Package harpoon.IR.Quads

A flat, typed, high-level quadruple-based IR.

See:
Description

Interface Summary

HANDLER.ProtectedSet

An interface to specify which Quads a particular HANDLER protects.

Class Summary

AGET	AGET represents an element fetch from an array object.
ALENGTH	ALENGTH represents an array length query.
ANEW	ANEW represents an array creation operation.
ARRAYINIT	ARRAYINIT represents an array initialization operation.
ASET	ASET represents an array element assignment.
CALL	CALL objects represent method invocations.
CJMP	CJMP represents conditional branches.
Code	Quads.Code is an abstract superclass of codeviews using the components in IR.Quads.
COMPONENTOF	COMPONENTOF objects implement the test needed to determine if an ASET needs to throw an exception.
CONST	CONST objects represent an assignment of a constant value to a compiler temporary.
DEBUG	DEBUG prints a debugging string to standard error.
Edge	Edge objects connect Quad nodes in the control-flow graph.
FOOTER	FOOTER nodes are used to anchor the bottom end of the quad graph.
GET	GET represent field access (get) operations.
HANDLER	A HANDLER quad marks an entry to an exception handler.
HandlerSet	A HandlerSet is a linked list of handlers, for purposes of comparison.
HEADER	HEADER nodes are used to anchor the top end of the quad graph.
INSTANCEOF	INSTANCEOF objects represent an 'instanceof' evaluation.
LABEL	LABEL marks a basic-block entrance.
METHOD	Quads.METHOD nodes encode method-specific information: the mapping of method formals to temporary variables, and links to the exception handlers for the method.
MONITORENTER	MONITORENTER acquires the monitor lock of a particular object.
MONITOREXIT	MONITOREXIT releases the monitor lock of a particular object.
MOVE	MOVE objects represent an assignment to a compiler temporary.
NEW	NEW represents an object creation operation.
NOP	NOP nodes do nothing.
OPER	OPER objects represent arithmetic/logical operations, including mathematical operators such as add and subtract, conversion operators such as double-to-int, and comparison operators such as greater than and equals.
OperVisitor	An OperVisitor is a visitor pattern for opcodes of the OPER quad.
Pattern	Pattern please document me if I'm public!
PHI	PHI objects represent blocks of phi functions.
Qop	Qop is an enumerated type for the various kinds of OPER opcodes.
Quad	Quad is the base class for the quadruple representation.
QuadFactory	A QuadFactory is responsible for assigning unique numbers to the Quads in a method, and for maintaining some method-wide information (such as a pointer to the parent HCode).
QuadKind	QuadKind is an enumerated type for the various kinds of Quads.
QuadNoSSA	QuadNoSSA is a code view with explicit exception handling.
QuadRSSx	Quads.QuadRSSx is a code view in relaxed SSI form.
QuadSSA	Quads.QuadSSA is a code view in SSA form.
QuadSSI	Quads.QuadSSI is a code view in SSI form.
QuadValueVisitor<T>	QuadValueVisitor is a visitor class that returns a (parameterized) value.
QuadVisitor	QuadVisitor is a Design Pattern, courtesy of Martin.
QuadWithTry	QuadWithTry is a code view with explicit try-block handlers.
ResilientNoSSA	ResilientNoSSA is a code view with resilient exception handling.
RETURN	RETURN objects indicate a method return, with an optional return value.
RSSxToNoSSA	RSSxToNoSSA converts "relaxed-ssx" form into quads without phi or sigma functions.
SET	SET represents field assignment-to operations.
SIGMA	SIGMA functions are added where control flow splits.
SSIRename	SSIRename is a new, improved, fast SSI-renaming algorithm.
SSIToSSA	SSIToSSA renames variables to eliminate sigma functions in an SSI-form codeview, yielding an SSA codeview.
SWITCH	SWITCH represents a switch construct.
TempChain	TempChain needs to be documented.
ThreadInliner	ThreadInliner
THROW	THROW represents a throw statement.
ToNoSSA	The ToNoSSA class implements the translation between SSA and No-SSA form.
TYPECAST	TYPECAST performs a typecast on a given variable.
TYPESWITCH	TYPESWITCH represents a multiple-way branch dependent on the class type of the argument.

Package harpoon.IR.Quads Description

A flat, typed, high-level quadruple-based IR.

Quad form is used for most analysis and transformation in the compiler. It maintains strong typing, and tries to be minimal. There are three main variants, and an additional variant which is occasionally useful as an intermediate:

• QuadWithTry, which contains HANDLER quads to handle thrown exceptions, and does implicit safety-checking.
• QuadNoSSA which handles all exceptions explicitly.
• QuadSSI which is the same as the above, except it is in SSI form.
• QuadRSSx is a relaxed version of QuadSSA/QuadSSI; during program transformations it is sometimes easier to break the phi/sigma constraints of SSA/SSI form without doing a full translation to/from QuadNoSSA. Relaxed-SSx (RSSx) form is what we call this "SSA/SSI form with broken constraints".

For lower-level transformations involving explicit pointer arithmetic, LowQuad form must be used.

Related Documentation

For further information, see:

• Tutorial on FLEX compiler intermediate representation

Author:

C. Scott Ananian <cananian@alumni.princeton.edu>