Annotation of 43BSDTahoe/usr.lib/libm/common/trig.h, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1987 Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * Redistribution and use in source and binary forms are permitted
        !             6:  * provided that the above copyright notice and this paragraph are
        !             7:  * duplicated in all such forms and that any documentation,
        !             8:  * advertising materials, and other materials related to such
        !             9:  * distribution and use acknowledge that the software was developed
        !            10:  * by the University of California, Berkeley.  The name of the
        !            11:  * University may not be used to endorse or promote products derived
        !            12:  * from this software without specific prior written permission.
        !            13:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            14:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            15:  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            16:  *
        !            17:  * All recipients should regard themselves as participants in an ongoing
        !            18:  * research project and hence should feel obligated to report their
        !            19:  * experiences (good or bad) with these elementary function codes, using
        !            20:  * the sendbug(8) program, to the authors.
        !            21:  *
        !            22:  *     @(#)trig.h      5.3 (Berkeley) 6/30/88
        !            23:  */
        !            24: 
        !            25: #if defined(vax)||defined(tahoe)
        !            26: #ifdef vax
        !            27: #define _0x(A,B)       0x/**/A/**/B
        !            28: #else  /* vax */
        !            29: #define _0x(A,B)       0x/**/B/**/A
        !            30: #endif /* vax */
        !            31: /*thresh =  2.6117239648121182150E-1    , Hex  2^ -1   *  .85B8636B026EA0 */
        !            32: /*PIo4   =  7.8539816339744830676E-1    , Hex  2^  0   *  .C90FDAA22168C2 */
        !            33: /*PIo2   =  1.5707963267948966135E0     , Hex  2^  1   *  .C90FDAA22168C2 */
        !            34: /*PI3o4  =  2.3561944901923449203E0     , Hex  2^  2   *  .96CBE3F9990E92 */
        !            35: /*PI     =  3.1415926535897932270E0     , Hex  2^  2   *  .C90FDAA22168C2 */
        !            36: /*PI2    =  6.2831853071795864540E0     ; Hex  2^  3   *  .C90FDAA22168C2 */
        !            37: static long threshx[]  = { _0x(b863,3f85), _0x(6ea0,6b02)};
        !            38: static long PIo4x[]    = { _0x(0fda,4049), _0x(68c2,a221)};
        !            39: static long PIo2x[]    = { _0x(0fda,40c9), _0x(68c2,a221)};
        !            40: static long PI3o4x[]   = { _0x(cbe3,4116), _0x(0e92,f999)};
        !            41: static long PIx[]      = { _0x(0fda,4149), _0x(68c2,a221)};
        !            42: static long PI2x[]     = { _0x(0fda,41c9), _0x(68c2,a221)};
        !            43: #define thresh (*(double*)threshx)
        !            44: #define PIo4   (*(double*)PIo4x)
        !            45: #define PIo2   (*(double*)PIo2x)
        !            46: #define PI3o4  (*(double*)PI3o4x)
        !            47: #define PI     (*(double*)PIx)
        !            48: #define PI2    (*(double*)PI2x)
        !            49: #else   /* defined(vax)||defined(tahoe) */
        !            50: static double
        !            51: thresh =  2.6117239648121182150E-1    , /*Hex  2^ -2   *  1.0B70C6D604DD4 */
        !            52: PIo4   =  7.8539816339744827900E-1    , /*Hex  2^ -1   *  1.921FB54442D18 */
        !            53: PIo2   =  1.5707963267948965580E0     , /*Hex  2^  0   *  1.921FB54442D18 */
        !            54: PI3o4  =  2.3561944901923448370E0     , /*Hex  2^  1   *  1.2D97C7F3321D2 */
        !            55: PI     =  3.1415926535897931160E0     , /*Hex  2^  1   *  1.921FB54442D18 */
        !            56: PI2    =  6.2831853071795862320E0     ; /*Hex  2^  2   *  1.921FB54442D18 */
        !            57: #ifdef national
        !            58: static long fmaxx[]    = { 0xffffffff, 0x7fefffff};
        !            59: #define   fmax    (*(double*)fmaxx)
        !            60: #endif /* national */
        !            61: #endif /* defined(vax)||defined(tahoe) */
        !            62: static double
        !            63:        zero = 0,
        !            64:        one = 1,
        !            65:        negone = -1,
        !            66:        half = 1.0/2.0, 
        !            67:        small = 1E-10,  /* 1+small**2 == 1; better values for small:
        !            68:                         *              small   = 1.5E-9 for VAX D
        !            69:                         *                      = 1.2E-8 for IEEE Double
        !            70:                         *                      = 2.8E-10 for IEEE Extended
        !            71:                         */
        !            72:        big = 1E20;     /* big := 1/(small**2) */
        !            73: 
        !            74: /* sin__S(x*x) ... re-implemented as a macro
        !            75:  * DOUBLE PRECISION (VAX D format 56 bits, IEEE DOUBLE 53 BITS)
        !            76:  * STATIC KERNEL FUNCTION OF SIN(X), COS(X), AND TAN(X) 
        !            77:  * CODED IN C BY K.C. NG, 1/21/85; 
        !            78:  * REVISED BY K.C. NG on 8/13/85.
        !            79:  *
        !            80:  *         sin(x*k) - x
        !            81:  * RETURN  --------------- on [-PI/4,PI/4] , where k=pi/PI, PI is the rounded
        !            82:  *                 x   
        !            83:  * value of pi in machine precision:
        !            84:  *
        !            85:  *     Decimal:
        !            86:  *             pi = 3.141592653589793 23846264338327 ..... 
        !            87:  *    53 bits   PI = 3.141592653589793 115997963 ..... ,
        !            88:  *    56 bits   PI = 3.141592653589793 227020265 ..... ,  
        !            89:  *
        !            90:  *     Hexadecimal:
        !            91:  *             pi = 3.243F6A8885A308D313198A2E....
        !            92:  *    53 bits   PI = 3.243F6A8885A30  =  2 * 1.921FB54442D18
        !            93:  *    56 bits   PI = 3.243F6A8885A308 =  4 * .C90FDAA22168C2    
        !            94:  *
        !            95:  * Method:
        !            96:  *     1. Let z=x*x. Create a polynomial approximation to 
        !            97:  *         (sin(k*x)-x)/x  =  z*(S0 + S1*z^1 + ... + S5*z^5).
        !            98:  *     Then
        !            99:  *      sin__S(x*x) = z*(S0 + S1*z^1 + ... + S5*z^5)
        !           100:  *
        !           101:  *     The coefficient S's are obtained by a special Remez algorithm.
        !           102:  *
        !           103:  * Accuracy:
        !           104:  *     In the absence of rounding error, the approximation has absolute error 
        !           105:  *     less than 2**(-61.11) for VAX D FORMAT, 2**(-57.45) for IEEE DOUBLE. 
        !           106:  *
        !           107:  * Constants:
        !           108:  * The hexadecimal values are the intended ones for the following constants.
        !           109:  * The decimal values may be used, provided that the compiler will convert
        !           110:  * from decimal to binary accurately enough to produce the hexadecimal values
        !           111:  * shown.
        !           112:  *
        !           113:  */
        !           114: 
        !           115: #if defined(vax)||defined(tahoe)
        !           116: /*S0     = -1.6666666666666646660E-1    , Hex  2^ -2   * -.AAAAAAAAAAAA71 */
        !           117: /*S1     =  8.3333333333297230413E-3    , Hex  2^ -6   *  .8888888888477F */
        !           118: /*S2     = -1.9841269838362403710E-4    , Hex  2^-12   * -.D00D00CF8A1057 */
        !           119: /*S3     =  2.7557318019967078930E-6    , Hex  2^-18   *  .B8EF1CA326BEDC */
        !           120: /*S4     = -2.5051841873876551398E-8    , Hex  2^-25   * -.D73195374CE1D3 */
        !           121: /*S5     =  1.6028995389845827653E-10   , Hex  2^-32   *  .B03D9C6D26CCCC */
        !           122: /*S6     = -6.2723499671769283121E-13   ; Hex  2^-40   * -.B08D0B7561EA82 */
        !           123: static long S0x[]      = { _0x(aaaa,bf2a), _0x(aa71,aaaa)};
        !           124: static long S1x[]      = { _0x(8888,3d08), _0x(477f,8888)};
        !           125: static long S2x[]      = { _0x(0d00,ba50), _0x(1057,cf8a)};
        !           126: static long S3x[]      = { _0x(ef1c,3738), _0x(bedc,a326)};
        !           127: static long S4x[]      = { _0x(3195,b3d7), _0x(e1d3,374c)};
        !           128: static long S5x[]      = { _0x(3d9c,3030), _0x(cccc,6d26)};
        !           129: static long S6x[]      = { _0x(8d0b,ac30), _0x(ea82,7561)};
        !           130: #define S0     (*(double*)S0x)
        !           131: #define S1     (*(double*)S1x)
        !           132: #define S2     (*(double*)S2x)
        !           133: #define S3     (*(double*)S3x)
        !           134: #define S4     (*(double*)S4x)
        !           135: #define S5     (*(double*)S5x)
        !           136: #define S6     (*(double*)S6x)
        !           137: #else  /* IEEE double  */
        !           138: static double
        !           139: S0     = -1.6666666666666463126E-1    , /*Hex  2^ -3   * -1.555555555550C */
        !           140: S1     =  8.3333333332992771264E-3    , /*Hex  2^ -7   *  1.111111110C461 */
        !           141: S2     = -1.9841269816180999116E-4    , /*Hex  2^-13   * -1.A01A019746345 */
        !           142: S3     =  2.7557309793219876880E-6    , /*Hex  2^-19   *  1.71DE3209CDCD9 */
        !           143: S4     = -2.5050225177523807003E-8    , /*Hex  2^-26   * -1.AE5C0E319A4EF */
        !           144: S5     =  1.5868926979889205164E-10   ; /*Hex  2^-33   *  1.5CF61DF672B13 */
        !           145: #endif
        !           146: 
        !           147: #if defined(vax)||defined(tahoe)
        !           148: #define sin__S(z)      (z*(S0+z*(S1+z*(S2+z*(S3+z*(S4+z*(S5+z*S6)))))))
        !           149: #else  /* defined(vax)||defined(tahoe) */
        !           150: #define sin__S(z)      (z*(S0+z*(S1+z*(S2+z*(S3+z*(S4+z*S5))))))
        !           151: #endif         /* defined(vax)||defined(tahoe) */
        !           152: 
        !           153: /* cos__C(x*x) ... re-implemented as a macro
        !           154:  * DOUBLE PRECISION (VAX D FORMAT 56 BITS, IEEE DOUBLE 53 BITS)
        !           155:  * STATIC KERNEL FUNCTION OF SIN(X), COS(X), AND TAN(X) 
        !           156:  * CODED IN C BY K.C. NG, 1/21/85; 
        !           157:  * REVISED BY K.C. NG on 8/13/85.
        !           158:  *
        !           159:  *                         x*x 
        !           160:  * RETURN   cos(k*x) - 1 + ----- on [-PI/4,PI/4],  where k = pi/PI,
        !           161:  *                          2  
        !           162:  * PI is the rounded value of pi in machine precision :
        !           163:  *
        !           164:  *     Decimal:
        !           165:  *             pi = 3.141592653589793 23846264338327 ..... 
        !           166:  *    53 bits   PI = 3.141592653589793 115997963 ..... ,
        !           167:  *    56 bits   PI = 3.141592653589793 227020265 ..... ,  
        !           168:  *
        !           169:  *     Hexadecimal:
        !           170:  *             pi = 3.243F6A8885A308D313198A2E....
        !           171:  *    53 bits   PI = 3.243F6A8885A30  =  2 * 1.921FB54442D18
        !           172:  *    56 bits   PI = 3.243F6A8885A308 =  4 * .C90FDAA22168C2    
        !           173:  *
        !           174:  *
        !           175:  * Method:
        !           176:  *     1. Let z=x*x. Create a polynomial approximation to 
        !           177:  *         cos(k*x)-1+z/2  =  z*z*(C0 + C1*z^1 + ... + C5*z^5)
        !           178:  *     then
        !           179:  *      cos__C(z) =  z*z*(C0 + C1*z^1 + ... + C5*z^5)
        !           180:  *
        !           181:  *     The coefficient C's are obtained by a special Remez algorithm.
        !           182:  *
        !           183:  * Accuracy:
        !           184:  *     In the absence of rounding error, the approximation has absolute error 
        !           185:  *     less than 2**(-64) for VAX D FORMAT, 2**(-58.3) for IEEE DOUBLE. 
        !           186:  *     
        !           187:  *
        !           188:  * Constants:
        !           189:  * The hexadecimal values are the intended ones for the following constants.
        !           190:  * The decimal values may be used, provided that the compiler will convert
        !           191:  * from decimal to binary accurately enough to produce the hexadecimal values
        !           192:  * shown.
        !           193:  *
        !           194:  */
        !           195: 
        !           196: #if defined(vax)||defined(tahoe)
        !           197: /*C0     =  4.1666666666666504759E-2    , Hex  2^ -4   *  .AAAAAAAAAAA9F0 */
        !           198: /*C1     = -1.3888888888865302059E-3    , Hex  2^ -9   * -.B60B60B60A0CCA */
        !           199: /*C2     =  2.4801587285601038265E-5    , Hex  2^-15   *  .D00D00CDCD098F */
        !           200: /*C3     = -2.7557313470902390219E-7    , Hex  2^-21   * -.93F27BB593E805 */
        !           201: /*C4     =  2.0875623401082232009E-9    , Hex  2^-28   *  .8F74C8FA1E3FF0 */
        !           202: /*C5     = -1.1355178117642986178E-11   ; Hex  2^-36   * -.C7C32D0A5C5A63 */
        !           203: static long C0x[]      = { _0x(aaaa,3e2a), _0x(a9f0,aaaa)};
        !           204: static long C1x[]      = { _0x(0b60,bbb6), _0x(0cca,b60a)};
        !           205: static long C2x[]      = { _0x(0d00,38d0), _0x(098f,cdcd)};
        !           206: static long C3x[]      = { _0x(f27b,b593), _0x(e805,b593)};
        !           207: static long C4x[]      = { _0x(74c8,320f), _0x(3ff0,fa1e)};
        !           208: static long C5x[]      = { _0x(c32d,ae47), _0x(5a63,0a5c)};
        !           209: #define C0     (*(double*)C0x)
        !           210: #define C1     (*(double*)C1x)
        !           211: #define C2     (*(double*)C2x)
        !           212: #define C3     (*(double*)C3x)
        !           213: #define C4     (*(double*)C4x)
        !           214: #define C5     (*(double*)C5x)
        !           215: #else  /* defined(vax)||defined(tahoe) */
        !           216: static double
        !           217: C0     =  4.1666666666666504759E-2    , /*Hex  2^ -5   *  1.555555555553E */
        !           218: C1     = -1.3888888888865301516E-3    , /*Hex  2^-10   * -1.6C16C16C14199 */
        !           219: C2     =  2.4801587269650015769E-5    , /*Hex  2^-16   *  1.A01A01971CAEB */
        !           220: C3     = -2.7557304623183959811E-7    , /*Hex  2^-22   * -1.27E4F1314AD1A */
        !           221: C4     =  2.0873958177697780076E-9    , /*Hex  2^-29   *  1.1EE3B60DDDC8C */
        !           222: C5     = -1.1250289076471311557E-11   ; /*Hex  2^-37   * -1.8BD5986B2A52E */
        !           223: #endif /* defined(vax)||defined(tahoe) */
        !           224: 
        !           225: #define cos__C(z)      (z*z*(C0+z*(C1+z*(C2+z*(C3+z*(C4+z*C5))))))
        !           226: 
        !           227: extern int finite();
        !           228: extern double copysign(),drem();

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