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Re: IDEA vs DES
According to my references, the PowerPC 601 does an integer multiply
in 9 cycles (5 if the 2nd operand is 16 bits or less). An integer
divide takes 36 cycles. Adds, etc. take 1 cycle.
Floating-point multiplies take 1 cycle for single precision, 2 for double.
However, they are pipelined, so if you need to use the results of the
multiply on the next instruction, they will take 3 cycles. Floating-point
adds take 1 cycle, again with the results available in 3.
There is a floating-point (but no integer) multiply-and-add instruction.
It has the same timing as the multiply.
Hal