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resolve #4, h/t ksherlock

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mgcaret 2020-01-03 19:41:25 -08:00
parent 30a8a259c7
commit 7f57ba6f06
1 changed files with 3 additions and 8 deletions
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11
asm/mathlib.s
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@ -8,14 +8,9 @@
lda STACKBASE+6,x lda STACKBASE+6,x
eor STACKBASE+2,x eor STACKBASE+2,x
bpl samesign bpl samesign
lda STACKBASE+4,x lda STACKBASE+2,x ; Kelvin's excellent solution
cmp STACKBASE+0,x sec
lda STACKBASE+6,x rol
sbc STACKBASE+2,x
bvs :+
eor #$8000
: sec ; make sure we don't set Z
rol ; move comparison into carry
rts rts
samesign: lda STACKBASE+6,x samesign: lda STACKBASE+6,x
cmp STACKBASE+2,x cmp STACKBASE+2,x