Macro Magic - Two Useful Macros

[John Metcalf]

Here are a couple of pMARS macros which I've found useful.

The first calculates powers using the square-and-multiply algorithm. In the
example it's used to calculate the inverse for a qscan:

qfac equ 1111
power equ 3199

; --------------------------------------

; qdec equ 1+qfac^power

for 20+!(r=1)*(x=qfac)*(n=power)
for n%2
for !r=(r*x)%CORESIZE
rof
rof
for !x=(x*x)%CORESIZE+!n=n/2
rof
rof

qdec equ (r+1)

; --------------------------------------

The second calculates how many times a scanner can scan (or a bomber can
bomb) with a given step before it self-scans (or self-bombs). It needs to
know the length of the warrior and which instruction to scan (or bomb) to
end the scanning phase.

step equ 4961
hit equ 3 ; location of the final scan (first line is 0)
invis equ 5 ; location of invisible instruction
length equ 9 ; length of scanner

; --------------------------------------

for CORESIZE+!(f=1)*(h=hit)
for !t=t+(f=f*((h=(h+step)%CORESIZE)>=length||h==invis))
rof
rof

time equ t

; --------------------------------------

I've used both macros in Macro Magic so you can see them in action:

http://corewar.co.uk/macromagic.htm

;redcode-94nop
;name Macro Magic
;author John Metcalf
;strategy scanner
;assert CORESIZE == 8000

org qscan

step equ 4961
hit equ 3 ; location of the final scan (first line is 0)
invis equ 5 ; location of invisible instruction
length equ 9 ; length of scanner

; --------------------------------------

for CORESIZE+!(f=1)*(h=hit)
for !t=t+(f=f*((h=(h+step)%CORESIZE)>=length||h==invis))
rof
rof

time equ t
first equ (hit+attack+step*time)

; --------------------------------------

warr equ scan+1
gate equ scan

attack mov *sbmb, >scan
mov jbmb, @scan
scan sub #step, #first
jbmb jmz.f scan, @scan ; hit
djn @0, @attack
sbmb spl #0, 0 ; invis
clear mov dbmb, >gate
djn.f clear, >gate
dbmb dat <1, 3-gate

for 61
dat 0,0
rof

qfac equ 1111
power equ 3199

; --------------------------------------

; qdec equ qfac^power

for 20+!(r=1)*(x=qfac)*(n=power)
for n%2
for !r=(r*x)%CORESIZE
rof
rof
for !x=(x*x)%CORESIZE+!n=n/2
rof
rof

qdec equ (r+1)

; --------------------------------------

qa equ (qfac*(qtab0-1-qptr)+1)
qb equ (qfac*(qtab0-qptr)+1)
qc equ (qfac*(qtab1-1-qptr)+1)
qd equ (qfac*(qtab1-qptr)+1)
qe equ (qfac*(qtab1+1-qptr)+1)
qf equ (qfac*(qtab2-qptr)+1)

qtime equ 18
qstep equ -7
qgap equ 87

qdecode mul.b *q1, qptr
q0 sne <qtab0, @qptr
q1 add.b qtab1, qptr
q2 mov qtab2, @qptr
qptr mov qtab2, *qdec
add #qstep, qptr
djn q2, #qtime
jmp warr, qc
qtab1 dat 4000, qd
dat 4000, qe

qscan sne qptr+qdec*qe, qptr+qdec*qe+qe
seq <qtab1+1, qptr+qdec*(qe-1)+qe-1
jmp qdecode, }q1
sne qptr+qdec*qb, qptr+qdec*qb+qd
seq <qtab0, qptr+qdec*(qb-1)+qd
jmp qdecode, {qdecode
sne qptr+qdec*qa, qptr+qdec*qa+qd
seq <qtab0-1, qptr+qdec*(qa-1)+qd
djn.a qdecode, {qdecode
sne qptr+qdec*qf, qptr+qdec*qf+qd
seq <qtab2, qptr+qdec*(qf-1)+qd
jmp qdecode, }qdecode
sne qptr+qdec*qc, qptr+qdec*qc+qc
seq <qtab1-1, qptr+qdec*(qc-1)+qc-1
jmp qdecode, {q1
sne qptr+qdec*qd, qptr+qdec*qd+qd
seq <qtab1, qptr+qdec*(qd-1)+qd-1
jmp qdecode, <qa
qtab0 jmp warr, <qb
qtab2 dat qgap, qf

end