prog8/compiler/res/prog8lib/c64/floats.p8

; Prog8 definitions for floating point handling on the Commodore-64

%option enable_floats, no_symbol_prefixing, ignore_unused
%import shared_floats_functions

floats {
; ---- this block contains C-64 floating point related functions ----

; ---- C64 basic and kernal ROM float constants and functions ----

		; note: the fac1 and fac2 are working registers and take 6 bytes each,
		; floats in memory  (and rom) are stored in 5-byte MFLPT packed format.


; note: fac1/2 might get clobbered even if not mentioned in the function's name.
; note: for subtraction and division, the left operand is in fac2, the right operand in fac1.

extsub $bba2 = MOVFM(uword mflpt @ AY) clobbers(A,Y)        ; load mflpt value from memory  in A/Y into fac1
extsub $bba6 = FREADMEM() clobbers(A,Y)                     ; load mflpt value from memory  in $22/$23 into fac1
extsub $ba8c = CONUPK(uword mflpt @ AY) clobbers(A,Y)       ; load mflpt value from memory  in A/Y into fac2
extsub $ba90 = FAREADMEM() clobbers(A,Y)                    ; load mflpt value from memory  in $22/$23 into fac2
extsub $bbfc = MOVFA() clobbers(A,X)                        ; copy fac2 to fac1
extsub $bc0c = MOVAF() clobbers(A,X)                        ; copy fac1 to fac2  (rounded the least significant bit)
extsub $bc0f = MOVEF() clobbers(A,X)                        ; copy fac1 to fac2
extsub $bbd4 = MOVMF(uword mflpt @ XY) clobbers(A,Y)        ; store fac1 to memory  X/Y as 5-byte mflpt

; fac1 -> unsigned word in Y/A (might throw ILLEGAL QUANTITY) (result also in $14/15)
; (tip: use floats.GETADRAY to get A/Y output; lo/hi switched to normal little endian order)
extsub $b7f7 = GETADR() clobbers(X) -> ubyte @ Y, ubyte @ A

extsub $bc9b = QINT() clobbers(A,X,Y)           ; fac1 -> 4-byte signed integer in 98-101 ($62-$65), with the MSB FIRST.
extsub $b1bf = AYINT() clobbers(A,X,Y)          ; fac1-> signed word in 100-101 ($64-$65) MSB FIRST. (might throw ILLEGAL QUANTITY) DON'T USE THIS, USE WRAPPER 'AYINT2' INSTEAD.

; GIVAYF: signed word in Y/A (note different lsb/msb order) -> float in fac1
; (tip: use floats.GIVAYFAY to use A/Y input; lo/hi switched to normal order)
; there is also floats.GIVUAYFAY - unsigned word in A/Y (lo/hi) to fac1
; there is also floats.FREADS32  that reads from 98-101 ($62-$65) MSB FIRST
; there is also floats.FREADUS32  that reads from 98-101 ($62-$65) MSB FIRST
; there is also floats.FREAD{S,U}24AXY  that read (un)signed int24 into fac1 from A/X/Y (lo/mid/hi bytes)
extsub $b391 = GIVAYF(ubyte lo @ Y, ubyte hi @ A) clobbers(A,X,Y)

extsub $b3a2 = FREADUY(ubyte value @ Y) clobbers(A,X,Y)     ; 8 bit unsigned Y -> float in fac1
extsub $bc3c = FREADSA(byte value @ A) clobbers(A,X,Y)      ; 8 bit signed A -> float in fac1
extsub $b7b5 = FREADSTR(ubyte length @ A) clobbers(A,X,Y)   ; str -> fac1, $22/23 must point to string, A=string length.  Also see parse()
extsub $aabc = FPRINTLN() clobbers(A,X,Y)                   ; print string of fac1, on one line (= with newline) destroys fac1.  (consider FOUT + STROUT as well)
extsub $bddd = FOUT() clobbers(X) -> uword @ AY             ; fac1 -> string, address returned in AY ($0100)

extsub $b849 = FADDH() clobbers(A,X,Y)                      ; fac1 += 0.5, for integer rounding- call this before INT
extsub $bae2 = MUL10() clobbers(A,X,Y)                      ; fac1 *= 10
extsub $bafe = DIV10() clobbers(A,X,Y)                      ; fac1 /= 10 , CAUTION: result is always positive! You have to fix sign manually!
extsub $bc5b = FCOMP(uword mflpt @ AY) clobbers(X,Y) -> ubyte @ A   ; A = compare fac1 to mflpt in A/Y, 0=equal 1=fac1 is greater, 255=fac1 is less than

extsub $b86a = FADDT() clobbers(A,X,Y)                      ; fac1 += fac2
extsub $b867 = FADD(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 += mflpt value from A/Y
extsub $b853 = FSUBT() clobbers(A,X,Y)                      ; fac1 = fac2-fac1   mind the order of the operands
extsub $b850 = FSUB(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = mflpt from A/Y - fac1
extsub $ba2b = FMULTT() clobbers(A,X,Y)                     ; fac1 *= fac2
extsub $ba28 = FMULT(uword mflpt @ AY) clobbers(A,X,Y)      ; fac1 *= mflpt value from A/Y
extsub $bb12 = FDIVT() clobbers(A,X,Y)                      ; fac1 = fac2/fac1  mind the order of the operands
extsub $bb0f = FDIV(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = mflpt in A/Y / fac1
extsub $bf7b = FPWRT() clobbers(A,X,Y)                      ; fac1 = fac2 ** fac1
extsub $bf78 = FPWR(uword mflpt @ AY) clobbers(A,X,Y)       ; fac1 = fac2 ** mflpt from A/Y
extsub $bd7e = FINLOG(byte value @A) clobbers (A, X, Y)     ; fac1 += signed byte in A

extsub $aed4 = NOTOP() clobbers(A,X,Y)                      ; fac1 = NOT(fac1)
extsub $bccc = INT() clobbers(A,X,Y)                        ; INT() truncates, use FADDH first to integer round instead of trunc
extsub $b9ea = LOG() clobbers(A,X,Y)                        ; fac1 = LN(fac1)  (natural log)
extsub $bc39 = SGN() clobbers(A,X,Y)                        ; fac1 = SGN(fac1), result of SIGN (-1, 0 or 1)
extsub $bc2b = SIGN() -> ubyte @ A                          ; SIGN(fac1) to A, $ff, $0, $1 for negative, zero, positive
extsub $bc58 = ABS()                                        ; fac1 = ABS(fac1)
extsub $bf71 = SQR() clobbers(A,X,Y)                        ; fac1 = SQRT(fac1)
extsub $bf74 = SQRA() clobbers(A,X,Y)                       ; fac1 = SQRT(fac2)
extsub $bfed = EXP() clobbers(A,X,Y)                        ; fac1 = EXP(fac1)  (e ** fac1)
extsub $bfb4 = NEGOP() clobbers(A)                          ; switch the sign of fac1 (fac1 = -fac1)
extsub $b8d7 = NORMAL() clobbers(A)                         ; normalize FAC1
extsub $e097 = RND() clobbers(A,X,Y)                        ; fac1 = RND(fac1) float random number generator
extsub $e264 = COS() clobbers(A,X,Y)                        ; fac1 = COS(fac1)
extsub $e26b = SIN() clobbers(A,X,Y)                        ; fac1 = SIN(fac1)
extsub $e2b4 = TAN() clobbers(A,X,Y)                        ; fac1 = TAN(fac1)
extsub $e30e = ATN() clobbers(A,X,Y)                        ; fac1 = ATN(fac1)


asmsub  AYINT2() clobbers(X) -> word @AY {
    ; fac1-> signed word in AY. Safe wrapper around the AYINT kernal routine (not reading internal memory locations)
    ; (might throw ILLEGAL QUANTITY)
    %asm {{
		jsr  AYINT
		ldx  #<floats_temp_var
		ldy  #>floats_temp_var
		jsr  MOVMF
		lda  floats_temp_var+4
		ldy  floats_temp_var+3
        rts
    }}
}

asmsub  FREADS32() clobbers(A,X,Y)  {
	; ---- fac1 = signed int32 from $62-$65 big endian (MSB FIRST)
	%asm {{
		lda  $62
		eor  #$ff
		asl  a
		lda  #0
		ldx  #$a0
		jmp  $bc4f		; internal BASIC routine
	}}
}

asmsub  FREADUS32  () clobbers(A,X,Y)  {
	; ---- fac1 = uint32 from $62-$65 big endian (MSB FIRST)
	%asm {{
		sec
		lda  #0
		ldx  #$a0
		jmp  $bc4f		; internal BASIC routine
	}}
}

asmsub  FREADS24AXY  (ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) clobbers(A,X,Y)  {
	; ---- fac1 = signed int24 (A/X/Y contain lo/mid/hi bytes)
	%asm {{
		sty  $62
		stx  $63
		sta  $64
		lda  $62
		eor  #$FF
		asl  a
		lda  #0
		sta  $65
		ldx  #$98
		jmp  $bc4f		; internal BASIC routine
	}}
}

asmsub FREADU24AXY(ubyte lo @ A, ubyte mid @ X, ubyte hi @ Y) clobbers(A, X, Y) -> float @FAC1 {
    ; ---- fac1 = unsigned int24 (A/X/Y contain lo/mid/hi bytes)
        %asm{{
                 FAC = $61
                 sty FAC+1
                 stx FAC+2
                 sta FAC+3

                 cpy #$00
                 bne +
                 cpx #$00
                 bne +
                 cmp #$00
                 beq ++

              +  ldx #$98
                 bit FAC+1
                 bmi +

              -  dex
                 asl FAC+3
                 rol FAC+2
                 rol FAC+1
                 bpl -

              +  stx FAC
                 lda #$00
                 sta FAC+4
                 sta FAC+5
                 rts
       }}
}

asmsub  GIVUAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
	; ---- unsigned 16 bit word in A/Y (lo/hi) to fac1
	%asm {{
		sty  $62    ; facmo
		sta  $63
		ldx  #$90
		sec
		jmp  $bc49		; internal BASIC routine
	}}
}

asmsub  GIVAYFAY  (uword value @ AY) clobbers(A,X,Y)  {
	; ---- signed 16 bit word in A/Y (lo/hi) to float in fac1
	%asm {{
		sta  P8ZP_SCRATCH_REG
		tya
		ldy  P8ZP_SCRATCH_REG
		jmp  GIVAYF		; this uses the inverse order, Y/A
	}}
}

asmsub  GETADRAY  () clobbers(X) -> uword @ AY  {
	; ---- fac1 to unsigned word in A/Y
	%asm {{
		jsr  GETADR		; this uses the inverse order, Y/A
		sta  P8ZP_SCRATCH_B1
		tya
		ldy  P8ZP_SCRATCH_B1
		rts
	}}
}


sub rnd() -> float {
    %asm {{
        lda  #1
        jsr  FREADSA
        jmp  RND		; rng into fac1
    }}
}

asmsub parse(str value @AY) -> float @FAC1 {
    %asm {{
        sta  $22
        sty  $23
        jsr  prog8_lib.strlen
        tya
        jmp  FREADSTR
    }}
}

asmsub normalize(float value @FAC1) -> float @ FAC1 {
    %asm {{
        jmp  floats.NORMAL
    }}
}

; get the jiffy clock as a float
asmsub time() -> float @ FAC1 {
    %asm {{
        jsr cbm.RDTIM
        jmp floats.FREADU24AXY
    }}
}

%asminclude "library:c64/floats.asm"
%asminclude "library:c64/floats_funcs.asm"

}