50g Mini-Challenge: Number of positive divisors of x!

[Joe Horn]

(09-30-2017 04:29 PM)Gerald H Wrote:  Here a SysRPL programme following Thomas' suggestion which correctly processes 100 in 0.5604s, a definite improvement on my first attempt.
Size: 147.0000
CkSum: # FDBAh

Wow, very impressive! Two quick questions:

(1) FPTR 6 119 (^RADDext) and FPTR 6 118 (^QAdd) both resolve to address 6:5253B, so they are really identical functions. Is there a reason that you prefer using ^RADDext instead of ^QAdd in this program? Same question for the identical functions ^RMULText and ^QMul. (It might help if I knew what the "Q" and the "R" stand for in those function names.)

(2) Your second System RPL program evaluates an input of 100 in half a second, so when I keyed up the same program in User RPL (exactly the same, step-by-step, just in URPL), I expected it to run slower, but it ran MUCH slower than I anticipated. URPL is always slower than SysRPL, but this difference seems crazy:

320 SysRPL --> 1.5 seconds
320 URPL --> 18.6 seconds!

Why is this SysRPL program so much faster? Is it simply because SysRPL is always faster, especially when looping is involved?

Always eager to learn! Thanks in advance for your insights!