A2osX/SYS/KERNEL.S.MATH32.txt

NEW
  AUTO 3,1
*--------------------------------------
MATH32			jmp (.1,x)
.1				.DA MATH32.ADD
				.DA MATH32.SUB
				.DA MATH32.UMUL
				.DA MATH32.IMUL
				.DA MATH32.UDIV
				.DA MATH32.IDIV
				.DA MATH32.UMOD
				.DA MATH32.IMOD
				.DA MATH32.UCMP
				.DA MATH32.ICMP
*--------------------------------------
MATH32.ADD		clc
				.HS B0					BCS
MATH32.SUB		sec
				php
				jsr MATH32.PopACC32

				ldy #0
				ldx #3
				plp
				bcs .1

				lda #$79				ADC Absolute,Y
				.HS 2C					BIT ABS
.1				lda #$F9				SBC Absolute,Y
				sta .3

.2				lda (pStack),y
.3				adc ACC32,y				SELF MODIFIED
				sta (pStack),y
				iny
				dex
				bpl .2

MATH32.SUB.RTS	rts
*--------------------------------------
* Returns:
*  ff X < Y
*   0 X = Y
*   1 X > Y
*--------------------------------------
MATH32.UCMP
MATH32.ICMP		jsr MATH32.SUB
				jsr MATH32.PopACC32		A = ACC32+3 (sign)
				tay
				bmi .2

.1				ora ACC32+2
				ora ACC32+1
				ora ACC32
				beq .8
				lda #1
				rts

.2				lda #$ff
.8				rts			
*--------------------------------------
MATH32.UMUL		clc
				.HS B0					BCS
MATH32.IMUL		sec

				php
				jsr MATH32.MULDIVMOD.COMMON
				jsr MATH32.MUL

				plp
				bcc MATH32.PutTMP32
MATH32.RETURN.ITMP
				lda ACC32.Sign
				eor ARG32.Sign
				bpl MATH32.PutTMP32
				bra MATH32.PutNotTMP32
*--------------------------------------
MATH32.UDIV		clc
				.HS B0					BCS
MATH32.IDIV		sec
				clv
				bra MATH32.MOD
				
MATH32.UMOD		clc
				.HS B0					BCS
MATH32.IMOD		sec
				bit MATH32.SUB.RTS		$60

MATH32.MOD		php
				jsr MATH32.MULDIVMOD.COMMON
				jsr MATH32.DIVMOD

				plp
				bcc .3					unsigned

				bvs MATH32.RETURN.ITMP	IMOD

				lda ACC32.Sign			IDIV
				eor ARG32.Sign
				bpl MATH32.PutARG32
				bra MATH32.PutNotARG32

.3				bvc MATH32.PutARG32		DIV
*--------------------------------------
MATH32.PutTMP32	lda #TMP32				MOD
				.HS 2C					BIT ABS
*--------------------------------------
MATH32.PutARG32	lda #ARG32
				sta .1+1
				
				ldy #3
				
.1				lda $ff,y				SELF MODIFIED
				sta (pStack),y
				dey
				bpl .1

				rts
*--------------------------------------
MATH32.PutNotTMP32
				lda #TMP32
				.HS 2C					BIT ABS
*--------------------------------------
MATH32.PutNotARG32
				lda #ARG32
				sta .1+1
				ldy #0
				ldx #3
				sec

.1				lda $ff,y				SELF MODIFIED
				eor #$ff				two's complement of X bytes
				adc #0
				sta (pStack),y
				iny
				dex
				bpl .1
				rts
*--------------------------------------
MATH32.PopACC32	ldy #0

.1				lda (pStack)
				inc pStack
				sta ACC32,y
				iny
				cpy #4
				bne .1
				sta ACC32.Sign
				rts
*--------------------------------------
MATH32.GetARG32	ldy #0

.1				lda (pStack),y
				sta ARG32,y
				iny
				cpy #4
				bne .1

				sta ARG32.Sign

MATH32.GetARG32.RTS
				rts
*--------------------------------------
MATH32.MULDIVMOD.COMMON
				php
				jsr MATH32.PopACC32
				jsr MATH32.GetARG32
				plp
				bcc MATH32.GetARG32.RTS
				jsr MATH.ACC32ABS
				jmp MATH.ARG32ABS
*--------------------------------------
* http://6502.org/source/integers/32muldiv.htm
* http://nparker.llx.com/a2/mult.html
*--------------------------------------
* ARG32*ACC32->TMP32
*--------------------------------------
MATH32.MUL		jsr MATH.TMP32ZERO
				ldx #32
.1				lsr ARG32+3
				ror ARG32+2
				ror ARG32+1
				ror ARG32
				bcc .3
				clc

				ldy #0
.2				lda TMP32,y
				adc ACC32,y
				sta TMP32,y

				iny
				tya
				eor #4
				bne .2
.3				jsr MATH.ACC32.T2
				dex
				bne  .1
				clc
				rts
*--------------------------------------
* ARG32 = ARG32 div ACC32
* TMP32 = ARG32 mod ACC32
*--------------------------------------
MATH32.DIVMOD	jsr MATH.TMP32ZERO
				
				ldx #32
				
.1				asl ARG32
				rol ARG32+1
				rol ARG32+2
				rol ARG32+3
				rol TMP32
				rol TMP32+1
				rol TMP32+2
				rol TMP32+3
				sec 
				lda TMP32
				sbc ACC32
				pha
				lda TMP32+1
				sbc ACC32+1
				pha
				lda TMP32+2
				sbc ACC32+2
				pha
				lda TMP32+3
				sbc ACC32+3
				bcs .2
				
				pla
				pla
				pla
				dex
				bne .1

				rts
				
.2				sta TMP32+3
				pla
				sta TMP32+2
				pla
				sta TMP32+1
				pla
				sta TMP32
				inc ARG32				bit0 always 0 because of .1 asl

				dex
				bne .1

				rts
*--------------------------------------
MAN
SAVE USR/SRC/SYS/KERNEL.S.MATH32
LOAD USR/SRC/SYS/KERNEL.S
ASM