jlm::llvm::StoreValueForwarding Class Reference

Store Value Forwarding Optimization. More...

#include <StoreValueForwarding.hpp>

Inheritance diagram for jlm::llvm::StoreValueForwarding:

Collaboration diagram for jlm::llvm::StoreValueForwarding:

Classes
struct	Context
class	Statistics
	Store Value Forwarding Statistics class. More...

Public Member Functions
	~StoreValueForwarding () noexcept override
	StoreValueForwarding ()
	StoreValueForwarding (const StoreValueForwarding &)=delete
	StoreValueForwarding (StoreValueForwarding &&)=delete
StoreValueForwarding &	operator= (const StoreValueForwarding &)=delete
StoreValueForwarding &	operator= (StoreValueForwarding &&)=delete
void	Run (rvsdg::RvsdgModule &module, util::StatisticsCollector &statisticsCollector) override
	Perform RVSDG transformation. More...
Public Member Functions inherited from jlm::rvsdg::Transformation
virtual	~Transformation () noexcept
	Transformation (std::string_view Name)
const std::string_view &	GetName () const noexcept
void	Run (RvsdgModule &module)
	Perform RVSDG transformation. More...

Private Member Functions
void	traverseInterProceduralRegion (rvsdg::Region &region)
void	traverseIntraProceduralRegion (rvsdg::Region &region)
void	processLoadNode (rvsdg::SimpleNode &loadNode)
void	forwardStoredValues (LoadTracingInfo &tracingInfo)
rvsdg::Output &	getStoredValueOrigin (StoreValueOrigin storeValueOrigin, rvsdg::Region &targetRegion, LoadTracingInfo &tracingInfo)
void	connectUnroutedLoopPosts (LoadTracingInfo &tracingInfo)
rvsdg::Output &	routeOutputToRegion (rvsdg::Output &output, rvsdg::Region &region)

Private Attributes
std::unique_ptr< Context >	context_

Detailed Description

Store Value Forwarding Optimization.

Store Value Forwarding is an optimization that forwards store values to eliminate redundant loads.

Definition at line 29 of file StoreValueForwarding.hpp.

Constructor & Destructor Documentation

~StoreValueForwarding()

jlm::llvm::StoreValueForwarding::~StoreValueForwarding ( )

overridedefaultnoexcept

StoreValueForwarding() [1/3]

jlm::llvm::StoreValueForwarding::StoreValueForwarding

(

)

Definition at line 167 of file StoreValueForwarding.cpp.

StoreValueForwarding() [2/3]

jlm::llvm::StoreValueForwarding::StoreValueForwarding ( const StoreValueForwarding &  )

delete

StoreValueForwarding() [3/3]

jlm::llvm::StoreValueForwarding::StoreValueForwarding ( StoreValueForwarding &&  )

delete

Member Function Documentation

connectUnroutedLoopPosts()

void jlm::llvm::StoreValueForwarding::connectUnroutedLoopPosts ( LoadTracingInfo &  tracingInfo )

private

In getStoredValueOrigin(), all loop variables are created as invariant, to avoid recursive function calls looping around the graph. Instead, the post results of all created loop variables are added to a queue, and properly diverted to their correct origins by this function.

Definition at line 857 of file StoreValueForwarding.cpp.

forwardStoredValues()

void jlm::llvm::StoreValueForwarding::forwardStoredValues ( LoadTracingInfo &  tracingInfo )

private

Performs store value forwarding to the load node represented by the given tracingInfo. Uses the metadata stored during tracing to replace the value output of the load node with the last value that was stored to the memory loaded by it.

Parameters

tracingInfo

the metadata created during store value origin tracing.

Definition at line 710 of file StoreValueForwarding.cpp.

getStoredValueOrigin()

rvsdg::Output & jlm::llvm::StoreValueForwarding::getStoredValueOrigin ( StoreValueOrigin  storeValueOrigin, rvsdg::Region &  targetRegion, LoadTracingInfo &  tracingInfo  )

private

Gets an output providing the value stored at the given storeValueOrigin. The returned output is in the specified targetRegion. It must be the same region as the storeValueOrigin itself, or a parent region. Getting it may involve routing and creating new structural node inputs and outputs.

Parameters

storeValueOrigin	the origin of the last stored value along some memory state.
targetRegion	the region the returned output should be in.
tracingInfo	the metadata created during store value origin tracing.

Returns

the rvsdg output providing the stored value in the given region.

Definition at line 740 of file StoreValueForwarding.cpp.

operator=() [1/2]

StoreValueForwarding& jlm::llvm::StoreValueForwarding::operator= ( const StoreValueForwarding &  )

delete

operator=() [2/2]

StoreValueForwarding& jlm::llvm::StoreValueForwarding::operator= ( StoreValueForwarding &&  )

delete

processLoadNode()

void jlm::llvm::StoreValueForwarding::processLoadNode ( rvsdg::SimpleNode &  loadNode )

private

Process a non-volatile load node during traversal

Parameters

loadNode

the load node to handle

Definition at line 684 of file StoreValueForwarding.cpp.

routeOutputToRegion()

rvsdg::Output & jlm::llvm::StoreValueForwarding::routeOutputToRegion ( rvsdg::Output &  output, rvsdg::Region &  region  )

private

Helper for routing outputs that memoizes the routing to avoid creating duplicate inputs and outputs in structural nodes. The output must be in the region, or in an ancestor of the region.

Parameters

output	the output to route
region	the destination of the routing

Returns

an output inside region that provides the same value as output

Definition at line 874 of file StoreValueForwarding.cpp.

Run()

void jlm::llvm::StoreValueForwarding::Run ( rvsdg::RvsdgModule &  module, util::StatisticsCollector &  statisticsCollector  )

overridevirtual

Perform RVSDG transformation.

Note

This method is expected to be called multiple times. An implementation is required to reset the objects' internal state to ensure correct behavior after every invocation.

Parameters

module	RVSDG module the transformation is performed on.
statisticsCollector	Statistics collector for collecting transformation statistics.

Implements jlm::rvsdg::Transformation.

Definition at line 943 of file StoreValueForwarding.cpp.

traverseInterProceduralRegion()

void jlm::llvm::StoreValueForwarding::traverseInterProceduralRegion ( rvsdg::Region &  region )

private

Traverse the given inter-procedural region

Parameters

region

the region to traverse

Definition at line 172 of file StoreValueForwarding.cpp.

traverseIntraProceduralRegion()

void jlm::llvm::StoreValueForwarding::traverseIntraProceduralRegion ( rvsdg::Region &  region )

private

Traverse the given intra-procedural region

Parameters

region

the region to traverse

Definition at line 199 of file StoreValueForwarding.cpp.

Member Data Documentation

context_

std::unique_ptr<Context> jlm::llvm::StoreValueForwarding::context_

private

Definition at line 122 of file StoreValueForwarding.hpp.

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The documentation for this class was generated from the following files:

• jlm/llvm/opt/StoreValueForwarding.hpp
• jlm/llvm/opt/StoreValueForwarding.cpp