[A83] Re: HL / 12 (fast)

To: <assembly-83@lists.ticalc.org>
Subject: [A83] Re: HL / 12 (fast)
From: "Tijl Coosemans" <tijl@ulyssis.org>
Date: Wed, 24 Apr 2002 00:58:40 +0200
References: <3CC6443C.950976B8@dingoblue.net.au> <5.1.0.14.2.20020423092832.025900a0@pop.prism.gatech.edu> <014501c1eb16$f2136610$d905040a@tijl>
Reply-To: assembly-83@lists.ticalc.org


slightly faster

; de = hl / 12
; af,bc,de,hl destroyed
; 434-476 tstates w/o ret
 
    ld     b,h
    ld     c,l
    xor    a
    ld     d,a
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,bc
    jr     nc,$+5
    ld     e,a
    inc    de
    ld     a,e
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,hl
    adc    a,a 
    rl     d
    add    hl,bc
    jr     nc,$+5
    ld     e,a
    inc    de
    ld     a,e
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,hl
    adc    a,a 
    rl     d
    add    hl,bc
    jr     nc,$+5
    ld     e,a
    inc    de
    ld     a,e
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,hl
    adc    a,a 
    rl     d
    add    hl,bc
    jr     nc,$+5
    ld     e,a
    inc    de
    ld     a,e
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,hl
    adc    a,a 
    rl     d
    add    hl,bc
    jr     nc,$+5
    ld     e,a
    inc    de
    ld     a,e
    add    hl,hl
    adc    a,a
    rl     d
    add    hl,bc
    jr     nc,$+5
    ld     e,a
    inc    de
    ld     a,e
    add    hl,hl
    adc    a,a 
    rl     d
    ld     e,a

References:

[A83] HL = A * 12 (fast)

From: Darren <qarnos@dingoblue.net.au>

[A83] Re: HL = A * 12 (fast)

From: Harper Maddox <gte172i@prism.gatech.edu>

[A83] Re: HL / 12 (fast)

From: "Tijl Coosemans" <tijl@ulyssis.org>