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56.1
date     91.11.05.09.34.16;  author jwh;  state Exp;
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desc
@
first version.

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@a0 435
*
*       stan.sa 3.1 12/10/90
*
*       The entry point stan computes the tangent of
*       an input argument;
*       stand does the same except for denormalized input.
*
*       Input: Double-extended number X in location pointed to
*               by address register a0.
*
*       Output: The value tan(X) returned in floating-point register Fp0.
*
*       Accuracy and Monotonicity: The returned result is within 3 ulp in
*               64 significant bit, i.e. within 0.5001 ulp to 53 bits if the
*               result is subsequently rounded to double precision. The
*               result is provably monotonic in double precision.
*
*       Speed: The program sTAN takes approximately 170 cycles for
*               input argument X such that |X| < 15Pi, which is the the usual
*               situation.
*
*       Algorithm:
*
*       1. If |X| >= 15Pi or |X| < 2**(-40), go to 6.
*
*       2. Decompose X as X = N(Pi/2) + r where |r| <= Pi/4. Let
*               k = N mod 2, so in particular, k = 0 or 1.
*
*       3. If k is odd, go to 5.
*
*       4. (k is even) Tan(X) = tan(r) and tan(r) is approximated by a
*               rational function U/V where
*               U = r + r*s*(P1 + s*(P2 + s*P3)), and
*               V = 1 + s*(Q1 + s*(Q2 + s*(Q3 + s*Q4))),  s = r*r.
*               Exit.
*
*       4. (k is odd) Tan(X) = -cot(r). Since tan(r) is approximated by a
*               rational function U/V where
*               U = r + r*s*(P1 + s*(P2 + s*P3)), and
*               V = 1 + s*(Q1 + s*(Q2 + s*(Q3 + s*Q4))), s = r*r,
*               -Cot(r) = -V/U. Exit.
*
*       6. If |X| > 1, go to 8.
*
*       7. (|X|<2**(-40)) Tan(X) = X. Exit.
*
*       8. Overwrite X by X := X rem 2Pi. Now that |X| <= Pi, go back to 2.
*

*               Copyright (C) Motorola, Inc. 1990
*                       All Rights Reserved
*
*       THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
*       The copyright notice above does not evidence any
*       actual or intended publication of such source code.



	include fpsp_h

* added to replace single precision immediates JWH 1/16/91.
V3F800000  DC.L  $3F800000
V00000000  DC.L  $00000000

BOUNDS1 DC.L $3FD78000,$4004BC7E
TWOBYPI DC.L $3FE45F30,$6DC9C883

TANQ4   DC.L $3EA0B759,$F50F8688
TANP3   DC.L $BEF2BAA5,$A8924F04

TANQ3   DC.L $BF346F59,$B39BA65F,$00000000,$00000000

TANP2   DC.L $3FF60000,$E073D3FC,$199C4A00,$00000000

TANQ2   DC.L $3FF90000,$D23CD684,$15D95FA1,$00000000

TANP1   DC.L $BFFC0000,$8895A6C5,$FB423BCA,$00000000

TANQ1   DC.L $BFFD0000,$EEF57E0D,$A84BC8CE,$00000000

INVTWOPI DC.L $3FFC0000,$A2F9836E,$4E44152A,$00000000

TWOPI1  DC.L $40010000,$C90FDAA2,$00000000,$00000000
TWOPI2  DC.L $3FDF0000,$85A308D4,$00000000,$00000000

*--N*PI/2, -32 <= N <= 32, IN A LEADING TERM IN EXT. AND TRAILING
*--TERM IN SGL. NOTE THAT PI IS 64-BIT LONG, THUS N*PI/2 IS AT
*--MOST 69 BITS LONG.
	def     PITBL
PITBL    equ    *
  DC.L  $C0040000,$C90FDAA2,$2168C235,$21800000
  DC.L  $C0040000,$C2C75BCD,$105D7C23,$A0D00000
  DC.L  $C0040000,$BC7EDCF7,$FF523611,$A1E80000
  DC.L  $C0040000,$B6365E22,$EE46F000,$21480000
  DC.L  $C0040000,$AFEDDF4D,$DD3BA9EE,$A1200000
  DC.L  $C0040000,$A9A56078,$CC3063DD,$21FC0000
  DC.L  $C0040000,$A35CE1A3,$BB251DCB,$21100000
  DC.L  $C0040000,$9D1462CE,$AA19D7B9,$A1580000
  DC.L  $C0040000,$96CBE3F9,$990E91A8,$21E00000
  DC.L  $C0040000,$90836524,$88034B96,$20B00000
  DC.L  $C0040000,$8A3AE64F,$76F80584,$A1880000
  DC.L  $C0040000,$83F2677A,$65ECBF73,$21C40000
  DC.L  $C0030000,$FB53D14A,$A9C2F2C2,$20000000
  DC.L  $C0030000,$EEC2D3A0,$87AC669F,$21380000
  DC.L  $C0030000,$E231D5F6,$6595DA7B,$A1300000
  DC.L  $C0030000,$D5A0D84C,$437F4E58,$9FC00000
  DC.L  $C0030000,$C90FDAA2,$2168C235,$21000000
  DC.L  $C0030000,$BC7EDCF7,$FF523611,$A1680000
  DC.L  $C0030000,$AFEDDF4D,$DD3BA9EE,$A0A00000
  DC.L  $C0030000,$A35CE1A3,$BB251DCB,$20900000
  DC.L  $C0030000,$96CBE3F9,$990E91A8,$21600000
  DC.L  $C0030000,$8A3AE64F,$76F80584,$A1080000
  DC.L  $C0020000,$FB53D14A,$A9C2F2C2,$1F800000
  DC.L  $C0020000,$E231D5F6,$6595DA7B,$A0B00000
  DC.L  $C0020000,$C90FDAA2,$2168C235,$20800000
  DC.L  $C0020000,$AFEDDF4D,$DD3BA9EE,$A0200000
  DC.L  $C0020000,$96CBE3F9,$990E91A8,$20E00000
  DC.L  $C0010000,$FB53D14A,$A9C2F2C2,$1F000000
  DC.L  $C0010000,$C90FDAA2,$2168C235,$20000000
  DC.L  $C0010000,$96CBE3F9,$990E91A8,$20600000
  DC.L  $C0000000,$C90FDAA2,$2168C235,$1F800000
  DC.L  $BFFF0000,$C90FDAA2,$2168C235,$1F000000
  DC.L  $00000000,$00000000,$00000000,$00000000
  DC.L  $3FFF0000,$C90FDAA2,$2168C235,$9F000000
  DC.L  $40000000,$C90FDAA2,$2168C235,$9F800000
  DC.L  $40010000,$96CBE3F9,$990E91A8,$A0600000
  DC.L  $40010000,$C90FDAA2,$2168C235,$A0000000
  DC.L  $40010000,$FB53D14A,$A9C2F2C2,$9F000000
  DC.L  $40020000,$96CBE3F9,$990E91A8,$A0E00000
  DC.L  $40020000,$AFEDDF4D,$DD3BA9EE,$20200000
  DC.L  $40020000,$C90FDAA2,$2168C235,$A0800000
  DC.L  $40020000,$E231D5F6,$6595DA7B,$20B00000
  DC.L  $40020000,$FB53D14A,$A9C2F2C2,$9F800000
  DC.L  $40030000,$8A3AE64F,$76F80584,$21080000
  DC.L  $40030000,$96CBE3F9,$990E91A8,$A1600000
  DC.L  $40030000,$A35CE1A3,$BB251DCB,$A0900000
  DC.L  $40030000,$AFEDDF4D,$DD3BA9EE,$20A00000
  DC.L  $40030000,$BC7EDCF7,$FF523611,$21680000
  DC.L  $40030000,$C90FDAA2,$2168C235,$A1000000
  DC.L  $40030000,$D5A0D84C,$437F4E58,$1FC00000
  DC.L  $40030000,$E231D5F6,$6595DA7B,$21300000
  DC.L  $40030000,$EEC2D3A0,$87AC669F,$A1380000
  DC.L  $40030000,$FB53D14A,$A9C2F2C2,$A0000000
  DC.L  $40040000,$83F2677A,$65ECBF73,$A1C40000
  DC.L  $40040000,$8A3AE64F,$76F80584,$21880000
  DC.L  $40040000,$90836524,$88034B96,$A0B00000
  DC.L  $40040000,$96CBE3F9,$990E91A8,$A1E00000
  DC.L  $40040000,$9D1462CE,$AA19D7B9,$21580000
  DC.L  $40040000,$A35CE1A3,$BB251DCB,$A1100000
  DC.L  $40040000,$A9A56078,$CC3063DD,$A1FC0000
  DC.L  $40040000,$AFEDDF4D,$DD3BA9EE,$21200000
  DC.L  $40040000,$B6365E22,$EE46F000,$A1480000
  DC.L  $40040000,$BC7EDCF7,$FF523611,$21E80000
  DC.L  $40040000,$C2C75BCD,$105D7C23,$20D00000
  DC.L  $40040000,$C90FDAA2,$2168C235,$A1800000

INARG   equ     FP_SCR4

TWOTO63 equ     L_SCR1
ENDFLAG equ     L_SCR2
N       equ     L_SCR3

	refr    t_frcinx
	refr    t_extdnrm

	def     stand
stand    equ    *
*--TAN(X) = X FOR DENORMALIZED X

	bra             t_extdnrm

	def     stan
stan    equ    *
	FMOVE.X         (a0),FP0        ...LOAD INPUT

	MOVE.L          (A0),D0
	MOVE.W          4(A0),D0
	ANDI.L          #$7FFFFFFF,D0

	CMPI.L          #$3FD78000,D0           ...|X| >= 2**(-40)?
	BGE.B           TANOK1
	BRA.W           TANSM
TANOK1    equ    *
	CMPI.L          #$4004BC7E,D0           ...|X| < 15 PI?
	BLT.B           TANMAIN
	BRA.W           REDUCEX


TANMAIN    equ    *
*--THIS IS THE USUAL CASE, |X| <= 15 PI.
*--THE ARGUMENT REDUCTION IS DONE BY TABLE LOOK UP.
	FMOVE.X         FP0,FP1
	FMUL.D          TWOBYPI,FP1     ...X*2/PI

*--HIDE THE NEXT TWO INSTRUCTIONS
	lea             PITBL+$200,a1 ...TABLE OF N*PI/2, N = -32,...,32

*--FP1 IS NOW READY
	FMOVE.L         FP1,D0          ...CONVERT TO INTEGER

	ASL.L           #4,D0
	ADDA.L          D0,a1           ...ADDRESS N*PIBY2 IN Y1, Y2

	FSUB.X          (a1)+,FP0       ...X-Y1
*--HIDE THE NEXT ONE

	FSUB.S          (a1),FP0        ...FP0 IS R = (X-Y1)-Y2

	ROR.L           #5,D0
	ANDI.L          #$80000000,D0   ...D0 WAS ODD IFF D0 < 0

TANCONT    equ    *

	CMPI.L          #0,D0
	BLT.W           NODD

	FMOVE.X         FP0,FP1
	FMUL.X          FP1,FP1         ...S = R*R

	FMOVE.D         TANQ4,FP3
	FMOVE.D         TANP3,FP2

	FMUL.X          FP1,FP3         ...SQ4
	FMUL.X          FP1,FP2         ...SP3

	FADD.D          TANQ3,FP3       ...Q3+SQ4
	FADD.X          TANP2,FP2       ...P2+SP3

	FMUL.X          FP1,FP3         ...S(Q3+SQ4)
	FMUL.X          FP1,FP2         ...S(P2+SP3)

	FADD.X          TANQ2,FP3       ...Q2+S(Q3+SQ4)
	FADD.X          TANP1,FP2       ...P1+S(P2+SP3)

	FMUL.X          FP1,FP3         ...S(Q2+S(Q3+SQ4))
	FMUL.X          FP1,FP2         ...S(P1+S(P2+SP3))

	FADD.X          TANQ1,FP3       ...Q1+S(Q2+S(Q3+SQ4))
	FMUL.X          FP0,FP2         ...RS(P1+S(P2+SP3))

	FMUL.X          FP3,FP1         ...S(Q1+S(Q2+S(Q3+SQ4)))


	FADD.X          FP2,FP0         ...R+RS(P1+S(P2+SP3))


*       FADD.S          #:3F800000,FP1  ...1+S(Q1+...)
	FADD.s          V3F800000,FP1   ...1+S(Q1+...)

	FMOVE.L         d1,FPCONTROL            ;restore users exceptions
	FDIV.X          FP1,FP0         ;last inst - possible exception set

	bra             t_frcinx

NODD    equ    *
	FMOVE.X         FP0,FP1
	FMUL.X          FP0,FP0         ...S = R*R

	FMOVE.D         TANQ4,FP3
	FMOVE.D         TANP3,FP2

	FMUL.X          FP0,FP3         ...SQ4
	FMUL.X          FP0,FP2         ...SP3

	FADD.D          TANQ3,FP3       ...Q3+SQ4
	FADD.X          TANP2,FP2       ...P2+SP3

	FMUL.X          FP0,FP3         ...S(Q3+SQ4)
	FMUL.X          FP0,FP2         ...S(P2+SP3)

	FADD.X          TANQ2,FP3       ...Q2+S(Q3+SQ4)
	FADD.X          TANP1,FP2       ...P1+S(P2+SP3)

	FMUL.X          FP0,FP3         ...S(Q2+S(Q3+SQ4))
	FMUL.X          FP0,FP2         ...S(P1+S(P2+SP3))

	FADD.X          TANQ1,FP3       ...Q1+S(Q2+S(Q3+SQ4))
	FMUL.X          FP1,FP2         ...RS(P1+S(P2+SP3))

	FMUL.X          FP3,FP0         ...S(Q1+S(Q2+S(Q3+SQ4)))


	FADD.X          FP2,FP1         ...R+RS(P1+S(P2+SP3))
*       FADD.S          #:3F800000,FP0  ...1+S(Q1+...)
	FADD.s          V3F800000,FP0   ...1+S(Q1+...)


	FMOVE.X         FP1,-(sp)
	EORI.L          #$80000000,(sp)

	FMOVE.L         d1,FPCONTROL            ;restore users exceptions
	FDIV.X          (sp)+,FP0       ;last inst - possible exception set

	bra             t_frcinx

TANBORS    equ    *
*--IF |X| > 15PI, WE USE THE GENERAL ARGUMENT REDUCTION.
*--IF |X| < 2**(-40), RETURN X OR 1.
	CMPI.L          #$3FFF8000,D0
	BGT.B           REDUCEX

TANSM    equ    *

	FMOVE.X         FP0,-(sp)
	FMOVE.L         d1,FPCONTROL             ;restore users exceptions
	FMOVE.X         (sp)+,FP0       ;last inst - posibble exception set

	bra             t_frcinx


REDUCEX    equ    *
*--WHEN REDUCEX IS USED, THE CODE WILL INEVITABLY BE SLOW.
*--THIS REDUCTION METHOD, HOWEVER, IS MUCH FASTER THAN USING
*--THE REMAINDER INSTRUCTION WHICH IS NOW IN SOFTWARE.

	FMOVEM.X        FP2-FP5,-(A7)   ...save FP2 through FP5
	MOVE.L          D2,-(A7)
*       FMOVE.S         #:00000000,FP1
	FMOVE.s         V00000000,FP1

*--ON ENTRY, FP0 IS X, ON RETURN, FP0 IS X REM PI/2, |X| <= PI/4.
*--integer quotient will be stored in N
*--Intermeditate remainder is 66-bit long; (R,r) in (FP0,FP1)

LOOP    equ    *
	FMOVE.X         FP0,INARG(a6)   ...+-2**K * F, 1 <= F < 2
	MOVE.W          INARG(a6),D0
	MOVE.L          D0,A1           ...save a copy of D0
	ANDI.L          #$00007FFF,D0
	SUBI.L          #$00003FFF,D0   ...D0 IS K
	CMPI.L          #28,D0
	BLE.B           LASTLOOP
CONTLOOP    equ    *
	SUBI.L          #27,D0   ...D0 IS L := K-27
	MOVE.L          #0,ENDFLAG(a6)
	BRA.B           WORK
LASTLOOP    equ    *
	CLR.L           D0              ...D0 IS L := 0
	MOVE.L          #1,ENDFLAG(a6)

WORK    equ    *
*--FIND THE REMAINDER OF (R,r) W.R.T.   2**L * (PI/2). L IS SO CHOSEN
*--THAT INT( X * (2/PI) / 2**(L) ) < 2**29.

*--CREATE 2**(-L) * (2/PI), SIGN(INARG)*2**(63),
*--2**L * (PIby2_1), 2**L * (PIby2_2)

	MOVE.L          #$00003FFE,D2   ...BIASED EXPO OF 2/PI
	SUB.L           D0,D2           ...BIASED EXPO OF 2**(-L)*(2/PI)

	MOVE.L          #$A2F9836E,FP_SCR1+4(a6)
	MOVE.L          #$4E44152A,FP_SCR1+8(a6)
	MOVE.W          D2,FP_SCR1(a6)  ...FP_SCR1 is 2**(-L)*(2/PI)

	FMOVE.X         FP0,FP2
	FMUL.X          FP_SCR1(a6),FP2
*--WE MUST NOW FIND INT(FP2). SINCE WE NEED THIS VALUE IN
*--FLOATING POINT FORMAT, THE TWO FMOVE'S       FMOVE.L FP <--> N
*--WILL BE TOO INEFFICIENT. THE WAY AROUND IT IS THAT
*--(SIGN(INARG)*2**63   +       FP2) - SIGN(INARG)*2**63 WILL GIVE
*--US THE DESIRED VALUE IN FLOATING POINT.

*--HIDE SIX CYCLES OF INSTRUCTION
	MOVE.L          A1,D2
	SWAP            D2
	ANDI.L          #$80000000,D2
	ORI.L           #$5F000000,D2   ...D2 IS SIGN(INARG)*2**63 IN SGL
	MOVE.L          D2,TWOTO63(a6)

	MOVE.L          D0,D2
	ADDI.L          #$00003FFF,D2   ...BIASED EXPO OF 2**L * (PI/2)

*--FP2 IS READY
	FADD.S          TWOTO63(a6),FP2 ...THE FRACTIONAL PART OF FP1 IS ROUNDED

*--HIDE 4 CYCLES OF INSTRUCTION; creating 2**(L)*Piby2_1  and  2**(L)*Piby2_2
	MOVE.W          D2,FP_SCR2(a6)
	CLR.W           FP_SCR2+2(a6)
	MOVE.L          #$C90FDAA2,FP_SCR2+4(a6)
	CLR.L           FP_SCR2+8(a6)           ...FP_SCR2 is  2**(L) * Piby2_1

*--FP2 IS READY
	FSUB.S          TWOTO63(a6),FP2         ...FP2 is N

	ADDI.L          #$00003FDD,D0
	MOVE.W          D0,FP_SCR3(a6)
	CLR.W           FP_SCR3+2(a6)
	MOVE.L          #$85A308D3,FP_SCR3+4(a6)
	CLR.L           FP_SCR3+8(a6)           ...FP_SCR3 is 2**(L) * Piby2_2

	MOVE.L          ENDFLAG(a6),D0

*--We are now ready to perform (R+r) - N*P1 - N*P2, P1 = 2**(L) * Piby2_1 and
*--P2 = 2**(L) * Piby2_2
	FMOVE.X         FP2,FP4
	FMul.X          FP_SCR2(a6),FP4         ...W = N*P1
	FMove.X         FP2,FP5
	FMul.X          FP_SCR3(a6),FP5         ...w = N*P2
	FMove.X         FP4,FP3
*--we want P+p = W+w  but  |p| <= half ulp of P
*--Then, we need to compute  A := R-P   and  a := r-p
	FAdd.X          FP5,FP3                 ...FP3 is P
	FSub.X          FP3,FP4                 ...W-P

	FSub.X          FP3,FP0                 ...FP0 is A := R - P
	FAdd.X          FP5,FP4                 ...FP4 is p = (W-P)+w

	FMove.X         FP0,FP3                 ...FP3 A
	FSub.X          FP4,FP1                 ...FP1 is a := r - p

*--Now we need to normalize (A,a) to  "new (R,r)" where R+r = A+a but
*--|r| <= half ulp of R.
	FAdd.X          FP1,FP0                 ...FP0 is R := A+a
*--No need to calculate r if this is the last loop
	CMPI.L          #0,D0
	BGT.W           RESTORE

*--Need to calculate r
	FSub.X          FP0,FP3                 ...A-R
	FAdd.X          FP3,FP1                 ...FP1 is r := (A-R)+a
	BRA.W           LOOP

RESTORE    equ    *
	FMOVE.L         FP2,N(a6)
	MOVE.L          (A7)+,D2
	FMOVEM.X        (A7)+,FP2-FP5


	MOVE.L          N(a6),D0
	ROR.L           #1,D0


	BRA.W           TANCONT

	end
@


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@Automatic bump of revision number for PWS version 3.24B
@
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@Automatic bump of revision number for PWS version 3.24A
@
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@d59 1
a59 1
	include fpsp.h
@


1.2
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@
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1.1
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@Initial revision
@
text
@d2 1
a2 1
*	stan.sa 3.1 12/10/90
d4 3
a6 3
*	The entry point stan computes the tangent of
*	an input argument;
*	stand does the same except for denormalized input.
d8 2
a9 2
*	Input: Double-extended number X in location pointed to
*		by address register a0.
d11 1
a11 1
*	Output: The value tan(X) returned in floating-point register Fp0.
d13 4
a16 4
*	Accuracy and Monotonicity: The returned result is within 3 ulp in
*		64 significant bit, i.e. within 0.5001 ulp to 53 bits if the
*		result is subsequently rounded to double precision. The
*		result is provably monotonic in double precision.
d18 3
a20 3
*	Speed: The program sTAN takes approximately 170 cycles for
*		input argument X such that |X| < 15Pi, which is the the usual
*		situation.
d22 1
a22 1
*	Algorithm:
d24 1
a24 1
*	1. If |X| >= 15Pi or |X| < 2**(-40), go to 6.
d26 2
a27 2
*	2. Decompose X as X = N(Pi/2) + r where |r| <= Pi/4. Let
*		k = N mod 2, so in particular, k = 0 or 1.
d29 1
a29 1
*	3. If k is odd, go to 5.
d31 5
a35 5
*	4. (k is even) Tan(X) = tan(r) and tan(r) is approximated by a
*		rational function U/V where
*		U = r + r*s*(P1 + s*(P2 + s*P3)), and
*		V = 1 + s*(Q1 + s*(Q2 + s*(Q3 + s*Q4))),  s = r*r.
*		Exit.
d37 5
a41 5
*	4. (k is odd) Tan(X) = -cot(r). Since tan(r) is approximated by a
*		rational function U/V where
*		U = r + r*s*(P1 + s*(P2 + s*P3)), and
*		V = 1 + s*(Q1 + s*(Q2 + s*(Q3 + s*Q4))), s = r*r,
*		-Cot(r) = -V/U. Exit.
d43 1
a43 1
*	6. If |X| > 1, go to 8.
d45 1
a45 1
*	7. (|X|<2**(-40)) Tan(X) = X. Exit.
d47 1
a47 1
*	8. Overwrite X by X := X rem 2Pi. Now that |X| <= Pi, go back to 2.
d50 2
a51 2
*		Copyright (C) Motorola, Inc. 1990
*			All Rights Reserved
d53 3
a55 3
*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA 
*	The copyright notice above does not evidence any  
*	actual or intended publication of such source code.
d65 2
a66 2
BOUNDS1	DC.L $3FD78000,$4004BC7E
TWOBYPI	DC.L $3FE45F30,$6DC9C883
d68 2
a69 2
TANQ4	DC.L $3EA0B759,$F50F8688
TANP3	DC.L $BEF2BAA5,$A8924F04
d71 1
a71 1
TANQ3	DC.L $BF346F59,$B39BA65F,$00000000,$00000000
d73 1
a73 1
TANP2	DC.L $3FF60000,$E073D3FC,$199C4A00,$00000000
d75 1
a75 1
TANQ2	DC.L $3FF90000,$D23CD684,$15D95FA1,$00000000
d77 1
a77 1
TANP1	DC.L $BFFC0000,$8895A6C5,$FB423BCA,$00000000
d79 1
a79 1
TANQ1	DC.L $BFFD0000,$EEF57E0D,$A84BC8CE,$00000000
d83 2
a84 2
TWOPI1	DC.L $40010000,$C90FDAA2,$00000000,$00000000
TWOPI2	DC.L $3FDF0000,$85A308D4,$00000000,$00000000
d89 1
a89 1
	def	PITBL
d157 1
a157 1
INARG	equ	FP_SCR4
d160 1
a160 1
ENDFLAG	equ	L_SCR2
d163 2
a164 2
	refr	t_frcinx
	refr	t_extdnrm
d166 1
a166 1
	def	stand
d170 1
a170 1
	bra		t_extdnrm
d172 1
a172 1
	def	stan
d174 1
a174 1
	FMOVE.X		(a0),FP0	...LOAD INPUT
d176 3
a178 3
	MOVE.L		(A0),D0
	MOVE.W		4(A0),D0
	ANDI.L		#$7FFFFFFF,D0
d180 3
a182 3
	CMPI.L		#$3FD78000,D0		...|X| >= 2**(-40)?
	BGE.B		TANOK1
	BRA.W		TANSM
d184 3
a186 3
	CMPI.L		#$4004BC7E,D0		...|X| < 15 PI?
	BLT.B		TANMAIN
	BRA.W		REDUCEX
d192 2
a193 2
	FMOVE.X		FP0,FP1
	FMUL.D		TWOBYPI,FP1	...X*2/PI
d196 1
a196 1
	lea		PITBL+$200,a1 ...TABLE OF N*PI/2, N = -32,...,32
d199 1
a199 1
	FMOVE.L		FP1,D0		...CONVERT TO INTEGER
d201 2
a202 2
	ASL.L		#4,D0
	ADDA.L		D0,a1		...ADDRESS N*PIBY2 IN Y1, Y2
d204 1
a204 1
	FSUB.X		(a1)+,FP0	...X-Y1
d207 1
a207 1
	FSUB.S		(a1),FP0	...FP0 IS R = (X-Y1)-Y2
d209 2
a210 2
	ROR.L		#5,D0
	ANDI.L		#$80000000,D0	...D0 WAS ODD IFF D0 < 0
d214 2
a215 2
	CMPI.L		#0,D0
	BLT.W		NODD
d217 2
a218 2
	FMOVE.X		FP0,FP1
	FMUL.X		FP1,FP1	 	...S = R*R
d220 2
a221 2
	FMOVE.D		TANQ4,FP3
	FMOVE.D		TANP3,FP2
d223 2
a224 2
	FMUL.X		FP1,FP3	 	...SQ4
	FMUL.X		FP1,FP2	 	...SP3
d226 2
a227 2
	FADD.D		TANQ3,FP3	...Q3+SQ4
	FADD.X		TANP2,FP2	...P2+SP3
d229 2
a230 2
	FMUL.X		FP1,FP3	 	...S(Q3+SQ4)
	FMUL.X		FP1,FP2	 	...S(P2+SP3)
d232 2
a233 2
	FADD.X		TANQ2,FP3	...Q2+S(Q3+SQ4)
	FADD.X		TANP1,FP2	...P1+S(P2+SP3)
d235 2
a236 2
	FMUL.X		FP1,FP3	 	...S(Q2+S(Q3+SQ4))
	FMUL.X		FP1,FP2	 	...S(P1+S(P2+SP3))
d238 2
a239 2
	FADD.X		TANQ1,FP3	...Q1+S(Q2+S(Q3+SQ4))
	FMUL.X		FP0,FP2	 	...RS(P1+S(P2+SP3))
d241 1
a241 2
	FMUL.X		FP3,FP1	 	...S(Q1+S(Q2+S(Q3+SQ4)))
	
a242 2
	FADD.X		FP2,FP0	 	...R+RS(P1+S(P2+SP3))
	
d244 1
a244 2
*       FADD.S		#:3F800000,FP1	...1+S(Q1+...)
        FADD.s		V3F800000,FP1	...1+S(Q1+...)
a245 2
	FMOVE.L		d1,FPCONTROL		;restore users exceptions
	FDIV.X		FP1,FP0		;last inst - possible exception set
d247 2
a248 1
	bra		t_frcinx
d250 5
d256 2
a257 2
	FMOVE.X		FP0,FP1
	FMUL.X		FP0,FP0	 	...S = R*R
d259 2
a260 2
	FMOVE.D		TANQ4,FP3
	FMOVE.D		TANP3,FP2
d262 2
a263 2
	FMUL.X		FP0,FP3	 	...SQ4
	FMUL.X		FP0,FP2	 	...SP3
d265 2
a266 2
	FADD.D		TANQ3,FP3	...Q3+SQ4
	FADD.X		TANP2,FP2	...P2+SP3
d268 2
a269 2
	FMUL.X		FP0,FP3	 	...S(Q3+SQ4)
	FMUL.X		FP0,FP2	 	...S(P2+SP3)
d271 2
a272 2
	FADD.X		TANQ2,FP3	...Q2+S(Q3+SQ4)
	FADD.X		TANP1,FP2	...P1+S(P2+SP3)
d274 2
a275 2
	FMUL.X		FP0,FP3	 	...S(Q2+S(Q3+SQ4))
	FMUL.X		FP0,FP2	 	...S(P1+S(P2+SP3))
d277 2
a278 2
	FADD.X		TANQ1,FP3	...Q1+S(Q2+S(Q3+SQ4))
	FMUL.X		FP1,FP2	 	...RS(P1+S(P2+SP3))
d280 1
a280 2
	FMUL.X		FP3,FP0	 	...S(Q1+S(Q2+S(Q3+SQ4)))
	
a281 4
	FADD.X		FP2,FP1	 	...R+RS(P1+S(P2+SP3))
*       FADD.S		#:3F800000,FP0	...1+S(Q1+...)
        FADD.s		V3F800000,FP0	...1+S(Q1+...)
	
d283 3
a285 2
	FMOVE.X		FP1,-(sp)
	EORI.L		#$80000000,(sp)
a286 2
	FMOVE.L		d1,FPCONTROL	 	;restore users exceptions
	FDIV.X		(sp)+,FP0	;last inst - possible exception set
d288 2
a289 1
	bra		t_frcinx
d291 5
d299 2
a300 2
	CMPI.L		#$3FFF8000,D0
	BGT.B		REDUCEX
d304 3
a306 3
	FMOVE.X		FP0,-(sp)
	FMOVE.L		d1,FPCONTROL		 ;restore users exceptions
	FMOVE.X		(sp)+,FP0	;last inst - posibble exception set
d308 1
a308 1
	bra		t_frcinx
d316 2
a317 2
	FMOVEM.X	FP2-FP5,-(A7)	...save FP2 through FP5
	MOVE.L		D2,-(A7)
d319 1
a319 1
        FMOVE.s         V00000000,FP1
d326 7
a332 7
	FMOVE.X		FP0,INARG(a6)	...+-2**K * F, 1 <= F < 2
	MOVE.W		INARG(a6),D0
        MOVE.L          D0,A1		...save a copy of D0
	ANDI.L		#$00007FFF,D0
	SUBI.L		#$00003FFF,D0	...D0 IS K
	CMPI.L		#28,D0
	BLE.B		LASTLOOP
d334 3
a336 3
	SUBI.L		#27,D0	 ...D0 IS L := K-27
	MOVE.L		#0,ENDFLAG(a6)
	BRA.B		WORK
d338 2
a339 2
	CLR.L		D0		...D0 IS L := 0
	MOVE.L		#1,ENDFLAG(a6)
d342 2
a343 2
*--FIND THE REMAINDER OF (R,r) W.R.T.	2**L * (PI/2). L IS SO CHOSEN
*--THAT	INT( X * (2/PI) / 2**(L) ) < 2**29.
d348 2
a349 2
	MOVE.L		#$00003FFE,D2	...BIASED EXPO OF 2/PI
	SUB.L		D0,D2		...BIASED EXPO OF 2**(-L)*(2/PI)
d351 3
a353 3
	MOVE.L		#$A2F9836E,FP_SCR1+4(a6)
	MOVE.L		#$4E44152A,FP_SCR1+8(a6)
	MOVE.W		D2,FP_SCR1(a6)	...FP_SCR1 is 2**(-L)*(2/PI)
d355 2
a356 2
	FMOVE.X		FP0,FP2
	FMUL.X		FP_SCR1(a6),FP2
d358 1
a358 1
*--FLOATING POINT FORMAT, THE TWO FMOVE'S	FMOVE.L FP <--> N
d360 1
a360 1
*--(SIGN(INARG)*2**63	+	FP2) - SIGN(INARG)*2**63 WILL GIVE
d364 5
a368 5
        MOVE.L		A1,D2
        SWAP		D2
	ANDI.L		#$80000000,D2
	ORI.L		#$5F000000,D2	...D2 IS SIGN(INARG)*2**63 IN SGL
	MOVE.L		D2,TWOTO63(a6)
d370 2
a371 2
	MOVE.L		D0,D2
	ADDI.L		#$00003FFF,D2	...BIASED EXPO OF 2**L * (PI/2)
d374 1
a374 1
	FADD.S		TWOTO63(a6),FP2	...THE FRACTIONAL PART OF FP1 IS ROUNDED
d377 1
a377 1
        MOVE.W		D2,FP_SCR2(a6)
d379 2
a380 2
	MOVE.L		#$C90FDAA2,FP_SCR2+4(a6)
	CLR.L		FP_SCR2+8(a6)		...FP_SCR2 is  2**(L) * Piby2_1	
d383 1
a383 1
	FSUB.S		TWOTO63(a6),FP2		...FP2 is N
d385 2
a386 2
	ADDI.L		#$00003FDD,D0
        MOVE.W		D0,FP_SCR3(a6)
d388 2
a389 2
	MOVE.L		#$85A308D3,FP_SCR3+4(a6)
	CLR.L		FP_SCR3+8(a6)		...FP_SCR3 is 2**(L) * Piby2_2
d391 1
a391 1
	MOVE.L		ENDFLAG(a6),D0
d395 5
a399 5
	FMOVE.X		FP2,FP4
	FMul.X		FP_SCR2(a6),FP4		...W = N*P1
	FMove.X		FP2,FP5
	FMul.X		FP_SCR3(a6),FP5		...w = N*P2
	FMove.X		FP4,FP3
d402 2
a403 2
	FAdd.X		FP5,FP3			...FP3 is P
	FSub.X		FP3,FP4			...W-P
d405 2
a406 2
	FSub.X		FP3,FP0			...FP0 is A := R - P
        FAdd.X		FP5,FP4			...FP4 is p = (W-P)+w
d408 2
a409 2
	FMove.X		FP0,FP3			...FP3 A
	FSub.X		FP4,FP1			...FP1 is a := r - p
d413 1
a413 1
	FAdd.X		FP1,FP0			...FP0 is R := A+a
d415 2
a416 2
	CMPI.L		#0,D0
	BGT.W		RESTORE
d419 3
a421 3
	FSub.X		FP0,FP3			...A-R
	FAdd.X		FP3,FP1			...FP1 is r := (A-R)+a
	BRA.W		LOOP
d424 3
a426 3
        FMOVE.L		FP2,N(a6)
	MOVE.L		(A7)+,D2
	FMOVEM.X	(A7)+,FP2-FP5
a427 3
	
	MOVE.L		N(a6),D0
        ROR.L		#1,D0
d429 2
d432 2
a433 1
	BRA.W		TANCONT
@
