newRPL - build 1255 released! [updated to 1299]

[Claudio L.]

I updated all ROMs to build 1323.
It fixes a few bugs and introduces 2 new assembly-like commands:
SGET and SPUT (as in Stack GET and Stack PUT).

Playing with the N-queens benchmark I realized access to the stack was always in hard-coded terms (using the pseudo registers S1..S7) and there was no indexed access to the stack.
SGET/SPUT use the stack as a vector of objects:

SGET.lvl --> Reads the stack at level lvl, where 'lvl' can be a register, a literal or a stack reference to an index number.
SPUT.lvl.A --> Stores A into stack level 'lvl'. Both A and 'lvl' can be anything.

With these 2 commands, indirect access to the stack is provided.

I used it to code one more example:

Code:


«
:CLR.A.8
:PUSH.A.8

:CMP.B.8
:LOOP.NE
::
    :B+=1
    :SPUT.B.8
    :CMP.2.1
    :LOOP.NE
    ::
        :A+=1
        :C=B
        :CMP.C.1
        :LOOP.GT
        ::
            :C-=1
            :D=SGET.B
            :D-=SGET.C
            :CMP.D.0
            :E=CHK.EQ
            :F=B-C
            :G=ABS.D
            :CMP.G.F
            :F=CHK.EQ
            :OR.E.F
            :SKIP.EQ
            ::
                :C=0
    
                :F=SGET.B
                :F-=1
                :SPUT.B.F
    
                :CMP.F.0
                :LOOP.EQ
                ::
                    :B-=1
                    :F=SGET.B
                    :F-=1
                    :SPUT.B.F
                    :CMP.F.0
                ;
            ;
            :CMP.C.1
        ;
    ;
    :CMP.B.8
;

:POP.1.7
:S1=A

»

The code above is the N-queens benchmark, verbatim translation of the Pascal sample code.
Interestingly enough (and sort-of expected), the RPL solution using stackrobatics is slightly faster than this one (106 ms vs. 114 ms).