avrora.sim.util
Class MemoryMatrixProfiler

java.lang.Object
  avrora.sim.util.MemoryMatrixProfiler

public class MemoryMatrixProfiler

extends java.lang.Object

The MemoryMatrixProfiler class collects information about a program's usage of memory. For each instruction in the program, it tracks the memory locations read and written by that instruction. For example, a load instruction that uses an address in a register might load bytes from various locations in the data memory. This class maintains two internal two-dimensional matrices, one for read counts and one for write counts. The matrices are indexed by code address and data address.

Field Summary

int	ramSize The ramSize field stores the maximum RAM address that should be recorded.
long[][]	rcount The rcount field stores a two dimensional array that records the read count for each memory location for each instruction.
long[][]	wcount The rcount field stores a two dimensional array that records the write count for each memory location for each instruction.

Constructor Summary

MemoryMatrixProfiler(Program p, int size)
The constructor for the MemoryMatrixProfiler class creates a new memory probe that can be inserted into the simulator to record the full memory access statistics of the program.

Method Summary

void	fireAfterRead(Instr i, int address, State state, int data_addr, byte value) The fireAfterRead() method is called after the data address is read by the program.
void	fireAfterWrite(Instr i, int address, State state, int data_addr, byte value) The fireAfterWrite() method is called after the data address is written by the program.
void	fireBeforeRead(Instr i, int address, State state, int data_addr, byte value) The fireBeforeRead() method is called before the data address is read by the program.
void	fireBeforeWrite(Instr i, int address, State state, int data_addr, byte value) The fireBeforeWrite() method is called before the data address is written by the program.
long	getReadCount(int address, int data_addr) The getReadCount() method returns the number of times the specified instruction read the specified memory address.
long	getWriteCount(int address, int data_addr) The getWriteCount() method returns the number of times the specified instruction wrote the specified memory address.

Methods inherited from class java.lang.Object

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

Field Detail

rcount

public final long[][] rcount

The rcount field stores a two dimensional array that records the read count for each memory location for each instruction. It is indexed by program address, and then by data address. This matrix is row-sparse in that rows of all zero (e.g. a non-memory instruction) are not stored. To access this matrix, use the getReadCount() method.

wcount

public final long[][] wcount

The rcount field stores a two dimensional array that records the write count for each memory location for each instruction. It is indexed by program address, and then by data address. This matrix is row-sparse in that rows of all zero (e.g. a non-memory instruction) are not stored. To access this matrix, use the getWriteCount() method.

ramSize

public final int ramSize

The ramSize field stores the maximum RAM address that should be recorded.

Constructor Detail

MemoryMatrixProfiler

public MemoryMatrixProfiler(Program p,
                            int size)

The constructor for the MemoryMatrixProfiler class creates a new memory probe that can be inserted into the simulator to record the full memory access statistics of the program.

Parameters:

p - the program to record statistics for

size - the size of the RAM in bytes

Method Detail

fireBeforeRead

public void fireBeforeRead(Instr i,
                           int address,
                           State state,
                           int data_addr,
                           byte value)

The fireBeforeRead() method is called before the data address is read by the program. In the implementation of MemoryMatrixProfiler, it simply increments the count of reads at the address of the instruction and memory location by one.

Parameters:

i - the instruction being probed

address - the address at which this instruction resides

state - the state of the simulation

data_addr - the address of the data being referenced

value - the value of the memory location being read

fireBeforeWrite

public void fireBeforeWrite(Instr i,
                            int address,
                            State state,
                            int data_addr,
                            byte value)

The fireBeforeWrite() method is called before the data address is written by the program. In the implementation of MemoryMatrixProfiler, it simply increments the count of writes at the address of the instruction and memory location by one.

Parameters:

i - the instruction being probed

address - the address at which this instruction resides

state - the state of the simulation

data_addr - the address of the data being referenced

value - the value being written to the memory location

fireAfterRead

public void fireAfterRead(Instr i,
                          int address,
                          State state,
                          int data_addr,
                          byte value)

The fireAfterRead() method is called after the data address is read by the program. In the implementation of MemoryMatrixProfiler, it does nothing.

Parameters:

i - the instruction being probed

address - the address at which this instruction resides

state - the state of the simulation

data_addr - the address of the data being referenced

value - the value of the memory location being read

fireAfterWrite

public void fireAfterWrite(Instr i,
                           int address,
                           State state,
                           int data_addr,
                           byte value)

The fireAfterWrite() method is called after the data address is written by the program. In the implementation of MemoryMatrixProfiler, it does nothing.

Parameters:

i - the instruction being probed

address - the address at which this instruction resides

state - the state of the simulation

data_addr - the address of the data being referenced

value - the value being written to the memory location

getReadCount

public long getReadCount(int address,
                         int data_addr)

The getReadCount() method returns the number of times the specified instruction read the specified memory address.

Parameters:

address - the program address of the instruction

data_addr - the address of the byte of memory

Returns:

the number of times the specified instruction read the specified memory address.

getWriteCount

public long getWriteCount(int address,
                          int data_addr)

The getWriteCount() method returns the number of times the specified instruction wrote the specified memory address.

Parameters:

address - the program address of the instruction

data_addr - the address of the byte of memory

Returns:

the number of times the specified instruction wrote the specified memory address.