(11C) 100 virtual registers

03182018, 12:04 AM
Post: #1




(11C) 100 virtual registers
Get 100 virtual registers instead of just 20!
These are STO and RCL commands to store a number between 0 and 99 in a virtual register numbered 0 to 99. I recommend using labels D and E because they are in the same columns as STO and RCL. vRCL x Recall a number from virtual register X. Notice how this affects the stack: Before: T: ? Z: z Y: y X: Register number (099) After: T: z Z: z Y: y X: Register content y vSTO x Stores Y in virtual register X. Unlike regular STO, this removes the value from the stack so if you need it again you'll have to vRCL it. This also destroys T: Before: T: ? Z: z Y: Data (099) X: Register (099) After: T: Garbage Z: z Y: z X: z Only tested on the Android 11i simulator, but it should work on real devices (please comment if it doesn't): Code: LBL D 

03182018, 04:23 PM
Post: #2




RE: (11C) 100 virtual registers
If you take into account that the program itself takes about 9 registers worth of storage away it is still worth it if numbers in the range 099 are enough for your program because you effectively gained 35 more registers (100  9*5  20).
The method would also work for differenty sized virtual register: Code:


03182018, 06:29 PM
Post: #3




RE: (11C) 100 virtual registers
(03182018 12:04 AM)michaelzinn Wrote: Get 100 virtual registers instead of just 20! I see you are rediscovering techniques from the Seventies. ;) Storing multiple integers in a single data register soon became popular with the advent of the HP67/97 in 1976, as these were – as far as I know – the first HPs that offered indirect addressing. There are even HP programs where you can see this method at work. Take a look at this moon phase program for the HP41. The initialization routine prestores numerous twodigit integers where each register holds three or five at a time. By the way: instead of 2 [10^x] you better use [EEX] 2. That's faster and it's also safe on early HPs where 10^x is prone to roundoff errors (HP25: 8 [10^x] => 99999999,60). That's exactly why HP soon switched to 13digit internal precision. Dieter 

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