From b12a73d5bf595b7fbb73db30c6bb144078e86ef5 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Tue, 11 Dec 2012 23:56:59 +0100 Subject: [PATCH] math: clean up inverse trigonometric functions modifications: * avoid unsigned->signed conversions * removed various volatile hacks * use FORCE_EVAL when evaluating only for side-effects * factor out R() rational approximation instead of manual inline * __invtrigl.h now only provides __invtrigl_R, __pio2_hi and __pio2_lo * use 2*pio2_hi, 2*pio2_lo instead of pi_hi, pi_lo otherwise the logic is not changed, long double versions will need a revisit when a genaral long double cleanup happens --- src/math/__invtrigl.c | 41 ++++++----------------- src/math/__invtrigl.h | 66 +++---------------------------------- src/math/acos.c | 74 ++++++++++++++++++++--------------------- src/math/acosf.c | 77 +++++++++++++++++++++---------------------- src/math/acosl.c | 61 +++++++++++++++------------------- src/math/asin.c | 71 +++++++++++++++++++-------------------- src/math/asinf.c | 51 ++++++++++++++-------------- src/math/asinl.c | 61 ++++++++++++++-------------------- src/math/atan.c | 32 ++++++++---------- src/math/atan2l.c | 40 +++++++++++----------- src/math/atanf.c | 28 ++++++++-------- src/math/atanl.c | 33 ++++++++----------- 12 files changed, 258 insertions(+), 377 deletions(-) diff --git a/src/math/__invtrigl.c b/src/math/__invtrigl.c index a51330e2..f2d33d3e 100644 --- a/src/math/__invtrigl.c +++ b/src/math/__invtrigl.c @@ -1,36 +1,8 @@ -/* origin: FreeBSD /usr/src/lib/msun/src/ld80/invtrig.c */ -/*- - * Copyright (c) 2008 David Schultz - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - #include "__invtrigl.h" #if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 -/* coefficients used in asinl() and acosl() */ -const long double +static const long double pS0 = 1.66666666666666666631e-01L, pS1 = -4.16313987993683104320e-01L, pS2 = 3.69068046323246813704e-01L, @@ -44,9 +16,16 @@ qS3 = -1.68285799854822427013e+00L, qS4 = 3.90699412641738801874e-01L, qS5 = -3.14365703596053263322e-02L; -const long double pi_hi = 3.1415926535897932384626433832795L; -const long double pi_lo = -5.01655761266833202345e-20L; const long double pio2_hi = 1.57079632679489661926L; const long double pio2_lo = -2.50827880633416601173e-20L; +/* used in asinl() and acosl() */ +/* R(x^2) is a rational approximation of (asin(x)-x)/x^3 with Remez algorithm */ +long double __invtrigl_R(long double z) +{ + long double p, q; + p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*(pS5+z*pS6)))))); + q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*(qS4+z*qS5)))); + return p/q; +} #endif diff --git a/src/math/__invtrigl.h b/src/math/__invtrigl.h index 22748b68..cac465c2 100644 --- a/src/math/__invtrigl.h +++ b/src/math/__invtrigl.h @@ -1,68 +1,10 @@ -/* origin: FreeBSD /usr/src/lib/msun/src/ld80/invtrig.h */ -/*- - * Copyright (c) 2008 David Schultz - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include "libm.h" +#include #if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 - -#define BIAS (LDBL_MAX_EXP - 1) -#define MANH_SIZE LDBL_MANH_SIZE - -/* Constants shared by the long double inverse trig functions. */ -#define pS0 __pS0 -#define pS1 __pS1 -#define pS2 __pS2 -#define pS3 __pS3 -#define pS4 __pS4 -#define pS5 __pS5 -#define pS6 __pS6 -#define qS1 __qS1 -#define qS2 __qS2 -#define qS3 __qS3 -#define qS4 __qS4 -#define qS5 __qS5 -#define pi_hi __pi_hi -#define pi_lo __pi_lo +/* shared by acosl, asinl and atan2l */ #define pio2_hi __pio2_hi #define pio2_lo __pio2_lo +extern const long double pio2_hi, pio2_lo; -extern const long double pS0, pS1, pS2, pS3, pS4, pS5, pS6; -extern const long double qS1, qS2, qS3, qS4, qS5; -extern const long double pi_hi, pi_lo, pio2_hi, pio2_lo; - -static long double P(long double x) -{ - return x * (pS0 + x * (pS1 + x * (pS2 + x * (pS3 + - x * (pS4 + x * (pS5 + x * pS6)))))); -} - -static long double Q(long double x) -{ - return 1.0 + x * (qS1 + x * (qS2 + x * (qS3 + x * (qS4 + x * qS5)))); -} - +long double __invtrigl_R(long double z); #endif diff --git a/src/math/acos.c b/src/math/acos.c index 0eb15bed..be95d25e 100644 --- a/src/math/acos.c +++ b/src/math/acos.c @@ -36,12 +36,8 @@ #include "libm.h" static const double -pi = 3.14159265358979311600e+00, /* 0x400921FB, 0x54442D18 */ -pio2_hi = 1.57079632679489655800e+00; /* 0x3FF921FB, 0x54442D18 */ -// FIXME -static const volatile double -pio2_lo = 6.12323399573676603587e-17; /* 0x3C91A626, 0x33145C07 */ -static const double +pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */ +pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */ pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */ pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */ pS2 = 2.01212532134862925881e-01, /* 0x3FC9C155, 0x0E884455 */ @@ -53,49 +49,53 @@ qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */ qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */ qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */ +static double R(double z) +{ + double p, q; + p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); + q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4))); + return p/q; +} + double acos(double x) { - double z,p,q,r,w,s,c,df; - int32_t hx,ix; + double z,w,s,c,df; + uint32_t hx,ix; GET_HIGH_WORD(hx, x); ix = hx & 0x7fffffff; - if (ix >= 0x3ff00000) { /* |x| >= 1 */ + /* |x| >= 1 or nan */ + if (ix >= 0x3ff00000) { uint32_t lx; GET_LOW_WORD(lx,x); - if ((ix-0x3ff00000 | lx) == 0) { /* |x|==1 */ - if (hx > 0) return 0.0; /* acos(1) = 0 */ - return pi + 2.0*pio2_lo; /* acos(-1)= pi */ + if ((ix-0x3ff00000 | lx) == 0) { + /* acos(1)=0, acos(-1)=pi */ + if (hx >> 31) + return 2*pio2_hi + 0x1p-1000; + return 0; } - return (x-x)/(x-x); /* acos(|x|>1) is NaN */ + return 0/(x-x); } - if (ix < 0x3fe00000) { /* |x| < 0.5 */ + /* |x| < 0.5 */ + if (ix < 0x3fe00000) { if (ix <= 0x3c600000) /* |x| < 2**-57 */ - return pio2_hi + pio2_lo; - z = x*x; - p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); - q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4))); - r = p/q; - return pio2_hi - (x - (pio2_lo-x*r)); - } else if (hx < 0) { /* x < -0.5 */ + return pio2_hi + 0x1p-1000; + return pio2_hi - (x - (pio2_lo-x*R(x*x))); + } + /* x < -0.5 */ + if (hx >> 31) { z = (1.0+x)*0.5; - p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); - q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4))); - s = sqrt(z); - r = p/q; - w = r*s-pio2_lo; - return pi - 2.0*(s+w); - } else { /* x > 0.5 */ - z = (1.0-x)*0.5; s = sqrt(z); - df = s; - SET_LOW_WORD(df,0); - c = (z-df*df)/(s+df); - p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); - q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4))); - r = p/q; - w = r*s+c; - return 2.0*(df+w); + w = R(z)*s-pio2_lo; + return 2*(pio2_hi - (s+w)); } + /* x > 0.5 */ + z = (1.0-x)*0.5; + s = sqrt(z); + df = s; + SET_LOW_WORD(df,0); + c = (z-df*df)/(s+df); + w = R(z)*s+c; + return 2*(df+w); } diff --git a/src/math/acosf.c b/src/math/acosf.c index d875f3ef..5d7c0270 100644 --- a/src/math/acosf.c +++ b/src/math/acosf.c @@ -16,59 +16,56 @@ #include "libm.h" static const float -pi = 3.1415925026e+00, /* 0x40490fda */ -pio2_hi = 1.5707962513e+00; /* 0x3fc90fda */ -static const volatile float -pio2_lo = 7.5497894159e-08; /* 0x33a22168 */ -static const float +pio2_hi = 1.5707962513e+00, /* 0x3fc90fda */ +pio2_lo = 7.5497894159e-08, /* 0x33a22168 */ pS0 = 1.6666586697e-01, pS1 = -4.2743422091e-02, pS2 = -8.6563630030e-03, qS1 = -7.0662963390e-01; +static float R(float z) +{ + float p, q; + p = z*(pS0+z*(pS1+z*pS2)); + q = 1.0f+z*qS1; + return p/q; +} + float acosf(float x) { - float z,p,q,r,w,s,c,df; - int32_t hx,ix; + float z,w,s,c,df; + uint32_t hx,ix; GET_FLOAT_WORD(hx, x); ix = hx & 0x7fffffff; - if (ix >= 0x3f800000) { /* |x| >= 1 */ - if (ix == 0x3f800000) { /* |x| == 1 */ - if (hx > 0) return 0.0f; /* acos(1) = 0 */ - return pi + 2.0f*pio2_lo; /* acos(-1)= pi */ + /* |x| >= 1 or nan */ + if (ix >= 0x3f800000) { + if (ix == 0x3f800000) { + if (hx >> 31) + return 2*pio2_hi + 0x1p-120f; + return 0; } - return (x-x)/(x-x); /* acos(|x|>1) is NaN */ + return 0/(x-x); } - if (ix < 0x3f000000) { /* |x| < 0.5 */ + /* |x| < 0.5 */ + if (ix < 0x3f000000) { if (ix <= 0x32800000) /* |x| < 2**-26 */ - return pio2_hi + pio2_lo; - z = x*x; - p = z*(pS0+z*(pS1+z*pS2)); - q = 1.0f+z*qS1; - r = p/q; - return pio2_hi - (x - (pio2_lo-x*r)); - } else if (hx < 0) { /* x < -0.5 */ - z = (1.0f+x)*0.5f; - p = z*(pS0+z*(pS1+z*pS2)); - q = 1.0f+z*qS1; - s = sqrtf(z); - r = p/q; - w = r*s-pio2_lo; - return pi - 2.0f*(s+w); - } else { /* x > 0.5 */ - int32_t idf; - - z = (1.0f-x)*0.5f; + return pio2_hi + 0x1p-120f; + return pio2_hi - (x - (pio2_lo-x*R(x*x))); + } + /* x < -0.5 */ + if (hx >> 31) { + z = (1+x)*0.5f; s = sqrtf(z); - df = s; - GET_FLOAT_WORD(idf,df); - SET_FLOAT_WORD(df,idf&0xfffff000); - c = (z-df*df)/(s+df); - p = z*(pS0+z*(pS1+z*pS2)); - q = 1.0f+z*qS1; - r = p/q; - w = r*s+c; - return 2.0f*(df+w); + w = R(z)*s-pio2_lo; + return 2*(pio2_hi - (s+w)); } + /* x > 0.5 */ + z = (1-x)*0.5f; + s = sqrtf(z); + GET_FLOAT_WORD(hx,s); + SET_FLOAT_WORD(df,hx&0xfffff000); + c = (z-df*df)/(s+df); + w = R(z)*s+c; + return 2*(df+w); } diff --git a/src/math/acosl.c b/src/math/acosl.c index 83857d49..9e9b01e4 100644 --- a/src/math/acosl.c +++ b/src/math/acosl.c @@ -23,55 +23,46 @@ long double acosl(long double x) } #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 #include "__invtrigl.h" -#define ACOS_CONST (BIAS - 65) /* 2**-65 */ long double acosl(long double x) { union IEEEl2bits u; - long double z, p, q, r, w, s, c, df; + long double z, w, s, c, df; int16_t expsign, expt; u.e = x; expsign = u.xbits.expsign; expt = expsign & 0x7fff; - if (expt >= BIAS) { /* |x| >= 1 */ - if (expt == BIAS && + /* |x| >= 1 or nan */ + if (expt >= 0x3fff) { + if (expt == 0x3fff && ((u.bits.manh & ~LDBL_NBIT) | u.bits.manl) == 0) { if (expsign > 0) - return 0.0; /* acos(1) = 0 */ - else - // FIXME - return pi_hi + 2.0 * pio2_lo; /* acos(-1)= pi */ + return 0; /* acos(1) = 0 */ + return 2*pio2_hi + 0x1p-1000; /* acos(-1)= pi */ } - return (x - x) / (x - x); /* acos(|x|>1) is NaN */ + return 0/(x-x); /* acos(|x|>1) is NaN */ } - if (expt < BIAS - 1) { /* |x| < 0.5 */ - if (expt < ACOS_CONST) - return pio2_hi + pio2_lo; /* x tiny: acosl=pi/2 */ - z = x * x; - p = P(z); - q = Q(z); - r = p / q; - return pio2_hi - (x - (pio2_lo - x * r)); - } else if (expsign < 0) { /* x < -0.5 */ + /* |x| < 0.5 */ + if (expt < 0x3fff - 1) { + if (expt < 0x3fff - 65) + return pio2_hi + 0x1p-1000; /* x < 0x1p-65: acosl(x)=pi/2 */ + return pio2_hi - (x - (pio2_lo - x * __invtrigl_R(x*x))); + } + /* x < -0.5 */ + if (expsign < 0) { z = (1.0 + x) * 0.5; - p = P(z); - q = Q(z); - s = sqrtl(z); - r = p / q; - w = r * s - pio2_lo; - return pi_hi - 2.0 * (s + w); - } else { /* x > 0.5 */ - z = (1.0 - x) * 0.5; s = sqrtl(z); - u.e = s; - u.bits.manl = 0; - df = u.e; - c = (z - df * df) / (s + df); - p = P(z); - q = Q(z); - r = p / q; - w = r * s + c; - return 2.0 * (df + w); + w = __invtrigl_R(z) * s - pio2_lo; + return 2*(pio2_hi - (s + w)); } + /* x > 0.5 */ + z = (1.0 - x) * 0.5; + s = sqrtl(z); + u.e = s; + u.bits.manl = 0; + df = u.e; + c = (z - df * df) / (s + df); + w = __invtrigl_R(z) * s + c; + return 2*(df + w); } #endif diff --git a/src/math/asin.c b/src/math/asin.c index e3d8b250..a1906b08 100644 --- a/src/math/asin.c +++ b/src/math/asin.c @@ -42,10 +42,8 @@ #include "libm.h" static const double -huge = 1.000e+300, pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */ pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */ -pio4_hi = 7.85398163397448278999e-01, /* 0x3FE921FB, 0x54442D18 */ /* coefficients for R(x^2) */ pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */ pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */ @@ -58,51 +56,54 @@ qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */ qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */ qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */ +static double R(double z) +{ + double p, q; + p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); + q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4))); + return p/q; +} + double asin(double x) { - double t=0.0,w,p,q,c,r,s; - int32_t hx,ix; + double z,r,s; + uint32_t hx,ix; GET_HIGH_WORD(hx, x); ix = hx & 0x7fffffff; - if (ix >= 0x3ff00000) { /* |x|>= 1 */ + /* |x| >= 1 or nan */ + if (ix >= 0x3ff00000) { uint32_t lx; - GET_LOW_WORD(lx, x); if ((ix-0x3ff00000 | lx) == 0) /* asin(1) = +-pi/2 with inexact */ - return x*pio2_hi + x*pio2_lo; - return (x-x)/(x-x); /* asin(|x|>1) is NaN */ - } else if (ix < 0x3fe00000) { /* |x|<0.5 */ - if (ix < 0x3e500000) { /* if |x| < 2**-26 */ - if (huge+x > 1.0) - return x; /* return x with inexact if x!=0*/ + return x*pio2_hi + 0x1p-1000; + return 0/(x-x); + } + /* |x| < 0.5 */ + if (ix < 0x3fe00000) { + if (ix < 0x3e500000) { + /* |x|<0x1p-26, return x with inexact if x!=0*/ + FORCE_EVAL(x + 0x1p1000); + return x; } - t = x*x; - p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5))))); - q = 1.0+t*(qS1+t*(qS2+t*(qS3+t*qS4))); - w = p/q; - return x + x*w; + return x + x*R(x*x); } /* 1 > |x| >= 0.5 */ - w = 1.0 - fabs(x); - t = w*0.5; - p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5))))); - q = 1.0+t*(qS1+t*(qS2+t*(qS3+t*qS4))); - s = sqrt(t); - if (ix >= 0x3FEF3333) { /* if |x| > 0.975 */ - w = p/q; - t = pio2_hi-(2.0*(s+s*w)-pio2_lo); + z = (1 - fabs(x))*0.5; + s = sqrt(z); + r = R(z); + if (ix >= 0x3fef3333) { /* if |x| > 0.975 */ + x = pio2_hi-(2*(s+s*r)-pio2_lo); } else { - w = s; - SET_LOW_WORD(w,0); - c = (t-w*w)/(s+w); - r = p/q; - p = 2.0*s*r-(pio2_lo-2.0*c); - q = pio4_hi - 2.0*w; - t = pio4_hi - (p-q); + double f,c; + /* f+c = sqrt(z) */ + f = s; + SET_LOW_WORD(f,0); + c = (z-f*f)/(s+f); + x = 0.5*pio2_hi - (2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f)); } - if (hx > 0) - return t; - return -t; + if (hx >> 31) + return -x; + return x; } diff --git a/src/math/asinf.c b/src/math/asinf.c index c1c42c7b..462bf043 100644 --- a/src/math/asinf.c +++ b/src/math/asinf.c @@ -12,52 +12,51 @@ * is preserved. * ==================================================== */ - #include "libm.h" +static const double +pio2 = 1.570796326794896558e+00; + static const float -huge = 1.000e+30, /* coefficients for R(x^2) */ pS0 = 1.6666586697e-01, pS1 = -4.2743422091e-02, pS2 = -8.6563630030e-03, qS1 = -7.0662963390e-01; -static const double -pio2 = 1.570796326794896558e+00; +static float R(float z) +{ + float p, q; + p = z*(pS0+z*(pS1+z*pS2)); + q = 1.0f+z*qS1; + return p/q; +} float asinf(float x) { double s; - float t,w,p,q; - int32_t hx,ix; + float z; + uint32_t hx,ix; GET_FLOAT_WORD(hx, x); ix = hx & 0x7fffffff; if (ix >= 0x3f800000) { /* |x| >= 1 */ if (ix == 0x3f800000) /* |x| == 1 */ - return x*pio2; /* asin(+-1) = +-pi/2 with inexact */ - return (x-x)/(x-x); /* asin(|x|>1) is NaN */ - } else if (ix < 0x3f000000) { /* |x|<0.5 */ + return x*pio2 + 0x1p-120f; /* asin(+-1) = +-pi/2 with inexact */ + return 0/(x-x); /* asin(|x|>1) is NaN */ + } + if (ix < 0x3f000000) { /* |x| < 0.5 */ if (ix < 0x39800000) { /* |x| < 2**-12 */ - if (huge+x > 1.0f) - return x; /* return x with inexact if x!=0 */ + FORCE_EVAL(x + 0x1p120f); + return x; /* return x with inexact if x!=0 */ } - t = x*x; - p = t*(pS0+t*(pS1+t*pS2)); - q = 1.0f+t*qS1; - w = p/q; - return x + x*w; + return x + x*R(x*x); } /* 1 > |x| >= 0.5 */ - w = 1.0f - fabsf(x); - t = w*0.5f; - p = t*(pS0+t*(pS1+t*pS2)); - q = 1.0f+t*qS1; - s = sqrt(t); - w = p/q; - t = pio2-2.0*(s+s*w); - if (hx > 0) - return t; - return -t; + z = (1 - fabsf(x))*0.5f; + s = sqrt(z); + x = pio2 - 2*(s+s*R(z)); + if (hx >> 31) + return -x; + return x; } diff --git a/src/math/asinl.c b/src/math/asinl.c index 7572767c..0ef9853b 100644 --- a/src/math/asinl.c +++ b/src/math/asinl.c @@ -23,60 +23,49 @@ long double asinl(long double x) } #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 #include "__invtrigl.h" -static const long double huge = 1.000e+300; -static const long double pio4_hi = 7.85398163397448309628e-01L; -#define ASIN_LINEAR (BIAS - 32) /* 2**-32 */ /* 0.95 */ -#define THRESH ((0xe666666666666666ULL>>(64-(MANH_SIZE-1)))|LDBL_NBIT) +#define THRESH ((0xe666666666666666ULL>>(64-(LDBL_MANH_SIZE-1)))|LDBL_NBIT) long double asinl(long double x) { union IEEEl2bits u; - long double t=0.0,w,p,q,c,r,s; - int16_t expsign, expt; + long double z,r,s; + uint16_t expsign, expt; u.e = x; expsign = u.xbits.expsign; expt = expsign & 0x7fff; - if (expt >= BIAS) { /* |x|>= 1 */ - if (expt == BIAS && + if (expt >= 0x3fff) { /* |x| >= 1 or nan */ + if (expt == 0x3fff && ((u.bits.manh&~LDBL_NBIT)|u.bits.manl) == 0) - /* asin(1)=+-pi/2 with inexact */ - return x*pio2_hi + x*pio2_lo; - return (x-x)/(x-x); /* asin(|x|>1) is NaN */ - } else if (expt < BIAS-1) { /* |x|<0.5 */ - if (expt < ASIN_LINEAR) { /* if |x| is small, asinl(x)=x */ + /* asin(+-1)=+-pi/2 with inexact */ + return x*pio2_hi + 0x1p-1000; + return 0/(x-x); + } + if (expt < 0x3fff - 1) { /* |x| < 0.5 */ + if (expt < 0x3fff - 32) { /* |x|<0x1p-32, asinl(x)=x */ /* return x with inexact if x!=0 */ - if (huge+x > 1.0) - return x; + FORCE_EVAL(x + 0x1p1000); + return x; } - t = x*x; - p = P(t); - q = Q(t); - w = p/q; - return x + x*w; + return x + x*__invtrigl_R(x*x); } /* 1 > |x| >= 0.5 */ - w = 1.0 - fabsl(x); - t = w*0.5; - p = P(t); - q = Q(t); - s = sqrtl(t); + z = (1.0 - fabsl(x))*0.5; + s = sqrtl(z); + r = __invtrigl_R(z); if (u.bits.manh >= THRESH) { /* if |x| is close to 1 */ - w = p/q; - t = pio2_hi-(2.0*(s+s*w)-pio2_lo); + x = pio2_hi - (2*(s+s*r)-pio2_lo); } else { + long double f, c; u.e = s; u.bits.manl = 0; - w = u.e; - c = (t-w*w)/(s+w); - r = p/q; - p = 2.0*s*r-(pio2_lo-2.0*c); - q = pio4_hi-2.0*w; - t = pio4_hi-(p-q); + f = u.e; + c = (z-f*f)/(s+f); + x = 0.5*pio2_hi-(2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f)); } - if (expsign > 0) - return t; - return -t; + if (expsign>>15) + return -x; + return x; } #endif diff --git a/src/math/atan.c b/src/math/atan.c index f34551c7..7fd8a3b8 100644 --- a/src/math/atan.c +++ b/src/math/atan.c @@ -60,32 +60,26 @@ static const double aT[] = { 1.62858201153657823623e-02, /* 0x3F90AD3A, 0xE322DA11 */ }; -static const double huge = 1.0e300; - double atan(double x) { double w,s1,s2,z; - int32_t ix,hx,id; + uint32_t ix,sign; + int id; - GET_HIGH_WORD(hx, x); - ix = hx & 0x7fffffff; + GET_HIGH_WORD(ix, x); + sign = ix >> 31; + ix &= 0x7fffffff; if (ix >= 0x44100000) { /* if |x| >= 2^66 */ - uint32_t low; - - GET_LOW_WORD(low, x); - if (ix > 0x7ff00000 || - (ix == 0x7ff00000 && low != 0)) /* NaN */ - return x+x; - if (hx > 0) - return atanhi[3] + *(volatile double *)&atanlo[3]; - else - return -atanhi[3] - *(volatile double *)&atanlo[3]; + if (isnan(x)) + return x; + z = atanhi[3] + 0x1p-1000; + return sign ? -z : z; } if (ix < 0x3fdc0000) { /* |x| < 0.4375 */ if (ix < 0x3e400000) { /* |x| < 2^-27 */ - /* raise inexact */ - if (huge+x > 1.0) - return x; + /* raise inexact if x!=0 */ + FORCE_EVAL(x + 0x1p1000); + return x; } id = -1; } else { @@ -117,5 +111,5 @@ double atan(double x) if (id < 0) return x - x*(s1+s2); z = atanhi[id] - (x*(s1+s2) - atanlo[id] - x); - return hx < 0 ? -z : z; + return sign ? -z : z; } diff --git a/src/math/atan2l.c b/src/math/atan2l.c index 45cbfcc1..e86dbffb 100644 --- a/src/math/atan2l.c +++ b/src/math/atan2l.c @@ -24,8 +24,6 @@ long double atan2l(long double y, long double x) } #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 #include "__invtrigl.h" -// FIXME: -static const volatile long double tiny = 1.0e-300; long double atan2l(long double y, long double x) { @@ -40,12 +38,12 @@ long double atan2l(long double y, long double x) ux.e = x; expsignx = ux.xbits.expsign; exptx = expsignx & 0x7fff; - if ((exptx==BIAS+LDBL_MAX_EXP && + if ((exptx==0x7fff && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)!=0) || /* x is NaN */ - (expty==BIAS+LDBL_MAX_EXP && + (expty==0x7fff && ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl)!=0)) /* y is NaN */ return x+y; - if (expsignx==BIAS && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0) /* x=1.0 */ + if (expsignx==0x3fff && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0) /* x=1.0 */ return atanl(y); m = ((expsigny>>15)&1) | ((expsignx>>14)&2); /* 2*sign(x)+sign(y) */ @@ -54,39 +52,39 @@ long double atan2l(long double y, long double x) switch(m) { case 0: case 1: return y; /* atan(+-0,+anything)=+-0 */ - case 2: return pi_hi+tiny; /* atan(+0,-anything) = pi */ - case 3: return -pi_hi-tiny; /* atan(-0,-anything) =-pi */ + case 2: return 2*pio2_hi+0x1p-1000; /* atan(+0,-anything) = pi */ + case 3: return -2*pio2_hi-0x1p-1000; /* atan(-0,-anything) =-pi */ } } /* when x = 0 */ if (exptx==0 && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0) - return expsigny < 0 ? -pio2_hi-tiny : pio2_hi+tiny; + return expsigny < 0 ? -pio2_hi-0x1p-1000 : pio2_hi+0x1p-1000; /* when x is INF */ - if (exptx == BIAS+LDBL_MAX_EXP) { - if (expty == BIAS+LDBL_MAX_EXP) { + if (exptx == 0x7fff) { + if (expty == 0x7fff) { switch(m) { - case 0: return pio2_hi*0.5+tiny; /* atan(+INF,+INF) */ - case 1: return -pio2_hi*0.5-tiny; /* atan(-INF,+INF) */ - case 2: return 1.5*pio2_hi+tiny; /* atan(+INF,-INF) */ - case 3: return -1.5*pio2_hi-tiny; /* atan(-INF,-INF) */ + case 0: return pio2_hi*0.5+0x1p-1000; /* atan(+INF,+INF) */ + case 1: return -pio2_hi*0.5-0x1p-1000; /* atan(-INF,+INF) */ + case 2: return 1.5*pio2_hi+0x1p-1000; /* atan(+INF,-INF) */ + case 3: return -1.5*pio2_hi-0x1p-1000; /* atan(-INF,-INF) */ } } else { switch(m) { case 0: return 0.0; /* atan(+...,+INF) */ case 1: return -0.0; /* atan(-...,+INF) */ - case 2: return pi_hi+tiny; /* atan(+...,-INF) */ - case 3: return -pi_hi-tiny; /* atan(-...,-INF) */ + case 2: return 2*pio2_hi+0x1p-1000; /* atan(+...,-INF) */ + case 3: return -2*pio2_hi-0x1p-1000; /* atan(-...,-INF) */ } } } /* when y is INF */ - if (expty == BIAS+LDBL_MAX_EXP) - return expsigny < 0 ? -pio2_hi-tiny : pio2_hi+tiny; + if (expty == 0x7fff) + return expsigny < 0 ? -pio2_hi-0x1p-1000 : pio2_hi+0x1p-1000; /* compute y/x */ k = expty-exptx; if(k > LDBL_MANT_DIG+2) { /* |y/x| huge */ - z = pio2_hi+pio2_lo; + z = pio2_hi+0x1p-1000; m &= 1; } else if (expsignx < 0 && k < -LDBL_MANT_DIG-2) /* |y/x| tiny, x<0 */ z = 0.0; @@ -95,9 +93,9 @@ long double atan2l(long double y, long double x) switch (m) { case 0: return z; /* atan(+,+) */ case 1: return -z; /* atan(-,+) */ - case 2: return pi_hi-(z-pi_lo); /* atan(+,-) */ + case 2: return 2*pio2_hi-(z-2*pio2_lo); /* atan(+,-) */ default: /* case 3 */ - return (z-pi_lo)-pi_hi; /* atan(-,-) */ + return (z-2*pio2_lo)-2*pio2_hi; /* atan(-,-) */ } } #endif diff --git a/src/math/atanf.c b/src/math/atanf.c index 4e31b902..4b59509a 100644 --- a/src/math/atanf.c +++ b/src/math/atanf.c @@ -38,28 +38,26 @@ static const float aT[] = { 6.1687607318e-02, }; -static const float huge = 1.0e30; - float atanf(float x) { float w,s1,s2,z; - int32_t ix,hx,id; + uint32_t ix,sign; + int id; - GET_FLOAT_WORD(hx, x); - ix = hx & 0x7fffffff; + GET_FLOAT_WORD(ix, x); + sign = ix>>31; + ix &= 0x7fffffff; if (ix >= 0x4c800000) { /* if |x| >= 2**26 */ - if (ix > 0x7f800000) /* NaN */ - return x+x; - if (hx > 0) - return atanhi[3] + *(volatile float *)&atanlo[3]; - else - return -atanhi[3] - *(volatile float *)&atanlo[3]; + if (isnan(x)) + return x; + z = atanhi[3] + 0x1p-120f; + return sign ? -z : z; } if (ix < 0x3ee00000) { /* |x| < 0.4375 */ if (ix < 0x39800000) { /* |x| < 2**-12 */ - /* raise inexact */ - if(huge+x>1.0f) - return x; + /* raise inexact if x!=0 */ + FORCE_EVAL(x + 0x1p120f); + return x; } id = -1; } else { @@ -91,5 +89,5 @@ float atanf(float x) if (id < 0) return x - x*(s1+s2); z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x); - return hx < 0 ? -z : z; + return sign ? -z : z; } diff --git a/src/math/atanl.c b/src/math/atanl.c index 33ecff0d..6a480a7a 100644 --- a/src/math/atanl.c +++ b/src/math/atanl.c @@ -22,11 +22,6 @@ long double atanl(long double x) return atan(x); } #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 -#include "__invtrigl.h" - -#define ATAN_CONST (BIAS + 65) /* 2**65 */ -#define ATAN_LINEAR (BIAS - 32) /* 2**-32 */ -static const long double huge = 1.0e300; static const long double atanhi[] = { 4.63647609000806116202e-01L, @@ -81,29 +76,27 @@ long double atanl(long double x) u.e = x; expsign = u.xbits.expsign; expt = expsign & 0x7fff; - if (expt >= ATAN_CONST) { /* if |x| is large, atan(x)~=pi/2 */ - if (expt == BIAS + LDBL_MAX_EXP && + if (expt >= 0x3fff + 65) { /* if |x| is large, atan(x)~=pi/2 */ + if (expt == 0x7fff && ((u.bits.manh&~LDBL_NBIT)|u.bits.manl)!=0) /* NaN */ return x+x; - if (expsign > 0) - return atanhi[3]+atanlo[3]; - else - return -atanhi[3]-atanlo[3]; + z = atanhi[3] + 0x1p-1000; + return expsign < 0 ? -z : z; } /* Extract the exponent and the first few bits of the mantissa. */ /* XXX There should be a more convenient way to do this. */ - expman = (expt << 8) | ((u.bits.manh >> (MANH_SIZE - 9)) & 0xff); - if (expman < ((BIAS - 2) << 8) + 0xc0) { /* |x| < 0.4375 */ - if (expt < ATAN_LINEAR) { /* if |x| is small, atanl(x)~=x */ - /* raise inexact */ - if (huge+x > 1.0) - return x; + expman = (expt << 8) | ((u.bits.manh >> (LDBL_MANH_SIZE - 9)) & 0xff); + if (expman < ((0x3fff - 2) << 8) + 0xc0) { /* |x| < 0.4375 */ + if (expt < 0x3fff - 32) { /* if |x| is small, atanl(x)~=x */ + /* raise inexact if x!=0 */ + FORCE_EVAL(x + 0x1p1000); + return x; } id = -1; } else { x = fabsl(x); - if (expman < (BIAS << 8) + 0x30) { /* |x| < 1.1875 */ - if (expman < ((BIAS - 1) << 8) + 0x60) { /* 7/16 <= |x| < 11/16 */ + if (expman < (0x3fff << 8) + 0x30) { /* |x| < 1.1875 */ + if (expman < ((0x3fff - 1) << 8) + 0x60) { /* 7/16 <= |x| < 11/16 */ id = 0; x = (2.0*x-1.0)/(2.0+x); } else { /* 11/16 <= |x| < 19/16 */ @@ -111,7 +104,7 @@ long double atanl(long double x) x = (x-1.0)/(x+1.0); } } else { - if (expman < ((BIAS + 1) << 8) + 0x38) { /* |x| < 2.4375 */ + if (expman < ((0x3fff + 1) << 8) + 0x38) { /* |x| < 2.4375 */ id = 2; x = (x-1.5)/(1.0+1.5*x); } else { /* 2.4375 <= |x| < 2^ATAN_CONST */ -- 2.20.1