prog8/compiler/res/prog8lib/conv.p8
2020-10-11 18:36:20 +02:00

384 lines
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Lua

; Prog8 definitions for number conversions routines.
;
; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
;
; indent format: TABS, size=8
conv {
; ----- number conversions to decimal strings
asmsub ubyte2decimal (ubyte value @ A) -> ubyte @ Y, ubyte @ A, ubyte @ X {
; ---- A to decimal string in Y/A/X (100s in Y, 10s in A, 1s in X)
%asm {{
ldy #uword2decimal.ASCII_0_OFFSET
bne uword2decimal.hex_try200
rts
}}
}
asmsub uword2decimal (uword value @ AY) -> ubyte @Y, ubyte @A, ubyte @X {
; ---- convert 16 bit uword in A/Y to decimal
; output in uword2decimal.decTenThousands, decThousands, decHundreds, decTens, decOnes
; (these are terminated by a zero byte so they can be easily printed)
; also returns Y = 100's, A = 10's, X = 1's
%asm {{
;Convert 16 bit Hex to Decimal (0-65535) Rev 2
;By Omegamatrix Further optimizations by tepples
; routine from http://forums.nesdev.com/viewtopic.php?f=2&t=11341&start=15
;HexToDec99
; start in A
; end with A = 10's, decOnes (also in X)
;HexToDec255
; start in A
; end with Y = 100's, A = 10's, decOnes (also in X)
;HexToDec999
; start with A = high byte, Y = low byte
; end with Y = 100's, A = 10's, decOnes (also in X)
; requires 1 extra temp register on top of decOnes, could combine
; these two if HexToDec65535 was eliminated...
;HexToDec65535
; start with A/Y (low/high) as 16 bit value
; end with decTenThousand, decThousand, Y = 100's, A = 10's, decOnes (also in X)
; (irmen: I store Y and A in decHundreds and decTens too, so all of it can be easily printed)
ASCII_0_OFFSET = $30
temp = P8ZP_SCRATCH_B1 ; byte in zeropage
hexHigh = P8ZP_SCRATCH_W1 ; byte in zeropage
hexLow = P8ZP_SCRATCH_W1+1 ; byte in zeropage
HexToDec65535; SUBROUTINE
sty hexHigh ;3 @9
sta hexLow ;3 @12
tya
tax ;2 @14
lsr a ;2 @16
lsr a ;2 @18 integer divide 1024 (result 0-63)
cpx #$A7 ;2 @20 account for overflow of multiplying 24 from 43,000 ($A7F8) onward,
adc #1 ;2 @22 we can just round it to $A700, and the divide by 1024 is fine...
;at this point we have a number 1-65 that we have to times by 24,
;add to original sum, and Mod 1024 to get a remainder 0-999
sta temp ;3 @25
asl a ;2 @27
adc temp ;3 @30 x3
tay ;2 @32
lsr a ;2 @34
lsr a ;2 @36
lsr a ;2 @38
lsr a ;2 @40
lsr a ;2 @42
tax ;2 @44
tya ;2 @46
asl a ;2 @48
asl a ;2 @50
asl a ;2 @52
clc ;2 @54
adc hexLow ;3 @57
sta hexLow ;3 @60
txa ;2 @62
adc hexHigh ;3 @65
sta hexHigh ;3 @68
ror a ;2 @70
lsr a ;2 @72
tay ;2 @74 integer divide 1,000 (result 0-65)
lsr a ;2 @76 split the 1,000 and 10,000 digit
tax ;2 @78
lda ShiftedBcdTab,x ;4 @82
tax ;2 @84
rol a ;2 @86
and #$0F ;2 @88
ora #ASCII_0_OFFSET
sta decThousands ;3 @91
txa ;2 @93
lsr a ;2 @95
lsr a ;2 @97
lsr a ;2 @99
ora #ASCII_0_OFFSET
sta decTenThousands ;3 @102
lda hexLow ;3 @105
cpy temp ;3 @108
bmi _doSubtract ;2³ @110/111
beq _useZero ;2³ @112/113
adc #23 + 24 ;2 @114
_doSubtract
sbc #23 ;2 @116
sta hexLow ;3 @119
_useZero
lda hexHigh ;3 @122
sbc #0 ;2 @124
Start100s
and #$03 ;2 @126
tax ;2 @128 0,1,2,3
cmp #2 ;2 @130
rol a ;2 @132 0,2,5,7
ora #ASCII_0_OFFSET
tay ;2 @134 Y = Hundreds digit
lda hexLow ;3 @137
adc Mod100Tab,x ;4 @141 adding remainder of 256, 512, and 256+512 (all mod 100)
bcs hex_doSub200 ;2³ @143/144
hex_try200
cmp #200 ;2 @145
bcc hex_try100 ;2³ @147/148
hex_doSub200
iny ;2 @149
iny ;2 @151
sbc #200 ;2 @153
hex_try100
cmp #100 ;2 @155
bcc HexToDec99 ;2³ @157/158
iny ;2 @159
sbc #100 ;2 @161
HexToDec99; SUBROUTINE
lsr a ;2 @163
tax ;2 @165
lda ShiftedBcdTab,x ;4 @169
tax ;2 @171
rol a ;2 @173
and #$0F ;2 @175
ora #ASCII_0_OFFSET
sta decOnes ;3 @178
txa ;2 @180
lsr a ;2 @182
lsr a ;2 @184
lsr a ;2 @186
ora #ASCII_0_OFFSET
; irmen: load X with ones, and store Y and A too, for easy printing afterwards
sty decHundreds
sta decTens
ldx decOnes
rts ;6 @192 Y=hundreds, A = tens digit, X=ones digit
HexToDec999; SUBROUTINE
sty hexLow ;3 @9
jmp Start100s ;3 @12
Mod100Tab
.byte 0,56,12,56+12
ShiftedBcdTab
.byte $00,$01,$02,$03,$04,$08,$09,$0A,$0B,$0C
.byte $10,$11,$12,$13,$14,$18,$19,$1A,$1B,$1C
.byte $20,$21,$22,$23,$24,$28,$29,$2A,$2B,$2C
.byte $30,$31,$32,$33,$34,$38,$39,$3A,$3B,$3C
.byte $40,$41,$42,$43,$44,$48,$49,$4A,$4B,$4C
decTenThousands .byte 0
decThousands .byte 0
decHundreds .byte 0
decTens .byte 0
decOnes .byte 0
.byte 0 ; zero-terminate the decimal output string
}}
}
; ----- utility functions ----
asmsub byte2decimal (byte value @ A) -> ubyte @ Y, ubyte @ A, ubyte @ X {
; ---- A (signed byte) to decimal string in Y/A/X (100s in Y, 10s in A, 1s in X)
; note: if the number is negative, you have to deal with the '-' yourself!
%asm {{
cmp #0
bpl +
eor #255
clc
adc #1
+ jmp ubyte2decimal
}}
}
asmsub ubyte2hex (ubyte value @ A) -> ubyte @ A, ubyte @ Y {
; ---- A to hex petscii string in AY (first hex char in A, second hex char in Y)
%asm {{
stx P8ZP_SCRATCH_REG
pha
and #$0f
tax
ldy _hex_digits,x
pla
lsr a
lsr a
lsr a
lsr a
tax
lda _hex_digits,x
ldx P8ZP_SCRATCH_REG
rts
_hex_digits .text "0123456789abcdef" ; can probably be reused for other stuff as well
}}
}
asmsub uword2hex (uword value @ AY) clobbers(A,Y) {
; ---- convert 16 bit uword in A/Y into 4-character hexadecimal string 'uword2hex.output' (0-terminated)
%asm {{
sta P8ZP_SCRATCH_REG
tya
jsr ubyte2hex
sta output
sty output+1
lda P8ZP_SCRATCH_REG
jsr ubyte2hex
sta output+2
sty output+3
rts
output .text "0000", $00 ; 0-terminated output buffer (to make printing easier)
}}
}
asmsub str2ubyte(str string @ AY) clobbers(Y) -> ubyte @A {
; -- returns the unsigned byte value of the string number argument in AY
; the number may NOT be preceded by a + sign and may NOT contain spaces
; (any non-digit character will terminate the number string that is parsed)
; TODO implement optimized custom version of this instead of simply reusing str2uword
%asm {{
jmp str2uword
}}
}
asmsub str2byte(str string @ AY) clobbers(Y) -> ubyte @A {
; -- returns the signed byte value of the string number argument in AY
; the number may be preceded by a + or - sign but may NOT contain spaces
; (any non-digit character will terminate the number string that is parsed)
; TODO implement optimized custom version of this instead of simply reusing str2word
%asm {{
jmp str2word
}}
}
asmsub str2uword(str string @ AY) -> uword @ AY {
; -- returns the unsigned word value of the string number argument in AY
; the number may NOT be preceded by a + sign and may NOT contain spaces
; (any non-digit character will terminate the number string that is parsed)
%asm {{
_result = P8ZP_SCRATCH_W2
sta _mod+1
sty _mod+2
ldy #0
sty _result
sty _result+1
_mod lda $ffff,y ; modified
sec
sbc #48
bpl +
_done ; return result
lda _result
ldy _result+1
rts
+ cmp #10
bcs _done
; add digit to result
pha
jsr _result_times_10
pla
clc
adc _result
sta _result
bcc +
inc _result+1
+ iny
bne _mod
; never reached
_result_times_10 ; (W*4 + W)*2
lda _result+1
sta P8ZP_SCRATCH_REG
lda _result
asl a
rol P8ZP_SCRATCH_REG
asl a
rol P8ZP_SCRATCH_REG
clc
adc _result
sta _result
lda P8ZP_SCRATCH_REG
adc _result+1
asl _result
rol a
sta _result+1
rts
}}
}
asmsub str2word(str string @ AY) -> word @ AY {
; -- returns the signed word value of the string number argument in AY
; the number may be preceded by a + or - sign but may NOT contain spaces
; (any non-digit character will terminate the number string that is parsed)
%asm {{
_result = P8ZP_SCRATCH_W2
sta P8ZP_SCRATCH_W1
sty P8ZP_SCRATCH_W1+1
ldy #0
sty _result
sty _result+1
sty _negative
lda (P8ZP_SCRATCH_W1),y
cmp #'+'
bne +
iny
+ cmp #'-'
bne _parse
inc _negative
iny
_parse lda (P8ZP_SCRATCH_W1),y
sec
sbc #48
bpl _digit
_done ; return result
lda _negative
beq +
sec
lda #0
sbc _result
sta _result
lda #0
sbc _result+1
sta _result+1
+ lda _result
ldy _result+1
rts
_digit cmp #10
bcs _done
; add digit to result
pha
jsr str2uword._result_times_10
pla
clc
adc _result
sta _result
bcc +
inc _result+1
+ iny
bne _parse
; never reached
_negative .byte 0
}}
}
}