preece@ccvaxa.UUCP (05/07/87)
doug@edge.UUCP: > I wasn't referring to efficiency. I was referring to predictability. I > can look in my book here and find that on a 10MHz 68000, the instruction > MOVE.W 6(A0),D0 will take exactly 1.6+.1w microseconds, for a "w" wait > state memory. I haven't the vaguest idea how long it will take to > execute > temp1 = ptr1->count; and what's worse, a change to some other part of > the same module could cause this statement to be faster or slower (as > the result of global optimization). Okay? ---------- It may be slightly harder to determine the execution time for the C code, but it should still be deterministic as long as you're using the same compiler and the same hardware. If you retarget your code you would need to review critical time dependencies, but the same would be true if you retargetted your assembler code to a different clock rate, different memory management hardware, or to hardware with more or less cache. -- scott preece gould/csd - urbana uucp: ihnp4!uiucdcs!ccvaxa!preece arpa: preece@gswd-vms