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Hi Ian,
It depends on how they did the
comparison. For in machine code you do a register to memory check or memory to
memory check or register to register check. The clock cycles are more in moving
memory or comparing memory because of the need to address the memory point.
It depends on how they wrote the
comparison. It also depends on the order of checking and if memory had to be
moved to do it and that to depends on the programmer and how they decided to do
the logic for the check.
Like assembler code:
cmp [i],1
jl move-on
cmp [i],9
jg move-on
do something here move-on:
I used [] brackets to indicate the memory
location of the i variable. Now in the other comparison I suspect that the way
that check goes they had to either create a location for 1 or move i into a
register and in either case more clock cycles needed to process the
check.
the first one above in my
example is the faster check and mirrors the second comparison and would be
standard machine code for the comparison. Now the other logic on how the
stringing of comparisons is done, I suspect that the one of those check objects
have to be moved into an area before the check in order to decode the
logic...
Thus the comparison in the first
case below just requires lots more clock cycles to process it.
Bruce
If I recall correctly, the syntax Ian |