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performance [2019/08/05 11:47] – [Tip #8 REPEAT ... UNTIL is faster than FOR ... NEXT] neilsperformance [2021/01/10 19:21] (current) – [Tip #3: Do arithmetic only when necessary] gabrielsroka
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 ==== Tip #3: Do arithmetic only when necessary ==== ==== Tip #3: Do arithmetic only when necessary ====
  
-Even the simplest addition or substraction can take precious time, especially when used in loops. Make sure to eliminate all the arithmetic operations that are not necessary in runtime.+Even the simplest addition or subtraction can take precious time, especially when used in loops. Make sure to eliminate all the arithmetic operations that are not necessary in runtime.
  
 Wrong example: Wrong example:
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   until i! = 100   until i! = 100
      
-==== Tip #9: Know the optimizer ====+==== Tip #9: Use LSHIFT() and RSHIFT() ==== 
 + 
 +It's much faster to multiply or divide by powers of two using bit shifting operations. Use [[lshift|LSHIFT()]] and [[rshift|RSHIFT()]] whenever you can. 
 + 
 +==== Tip #10: Know the optimizer ====
  
 **XC=BASIC** features a built-in optimizer that replaces commonly used program sequences with faster opcode sequences. To make good use of the optimizer, bear in mind the following program structures that can be optimized: **XC=BASIC** features a built-in optimizer that replaces commonly used program sequences with faster opcode sequences. To make good use of the optimizer, bear in mind the following program structures that can be optimized: