* MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
* M68000 Hi-Performance Microprocessor Division
* M68040 Software Package
*
* M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
* All rights reserved.
*
* THE SOFTWARE is provided on an "AS IS" basis and without warranty.
* To the maximum extent permitted by applicable law,
* MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
* INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
* PARTICULAR PURPOSE and any warranty against infringement with
* regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
* and any accompanying written materials.
*
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* IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
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* OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
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*
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* distribute the SOFTWARE so long as this entire notice is retained
* without alteration in any modified and/or redistributed versions,
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* under any patents or trademarks of Motorola, Inc.
*
* sasin.sa 3.3 12/19/90
*
* Description: The entry point sAsin computes the inverse sine of
* an input argument; sAsind does the same except for denormalized
* input.
*
* Input: Double-extended number X in location pointed to
* by address register a0.
*
* Output: The value arcsin(X) returned in floating-point register Fp0.
*
* Accuracy and Monotonicity: The returned result is within 3 ulps 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 sASIN takes approximately 310 cycles.
*
* Algorithm:
*
* ASIN
* 1. If |X| >= 1, go to 3.
*
* 2. (|X| < 1) Calculate asin(X) by
* z := sqrt( [1-X][1+X] )
* asin(X) = atan( x / z ).
* Exit.
*
* 3. If |X| > 1, go to 5.
*
* 4. (|X| = 1) sgn := sign(X), return asin(X) := sgn * Pi/2. Exit.
*
* 5. (|X| > 1) Generate an invalid operation by 0 * infinity.
* Exit.
*
SASIN IDNT 2,1 Motorola 040 Floating Point Software Package
FMOVE.X PIBY2,FP0
move.l (a0),d0
ANDI.L #$80000000,D0 ...SIGN BIT OF X
ORI.L #$3F800000,D0 ...+-1 IN SGL FORMAT
MOVE.L D0,-(sp) ...push SIGN(X) IN SGL-FMT
FMOVE.L d1,FPCR
FMUL.S (sp)+,FP0
bra t_frcinx
