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multiplication cleanup

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FeralChild64 committed 2020-02-27 19:46:49 +01:00
1 parent 9f29d058dd
commit e11bfe5a87
3 files changed
+28 -28
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c64/basic/math/mul_FAC2_FAC1.s
+5 -27
View File
@@ -17,8 +17,6 @@
// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
//
// XXX the code here is very imprecise, find out why
mul_FAC2_FAC1_done:
rts
@@ -98,31 +96,31 @@ mul_FAC2_FAC1_sub_exp_bias:
lda FACOV
jsr mul_FAC2_FAC1_by_A
jsr mul_FAC2_FAC1_shift_RESHO
jsr mul_FAC2_FAC1_shift
bcc !+
inc RESHO+0
!:
lda FAC1_mantissa+3
jsr mul_FAC2_FAC1_by_A
jsr mul_FAC2_FAC1_shift_RESHO
jsr mul_FAC2_FAC1_shift
bcc !+
inc RESHO+0
!:
lda FAC1_mantissa+2
jsr mul_FAC2_FAC1_by_A
jsr mul_FAC2_FAC1_shift_RESHO
jsr mul_FAC2_FAC1_shift
bcc !+
inc RESHO+0
!:
lda FAC1_mantissa+1
jsr mul_FAC2_FAC1_by_A
jsr mul_FAC2_FAC1_shift_RESHO
jsr mul_FAC2_FAC1_shift
bcc !+
inc RESHO+0
!:
lda FAC1_mantissa+0
jsr mul_FAC2_FAC1_by_A
jsr mul_FAC2_FAC1_shift_RESHO
jsr mul_FAC2_FAC1_shift
bcc !+
inc RESHO+0
!:
@@ -214,23 +212,3 @@ mul_FAC2_FAC1_by_A:
mul_FAC2_FAC1_by_A_done:
rts
mul_FAC2_FAC1_shift_RESHO: // XXX we should probably move this subroutine to a separate file
// Shift RESHO by one byte
lda RESHO+3
sta RESHO+4
lda RESHO+2
sta RESHO+3
lda RESHO+1
sta RESHO+2
lda RESHO+0
sta RESHO+1
lda #$00
sta RESHO+0
rts
c64/basic/math/mul_FAC2_FAC1_shift.s
+22
View File
@@ -0,0 +1,22 @@
// #LAYOUT# STD * #TAKE
// #LAYOUT# * BASIC_0 #TAKE
// #LAYOUT# * * #IGNORE
//
// Shift RESHO by one byte - for multiplication
//
mul_FAC2_FAC1_shift:
lda RESHO+3
sta RESHO+4
lda RESHO+2
sta RESHO+3
lda RESHO+1
sta RESHO+2
lda RESHO+0
sta RESHO+1
lda #$00
sta RESHO+0
rts