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Arduino cheat sheet: Difference between revisions
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==== Fast loops ==== | |||
[http://embeddedgurus.com/stack-overflow/2009/03/efficient-c-tips-7-fast-loops/ Efficient C Tips #7 – Fast loops « Stack Overflow] | |||
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So how does this efficiency arise? Well in the count up case, the assembly language generated by the compiler typically looks something like this: | |||
INC lpc ; Increment loop counter | |||
SUB lpc, #10 ; Compare loop counter to 10 | |||
BNZ loop ; Branch if loop counter not equal to 10 | |||
By contrast, in the count down case the assembly language looks something like this | |||
DEC lpc ; Decrement loop counter | |||
BNZ loop ; Branch if non zero | |||
Evidently, because of the ‘specialness’ of zero, more efficient code can be generated. | |||
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