org.jikesrvm.compilers.opt.depgraph

Class DepGraphStats

java.lang.Object

org.jikesrvm.compilers.opt.depgraph.DepGraphStats

public class DepGraphStats
extends Object

This module provides dependence graph statistics. It will only be used for for experimental measurements, so compile-time overhead is less of a concern.

See Also:

DepGraph

Constructor Summary

Constructors

Constructor and Description
DepGraphStats(DepGraph dg, String bbName) Create a statistical summary of a dependence graph for a given basic block.

Method Summary

Modifier and Type	Method and Description
(package private) int	estimateExecutionTime(Instruction instr) Returns an estimate of the number of cycles for a given instruction.
static void	printBasicBlockStatistics(IR ir) Print the dependence graph stats for all basic blocks in an IR.

Methods inherited from class java.lang.Object

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

Constructor Detail

DepGraphStats

DepGraphStats(DepGraph dg,
              String bbName)

Create a statistical summary of a dependence graph for a given basic block.

Parameters:

dg - the dependence graph

bbName - name of the basic block

Method Detail

printBasicBlockStatistics

public static void printBasicBlockStatistics(IR ir)

Print the dependence graph stats for all basic blocks in an IR.

Parameters:

ir - the IR

estimateExecutionTime

int estimateExecutionTime(Instruction instr)

Returns an estimate of the number of cycles for a given instruction. Currently, this estimate is comically simple (see below).

Parameters:

instr - the instruction

Returns:

0 or 1