Package at.dms.kjc.sir

Contains the heart of the StreamIt Intermediate Representation, or SIR for short.

See:
Description

Interface Summary

AttributeStreamVisitor	This visitor is for visiting stream structures in the SIR.
SIRCodeUnit	Interface of accessors for classes that define methods and field variables.
StreamVisitor	This visitor is for visiting stream structures in the SIR.

Class Summary

EmptyAttributeStreamVisitor	This is an empty attribute stream visitor that does nothing except the recursion.
EmptyStreamVisitor	This is a stream visitor that does nothing.
InlineAssembly	Statement used for generating inline assembly.
ReplacingStreamVisitor	Visits all stream structures and replaces children with result from recursion.
SemanticChecker	The purpose of this class it to semantic check a stream program.
SIRBeginMarker	This statement is an annotation that marks the beginning of a given function or stream so that it can be followed through fusion, etc.
SIRBuilder	This class is for building sample representations in the SIR.
SIRContainer	This represents a 1-to-1 stream that can contain other streams as a hierarchical unit.
SIRCreatePortal	Create Portal Expression.
SIRDummySink	This represents a StreamIT filter that just pushes 1 for int type and 1.0f for float.
SIRDummySource	This represents a StreamIT filter that just pushes 1 for int type and 1.0f for float.
SIRDynamicRateManager	This class governs how dynamic rates are interpreted at a given point in the compiler.
SIRDynamicRatePolicy	This represents a single policy for interpreting dynamic rates in a given part of the compiler.
SIRDynamicToken	This represents the dynmic token '*' as in an I/O rate declaration: [2,*,*].
SIREndMarker	This statement is an annotation that marks the end of a given function or stream so that it can be followed through fusion, etc.
SIRFeedbackLoop	This represents a feedback loop construct.
SIRFileReader	This represents a StreaMIT filter that reads from a data source.
SIRFileWriter	This represents a StreaMIT filter that writes a file to a data source.
SIRFilter	This represents a basic StreamIt filter.
SIRGlobal	This class represents a data that is available to all filters.
SIRHelper	This class represents a set of helper methods available to all filters.
SIRIdentity	This represents a StreaMIT filter that just reads item and sends it along.
SIRInitStatement	Init Statement.
SIRInterfaceTable	This represents an interface table.
SIRJoiner	This represents a stream construct with a single output and multiple inputs.
SIRJoinType	This class enumerates the types of joiners.
SIRLatency	This represents a latency for message delivery.
SIRLatencyMax	This represents a maximum latency for message delivery.
SIRLatencyRange	This represents a range of latencies for message delivery.
SIRLatencySet	A set of Integers corresponding to possible latencies for message delivery.
SIRMarker	This class represents an annotation in the IR.
SIRMessageStatement	Message Sending Statement.
SIRNavigationUtils
SIROperator	This represents an operator in the stream graph.
SIRPeekExpression	This represents a peek expression.
SIRPhasedFilter	A StreamIt phased filter.
SIRPipeline	This represents a pipeline of stream structures, as would be declared with a Stream construct in StreaMIT.
SIRPopExpression	This represents a pop expression.
SIRPortal	This represents a stream portal used for messaging
SIRPortalSender	Represents a SIRStream and SIRLatency pair
SIRPredefinedFilter	This represents a StreaMIT filter that has some compiler-defined functionality.
SIRPrintStatement	This represents a print statement, originally formulated with System.out.println in StreaMIT.
SIRPushExpression	This represents a push expression (can only be used as a statement).
SIRRangeExpression	This represents a range [min,average,max], e.g., [1,2,3] or [1,*,*] as used in the declaration of an I/O rate.
SIRRecursiveStub	This class represents a stub for something that was found to be recursive in the front-end, and needs to be expanded within the IR.
SIRRegReceiverStatement	Register Receiver Statement.
SIRRegSenderStatement	Register Sender Statement.
SIRSplitJoin	This represents a SplitJoin construct.
SIRSplitter	This represents a stream construct with a single input and multiple outputs.
SIRSplitType	This class enumerates the types of splitters.
SIRStream	This class represents a stream structure with one input and one output.
SIRStructure	This class represents a data structure that may be passed between streams on tapes.
SIRToStreamIt	Dump an SIR tree into a StreamIt program.
SIRTwoStageFilter	A two-stage filter is a filter that has two work phases.

Package at.dms.kjc.sir Description

Contains the heart of the StreamIt Intermediate Representation, or SIR for short. This intermediate representation exists at two levels:

• The stream graph level, which captures the hierarchy and connectivity of filters (for example, SIRPipeline.
• The statement level, which extends Kopi's IR with statements and expressions for StreamIt keywords.

The stream graph is encapsulated in a structured hierarchy of single-input, single-output modules. At the base of this hierarchy is SIRFilter, which represents the basic StreamIt filter. Filters are composed into hierarchical graphs using the SIRPipeline, SIRSplitJoin, and SIRFeedbackLoop classes. There are also special kinds of pre-defined filters, such as SIRFileReader, SIRFileWriter, and SIRIdentity.

For statement-level StreamIt IR constructs, this package contains classes such as SIRPushExpression, SIRPopExpression, and SIRPeekExpression that reflect uses of those expressions from within a filter's work function. There also exist some SIR statements that are only for internal use by the compiler, and do not directly correspond to a keyword in the language (such as SIRBeginMarker, which tracks the beginning of a filter's code through fusion events).

The other important component of the SIR are the stream-level visitors. These visitors descend through the hierarchical stream graph and can be extended to perform an operation on each filter, pipeline, etc. The StreamVisitor interface (implemented by EmptyAttributeStreamVisitor) performs the recursion automatically and has a return type of void from each visit, while the AttributeStreamVisitor interface (implemented by EmptyAttributeStreamVisitor) uses user-defined recursion with return types from visits.

The hierarchical structure of the SIR is utilized by many optimization passes (notably, all of those packages under the "sir" directory of the source tree). For certain backends (such as RawBackend and ClusterBackend) the hierarchy of the stream graph is eventaully eliminated to form a flat graph representation.

The rationale behind the hierarchy of the SIR is described in the research paper, StreamIt: A Language for Streaming Applications.

See Also:

at.dms.kjc.flatgraph