_global (cstring)

template<class T >
const T *	findContext () const

template<class T >
const T *	findContext (const Context *&c) const

template<class T >
const T *	findOrigCtxt () const

template<class T >
const T *	findOrigCtxt (const Context *&c) const

virtual Visitor &	flow_clone ()

virtual void	flow_merge (Visitor &)

virtual bool	flow_merge_closure (Visitor &)

virtual void	flow_merge_global_from (cstring)

virtual void	flow_merge_global_to (cstring)

const Context *	getChildContext () const

int	getChildrenVisited () const

const Context *	getContext () const

int	getContextDepth () const

const IR::Node *	getCurrentNode () const

template<class T >
const T *	getCurrentNode () const

const IR::Node *	getOriginal () const

template<class T >
const T *	getOriginal () const

template<class T >
const T *	getParent () const

virtual bool	has_flow_joins () const

profile_t	init_apply (const IR::Node root, const Context parent_context)

bool	isInContext (const IR::Node *n) const

virtual const char *	name () const

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name=0)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name=0)

void	print_context () const

const Visitor &	setCalledBy (const Visitor *visitor)

void	setName (const char *name)

void	visit (const IR::Node &n, const char *name, int cidx)

void	visit (const IR::Node &n, const char *name=0)

void	visit (const IR::Node &n, const char name, int cidx)

void	visit (const IR::Node &n, const char name=0)

void	visit (const IR::Node const &n, const char name, int cidx)

void	visit (const IR::Node const &n, const char name=0)

void	visit (IR::Node &n, const char *name, int cidx)

void	visit (IR::Node &n, const char *name=0)

void	visit (IR::Node &, const char =0, int=0)

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T> && !std::is_pointer_v<T>>, class... Args>
void	warn (const int kind, const char *format, const T &node, Args &&...args)
	The const ref variant of the above.

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T>>, class... Args>
void	warn (const int kind, const char format, const T node, Args &&...args)

bool	warning_enabled (int warning_kind) const

Public Member Functions inherited from P4::IHasDbPrint
void	print () const

Public Attributes
assoc::map< const PHV::Field , const IR::Expression >	field_to_expr

ordered_map< const PHV::Field , const PHV::Field >	field_to_valid_bit

assoc::map< const PHV::Field , ordered_set< const IR::MAU::Action > >	invalidate_to_action

const PhvInfo &	phv

assoc::map< const PHV::Field , ordered_set< const IR::MAU::Action > >	validate_to_action

assoc::map< const PHV::Field , ordered_set< const IR::BFN::ParserState > >	validate_to_extract

Public Attributes inherited from P4::Visitor
const Visitor *	called_by = nullptr

cstring	internalName

SplitFlowVisit_base *&	split_link

SplitFlowVisit_base *	split_link_mem = nullptr

Additional Inherited Members
Public Types inherited from P4::Visitor
typedef Visitor_Context	Context

Static Public Member Functions inherited from P4::Visitor
static cstring	demangle (const char *)

static bool	warning_enabled (const Visitor *visitor, int warning_kind)

Protected Member Functions inherited from P4::Visitor
virtual void	init_join_flows (const IR::Node *)

virtual bool	join_flows (const IR::Node *)

virtual void	post_join_flows (const IR::Node , const IR::Node )

void	visit_children (const IR::Node *, std::function< void()> fn)

Protected Attributes inherited from P4::Visitor
bool	dontForwardChildrenBeforePreorder = false

bool	joinFlows = false

bool	visitDagOnce = true

Member Function Documentation

◆ dbprint()

void CollectHeaderValidity::dbprint ( std::ostream & out ) const

inlinevirtual

Implements P4::IHasDbPrint.

◆ end_apply()

void CollectHeaderValidity::end_apply ( )

inlineoverridevirtual

Reimplemented from P4::Visitor.

◆ CollectWeakFields

class CollectWeakFields

We categorize fields that are referenced in the control flow as either strong or weak. The strong fields are ones that participate in match, non-move instruction, action data bus read, or other reasons (non packet defs, is part of a checksum update or digest). The weak fields are, by exclusion, the ones that are not strong. Weak fields also shall not have a transitive strong source. All weak fields are then decaf candidates.

Inheritance diagram for CollectWeakFields:

[legend]

Public Member Functions
	CollectWeakFields (const PhvInfo &phv, const PhvUse &uses, const FieldDefUse &defuse, const DependencyGraph &dg)

void	dbprint (std::ostream &out) const

const IR::MAU::Action *	get_action (const Assign *assign) const

const IR::MAU::Table *	get_table (const Assign *assign) const

std::string	print_assign (const Assign *assign) const

std::string	print_assign_context (const Assign *assign) const

void	remove_weak_field (const PHV::Field *field)

Public Member Functions inherited from P4::Inspector
const IR::Node *	apply_visitor (const IR::Node , const char name=0) override

profile_t	init_apply (const IR::Node *root) override

virtual void	loop_revisit (const IR::Node *)

virtual void	postorder (const IR::Node *)

virtual bool	preorder (const IR::Node *)

virtual void	revisit (const IR::Node *)

void	revisit_visited ()

bool	visit_in_progress (const IR::Node *n) const

void	visitAgain () const override

void	visitOnce () const override

Public Member Functions inherited from P4::Visitor
virtual void	end_apply (const IR::Node *root)

template<class T >
const T *	findContext () const

template<class T >
const T *	findContext (const Context *&c) const

template<class T >
const T *	findOrigCtxt () const

template<class T >
const T *	findOrigCtxt (const Context *&c) const

virtual bool	flow_merge_closure (Visitor &)

const Context *	getChildContext () const

int	getChildrenVisited () const

const Context *	getContext () const

int	getContextDepth () const

const IR::Node *	getCurrentNode () const

template<class T >
const T *	getCurrentNode () const

const IR::Node *	getOriginal () const

template<class T >
const T *	getOriginal () const

template<class T >
const T *	getParent () const

profile_t	init_apply (const IR::Node root, const Context parent_context)

bool	isInContext (const IR::Node *n) const

virtual const char *	name () const

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name=0)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name=0)

void	print_context () const

const Visitor &	setCalledBy (const Visitor *visitor)

void	setName (const char *name)

void	visit (const IR::Node &n, const char *name, int cidx)

void	visit (const IR::Node &n, const char *name=0)

void	visit (const IR::Node &n, const char name, int cidx)

void	visit (const IR::Node &n, const char name=0)

void	visit (const IR::Node const &n, const char name, int cidx)

void	visit (const IR::Node const &n, const char name=0)

void	visit (IR::Node &n, const char *name, int cidx)

void	visit (IR::Node &n, const char *name=0)

void	visit (IR::Node &, const char =0, int=0)

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T> && !std::is_pointer_v<T>>, class... Args>
void	warn (const int kind, const char *format, const T &node, Args &&...args)
	The const ref variant of the above.

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T>>, class... Args>
void	warn (const int kind, const char format, const T node, Args &&...args)

bool	warning_enabled (int warning_kind) const

Public Attributes
std::map< gress_t, ordered_set< const IR::Constant * > >	all_constants

ordered_map< const PHV::Field , ordered_set< const Assign > >	field_to_weak_assigns

FieldGroup	read_only_weak_fields

Public Attributes inherited from P4::Visitor
const Visitor *	called_by = nullptr

cstring	internalName

SplitFlowVisit_base *&	split_link

SplitFlowVisit_base *	split_link_mem = nullptr

Additional Inherited Members
Public Types inherited from P4::Visitor
typedef Visitor_Context	Context

Static Public Member Functions inherited from P4::Visitor
static cstring	demangle (const char *)

static bool	warning_enabled (const Visitor *visitor, int warning_kind)

Protected Member Functions inherited from P4::Visitor
void	visit_children (const IR::Node *, std::function< void()> fn)

Protected Attributes inherited from P4::Visitor
bool	dontForwardChildrenBeforePreorder = false

bool	joinFlows = false

bool	visitDagOnce = true

Member Function Documentation

◆ dbprint()

void CollectWeakFields::dbprint ( std::ostream & out ) const

virtual

Implements P4::IHasDbPrint.

◆ ComputeValuesAtDeparser

class ComputeValuesAtDeparser

Perform copy/constant propagation for the weak fields on table dependency. For each weak field, what are the all possible values that are reachable at the deparser?

Inheritance diagram for ComputeValuesAtDeparser:

[legend]

Public Member Functions
	ComputeValuesAtDeparser (CollectWeakFields &weak_fields)

bool	is_weak_assign (const IR::MAU::Instruction *instr) const

std::string	print_assign_chain (const AssignChain &chain) const

std::string	print_assign_chains (const ordered_set< AssignChain > &chains) const

std::string	print_value_map (const FieldGroup &weak_field_group, const ordered_set< AssignChain > &all_chains_in_group) const

Public Member Functions inherited from P4::Inspector
const IR::Node *	apply_visitor (const IR::Node , const char name=0) override

profile_t	init_apply (const IR::Node *root) override

virtual void	loop_revisit (const IR::Node *)

virtual void	postorder (const IR::Node *)

virtual bool	preorder (const IR::Node *)

virtual void	revisit (const IR::Node *)

void	revisit_visited ()

bool	visit_in_progress (const IR::Node *n) const

void	visitAgain () const override

void	visitOnce () const override

Public Member Functions inherited from P4::Visitor
virtual bool	check_global (cstring)

virtual void	clear_globals ()

virtual Visitor *	clone () const

virtual ControlFlowVisitor *	controlFlowVisitor ()

virtual void	end_apply ()

virtual void	end_apply (const IR::Node *root)

virtual void	erase_global (cstring)

template<class T >
const T *	findContext () const

template<class T >
const T *	findContext (const Context *&c) const

template<class T >
const T *	findOrigCtxt () const

template<class T >
const T *	findOrigCtxt (const Context *&c) const

virtual Visitor &	flow_clone ()

virtual void	flow_merge (Visitor &)

virtual bool	flow_merge_closure (Visitor &)

virtual void	flow_merge_global_from (cstring)

virtual void	flow_merge_global_to (cstring)

const Context *	getChildContext () const

int	getChildrenVisited () const

const Context *	getContext () const

int	getContextDepth () const

const IR::Node *	getCurrentNode () const

template<class T >
const T *	getCurrentNode () const

const IR::Node *	getOriginal () const

template<class T >
const T *	getOriginal () const

template<class T >
const T *	getParent () const

virtual bool	has_flow_joins () const

profile_t	init_apply (const IR::Node root, const Context parent_context)

bool	isInContext (const IR::Node *n) const

virtual const char *	name () const

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name=0)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name=0)

void	print_context () const

const Visitor &	setCalledBy (const Visitor *visitor)

void	setName (const char *name)

void	visit (const IR::Node &n, const char *name, int cidx)

void	visit (const IR::Node &n, const char *name=0)

void	visit (const IR::Node &n, const char name, int cidx)

void	visit (const IR::Node &n, const char name=0)

void	visit (const IR::Node const &n, const char name, int cidx)

void	visit (const IR::Node const &n, const char name=0)

void	visit (IR::Node &n, const char *name, int cidx)

void	visit (IR::Node &n, const char *name=0)

void	visit (IR::Node &, const char =0, int=0)

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T> && !std::is_pointer_v<T>>, class... Args>
void	warn (const int kind, const char *format, const T &node, Args &&...args)
	The const ref variant of the above.

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T>>, class... Args>
void	warn (const int kind, const char format, const T node, Args &&...args)

bool	warning_enabled (int warning_kind) const

Public Attributes
ordered_map< const PHV::Field *, ordered_map< Value, ordered_set< AssignChain > > >	value_to_chains

std::vector< FieldGroup >	weak_field_groups

CollectWeakFields &	weak_fields

Public Attributes inherited from P4::Visitor
const Visitor *	called_by = nullptr

cstring	internalName

SplitFlowVisit_base *&	split_link

SplitFlowVisit_base *	split_link_mem = nullptr

Additional Inherited Members
Public Types inherited from P4::Visitor
typedef Visitor_Context	Context

Static Public Member Functions inherited from P4::Visitor
static cstring	demangle (const char *)

static bool	warning_enabled (const Visitor *visitor, int warning_kind)

Protected Member Functions inherited from P4::Visitor
virtual void	init_join_flows (const IR::Node *)

virtual bool	join_flows (const IR::Node *)

virtual void	post_join_flows (const IR::Node , const IR::Node )

void	visit_children (const IR::Node *, std::function< void()> fn)

Protected Attributes inherited from P4::Visitor
bool	dontForwardChildrenBeforePreorder = false

bool	joinFlows = false

bool	visitDagOnce = true

◆ CreateConstants

class CreateConstants

Certain weak fields may have constant values. These constants need to be extracted by the parser in Tofino. In JBay, the deparser comes with 8 bytes of constants we can use, the rest still need to be extracted in the parser.

Inheritance diagram for CreateConstants:

[legend]

Public Member Functions
	CreateConstants (const ComputeValuesAtDeparser &values_at_deparser)

void	dbprint (std::ostream &out) const

bool	is_inserted (const IR::TempVar *constant) const

Public Attributes
std::map< gress_t, ordered_map< uint8_t, const IR::TempVar * > >	byte_to_temp_var

std::map< gress_t, ordered_map< const IR::Constant *, std::vector< uint8_t > > >	const_to_bytes

std::map< gress_t, ordered_set< uint8_t > >	deparser_bytes

Member Function Documentation

◆ dbprint()

void CreateConstants::dbprint ( std::ostream & out ) const

virtual

Implements P4::IHasDbPrint.

◆ DeparserCopyOpt

class DeparserCopyOpt

Top level PassManager.

Inheritance diagram for DeparserCopyOpt:

[legend]

Public Member Functions
	DeparserCopyOpt (const PhvInfo &phv, PhvUse &uses, const FieldDefUse &defuse, const DependencyGraph &dg)

Public Member Functions inherited from Logging::PassManager
	PassManager (cstring logFilePrefix, Logging::Mode logMode=Logging::Mode::CREATE)

Public Member Functions inherited from P4::PassManager
	PassManager (const PassManager &)=default

	PassManager (const std::initializer_list< VisitorRef > &init)

	PassManager (PassManager &&)=default

void	addDebugHook (DebugHook h, bool recursive=false)

void	addDebugHooks (std::vector< DebugHook > hooks, bool recursive=false)

void	addPasses (const std::initializer_list< VisitorRef > &init)

const IR::Node *	apply_visitor (const IR::Node , const char =0) override

bool	backtrack (trigger &trig) override

PassManager *	clone () const override

void	early_exit ()

void	listPasses (std::ostream &, cstring sep) const

bool	never_backtracks () override

void	removePasses (const std::vector< cstring > &exclude)

void	setStopOnError (bool stop)

Public Member Functions inherited from P4::Visitor
virtual bool	check_clone (const Visitor *a)

virtual bool	check_global (cstring)

virtual void	clear_globals ()

virtual ControlFlowVisitor *	controlFlowVisitor ()

virtual void	end_apply (const IR::Node *root)

virtual void	erase_global (cstring)

template<class T >
const T *	findContext () const

template<class T >
const T *	findContext (const Context *&c) const

template<class T >
const T *	findOrigCtxt () const

template<class T >
const T *	findOrigCtxt (const Context *&c) const

virtual Visitor &	flow_clone ()

virtual void	flow_merge (Visitor &)

virtual bool	flow_merge_closure (Visitor &)

virtual void	flow_merge_global_from (cstring)

virtual void	flow_merge_global_to (cstring)

const Context *	getChildContext () const

int	getChildrenVisited () const

const Context *	getContext () const

int	getContextDepth () const

const IR::Node *	getCurrentNode () const

template<class T >
const T *	getCurrentNode () const

const IR::Node *	getOriginal () const

template<class T >
const T *	getOriginal () const

template<class T >
const T *	getParent () const

virtual bool	has_flow_joins () const

profile_t	init_apply (const IR::Node root, const Context parent_context)

bool	isInContext (const IR::Node *n) const

virtual const char *	name () const

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name=0)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name=0)

void	print_context () const

const Visitor &	setCalledBy (const Visitor *visitor)

void	setName (const char *name)

void	visit (const IR::Node &n, const char *name, int cidx)

void	visit (const IR::Node &n, const char *name=0)

void	visit (const IR::Node &n, const char name, int cidx)

void	visit (const IR::Node &n, const char name=0)

void	visit (const IR::Node const &n, const char name, int cidx)

void	visit (const IR::Node const &n, const char name=0)

void	visit (IR::Node &n, const char *name, int cidx)

void	visit (IR::Node &n, const char *name=0)

void	visit (IR::Node &, const char =0, int=0)

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T> && !std::is_pointer_v<T>>, class... Args>
void	warn (const int kind, const char *format, const T &node, Args &&...args)
	The const ref variant of the above.

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T>>, class... Args>
void	warn (const int kind, const char format, const T node, Args &&...args)

bool	warning_enabled (int warning_kind) const

Public Member Functions inherited from P4::Backtrack
Public Attributes
RewriteDeparser	rewrite_deparser

Public Attributes inherited from P4::Visitor
const Visitor *	called_by = nullptr

cstring	internalName

SplitFlowVisit_base *&	split_link

SplitFlowVisit_base *	split_link_mem = nullptr

Additional Inherited Members
Public Types inherited from P4::Visitor
typedef Visitor_Context	Context

Static Public Member Functions inherited from Logging::PassManager
static cstring	getNewLogFileName (const cstring &prefix)

Static Public Member Functions inherited from P4::Visitor
static cstring	demangle (const char *)

static bool	warning_enabled (const Visitor *visitor, int warning_kind)

Protected Member Functions inherited from Logging::PassManager
void	end_apply () override

profile_t	init_apply (const IR::Node *root) override

Protected Member Functions inherited from P4::PassManager
profile_t	init_apply (const IR::Node *root) override

void	runDebugHooks (const char visitorName, const IR::Node node)

Protected Member Functions inherited from P4::Visitor
virtual void	init_join_flows (const IR::Node *)

virtual bool	join_flows (const IR::Node *)

virtual void	post_join_flows (const IR::Node , const IR::Node )

void	visit_children (const IR::Node *, std::function< void()> fn)

virtual void	visitAgain () const

virtual void	visitOnce () const

Protected Attributes inherited from Logging::PassManager
Logging::FileLog *	_logFile

cstring	_logFilePrefix

Logging::Mode	_logMode

Protected Attributes inherited from P4::PassManager
safe_vector< DebugHook >	debugHooks

safe_vector< Visitor * >	passes

bool	running = false

unsigned	seqNo = 0

bool	stop_on_error = true

Protected Attributes inherited from P4::Visitor
bool	dontForwardChildrenBeforePreorder = false

bool	joinFlows = false

bool	visitDagOnce = true

Static Protected Attributes inherited from Logging::PassManager
static int	invocationCount = -1

◆ FieldGroup

struct FieldGroup

Inheritance diagram for FieldGroup:

[legend]

Public Member Functions
	FieldGroup (int i)

Public Member Functions inherited from P4::ordered_set< const PHV::Field * >
	ordered_set (const ordered_set &a)

	ordered_set (InputIt first, InputIt last)

	ordered_set (ordered_set &&a)=default

	ordered_set (std::initializer_list< const PHV::Field * > init)

reference	back () const noexcept

const_iterator	begin () const noexcept

iterator	begin () noexcept

const_iterator	cbegin () const noexcept

const_iterator	cend () const noexcept

void	clear ()

size_type	count (const const PHV::Field *&a) const

const_reverse_iterator	crbegin () const noexcept

const_reverse_iterator	crend () const noexcept

std::pair< iterator, bool >	emplace (Args &&...args)

std::pair< iterator, bool >	emplace_back (Args &&...args)

bool	empty () const noexcept

const_iterator	end () const noexcept

iterator	end () noexcept

size_type	erase (const const PHV::Field *&v)

iterator	erase (const_iterator pos)

iterator	find (const const PHV::Field *&a)

const_iterator	find (const const PHV::Field *&a) const

reference	front () const noexcept

std::pair< iterator, bool >	insert (const const PHV::Field *&v)

std::pair< iterator, bool >	insert (const PHV::Field *&&v)

iterator	insert (const_iterator pos, const const PHV::Field *&v)

iterator	insert (const_iterator pos, const PHV::Field *&&v)

void	insert (ordered_set::const_iterator begin, ordered_set::const_iterator end)

iterator	lower_bound (const const PHV::Field *&a)

const_iterator	lower_bound (const const PHV::Field *&a) const

size_type	max_size () const noexcept

bool	operator!= (const ordered_set &a) const

bool	operator< (const ordered_set &a) const

ordered_set &	operator= (const ordered_set &a)

ordered_set &	operator= (ordered_set &&a)=default

bool	operator== (const ordered_set &a) const

void	push_back (const const PHV::Field *&v)

void	push_back (const PHV::Field *&&v)

const_reverse_iterator	rbegin () const noexcept

reverse_iterator	rbegin () noexcept

const_reverse_iterator	rend () const noexcept

reverse_iterator	rend () noexcept

size_type	size () const noexcept

sorted_iterator	sorted_begin () const noexcept

sorted_iterator	sorted_end () const noexcept

iterator	upper_bound (const const PHV::Field *&a)

const_iterator	upper_bound (const const PHV::Field *&a) const

Public Attributes
int	id = -1

Additional Inherited Members
Public Types inherited from P4::ordered_set< const PHV::Field * >
typedef std::allocator< const PHV::Field * >	allocator_type

typedef list_type::const_iterator	const_iterator

typedef const const PHV::Field *&	const_reference

typedef std::reverse_iterator< const_iterator >	const_reverse_iterator

typedef list_type::const_iterator	iterator

typedef std::less< const PHV::Field * >	key_compare

typedef const PHV::Field *	key_type

typedef const const PHV::Field *&	reference

typedef std::reverse_iterator< iterator >	reverse_iterator

typedef map_type::size_type	size_type

typedef std::less< const PHV::Field * >	value_compare

typedef const PHV::Field *	value_type

◆ RewriteDeparser

class RewriteDeparser

Rewrite deparser to insert new emits created for each of the weak field's reachable value at the deparser. Each value emit is predicated by the synthesized POV bit created in the SynthesizePovEncoder pass.

Inheritance diagram for RewriteDeparser:

[legend]

Public Member Functions
	RewriteDeparser (const PhvInfo &phv, const SynthesizePovEncoder &synth_pov_encoder, const CreateConstants &create_consts)

Public Attributes
ordered_set< cstring >	must_split_fields

◆ RewriteWeakFieldWrites

class RewriteWeakFieldWrites

Replace all move instructions that weak fields are involved in by a single bit set to the $ctl bits for each action that the move instructions are in. Typically, these are the tunnel encap/decap actions.

Inheritance diagram for RewriteWeakFieldWrites:

[legend]

Public Member Functions
	RewriteWeakFieldWrites (const ComputeValuesAtDeparser &values_at_deparser, const SynthesizePovEncoder &synth_pov_encoder)

Public Member Functions inherited from P4::Transform
const IR::Node *	apply_visitor (const IR::Node , const char name=0) override

profile_t	init_apply (const IR::Node *root) override

virtual void	loop_revisit (const IR::Node *)

virtual const IR::Node *	postorder (IR::Node *n)

virtual const IR::Node *	preorder (IR::Node *n)

void	prune ()

virtual void	revisit (const IR::Node , const IR::Node )

void	revisit_visited ()

bool	visit_in_progress (const IR::Node *) const

void	visitAgain () const override

void	visitOnce () const override

Public Member Functions inherited from P4::Visitor
virtual bool	check_global (cstring)

virtual void	clear_globals ()

virtual Visitor *	clone () const

virtual ControlFlowVisitor *	controlFlowVisitor ()

virtual void	end_apply (const IR::Node *root)

virtual void	erase_global (cstring)

template<class T >
const T *	findContext () const

template<class T >
const T *	findContext (const Context *&c) const

template<class T >
const T *	findOrigCtxt () const

template<class T >
const T *	findOrigCtxt (const Context *&c) const

virtual Visitor &	flow_clone ()

virtual void	flow_merge (Visitor &)

virtual bool	flow_merge_closure (Visitor &)

virtual void	flow_merge_global_from (cstring)

virtual void	flow_merge_global_to (cstring)

const Context *	getChildContext () const

int	getChildrenVisited () const

const Context *	getContext () const

int	getContextDepth () const

const IR::Node *	getCurrentNode () const

template<class T >
const T *	getCurrentNode () const

const IR::Node *	getOriginal () const

template<class T >
const T *	getOriginal () const

template<class T >
const T *	getParent () const

virtual bool	has_flow_joins () const

profile_t	init_apply (const IR::Node root, const Context parent_context)

bool	isInContext (const IR::Node *n) const

virtual const char *	name () const

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name=0)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name=0)

void	print_context () const

const Visitor &	setCalledBy (const Visitor *visitor)

void	setName (const char *name)

void	visit (const IR::Node &n, const char *name, int cidx)

void	visit (const IR::Node &n, const char *name=0)

void	visit (const IR::Node &n, const char name, int cidx)

void	visit (const IR::Node &n, const char name=0)

void	visit (const IR::Node const &n, const char name, int cidx)

void	visit (const IR::Node const &n, const char name=0)

void	visit (IR::Node &n, const char *name, int cidx)

void	visit (IR::Node &n, const char *name=0)

void	visit (IR::Node &, const char =0, int=0)

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T> && !std::is_pointer_v<T>>, class... Args>
void	warn (const int kind, const char *format, const T &node, Args &&...args)
	The const ref variant of the above.

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T>>, class... Args>
void	warn (const int kind, const char format, const T node, Args &&...args)

bool	warning_enabled (int warning_kind) const

Additional Inherited Members
Public Types inherited from P4::Visitor
typedef Visitor_Context	Context

Static Public Member Functions inherited from P4::Visitor
static cstring	demangle (const char *)

static bool	warning_enabled (const Visitor *visitor, int warning_kind)

Public Attributes inherited from P4::Visitor
const Visitor *	called_by = nullptr

cstring	internalName

SplitFlowVisit_base *&	split_link

SplitFlowVisit_base *	split_link_mem = nullptr

Protected Member Functions inherited from P4::Transform
const IR::Node *	transform_child (const IR::Node *child)

Protected Member Functions inherited from P4::Visitor
virtual void	init_join_flows (const IR::Node *)

virtual bool	join_flows (const IR::Node *)

virtual void	post_join_flows (const IR::Node , const IR::Node )

void	visit_children (const IR::Node *, std::function< void()> fn)

Protected Attributes inherited from P4::Transform
bool	forceClone = false

Protected Attributes inherited from P4::Visitor
bool	dontForwardChildrenBeforePreorder = false

bool	joinFlows = false

bool	visitDagOnce = true

◆ SynthesizePovEncoder

class SynthesizePovEncoder

Given a set of weak fields, and their reaching values/action chains at the deparser, we construct tables to synthesize the POV bits needed to deparse the right version at runtime.

Inheritance diagram for SynthesizePovEncoder:

[legend]

Public Member Functions
	SynthesizePovEncoder (const CollectHeaderValidity &pov_bits, const ComputeValuesAtDeparser &values_at_deparser)

void	dbprint (std::ostream &out) const

Public Member Functions inherited from P4::Transform
const IR::Node *	apply_visitor (const IR::Node , const char name=0) override

profile_t	init_apply (const IR::Node *root) override

virtual void	loop_revisit (const IR::Node *)

virtual const IR::Node *	postorder (IR::Node *n)

virtual const IR::Node *	preorder (IR::Node *n)

void	prune ()

virtual void	revisit (const IR::Node , const IR::Node )

void	revisit_visited ()

bool	visit_in_progress (const IR::Node *) const

void	visitAgain () const override

void	visitOnce () const override

Public Member Functions inherited from P4::Visitor
virtual bool	check_global (cstring)

virtual void	clear_globals ()

virtual Visitor *	clone () const

virtual ControlFlowVisitor *	controlFlowVisitor ()

virtual void	end_apply (const IR::Node *root)

virtual void	erase_global (cstring)

template<class T >
const T *	findContext () const

template<class T >
const T *	findContext (const Context *&c) const

template<class T >
const T *	findOrigCtxt () const

template<class T >
const T *	findOrigCtxt (const Context *&c) const

virtual Visitor &	flow_clone ()

virtual void	flow_merge (Visitor &)

virtual bool	flow_merge_closure (Visitor &)

virtual void	flow_merge_global_from (cstring)

virtual void	flow_merge_global_to (cstring)

const Context *	getChildContext () const

int	getChildrenVisited () const

const Context *	getContext () const

int	getContextDepth () const

const IR::Node *	getCurrentNode () const

template<class T >
const T *	getCurrentNode () const

const IR::Node *	getOriginal () const

template<class T >
const T *	getOriginal () const

template<class T >
const T *	getParent () const

virtual bool	has_flow_joins () const

profile_t	init_apply (const IR::Node root, const Context parent_context)

bool	isInContext (const IR::Node *n) const

virtual const char *	name () const

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (const IR::Vector< T > &v, const char *name=0)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name, int cidx)

template<class T >
void	parallel_visit (IR::Vector< T > &v, const char *name=0)

void	print_context () const

const Visitor &	setCalledBy (const Visitor *visitor)

void	setName (const char *name)

void	visit (const IR::Node &n, const char *name, int cidx)

void	visit (const IR::Node &n, const char *name=0)

void	visit (const IR::Node &n, const char name, int cidx)

void	visit (const IR::Node &n, const char name=0)

void	visit (const IR::Node const &n, const char name, int cidx)

void	visit (const IR::Node const &n, const char name=0)

void	visit (IR::Node &n, const char *name, int cidx)

void	visit (IR::Node &n, const char *name=0)

void	visit (IR::Node &, const char =0, int=0)

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T> && !std::is_pointer_v<T>>, class... Args>
void	warn (const int kind, const char *format, const T &node, Args &&...args)
	The const ref variant of the above.

template<class T , typename = std::enable_if_t<Util::has_SourceInfo_v<T>>, class... Args>
void	warn (const int kind, const char format, const T node, Args &&...args)

bool	warning_enabled (int warning_kind) const

Public Attributes
ordered_map< const IR::MAU::Action , const IR::TempVar >	action_to_ctl_bit

ordered_map< const IR::MAU::Instruction , const IR::TempVar >	assign_to_version_bit

ordered_map< const PHV::Field , const IR::TempVar >	default_pov_bit

ordered_map< const PHV::Field , ordered_map< Value, const IR::TempVar > >	value_to_pov_bit

Public Attributes inherited from P4::Visitor
const Visitor *	called_by = nullptr

cstring	internalName

SplitFlowVisit_base *&	split_link

SplitFlowVisit_base *	split_link_mem = nullptr

Additional Inherited Members
Public Types inherited from P4::Visitor
typedef Visitor_Context	Context

Static Public Member Functions inherited from P4::Visitor
static cstring	demangle (const char *)

static bool	warning_enabled (const Visitor *visitor, int warning_kind)

Protected Member Functions inherited from P4::Transform
const IR::Node *	transform_child (const IR::Node *child)

Protected Member Functions inherited from P4::Visitor
virtual void	init_join_flows (const IR::Node *)

virtual bool	join_flows (const IR::Node *)

virtual void	post_join_flows (const IR::Node , const IR::Node )

void	visit_children (const IR::Node *, std::function< void()> fn)

Protected Attributes inherited from P4::Transform
bool	forceClone = false

Protected Attributes inherited from P4::Visitor
bool	dontForwardChildrenBeforePreorder = false

bool	joinFlows = false

bool	visitDagOnce = true

Member Function Documentation

◆ dbprint()

void SynthesizePovEncoder::dbprint ( std::ostream & out ) const

virtual

Implements P4::IHasDbPrint.

◆ Value

struct Value

Public Member Functions
	Value (const IR::Constant *c)

	Value (const PHV::Field *f)

	Value (const Value &other)

bool	operator< (const Value &other) const

Value &	operator= (const Value &other)

bool	operator== (const Value &other) const

std::string	print () const

Public Attributes
const IR::Constant *	constant = nullptr

const PHV::Field *	field = nullptr

◆ VersionMap

struct VersionMap

Public Member Functions
ordered_set< const IR::TempVar * >	get_all_version_bits () const

Public Attributes
ordered_map< const PHV::Field , const IR::TempVar >	default_version

ordered_map< const PHV::Field , ordered_map< Value, const IR::TempVar > >	value_to_version

Classes

Detailed Description

TODO

Class Documentation

◆ Assign

Public Member Functions

Public Attributes

◆ AssignChain

Public Member Functions

◆ CollectHeaderValidity

Public Member Functions

Public Attributes

Additional Inherited Members

Member Function Documentation

◆ dbprint()

◆ end_apply()

◆ CollectWeakFields

Public Member Functions

Public Attributes

Additional Inherited Members

Member Function Documentation

◆ dbprint()

◆ ComputeValuesAtDeparser

Public Member Functions

Public Attributes

Additional Inherited Members

◆ CreateConstants

Public Member Functions

Public Attributes

Member Function Documentation

◆ dbprint()

◆ DeparserCopyOpt

Public Member Functions

Public Attributes

Additional Inherited Members

◆ FieldGroup

Public Member Functions

Public Attributes

Additional Inherited Members

◆ RewriteDeparser

Public Member Functions

Public Attributes

◆ RewriteWeakFieldWrites

Public Member Functions

Additional Inherited Members

◆ SynthesizePovEncoder

Public Member Functions

Public Attributes

Additional Inherited Members

Member Function Documentation

◆ dbprint()

◆ Value

Public Member Functions

Public Attributes

◆ VersionMap

Public Member Functions

Public Attributes