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BFN::AnnotateWithInHash
Midend

Set of passes that annotate specific assignment statements with the @in_hash annotation. More...

Collaboration diagram for BFN::AnnotateWithInHash:

Classes

class  BFN::AnnotateWithInHash
 Top level PassManager that governs annotation of specific assignment statements with the @in_hash annotation. More...
 
class  BFN::DoAnnotateWithInHash
 

Detailed Description

Set of passes that annotate specific assignment statements with the @in_hash annotation.

Copyright (C) 2024 Intel Corporation

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

The purpose is to eliminate some PHV and PARDE alignment issues caused by statements mapped to ALU units, namely binary arithmetic operations whose operands are casted or concatenated.

E.g.: 

meta.index = meta.index + (3w0 ++ hdr.vlan.pcp);

is converted to: 

\@in_hash { meta.index = meta.index + (3w0 ++ hdr.vlan.pcp); }

The first statement looked originally like: 

meta.index = meta.index + (bit<6>)hdr.vlan.pcp;

And was modified with the ElimCasts pass.

The pass performs several checks to be sure that annotating is added only if it can help with dealing an issue. Namely, it checks whether the operands of the arithmetic operation do not have appropriate width for ALU units (i.e. 8, 16, or 32 bits).

Precondition
The pass has to be preceeded with the BFN::ElimCasts pass, which replaces the cast operation with zero-extension using the concatenation operator, and with the P4::SynthesizeActions pass, which moves assignment statements from apply blocks into actions where annotating with the @in_hash annotation happens.

Also see the limitations of the @in_hash annotation.

Class Documentation

◆ BFN::AnnotateWithInHash

class BFN::AnnotateWithInHash

Top level PassManager that governs annotation of specific assignment statements with the @in_hash annotation.

Inheritance diagram for BFN::AnnotateWithInHash:
[legend]

Public Member Functions

 AnnotateWithInHash (P4::ReferenceMap *refMap, P4::TypeMap *typeMap, BFN::TypeChecking *typeChecking=nullptr)
 
- 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 ()
 
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

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::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 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
 

◆ BFN::DoAnnotateWithInHash

class BFN::DoAnnotateWithInHash
Inheritance diagram for BFN::DoAnnotateWithInHash:
[legend]

Public Member Functions

 DoAnnotateWithInHash (P4::TypeMap *typeMap)
 
const IR::Node * preorder (IR::AssignmentStatement *assignment) override
 
const IR::Node * preorder (IR::BlockStatement *b) override
 
const IR::Node * preorder (IR::Expression *e) override
 
- 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
 

Member Function Documentation

◆ preorder() [1/2]

const IR::Node * BFN::DoAnnotateWithInHash::preorder ( IR::BlockStatement * b)
override

If a block statement is already annotated with @in_hash or @in_vliw, do not annotate it again.

◆ preorder() [2/2]

const IR::Node * BFN::DoAnnotateWithInHash::preorder ( IR::Expression * e)
override

It is useless to traverse expressions.