/* sasin.s - Motorola 68040 FP arc-sine routines (EXC) *//* Copyright 1991-1993 Wind River Systems, Inc. */	.data	.globl	_copyright_wind_river	.long	_copyright_wind_river/*modification history--------------------01f,14jun95,tpr  changed fbxx to fbxxl.01e,21jul93,kdl  added .text (SPR #2372).01d,23aug92,jcf  changed bxxx to jxx.01c,26may92,rrr  the tree shuffle01b,10jan92,kdl  added modification history; general cleanup.01a,15aug91,kdl  original version, from Motorola FPSP v2.0.*//*DESCRIPTION	sasinsa 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.		Copyright (C) Motorola, Inc. 1990			All Rights Reserved	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA	The copyright notice above does not evidence any	actual or intended publication of such source code.SASIN	idnt	2,1 Motorola 040 Floating Point Software Package	section	8NOMANUAL*/PIBY2:	.long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000|	xref	__x_t_operr|	xref	__x_t_frcinx|	xref	__x_t_extdnrm|	xref	__x_satan	.text	.globl	__x_sasind__x_sasind:|--ASIN(X) = X FOR DENORMALIZED X	jra 		__x_t_extdnrm	.globl	__x_sasin__x_sasin:	fmovex		a0@,fp0		|...lOAD INPUT	movel		a0@,d0	movew		a0@(4),d0	andil		#0x7FFFFFFF,d0	cmpil		#0x3FFF8000,d0	jge 		asinbig|--THIS IS THE USUAL CASE, |X| < 1|--ASIN(X) = ATAN( X / SQRT( (1-X)(1+X) ) )	.long 0xf23c4480,0x3f800000	/*  fmoves  &0x3F800000,fp1 */	fsubx		fp0,fp1		|...1-X	fmovemx	fp2-fp2,a7@-	.long 0xf23c4500,0x3f800000	/*  fmoves  &0x3F800000,fp2 */	faddx		fp0,fp2		|...1+X	fmulx		fp2,fp1		|...(1+X)(1-X)	fmovemx	a7@+,fp2-fp2	fsqrtx		fp1		|...SQRT([1-X][1+X])	fdivx		fp1,fp0	 	|...X/SQRT([1-X][1+X])	fmovemx	fp0-fp0,a0@	bsrl		__x_satan	jra 		__x_t_frcinxasinbig:	fabsx		fp0,fp0	 	|...|X|	.long 0xf23c4438,0x3f800000	/*  fcmps  &0x3F800000,fp0 */	fbgtl		__x_t_operr		| cause an operr exception|--|X| = 1, ASIN(X) = +- PI/2.	fmovex		PIBY2,fp0	movel		a0@,d0	andil		#0x80000000,d0	|...SIGN BIT OF X	oril		#0x3F800000,d0	|...+-1 IN SGL FORMAT	movel		d0,a7@-		|...push SIGN(X) IN SGL-FMT	fmovel		d1,fpcr	fmuls		a7@+,fp0	jra 		__x_t_frcinx|	end