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Diffstat (limited to 'sys/arch/m68k/fpsp/sacos.sa')
| -rw-r--r-- | sys/arch/m68k/fpsp/sacos.sa | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/sys/arch/m68k/fpsp/sacos.sa b/sys/arch/m68k/fpsp/sacos.sa new file mode 100644 index 00000000000..7a904741823 --- /dev/null +++ b/sys/arch/m68k/fpsp/sacos.sa @@ -0,0 +1,140 @@ +* $NetBSD: sacos.sa,v 1.3 1994/10/26 07:49:27 cgd Exp $ + +* 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. +* +* To the maximum extent permitted by applicable law, +* IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER +* (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS +* PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR +* OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE +* SOFTWARE. Motorola assumes no responsibility for the maintenance +* and support of the SOFTWARE. +* +* You are hereby granted a copyright license to use, modify, and +* distribute the SOFTWARE so long as this entire notice is retained +* without alteration in any modified and/or redistributed versions, +* and that such modified versions are clearly identified as such. +* No licenses are granted by implication, estoppel or otherwise +* under any patents or trademarks of Motorola, Inc. + +* +* sacos.sa 3.3 12/19/90 +* +* Description: The entry point sAcos computes the inverse cosine of +* an input argument; sAcosd does the same except for denormalized +* input. +* +* Input: Double-extended number X in location pointed to +* by address register a0. +* +* Output: The value arccos(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 sCOS takes approximately 310 cycles. +* +* Algorithm: +* +* ACOS +* 1. If |X| >= 1, go to 3. +* +* 2. (|X| < 1) Calculate acos(X) by +* z := (1-X) / (1+X) +* acos(X) = 2 * atan( sqrt(z) ). +* Exit. +* +* 3. If |X| > 1, go to 5. +* +* 4. (|X| = 1) If X > 0, return 0. Otherwise, return Pi. Exit. +* +* 5. (|X| > 1) Generate an invalid operation by 0 * infinity. +* Exit. +* + +SACOS IDNT 2,1 Motorola 040 Floating Point Software Package + + section 8 + +PI DC.L $40000000,$C90FDAA2,$2168C235,$00000000 +PIBY2 DC.L $3FFF0000,$C90FDAA2,$2168C235,$00000000 + + xref t_operr + xref t_frcinx + xref satan + + xdef sacosd +sacosd: +*--ACOS(X) = PI/2 FOR DENORMALIZED X + fmove.l d1,fpcr ...load user's rounding mode/precision + FMOVE.X PIBY2,FP0 + bra t_frcinx + + xdef sacos +sacos: + FMOVE.X (a0),FP0 ...LOAD INPUT + + move.l (a0),d0 ...pack exponent with upper 16 fraction + move.w 4(a0),d0 + ANDI.L #$7FFFFFFF,D0 + CMPI.L #$3FFF8000,D0 + BGE.B ACOSBIG + +*--THIS IS THE USUAL CASE, |X| < 1 +*--ACOS(X) = 2 * ATAN( SQRT( (1-X)/(1+X) ) ) + + FMOVE.S #:3F800000,FP1 + FADD.X FP0,FP1 ...1+X + FNEG.X FP0 ... -X + FADD.S #:3F800000,FP0 ...1-X + FDIV.X FP1,FP0 ...(1-X)/(1+X) + FSQRT.X FP0 ...SQRT((1-X)/(1+X)) + fmovem.x fp0,(a0) ...overwrite input + move.l d1,-(sp) ;save original users fpcr + clr.l d1 + bsr satan ...ATAN(SQRT([1-X]/[1+X])) + fMOVE.L (sp)+,fpcr ;restore users exceptions + FADD.X FP0,FP0 ...2 * ATAN( STUFF ) + bra t_frcinx + +ACOSBIG: + FABS.X FP0 + FCMP.S #:3F800000,FP0 + fbgt t_operr ;cause an operr exception + +*--|X| = 1, ACOS(X) = 0 OR PI + move.l (a0),d0 ...pack exponent with upper 16 fraction + move.w 4(a0),d0 + TST.L D0 ;D0 has original exponent+fraction + BGT.B ACOSP1 + +*--X = -1 +*Returns PI and inexact exception + FMOVE.X PI,FP0 + FMOVE.L d1,FPCR + FADD.S #:00800000,FP0 ;cause an inexact exception to be put +* ;into the 040 - will not trap until next +* ;fp inst. + bra t_frcinx + +ACOSP1: + FMOVE.L d1,FPCR + FMOVE.S #:00000000,FP0 + rts ;Facos of +1 is exact + + end |