Is there such a Thing as a Program Optimizer?
MovieMaker
Posts: 502
Is there such a Thing as a Program Optimizer?
After you have gotten your program to work fine in what ever language (C for me right now), is there a Second compiler you can put it through that it would search for code that would do the same thing with less code and replace the main code with the shorter code and make things run faster?
It is a silly idea, but it seems it would certainly save some time and be very useful, at least to me.
If they make such an animal, what would it be called?
·
After you have gotten your program to work fine in what ever language (C for me right now), is there a Second compiler you can put it through that it would search for code that would do the same thing with less code and replace the main code with the shorter code and make things run faster?
It is a silly idea, but it seems it would certainly save some time and be very useful, at least to me.
If they make such an animal, what would it be called?
·
Comments
Most compilers (for mainstream languages) do all sorts of tricks to optimize for speed or size. Compiler Optimization has everything you may want to know.
But otherwise, you probably won't find a stand alone program that will take any program in and give any program out that's 'better'.
While the compilers can do a lot, they will still follow your basic algorithm. Most of the "big changes" tend to involve a different way of doing things.
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John R.
Click here to see my Nomad Build Log
Thanks~!
#include <MegaServo.h>
MegaServo myservo;
// Begin Robot Code
int micVal;
int cdsVal;
int irLval; // Left IR
int irCval; // Center IR
int irRval; // Right IR
int irRRval; // Rear IR
int i; // Generic Counter
int x; // Generic Counter
int PLval; // Pulse Width for Left Servo
int PRval; // Pulse Width for Right Servo
int cntr; // Generic Counter Used for Determining amt. of Object Detections
int counter; // Generic Counter
int clrpth; // amt. of Milliseconds Of Unobstructed Path
int objdet; // Time an Object was Detected
int task; // Routine to Follow for Clearest Path
int pwm; // Pulse Width for Pan Servo
boolean add; // Whether to Increment or Decrement PW Value for Pan Servo
int distance; // Distance to Object Detected via Ultrasonic Ranger
int oldDistance; // Previous Distance Value Read from Ultrasonic Ranger
float scale = 1.9866666666666666666666666666667; // *Not Currently Used*
int LeftPin = 6; // Left Servo
int RightPin = 9; // Right Servo
int PingServoPin = 5; // Pan Servo
int irLPin = 0; // Analog 0; Left IR
int irCPin = 1; // Analog 1; Center IR
int irRPin = 2; // Analog 2; Right IR
int irRRPin =3; // Analog 3; Rear IR
int ultraSoundSignal = 7; // Ultrasound signal pin
int val = 0; // Used for Ultrasonic Ranger
int ultrasoundValue = 0; // Raw Distance Val
int oldUltrasoundValue; // *Not used*
int pulseCount; // Generic Counter
int timecount = 0; // Echo counter
int ledPin = 13; // LED connected to digital pin 13
int pos = 0;
int SPKR = 4;
#define BAUD 9600
#define CmConstant 1/29.034
void setup() {
myservo.attach(11);
pos = 40;
myservo.write(pos);
delay(150);
myservo.detach();
Serial.begin(9600);
pinMode(SPKR, OUTPUT);
pinMode(ledPin, OUTPUT);
pinMode(LeftPin, OUTPUT);
pinMode(RightPin, OUTPUT);
pinMode(PingServoPin, OUTPUT);
pinMode(irLPin, INPUT);
pinMode(irCPin, INPUT);
pinMode(irRPin, INPUT);
pinMode(irRRPin, INPUT);
// Beep!
{
for (int i = 0; i<500; i++) { // generate a 1KHz tone for 1/2 second
digitalWrite(SPKR, HIGH);
delayMicroseconds(500);
digitalWrite(SPKR, LOW);
delayMicroseconds(500);
}
for(i = 0; i < 20; i++) {
digitalWrite(PingServoPin, HIGH);
delayMicroseconds(655 * 2);
digitalWrite(PingServoPin, LOW);
delay(20);
}
ultrasoundValue = 600;
i = 0;
}
}
void loop()
{
Look();
Go();
}
void Look() {
irLval = analogRead(irLPin);
irCval = analogRead(irCPin);
irRval = analogRead(irRPin);
if(irLval > 200) {
BrowUP();
PLval = 850;
PRval = 820;
x = 5;
cntr = cntr + 1;
clrpth = 0;
objdet = millis();
}
else if(irCval > 200) {
BrowUP();
PLval = 850;
PRval = 820;
x = 10;
cntr = cntr + 1;
clrpth = 0;
objdet = millis();
}
else if(irRval > 200) {
BrowUP();
PLval = 650;
PRval = 620;
x = 5;
cntr = cntr + 1;
clrpth = 0;
objdet = millis();
}
else {
x = 1;
PLval = 850;
PRval = 620;
counter = counter + 1;
clrpth = (millis() - objdet);
if(add == true) {
pwm = pwm + 50;
}
else if(add == false) {
pwm = pwm - 50;
}
if(pwm < 400) {
pwm = 400;
add = true;
}
if(pwm > 950) {
pwm = 950;
add = false;
}
digitalWrite(PingServoPin, HIGH);
delayMicroseconds(pwm * 2);
digitalWrite(PingServoPin, LOW);
delay(20);
readPing();
if(ultrasoundValue < 200) { // this value is the closeness of PING will get.
cntr = cntr + 1;
switch(pwm) {
case 400:
x = 7;
PLval = 650;
PRval = 650;
Go();
break;
case 500:
x = 10;
PLval = 650;
PRval = 650;
Go();
break;
case 600:
x = 14;
PLval = 850;
PRval = 850;
Go();
break;
case 700:
x = 10;
PLval = 850;
PRval = 850;
Go();
break;
case 950:
x = 7;
PLval = 850;
PRval = 850;
Go();
break;
}
}
}
if(cntr > 25 && clrpth < 2000) {
clrpth = 0;
cntr = 0;
Scan();
}
}
void Go() {
for(i = 0; i < x; i++) {
digitalWrite(LeftPin, HIGH);
delayMicroseconds(PLval * 2);
digitalWrite(LeftPin, LOW);
digitalWrite(RightPin, HIGH);
delayMicroseconds(PRval * 2);
digitalWrite(RightPin, LOW);
delay(20);
}
}
void readPing() { // Get Distance from Ultrasonic Ranger
timecount = 0;
val = 0;
pinMode(ultraSoundSignal, OUTPUT); // Switch signalpin to output
digitalWrite(ultraSoundSignal, LOW); // Send low pulse
delayMicroseconds(2); // Wait for 2 microseconds
digitalWrite(ultraSoundSignal, HIGH); // Send high pulse
delayMicroseconds(5); // Wait for 5 microseconds
digitalWrite(ultraSoundSignal, LOW); // Holdoff
pinMode(ultraSoundSignal, INPUT); // Switch signalpin to input
val = digitalRead(ultraSoundSignal); // Append signal value to val
while(val == LOW) { // Loop until pin reads a high value
val = digitalRead(ultraSoundSignal);
}
while(val == HIGH) { // Loop until pin reads a high value
val = digitalRead(ultraSoundSignal);
timecount = timecount +1; // Count echo pulse time
}
ultrasoundValue = timecount; // Append echo pulse time to ultrasoundValue
// Lite up LED if any value is passed by the echo pulse
if(timecount > 0){
digitalWrite(ledPin, HIGH);
}
}
void Scan() { // Scan for the Clearest Path
oldDistance = 10;
task = 0;
for(i = 1; i < 5; i++) {
switch(i) {
case 1:
//Serial.println("Pos. 1");
pwm = 1125; /// incr. by 100 from 1085
break;
case 2:
//Serial.println("Pos. 2");
pwm = 850; //// increased by 100 from 850
break;
case 3:
//Serial.println("Pos. 3");
pwm = 400;
break;
case 4:
//Serial.println("Pos. 4");
pwm = 235;
break;
}
for(pulseCount = 0; pulseCount < 20; pulseCount++) { // Adjust Pan Servo and Read USR
digitalWrite(PingServoPin, HIGH);
delayMicroseconds(pwm * 2);
digitalWrite(PingServoPin, LOW);
readPing();
delay(20);
}
distance = ((float)ultrasoundValue * CmConstant); // Calculate Distance in Cm
if(distance > oldDistance) { // If the Newest distance is longer, replace previous reading with it
oldDistance = distance;
task = i; // Set task equal to Pan Servo Position
}
}
distance = 50; // Prevents Scan from Looping
switch(task) { // Determine which task should be carried out
case 0: // Center was clearest
x = 28;
PLval = (850);
PRval = (850);
Go();
break;
case 1: // 90 degrees Left was Clearest
x = 14;
PLval = (650);
PRval = (650);
Go();
break;
case 2: // 45 degrees left
x = 7;
PLval = (650);
PRval = (650);
Go();
break;
case 3: // 45 degrees right
x = 7;
PLval = (850);
PRval = (850);
Go();
break;
case 4: // 90 degrees right
x = 14;
PLval = (850);
PRval = (850);
Go();
break;
}
}
void BrowUP()
{
myservo.attach(11);
pos = 0;
myservo.write(pos);
delay(500);
BrowDOWN();
delay(50);
myservo.detach();
return;
}
void BrowDOWN()
{
myservo.attach(11);
pos = 40;
myservo.write(pos);
delay(50);
myservo.detach();
return;
}
// End Robot Code
Thanks for your help.
#include <MegaServo.h>
MegaServo myservo;
// Begin Robot Code
//int micVal;
//int cdsVal;
int irLval; // Left IR
int irCval; // Center IR
int irRval; // Right IR
int i; // Generic Counter
int x; // Generic Counter
int PLval; // Pulse Width for Left Servo
int PRval; // Pulse Width for Right Servo
int cntr; // Generic Counter Used for Determining amt. of Object Detections
int counter; // Generic Counter
int clrpth; // amt. of Milliseconds Of Unobstructed Path
int objdet; // Time an Object was Detected
int task; // Routine to Follow for Clearest Path
int pwm; // Pulse Width for Pan Servo
boolean add; // Whether to Increment or Decrement PW Value for Pan Servo
int distance; // Distance to Object Detected via Ultrasonic Ranger
int oldDistance; // Previous Distance Value Read from Ultrasonic Ranger
float scale = 1.9866666666666666666666666666667; // *Not Currently Used*
int LeftPin = 6; // Left Servo
int RightPin = 9; // Right Servo
int PingServoPin = 5; // Pan Servo
int irLPin = 0; // Analog 0; Left IR
int irCPin = 1; // Analog 1; Center IR
int irRPin = 2; // Analog 2; Right IR
int ultraSoundSignal = 7; // Ultrasound signal pin
int val = 0; // Used for Ultrasonic Ranger
int ultrasoundValue = 0; // Raw Distance Val
int oldUltrasoundValue; // *Not used*
int pulseCount; // Generic Counter
int timecount = 0; // Echo counter
int ledPin = 13; // LED connected to digital pin 13
int pos = 0;
int SPKR = 4;
#define BAUD 9600
#define CmConstant 1/29.034
void setup() {
myservo.attach(11);
pos = 40;
myservo.write(pos);
delay(150);
myservo.detach();
Serial.begin(9600);
pinMode(SPKR, OUTPUT);
pinMode(ledPin, OUTPUT);
pinMode(LeftPin, OUTPUT);
pinMode(RightPin, OUTPUT);
pinMode(PingServoPin, OUTPUT);
pinMode(irLPin, INPUT);
pinMode(irCPin, INPUT);
pinMode(irRPin, INPUT);
// Beep!
{
for (int i = 0; i<500; i++) { // generate a 1KHz tone for 1/2 second
digitalWrite(SPKR, HIGH);
delayMicroseconds(400);
digitalWrite(SPKR, LOW);
delayMicroseconds(400);
}
for(i = 0; i < 20; i++) {
digitalWrite(PingServoPin, HIGH);
delayMicroseconds(655 * 2);
digitalWrite(PingServoPin, LOW);
delay(20);
}
ultrasoundValue = 600;
i = 0;
}
}
void loop()
{
Look();
Go();
}
void Look() {
irLval = analogRead(irLPin);
irCval = analogRead(irCPin);
irRval = analogRead(irRPin);
if(irLval > 200) {
BrowUP();
PLval = 850;
PRval = 820;
x = 5;
cntr = cntr + 1;
clrpth = 0;
objdet = millis();
}
else if(irCval > 200) {
BrowUP();
PLval = 850;
PRval = 820;
x = 10;
cntr = cntr + 1;
clrpth = 0;
objdet = millis();
}
else if(irRval > 200) {
BrowUP();
PLval = 650;
PRval = 620;
x = 5;
cntr = cntr + 1;
clrpth = 0;
objdet = millis();
}
else {
x = 1;
PLval = 850;
PRval = 620;
counter = counter + 1;
clrpth = (millis() - objdet);
if(add == true) {
pwm = pwm + 50;
}
else if(add == false) {
pwm = pwm - 50;
}
if(pwm < 400) {
pwm = 400;
add = true;
}
if(pwm > 950) {
pwm = 950;
add = false;
}
digitalWrite(PingServoPin, HIGH);
delayMicroseconds(pwm * 2);
digitalWrite(PingServoPin, LOW);
delay(20);
readPing();
if(ultrasoundValue < 150) { // this value is the closeness of PING will get.
cntr = cntr + 1;
switch(pwm) {
case 400:
x = 7;
PLval = 650;
PRval = 650;
Go();
break;
case 500:
x = 10;
PLval = 650;
PRval = 650;
Go();
break;
case 600:
x = 14;
PLval = 850;
PRval = 850;
Go();
break;
case 700:
x = 10;
PLval = 850;
PRval = 850;
Go();
break;
case 950:
x = 7;
PLval = 850;
PRval = 850;
Go();
break;
}
}
}
if(cntr > 25 && clrpth < 2000) {
clrpth = 0;
cntr = 0;
Scan();
}
}
void Go() {
for(i = 0; i < x; i++) {
digitalWrite(LeftPin, HIGH);
delayMicroseconds(PLval * 2);
digitalWrite(LeftPin, LOW);
digitalWrite(RightPin, HIGH);
delayMicroseconds(PRval * 2);
digitalWrite(RightPin, LOW);
delay(20);
}
}
void readPing() { // Get Distance from Ultrasonic Ranger
timecount = 0;
val = 0;
pinMode(ultraSoundSignal, OUTPUT); // Switch signalpin to output
digitalWrite(ultraSoundSignal, LOW); // Send low pulse
delayMicroseconds(2); // Wait for 2 microseconds
digitalWrite(ultraSoundSignal, HIGH); // Send high pulse
delayMicroseconds(5); // Wait for 5 microseconds
digitalWrite(ultraSoundSignal, LOW); // Holdoff
pinMode(ultraSoundSignal, INPUT); // Switch signalpin to input
val = digitalRead(ultraSoundSignal); // Append signal value to val
while(val == LOW) { // Loop until pin reads a high value
val = digitalRead(ultraSoundSignal);
}
while(val == HIGH) { // Loop until pin reads a high value
val = digitalRead(ultraSoundSignal);
timecount = timecount +1; // Count echo pulse time
}
ultrasoundValue = timecount; // Append echo pulse time to ultrasoundValue
// Lite up LED if any value is passed by the echo pulse
if(timecount > 0){
digitalWrite(ledPin, HIGH);
}
}
void Scan() { // Scan for the Clearest Path
oldDistance = 30;
task = 0;
for(i = 1; i < 5; i++) {
switch(i) {
case 1:
//Serial.println("Pos. 1");
pwm = 1125; /// incr. by 100 from 1085
break;
case 2:
//Serial.println("Pos. 2");
pwm = 850; //// increased by 100 from 850
break;
case 3:
//Serial.println("Pos. 3");
pwm = 400;
break;
case 4:
//Serial.println("Pos. 4");
pwm = 235;
break;
}
for(pulseCount = 0; pulseCount < 20; pulseCount++) { // Adjust Pan Servo and Read USR
digitalWrite(PingServoPin, HIGH);
delayMicroseconds(pwm * 2);
digitalWrite(PingServoPin, LOW);
readPing();
delay(20);
}
distance = ((float)ultrasoundValue * CmConstant); // Calculate Distance in Cm
if(distance > oldDistance) { // If the Newest distance is longer, replace previous reading with it
oldDistance = distance;
task = i; // Set task equal to Pan Servo Position
}
}
distance = 50; // Prevents Scan from Looping
switch(task) { // Determine which task should be carried out
case 0: // Center was clearest
x = 28;
PLval = (850);
PRval = (850);
Go();
break;
case 1: // 90 degrees Left was Clearest
x = 14;
PLval = (650);
PRval = (650);
Go();
break;
case 2: // 45 degrees left
x = 7;
PLval = (650);
PRval = (650);
Go();
break;
case 3: // 45 degrees right
x = 7;
PLval = (850);
PRval = (850);
Go();
break;
case 4: // 90 degrees right
x = 14;
PLval = (850);
PRval = (850);
Go();
break;
}
}
void BrowUP()
{
myservo.attach(11);
pos = 0;
myservo.write(pos);
delay(500);
BrowDOWN();
return;
}
void BrowDOWN()
{
myservo.attach(11);
pos = 40;
myservo.write(pos);
delay(120);
myservo.detach();
return;
}
// End Robot Code
I've never programmed a uC in C, but I do alot of C++ at school so some of the general algorithms are understandable.
Some tips for better C*:
1. Never use a global variable. It completely destroys the benefits of scope.
2. Use lots of functions. Most functions should take parameters and return a value (dependent on the function purpose)
3. Don't repeat yourself. For example, instead of controlling servos all throughout your code, use a single function, possibly with a header like "bool servo(int pin, int position)".
4. Avoid the use of 'magic numbers'. Use constants instead.
5. Encapsulate things that are likely to change in functions. For example, you may change the way you get distance readings. If it's in it's own function, you need to look in only one place.
6. Use lots of comments. At a minimum, comment every functions parameters and return value.
Anyway, HTH.
*These are how many people like to write C (and other HLL), and it's how I like to do it. Some people will probably just say of these rules "That's dumb" or "That's conformist c**p". They probably work harder than they have to by being stubborn.