cetus.transforms

Class ReductionTransform

java.lang.Object

cetus.transforms.TransformPass

cetus.transforms.ReductionTransform

public class ReductionTransform
extends TransformPass

This trasformation produces OpenMP-conforming codes from the reduction items recognized by Reduction. The recognition algorithm is lenient enough to allow arbitrary types of expressions in the reduction items, but appropriate code generation is required to produce a code that is accepted by the backend (OpenMP) compiler. The transformation assumes that the loop-parallelization pass does not allow nested parallelism. The command-line option -reduction=N affects the behavior of this transformation as follows:

• -reduction=1: Allows only scalar reduction
• -reduction=2: Generates code for array reduction with private copies
• -reduction=3: Protects reduction statement with synchronization
• -reduction=4: Protects reduction statement if code generation fails

Notice that the third and fourth options always result in parallelized loops even with possible data dependences but the resulting code may be inefficient because of the inserted synchronization.

Constructor Summary

Constructors

Constructor and Description
ReductionTransform(Program program) Constructs a new reduction transformation pass.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.String	getPassName() Returns the pass name.
void	start() Starts the transformation.

Methods inherited from class cetus.transforms.TransformPass

run

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReductionTransform

public ReductionTransform(Program program)

Constructs a new reduction transformation pass.

Parameters:

program - the input program.

Method Detail

start

public void start()

Starts the transformation.

Specified by:

start in class TransformPass

getPassName

public java.lang.String getPassName()

Returns the pass name.

Specified by:

getPassName in class TransformPass