#include <flattenUnions.h>

Inheritance diagram for P4::HandleValidityHeaderUnion:

Public Member Functions
	HandleValidityHeaderUnion (P4::ReferenceMap refMap, P4::TypeMap typeMap)

const IR::Node *	expandIsValid (const IR::Statement a, const IR::MethodCallExpression mce, IR::IndexedVector< IR::StatOrDecl > &code_block)

const IR::Node *	postorder (IR::AssignmentStatement *assn) override

const IR::Node *	postorder (IR::IfStatement *a) override

const IR::Node *	postorder (IR::MethodCallStatement *mcs) override

const IR::Node *	postorder (IR::P4Action *action) override

const IR::Node *	postorder (IR::P4Control *control) override

const IR::Node *	postorder (IR::P4Parser *parser) override

const IR::Node *	postorder (IR::SwitchStatement *a) override

const IR::MethodCallStatement *	processValidityForStr (const IR::Statement s, const IR::Member m, cstring headerElement, cstring setValid)

const IR::Node *	setInvalidforRest (const IR::Statement s, const IR::Member m, const IR::Type_HeaderUnion *hu, cstring exclude, bool setValidforCurrMem)

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 ()

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

Detailed Description

This pass handles the validity semantics of header union. 1) On assignment to any element of the header union, it is set to Valid and other elements of the header union are set to Invalid. a) U u; | if (my_h1.isValid()) { H1 my_h1 = { 8w0 }; | u_h1.setValid(); u.h1 = my_h1; | // all other elements set to Invalid | u_h1 = my_h1; | } else { | u_h1.setInvalid() | } b) u.h1 = {16W1} | This is already transformed into individual element copy | by earlier passes and individual assignment is translated | as same as (a) c) u1.h1 = u2.h1 | same as a) with my_h1 replaced with u2_h1 d) u1 = u2 | This is already transformed into individual element copy | by earlier passes and individual assignment is translated | same as (c) e) a = u.isValid() | tmp = 0; Only one element should be valid | for elements in union | if (element.isvalid) | tmp += 1; | a = tmp == 1

2) When isValid is used as if statement's condition or switch expression, the expression is replaced with tmp calculated in (1e) a) switch(u.isValid()) | switch (tmp == 1) b) if(u.isValid()) | if (tmp == 1) 3) When setValid method is called on a header element, it is translated to setValid for the given element and setInvalid for rest of the elements 4) Equality/inequality comparisons on unions are unrolled into element-wise comparisons by earlier passes and hence no-action required here.

Public Member Functions

Additional Inherited Members

Detailed Description