diff options
author | Jeff Hao <jeffhao@google.com> | 2014-08-08 21:29:19 +0000 |
---|---|---|
committer | Android Git Automerger <android-git-automerger@android.com> | 2014-08-08 21:29:19 +0000 |
commit | 01dc548e40d242636223d457b0e48845d7027f34 (patch) | |
tree | e8d4e6c62c45e9d728e7f0764dc8fb5c64d285e6 /luni | |
parent | e335f69663cb27eaf73aaf0c17a32521ded4c664 (diff) | |
parent | cf5219256c9a44e9b215ac645c1823238ebd31d7 (diff) | |
download | libcore-01dc548e40d242636223d457b0e48845d7027f34.zip libcore-01dc548e40d242636223d457b0e48845d7027f34.tar.gz libcore-01dc548e40d242636223d457b0e48845d7027f34.tar.bz2 |
am cf521925: Merge "Implements some math functions for faster performance"
* commit 'cf5219256c9a44e9b215ac645c1823238ebd31d7':
Implements some math functions for faster performance
Diffstat (limited to 'luni')
-rw-r--r-- | luni/src/main/java/java/lang/StrictMath.java | 1070 | ||||
-rw-r--r-- | luni/src/main/native/java_lang_StrictMath.cpp | 65 |
2 files changed, 1006 insertions, 129 deletions
diff --git a/luni/src/main/java/java/lang/StrictMath.java b/luni/src/main/java/java/lang/StrictMath.java index f409c06..2e848f2 100644 --- a/luni/src/main/java/java/lang/StrictMath.java +++ b/luni/src/main/java/java/lang/StrictMath.java @@ -15,6 +15,18 @@ * limitations under the License. */ +/* + * acos, asin, atan, cosh, sinh, tanh, exp, expm1, log, log10, log1p, and cbrt + * have been implemented with the following license. + * ==================================================== + * Copyright (C) 2004 by Sun Microsystems, Inc. All rights reserved. + * + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + package java.lang; /** @@ -102,6 +114,21 @@ public final class StrictMath { return Math.abs(l); } + private static final double PIO2_HI = 1.57079632679489655800e+00; + private static final double PIO2_LO = 6.12323399573676603587e-17; + private static final double PS0 = 1.66666666666666657415e-01; + private static final double PS1 = -3.25565818622400915405e-01; + private static final double PS2 = 2.01212532134862925881e-01; + private static final double PS3 = -4.00555345006794114027e-02; + private static final double PS4 = 7.91534994289814532176e-04; + private static final double PS5 = 3.47933107596021167570e-05; + private static final double QS1 = -2.40339491173441421878e+00; + private static final double QS2 = 2.02094576023350569471e+00; + private static final double QS3 = -6.88283971605453293030e-01; + private static final double QS4 = 7.70381505559019352791e-02; + private static final double HUGE = 1.000e+300; + private static final double PIO4_HI = 7.85398163397448278999e-01; + /** * Returns the closest double approximation of the arc cosine of the * argument within the range {@code [0..pi]}. @@ -113,11 +140,62 @@ public final class StrictMath { * <li>{@code acos(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value to compute arc cosine of. * @return the arc cosine of the argument. */ - public static native double acos(double d); + public static double acos(double x) { + double z, p, q, r, w, s, c, df; + int hx, ix; + final long bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >>> 32); + ix = hx & 0x7fffffff; + if (ix >= 0x3ff00000) { /* |x| >= 1 */ + if ((((ix - 0x3ff00000) | ((int) bits))) == 0) { /* |x|==1 */ + if (hx > 0) { + return 0.0; /* ieee_acos(1) = 0 */ + } else { + return 3.14159265358979311600e+00 + 2.0 * PIO2_LO; /* ieee_acos(-1)= pi */ + } + } + return (x - x) / (x - x); /* ieee_acos(|x|>1) is NaN */ + } + + if (ix < 0x3fe00000) { /* |x| < 0.5 */ + if (ix <= 0x3c600000) { + return PIO2_HI + PIO2_LO;/* if|x|<2**-57 */ + } + + z = x * x; + p = z * (PS0 + z + * (PS1 + z * (PS2 + z * (PS3 + z * (PS4 + z * PS5))))); + q = 1.00000000000000000000e+00 + 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 */ + z = (1.00000000000000000000e+00 + x) * 0.5; + p = z * (PS0 + z + * (PS1 + z * (PS2 + z * (PS3 + z * (PS4 + z * PS5))))); + q = 1.00000000000000000000e+00 + z * (QS1 + z * (QS2 + z * (QS3 + z * QS4))); + s = StrictMath.sqrt(z); + r = p / q; + w = r * s - PIO2_LO; + return 3.14159265358979311600e+00 - 2.0 * (s + w); + } else { /* x > 0.5 */ + z = (1.00000000000000000000e+00 - x) * 0.5; + s = StrictMath.sqrt(z); + df = s; + df = Double.longBitsToDouble( + Double.doubleToRawLongBits(df) & 0xffffffffL << 32); + c = (z - df * df) / (s + df); + p = z * (PS0 + z + * (PS1 + z * (PS2 + z * (PS3 + z * (PS4 + z * PS5))))); + q = 1.00000000000000000000e+00 + z * (QS1 + z * (QS2 + z * (QS3 + z * QS4))); + r = p / q; + w = r * s + c; + return 2.0 * (df + w); + } + } /** * Returns the closest double approximation of the arc sine of the argument @@ -130,11 +208,75 @@ public final class StrictMath { * <li>{@code asin(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose arc sine has to be computed. * @return the arc sine of the argument. */ - public static native double asin(double d); + public static double asin(double x) { + double t, w, p, q, c, r, s; + int hx, ix; + final long bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >>> 32); + ix = hx & 0x7fffffff; + if (ix >= 0x3ff00000) { /* |x|>= 1 */ + if ((((ix - 0x3ff00000) | ((int) bits))) == 0) { + /* ieee_asin(1)=+-pi/2 with inexact */ + return x * PIO2_HI + x * PIO2_LO; + } + return (x - x) / (x - x); /* ieee_asin(|x|>1) is NaN */ + } else if (ix < 0x3fe00000) { /* |x|<0.5 */ + if (ix < 0x3e400000) { /* if |x| < 2**-27 */ + if (HUGE + x > 1.00000000000000000000e+00) { + return x;/* return x with inexact if x!=0 */ + } + } else { + t = x * x; + p = t * (PS0 + t + * (PS1 + t * (PS2 + t * (PS3 + t * (PS4 + t * PS5))))); + q = 1.00000000000000000000e+00 + t * (QS1 + t * (QS2 + t * (QS3 + t * QS4))); + w = p / q; + return x + x * w; + } + } + /* 1> |x|>= 0.5 */ + w = 1.00000000000000000000e+00 - Math.abs(x); + t = w * 0.5; + p = t * (PS0 + t * (PS1 + t * (PS2 + t * (PS3 + t * (PS4 + t * PS5))))); + q = 1.00000000000000000000e+00 + t * (QS1 + t * (QS2 + t * (QS3 + t * QS4))); + s = StrictMath.sqrt(t); + if (ix >= 0x3FEF3333) { /* if |x| > 0.975 */ + w = p / q; + t = PIO2_HI - (2.0 * (s + s * w) - PIO2_LO); + } else { + w = s; + w = Double.longBitsToDouble( + Double.doubleToRawLongBits(w) & 0xffffffffL << 32); + 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); + } + return (hx > 0) ? t : -t; + } + + private static final double[] ATANHI = { 4.63647609000806093515e-01, + 7.85398163397448278999e-01, 9.82793723247329054082e-01, + 1.57079632679489655800e+00 }; + private static final double[] ATANLO = { 2.26987774529616870924e-17, + 3.06161699786838301793e-17, 1.39033110312309984516e-17, + 6.12323399573676603587e-17 }; + private static final double AT0 = 3.33333333333329318027e-01; + private static final double AT1 = -1.99999999998764832476e-01; + private static final double AT2 = 1.42857142725034663711e-01; + private static final double AT3 = -1.11111104054623557880e-01; + private static final double AT4 = 9.09088713343650656196e-02; + private static final double AT5 = -7.69187620504482999495e-02; + private static final double AT6 = 6.66107313738753120669e-02; + private static final double AT7= -5.83357013379057348645e-02; + private static final double AT8 = 4.97687799461593236017e-02; + private static final double AT9 = -3.65315727442169155270e-02; + private static final double AT10 = 1.62858201153657823623e-02; /** * Returns the closest double approximation of the arc tangent of the @@ -149,11 +291,73 @@ public final class StrictMath { * <li>{@code atan(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose arc tangent has to be computed. * @return the arc tangent of the argument. */ - public static native double atan(double d); + public static double atan(double x) { + double w, s1, s2, z; + int ix, hx, id; + + final long bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >>> 32); + ix = hx & 0x7fffffff; + if (ix >= 0x44100000) { /* if |x| >= 2^66 */ + if (ix > 0x7ff00000 || (ix == 0x7ff00000 && (((int) bits) != 0))) { + return x + x; /* NaN */ + } + if (hx > 0) { + return ATANHI[3] + ATANLO[3]; + } else { + return -ATANHI[3] - ATANLO[3]; + } + } + if (ix < 0x3fdc0000) { /* |x| < 0.4375 */ + if (ix < 0x3e200000) { /* |x| < 2^-29 */ + if (HUGE + x > 1.00000000000000000000e+00) { + return x; /* raise inexact */ + } + } + id = -1; + } else { + x = Math.abs(x); + if (ix < 0x3ff30000) { /* |x| < 1.1875 */ + if (ix < 0x3fe60000) { /* 7/16 <=|x|<11/16 */ + id = 0; + x = (2.0 * x - 1.00000000000000000000e+00) / (2.0 + x); + } else { /* 11/16<=|x|< 19/16 */ + id = 1; + x = (x - 1.00000000000000000000e+00) / (x + 1.00000000000000000000e+00); + } + } else { + if (ix < 0x40038000) { /* |x| < 2.4375 */ + id = 2; + x = (x - 1.5) / (1.00000000000000000000e+00 + 1.5 * x); + } else { /* 2.4375 <= |x| < 2^66 */ + id = 3; + x = -1.0 / x; + } + } + } + + /* end of argument reduction */ + z = x * x; + w = z * z; + /* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */ + s1 = z * (AT0 + w * (AT2 + w + * (AT4 + w * (AT6 + w * (AT8 + w * AT10))))); + s2 = w * (AT1 + w * (AT3 + w * (AT5 + w * (AT7 + w * AT9)))); + if (id < 0) { + return x - x * (s1 + s2); + } else { + z = ATANHI[id] - ((x * (s1 + s2) - ATANLO[id]) - x); + return (hx < 0) ? -z : z; + } + } + + private static final double PI_O_4 = 7.8539816339744827900E-01; + private static final double PI_O_2 = 1.5707963267948965580E+00; + private static final double PI_LO = 1.2246467991473531772E-16; /** * Returns the closest double approximation of the arc tangent of @@ -192,7 +396,108 @@ public final class StrictMath { * the denominator of the value whose atan has to be computed. * @return the arc tangent of {@code y/x}. */ - public static native double atan2(double y, double x); + public static double atan2(double y, double x) { + double z; + int k, m, hx, hy, ix, iy; + int lx, ly; // watch out, should be unsigned + + final long yBits = Double.doubleToRawLongBits(y); + final long xBits = Double.doubleToRawLongBits(x); + + hx = (int) (xBits >>> 32); // __HI(x); + ix = hx & 0x7fffffff; + lx = (int) xBits; // __LO(x); + hy = (int) (yBits >>> 32); // __HI(y); + iy = hy & 0x7fffffff; + ly = (int) yBits; // __LO(y); + if (((ix | ((lx | -lx) >> 31)) > 0x7ff00000) + || ((iy | ((ly | -ly) >> 31)) > 0x7ff00000)) { /* x or y is NaN */ + return x + y; + } + if ((hx - 0x3ff00000 | lx) == 0) { + return StrictMath.atan(y); /* x=1.0 */ + } + + m = ((hy >> 31) & 1) | ((hx >> 30) & 2); /* 2*sign(x)+sign(y) */ + + /* when y = 0 */ + if ((iy | ly) == 0) { + switch (m) { + case 0: + case 1: + return y; /* ieee_atan(+-0,+anything)=+-0 */ + case 2: + return 3.14159265358979311600e+00 + TINY;/* ieee_atan(+0,-anything) = pi */ + case 3: + return -3.14159265358979311600e+00 - TINY;/* ieee_atan(-0,-anything) =-pi */ + } + } + /* when x = 0 */ + if ((ix | lx) == 0) + return (hy < 0) ? -PI_O_2 - TINY : PI_O_2 + TINY; + + /* when x is INF */ + if (ix == 0x7ff00000) { + if (iy == 0x7ff00000) { + switch (m) { + case 0: + return PI_O_4 + TINY;/* ieee_atan(+INF,+INF) */ + case 1: + return -PI_O_4 - TINY;/* ieee_atan(-INF,+INF) */ + case 2: + return 3.0 * PI_O_4 + TINY;/* ieee_atan(+INF,-INF) */ + case 3: + return -3.0 * PI_O_4 - TINY;/* ieee_atan(-INF,-INF) */ + } + } else { + switch (m) { + case 0: + return 0.0; /* ieee_atan(+...,+INF) */ + case 1: + return -0.0; /* ieee_atan(-...,+INF) */ + case 2: + return 3.14159265358979311600e+00 + TINY; /* ieee_atan(+...,-INF) */ + case 3: + return -3.14159265358979311600e+00 - TINY; /* ieee_atan(-...,-INF) */ + } + } + } + /* when y is INF */ + if (iy == 0x7ff00000) + return (hy < 0) ? -PI_O_2 - TINY : PI_O_2 + TINY; + + /* compute y/x */ + k = (iy - ix) >> 20; + if (k > 60) { + z = PI_O_2 + 0.5 * PI_LO; /* |y/x| > 2**60 */ + } else if (hx < 0 && k < -60) { + z = 0.0; /* |y|/x < -2**60 */ + } else { + z = StrictMath.atan(Math.abs(y / x)); /* safe to do y/x */ + } + + switch (m) { + case 0: + return z; /* ieee_atan(+,+) */ + case 1: + // __HI(z) ^= 0x80000000; + z = Double.longBitsToDouble( + Double.doubleToRawLongBits(z) ^ (0x80000000L << 32)); + return z; /* ieee_atan(-,+) */ + case 2: + return 3.14159265358979311600e+00 - (z - PI_LO);/* ieee_atan(+,-) */ + default: /* case 3 */ + return (z - PI_LO) - 3.14159265358979311600e+00;/* ieee_atan(-,-) */ + } + } + + private static final int B1 = 715094163; + private static final int B2 = 696219795; + private static final double C = 5.42857142857142815906e-01; + private static final double D = -7.05306122448979611050e-01; + private static final double CBRTE = 1.41428571428571436819e+00; + private static final double F = 1.60714285714285720630e+00; + private static final double G = 3.57142857142857150787e-01; /** * Returns the closest double approximation of the cube root of the @@ -207,11 +512,79 @@ public final class StrictMath { * <li>{@code cbrt(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose cube root has to be computed. * @return the cube root of the argument. */ - public static native double cbrt(double d); + public static double cbrt(double x) { + if (x < 0) { + return -cbrt(-x); + } + int hx; + double r, s, w; + int sign; // caution: should be unsigned + long bits = Double.doubleToRawLongBits(x); + + hx = (int) (bits >>> 32); + sign = hx & 0x80000000; /* sign= sign(x) */ + hx ^= sign; + if (hx >= 0x7ff00000) { + return (x + x); /* ieee_cbrt(NaN,INF) is itself */ + } + + if ((hx | ((int) bits)) == 0) { + return x; /* ieee_cbrt(0) is itself */ + } + + // __HI(x) = hx; /* x <- |x| */ + bits &= 0x00000000ffffffffL; + bits |= ((long) hx << 32); + + long tBits = Double.doubleToRawLongBits(0.0) & 0x00000000ffffffffL; + double t = 0.0; + /* rough cbrt to 5 bits */ + if (hx < 0x00100000) { /* subnormal number */ + // __HI(t)=0x43500000; /*set t= 2**54*/ + tBits |= 0x43500000L << 32; + t = Double.longBitsToDouble(tBits); + t *= x; + + // __HI(t)=__HI(t)/3+B2; + tBits = Double.doubleToRawLongBits(t); + long tBitsHigh = tBits >> 32; + tBits &= 0x00000000ffffffffL; + tBits |= ((tBitsHigh / 3) + B2) << 32; + t = Double.longBitsToDouble(tBits); + + } else { + // __HI(t)=hx/3+B1; + tBits |= ((long) ((hx / 3) + B1)) << 32; + t = Double.longBitsToDouble(tBits); + } + + /* new cbrt to 23 bits, may be implemented in single precision */ + r = t * t / x; + s = C + r * t; + t *= G + F / (s + CBRTE + D / s); + + /* chopped to 20 bits and make it larger than ieee_cbrt(x) */ + tBits = Double.doubleToRawLongBits(t); + tBits &= 0xFFFFFFFFL << 32; + tBits += 0x00000001L << 32; + t = Double.longBitsToDouble(tBits); + + /* one step newton iteration to 53 bits with error less than 0.667 ulps */ + s = t * t; /* t*t is exact */ + r = x / s; + w = t + t; + r = (r - t) / (w + r); /* r-s is exact */ + t = t + t * r; + + /* retore the sign bit */ + tBits = Double.doubleToRawLongBits(t); + tBits |= ((long) sign) << 32; + return Double.longBitsToDouble(tBits); + } /** * Returns the double conversion of the most negative (closest to negative @@ -229,6 +602,8 @@ public final class StrictMath { */ public static native double ceil(double d); + private static final long ONEBITS = Double.doubleToRawLongBits(1.00000000000000000000e+00) + & 0x00000000ffffffffL; /** * Returns the closest double approximation of the hyperbolic cosine of the @@ -241,11 +616,54 @@ public final class StrictMath { * <li>{@code cosh(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose hyperbolic cosine has to be computed. * @return the hyperbolic cosine of the argument. */ - public static native double cosh(double d); + public static double cosh(double x) { + double t, w; + int ix; + final long bits = Double.doubleToRawLongBits(x); + ix = (int) (bits >>> 32) & 0x7fffffff; + + /* x is INF or NaN */ + if (ix >= 0x7ff00000) { + return x * x; + } + + /* |x| in [0,0.5*ln2], return 1+ieee_expm1(|x|)^2/(2*ieee_exp(|x|)) */ + if (ix < 0x3fd62e43) { + t = expm1(Math.abs(x)); + w = 1.00000000000000000000e+00 + t; + if (ix < 0x3c800000) + return w; /* ieee_cosh(tiny) = 1 */ + return 1.00000000000000000000e+00 + (t * t) / (w + w); + } + + /* |x| in [0.5*ln2,22], return (ieee_exp(|x|)+1/ieee_exp(|x|)/2; */ + if (ix < 0x40360000) { + t = exp(Math.abs(x)); + return 0.5 * t + 0.5 / t; + } + + /* |x| in [22, ieee_log(maxdouble)] return half*ieee_exp(|x|) */ + if (ix < 0x40862E42) { + return 0.5 * exp(Math.abs(x)); + } + + /* |x| in [log(maxdouble), overflowthresold] */ + final long lx = ((ONEBITS >>> 29) + ((int) bits)) & 0x00000000ffffffffL; + // watch out: lx should be an unsigned int + // lx = *( (((*(unsigned*)&one)>>29)) + (unsigned*)&x); + if (ix < 0x408633CE || (ix == 0x408633ce) && (lx <= 0x8fb9f87dL)) { + w = exp(0.5 * Math.abs(x)); + t = 0.5 * w; + return t * w; + } + + /* |x| > overflowthresold, ieee_cosh(x) overflow */ + return HUGE * HUGE; + } /** * Returns the closest double approximation of the cosine of the argument. @@ -263,6 +681,19 @@ public final class StrictMath { */ public static native double cos(double d); + private static final double TWON24 = 5.96046447753906250000e-08; + private static final double TWO54 = 1.80143985094819840000e+16, + TWOM54 = 5.55111512312578270212e-17; + private static final double TWOM1000 = 9.33263618503218878990e-302; + private static final double O_THRESHOLD = 7.09782712893383973096e+02; + private static final double U_THRESHOLD = -7.45133219101941108420e+02; + private static final double INVLN2 = 1.44269504088896338700e+00; + private static final double P1 = 1.66666666666666019037e-01; + private static final double P2 = -2.77777777770155933842e-03; + private static final double P3 = 6.61375632143793436117e-05; + private static final double P4 = -1.65339022054652515390e-06; + private static final double P5 = 4.13813679705723846039e-08; + /** * Returns the closest double approximation of the raising "e" to the power * of the argument. @@ -274,11 +705,88 @@ public final class StrictMath { * <li>{@code exp(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose exponential has to be computed. * @return the exponential of the argument. */ - public static native double exp(double d); + public static double exp(double x) { + double y, c, t; + double hi = 0, lo = 0; + int k = 0, xsb; + int hx; // should be unsigned, be careful! + final long bits = Double.doubleToRawLongBits(x); + int lowBits = (int) bits; + int highBits = (int) (bits >>> 32); + hx = highBits & 0x7fffffff; + xsb = (highBits >>> 31) & 1; + + /* filter out non-finite argument */ + if (hx >= 0x40862E42) { /* if |x|>=709.78... */ + if (hx >= 0x7ff00000) { + if (((hx & 0xfffff) | lowBits) != 0) { + return x + x; /* NaN */ + } else { + return (xsb == 0) ? x : 0.0; /* ieee_exp(+-inf)={inf,0} */ + } + } + + if (x > O_THRESHOLD) { + return HUGE * HUGE; /* overflow */ + } + + if (x < U_THRESHOLD) { + return TWOM1000 * TWOM1000; /* underflow */ + } + } + + /* argument reduction */ + if (hx > 0x3fd62e42) { /* if |x| > 0.5 ln2 */ + if (hx < 0x3FF0A2B2) { /* and |x| < 1.5 ln2 */ + hi = x - ((xsb == 0) ? 6.93147180369123816490e-01 : + -6.93147180369123816490e-01); // LN2HI[xsb]; + lo = (xsb == 0) ? 1.90821492927058770002e-10 : + -1.90821492927058770002e-10; // LN2LO[xsb]; + k = 1 - xsb - xsb; + } else { + k = (int) (INVLN2 * x + ((xsb == 0) ? 0.5 : -0.5 ));//halF[xsb]); + t = k; + hi = x - t * 6.93147180369123816490e-01; //ln2HI[0]; /* t*ln2HI is exact here */ + lo = t * 1.90821492927058770002e-10; //ln2LO[0]; + } + x = hi - lo; + } else if (hx < 0x3e300000) { /* when |x|<2**-28 */ + if (HUGE + x > 1.00000000000000000000e+00) + return 1.00000000000000000000e+00 + x;/* trigger inexact */ + } else { + k = 0; + } + + /* x is now in primary range */ + t = x * x; + c = x - t * (P1 + t * (P2 + t * (P3 + t * (P4 + t * P5)))); + if (k == 0) { + return 1.00000000000000000000e+00 - ((x * c) / (c - 2.0) - x); + } else { + y = 1.00000000000000000000e+00 - ((lo - (x * c) / (2.0 - c)) - hi); + } + long yBits = Double.doubleToRawLongBits(y); + if (k >= -1021) { + yBits += ((long) (k << 20)) << 32; /* add k to y's exponent */ + return Double.longBitsToDouble(yBits); + } else { + yBits += ((long) ((k + 1000) << 20)) << 32;/* add k to y's exponent */ + return Double.longBitsToDouble(yBits) * TWOM1000; + } + } + + private static final double TINY = 1.0e-300; + private static final double LN2_HI = 6.93147180369123816490e-01; + private static final double LN2_LO = 1.90821492927058770002e-10; + private static final double Q1 = -3.33333333333331316428e-02; + private static final double Q2 = 1.58730158725481460165e-03; + private static final double Q3 = -7.93650757867487942473e-05; + private static final double Q4 = 4.00821782732936239552e-06; + private static final double Q5 = -2.01099218183624371326e-07; /** * Returns the closest double approximation of <i>{@code e}</i><sup> @@ -295,17 +803,124 @@ public final class StrictMath { * <li>{@code expm1(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value to compute the <i>{@code e}</i><sup>{@code d}</sup> * {@code - 1} of. - * @return the <i>{@code e}</i><sup>{@code d}</sup>{@code - 1} value - * of the argument. + * @return the <i>{@code e}</i><sup>{@code d}</sup>{@code - 1} value of the + * argument. */ - public static native double expm1(double d); + public static double expm1(double x) { + double y, hi, lo, t, e, hxs, hfx, r1, c = 0.0; + int k, xsb; + long yBits = 0; + final long bits = Double.doubleToRawLongBits(x); + int highBits = (int) (bits >>> 32); + int lowBits = (int) (bits); + int hx = highBits & 0x7fffffff; // caution: should be unsigned! + xsb = highBits & 0x80000000; /* sign bit of x */ + y = xsb == 0 ? x : -x; /* y = |x| */ + + /* filter out huge and non-finite argument */ + if (hx >= 0x4043687A) { /* if |x|>=56*ln2 */ + if (hx >= 0x40862E42) { /* if |x|>=709.78... */ + if (hx >= 0x7ff00000) { + if (((hx & 0xfffff) | lowBits) != 0) { + return x + x; /* NaN */ + } else { + return (xsb == 0) ? x : -1.0;/* ieee_exp(+-inf)={inf,-1} */ + } + } + if (x > O_THRESHOLD) { + return HUGE * HUGE; /* overflow */ + } + } + if (xsb != 0) { /* x < -56*ln2, return -1.0 with inexact */ + if (x + TINY < 0.0) { /* raise inexact */ + return TINY - 1.00000000000000000000e+00; /* return -1 */ + } + } + } + /* argument reduction */ + if (hx > 0x3fd62e42) { /* if |x| > 0.5 ln2 */ + if (hx < 0x3FF0A2B2) { /* and |x| < 1.5 ln2 */ + if (xsb == 0) { + hi = x - LN2_HI; + lo = LN2_LO; + k = 1; + } else { + hi = x + LN2_HI; + lo = -LN2_LO; + k = -1; + } + } else { + k = (int) (INVLN2 * x + ((xsb == 0) ? 0.5 : -0.5)); + t = k; + hi = x - t * LN2_HI; /* t*ln2_hi is exact here */ + lo = t * LN2_LO; + } + x = hi - lo; + c = (hi - x) - lo; + } else if (hx < 0x3c900000) { /* when |x|<2**-54, return x */ + // t = huge+x; /* return x with inexact flags when x!=0 */ + // return x - (t-(huge+x)); + return x; // inexact flag is not set, but Java ignors this flag + // anyway + } else { + k = 0; + } + + /* x is now in primary range */ + hfx = 0.5 * x; + hxs = x * hfx; + r1 = 1.00000000000000000000e+00 + hxs * (Q1 + hxs * (Q2 + hxs * (Q3 + hxs * (Q4 + hxs * Q5)))); + t = 3.0 - r1 * hfx; + e = hxs * ((r1 - t) / (6.0 - x * t)); + if (k == 0) { + return x - (x * e - hxs); /* c is 0 */ + } else { + e = (x * (e - c) - c); + e -= hxs; + if (k == -1) { + return 0.5 * (x - e) - 0.5; + } + + if (k == 1) { + if (x < -0.25) { + return -2.0 * (e - (x + 0.5)); + } else { + return 1.00000000000000000000e+00 + 2.0 * (x - e); + } + } + + if (k <= -2 || k > 56) { /* suffice to return ieee_exp(x)-1 */ + y = 1.00000000000000000000e+00 - (e - x); + yBits = Double.doubleToRawLongBits(y); + yBits += (((long) k) << 52); /* add k to y's exponent */ + return Double.longBitsToDouble(yBits) - 1.00000000000000000000e+00; + } + + long tBits = Double.doubleToRawLongBits(1.00000000000000000000e+00) & 0x00000000ffffffffL; + + if (k < 20) { + tBits |= (((long) 0x3ff00000) - (0x200000 >> k)) << 32; + y = Double.longBitsToDouble(tBits) - (e - x); + yBits = Double.doubleToRawLongBits(y); + yBits += (((long) k) << 52); /* add k to y's exponent */ + return Double.longBitsToDouble(yBits); + } else { + tBits |= ((((long) 0x3ff) - k) << 52); /* 2^-k */ + y = x - (e + Double.longBitsToDouble(tBits)); + y += 1.00000000000000000000e+00; + yBits = Double.doubleToRawLongBits(y); + yBits += (((long) k) << 52); /* add k to y's exponent */ + return Double.longBitsToDouble(yBits); + } + } + } /** - * Returns the double conversion of the most positive (closest to - * positive infinity) integer less than or equal to the argument. + * Returns the double conversion of the most positive (closest to positive + * infinity) integer less than or equal to the argument. * <p> * Special cases: * <ul> @@ -319,9 +934,9 @@ public final class StrictMath { public static native double floor(double d); /** - * Returns {@code sqrt(}<i>{@code x}</i><sup>{@code 2}</sup>{@code +} - * <i> {@code y}</i><sup>{@code 2}</sup>{@code )}. The final result is - * without medium underflow or overflow. + * Returns {@code sqrt(}<i>{@code x}</i><sup>{@code 2}</sup>{@code +} <i> + * {@code y}</i><sup>{@code 2}</sup>{@code )}. The final result is without + * medium underflow or overflow. * <p> * Special cases: * <ul> @@ -369,6 +984,14 @@ public final class StrictMath { */ public static native double IEEEremainder(double x, double y); + private static final double LG1 = 6.666666666666735130e-01; + private static final double LG2 = 3.999999999940941908e-01; + private static final double LG3 = 2.857142874366239149e-01; + private static final double LG4 = 2.222219843214978396e-01; + private static final double LG5 = 1.818357216161805012e-01; + private static final double LG6 = 1.531383769920937332e-01; + private static final double LG7 = 1.479819860511658591e-01; + /** * Returns the closest double approximation of the natural logarithm of the * argument. @@ -383,11 +1006,95 @@ public final class StrictMath { * <li>{@code log(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose log has to be computed. * @return the natural logarithm of the argument. */ - public static native double log(double d); + public static double log(double x) { + double hfsq, f, s, z, R, w, t1, t2, dk; + int hx, i, j, k = 0; + int lx; // watch out, should be unsigned + + long bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >>> 32); /* high word of x */ + lx = (int) bits; /* low word of x */ + + if (hx < 0x00100000) { /* x < 2**-1022 */ + if (((hx & 0x7fffffff) | lx) == 0) { + return -TWO54 / 0.0; /* ieee_log(+-0)=-inf */ + } + + if (hx < 0) { + return (x - x) / 0.0; /* ieee_log(-#) = NaN */ + } + + k -= 54; + x *= TWO54; /* subnormal number, scale up x */ + bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >>> 32); /* high word of x */ + } + + if (hx >= 0x7ff00000) { + return x + x; + } + + k += (hx >> 20) - 1023; + hx &= 0x000fffff; + bits &= 0x00000000ffffffffL; + i = (hx + 0x95f64) & 0x100000; + bits |= ((long) hx | (i ^ 0x3ff00000)) << 32; /* normalize x or x/2 */ + x = Double.longBitsToDouble(bits); + k += (i >> 20); + f = x - 1.0; + + if ((0x000fffff & (2 + hx)) < 3) { /* |f| < 2**-20 */ + if (f == 0.0) { + if (k == 0) { + return 0.0; + } else { + dk = k; + } + return dk * LN2_HI + dk * LN2_LO; + } + + R = f * f * (0.5 - 0.33333333333333333 * f); + if (k == 0) { + return f - R; + } else { + dk = k; + return dk * LN2_HI - ((R - dk * LN2_LO) - f); + } + } + s = f / (2.0 + f); + dk = k; + z = s * s; + i = hx - 0x6147a; + w = z * z; + j = 0x6b851 - hx; + t1 = w * (LG2 + w * (LG4 + w * LG6)); + t2 = z * (LG1 + w * (LG3 + w * (LG5 + w * LG7))); + i |= j; + R = t2 + t1; + if (i > 0) { + hfsq = 0.5 * f * f; + if (k == 0) { + return f - (hfsq - s * (hfsq + R)); + } else { + return dk * LN2_HI + - ((hfsq - (s * (hfsq + R) + dk * LN2_LO)) - f); + } + } else { + if (k == 0) { + return f - s * (f - R); + } else { + return dk * LN2_HI - ((s * (f - R) - dk * LN2_LO) - f); + } + } + } + + private static final double IVLN10 = 4.34294481903251816668e-01; + private static final double LOG10_2HI = 3.01029995663611771306e-01; + private static final double LOG10_2LO = 3.69423907715893078616e-13; /** * Returns the closest double approximation of the base 10 logarithm of the @@ -403,11 +1110,54 @@ public final class StrictMath { * <li>{@code log10(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose base 10 log has to be computed. - * @return the natural logarithm of the argument. + * @return the the base 10 logarithm of x */ - public static native double log10(double d); + public static double log10(double x) { + double y, z; + int i, k = 0, hx; + int lx; // careful: lx should be unsigned! + long bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >> 32); /* high word of x */ + lx = (int) bits; /* low word of x */ + if (hx < 0x00100000) { /* x < 2**-1022 */ + if (((hx & 0x7fffffff) | lx) == 0) { + return -TWO54 / 0.0; /* ieee_log(+-0)=-inf */ + } + + if (hx < 0) { + return (x - x) / 0.0; /* ieee_log(-#) = NaN */ + } + + k -= 54; + x *= TWO54; /* subnormal number, scale up x */ + bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >> 32); /* high word of x */ + } + + if (hx >= 0x7ff00000) { + return x + x; + } + + k += (hx >> 20) - 1023; + i = (int) (((k & 0x00000000ffffffffL) & 0x80000000) >>> 31); + hx = (hx & 0x000fffff) | ((0x3ff - i) << 20); + y = k + i; + bits &= 0x00000000ffffffffL; + bits |= ((long) hx) << 32; + x = Double.longBitsToDouble(bits); // __HI(x) = hx; + z = y * LOG10_2LO + IVLN10 * log(x); + return z + y * LOG10_2HI; + } + + private static final double LP1 = 6.666666666666735130e-01, + LP2 = 3.999999999940941908e-01, /* 3FD99999 9997FA04 */ + LP3 = 2.857142874366239149e-01, /* 3FD24924 94229359 */ + LP4 = 2.222219843214978396e-01, /* 3FCC71C5 1D8E78AF */ + LP5 = 1.818357216161805012e-01, /* 3FC74664 96CB03DE */ + LP6 = 1.531383769920937332e-01, /* 3FC39A09 D078C69F */ + LP7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */ /** * Returns the closest double approximation of the natural logarithm of the @@ -426,11 +1176,107 @@ public final class StrictMath { * <li>{@code log1p(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value to compute the {@code ln(1+d)} of. * @return the natural logarithm of the sum of the argument and 1. */ - public static native double log1p(double d); + + public static double log1p(double x) { + double hfsq, f = 0.0, c = 0.0, s, z, R, u = 0.0; + int k, hx, hu = 0, ax; + + final long bits = Double.doubleToRawLongBits(x); + hx = (int) (bits >>> 32); /* high word of x */ + ax = hx & 0x7fffffff; + + k = 1; + if (hx < 0x3FDA827A) { /* x < 0.41422 */ + if (ax >= 0x3ff00000) { /* x <= -1.0 */ + if (x == -1.0) { + return -TWO54 / 0.0; /* ieee_log1p(-1)=+inf */ + } else { + return (x - x) / (x - x); /* ieee_log1p(x<-1)=NaN */ + } + } + if (ax < 0x3e200000) { + if (TWO54 + x > 0.0 && ax < 0x3c900000) { + return x; + } else { + return x - x * x * 0.5; + } + } + if (hx > 0 || hx <= 0xbfd2bec3) { + k = 0; + f = x; + hu = 1; + } /* -0.2929<x<0.41422 */ + } + + if (hx >= 0x7ff00000) { + return x + x; + } + + if (k != 0) { + long uBits; + if (hx < 0x43400000) { + u = 1.0 + x; + uBits = Double.doubleToRawLongBits(u); + hu = (int) (uBits >>> 32); + k = (hu >> 20) - 1023; + c = (k > 0) ? 1.0 - (u - x) : x - (u - 1.0);/* correction term */ + c /= u; + } else { + uBits = Double.doubleToRawLongBits(x); + hu = (int) (uBits >>> 32); + k = (hu >> 20) - 1023; + c = 0; + } + hu &= 0x000fffff; + if (hu < 0x6a09e) { + // __HI(u) = hu|0x3ff00000; /* normalize u */ + uBits &= 0x00000000ffffffffL; + uBits |= ((long) hu | 0x3ff00000) << 32; + u = Double.longBitsToDouble(uBits); + } else { + k += 1; + // __HI(u) = hu|0x3fe00000; /* normalize u/2 */ + uBits &= 0xffffffffL; + uBits |= ((long) hu | 0x3fe00000) << 32; + u = Double.longBitsToDouble(uBits); + hu = (0x00100000 - hu) >> 2; + } + f = u - 1.0; + } + hfsq = 0.5 * f * f; + if (hu == 0) { /* |f| < 2**-20 */ + if (f == 0.0) { + if (k == 0) { + return 0.0; + } else { + c += k * LN2_LO; + return k * LN2_HI + c; + } + } + + R = hfsq * (1.0 - 0.66666666666666666 * f); + if (k == 0) { + return f - R; + } else { + return k * LN2_HI - ((R - (k * LN2_LO + c)) - f); + } + } + + s = f / (2.0 + f); + z = s * s; + R = z * (LP1 + z * (LP2 + z + * (LP3 + z * (LP4 + z * (LP5 + z * (LP6 + z * LP7)))))); + if (k == 0) { + return f - (hfsq - s * (hfsq + R)); + } else { + return k * LN2_HI + - ((hfsq - (s * (hfsq + R) + (k * LN2_LO + c))) - f); + } + } /** * Returns the most positive (closest to positive infinity) of the two @@ -453,8 +1299,8 @@ public final class StrictMath { if (d1 != d2) return Double.NaN; /* max( +0.0,-0.0) == +0.0 */ - if (d1 == 0.0 - && ((Double.doubleToLongBits(d1) & Double.doubleToLongBits(d2)) & 0x8000000000000000L) == 0) + if (d1 == 0.0 && + ((Double.doubleToLongBits(d1) & Double.doubleToLongBits(d2)) & 0x8000000000000000L) == 0) return 0.0; return d1; } @@ -480,8 +1326,8 @@ public final class StrictMath { if (f1 != f2) return Float.NaN; /* max( +0.0,-0.0) == +0.0 */ - if (f1 == 0.0f - && ((Float.floatToIntBits(f1) & Float.floatToIntBits(f2)) & 0x80000000) == 0) + if (f1 == 0.0f && + ((Float.floatToIntBits(f1) & Float.floatToIntBits(f2)) & 0x80000000) == 0) return 0.0f; return f1; } @@ -523,8 +1369,8 @@ public final class StrictMath { if (d1 != d2) return Double.NaN; /* min( +0.0,-0.0) == -0.0 */ - if (d1 == 0.0 - && ((Double.doubleToLongBits(d1) | Double.doubleToLongBits(d2)) & 0x8000000000000000l) != 0) + if (d1 == 0.0 && + ((Double.doubleToLongBits(d1) | Double.doubleToLongBits(d2)) & 0x8000000000000000l) != 0) return 0.0 * (-1.0); return d1; } @@ -550,8 +1396,8 @@ public final class StrictMath { if (f1 != f2) return Float.NaN; /* min( +0.0,-0.0) == -0.0 */ - if (f1 == 0.0f - && ((Float.floatToIntBits(f1) | Float.floatToIntBits(f2)) & 0x80000000) != 0) + if (f1 == 0.0f && + ((Float.floatToIntBits(f1) | Float.floatToIntBits(f2)) & 0x80000000) != 0) return 0.0f * (-1.0f); return f1; } @@ -706,7 +1552,7 @@ public final class StrictMath { * the value whose signum has to be computed. * @return the value of the signum function. */ - public static double signum(double d){ + public static double signum(double d) { return Math.signum(d); } @@ -729,10 +1575,12 @@ public final class StrictMath { * the value whose signum has to be computed. * @return the value of the signum function. */ - public static float signum(float f){ + public static float signum(float f) { return Math.signum(f); } + private static final double shuge = 1.0e307; + /** * Returns the closest double approximation of the hyperbolic sine of the * argument. @@ -746,11 +1594,57 @@ public final class StrictMath { * <li>{@code sinh(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose hyperbolic sine has to be computed. * @return the hyperbolic sine of the argument. */ - public static native double sinh(double d); + public static double sinh(double x) { + double t, w, h; + int ix, jx; + final long bits = Double.doubleToRawLongBits(x); + + jx = (int) (bits >>> 32); + ix = jx & 0x7fffffff; + + /* x is INF or NaN */ + if (ix >= 0x7ff00000) { + return x + x; + } + + h = 0.5; + if (jx < 0) { + h = -h; + } + + /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ + if (ix < 0x40360000) { /* |x|<22 */ + if (ix < 0x3e300000) /* |x|<2**-28 */ + if (shuge + x > 1.00000000000000000000e+00) { + return x;/* ieee_sinh(tiny) = tiny with inexact */ + } + t = expm1(Math.abs(x)); + if (ix < 0x3ff00000) + return h * (2.0 * t - t * t / (t + 1.00000000000000000000e+00)); + return h * (t + t / (t + 1.00000000000000000000e+00)); + } + + /* |x| in [22, ieee_log(maxdouble)] return 0.5*ieee_exp(|x|) */ + if (ix < 0x40862E42) { + return h * exp(Math.abs(x)); + } + + /* |x| in [log(maxdouble), overflowthresold] */ + final long lx = ((ONEBITS >>> 29) + ((int) bits)) & 0x00000000ffffffffL; + // lx = *( (((*(unsigned*)&one)>>29)) + (unsigned*)&x); + if (ix < 0x408633CE || (ix == 0x408633ce) && (lx <= 0x8fb9f87dL)) { + w = exp(0.5 * Math.abs(x)); + t = h * w; + return t * w; + } + + /* |x| > overflowthresold, ieee_sinh(x) overflow */ + return x * shuge; + } /** * Returns the closest double approximation of the sine of the argument. @@ -816,11 +1710,47 @@ public final class StrictMath { * <li>{@code tanh(NaN) = NaN}</li> * </ul> * - * @param d + * @param x * the value whose hyperbolic tangent has to be computed. * @return the hyperbolic tangent of the argument */ - public static native double tanh(double d); + public static double tanh(double x) { + double t, z; + int jx, ix; + + final long bits = Double.doubleToRawLongBits(x); + /* High word of |x|. */ + jx = (int) (bits >>> 32); + ix = jx & 0x7fffffff; + + /* x is INF or NaN */ + if (ix >= 0x7ff00000) { + if (jx >= 0) { + return 1.00000000000000000000e+00 / x + 1.00000000000000000000e+00; /* ieee_tanh(+-inf)=+-1 */ + } else { + return 1.00000000000000000000e+00 / x - 1.00000000000000000000e+00; /* ieee_tanh(NaN) = NaN */ + } + } + + /* |x| < 22 */ + if (ix < 0x40360000) { /* |x|<22 */ + if (ix < 0x3c800000) { /* |x|<2**-55 */ + return x * (1.00000000000000000000e+00 + x);/* ieee_tanh(small) = small */ + } + + if (ix >= 0x3ff00000) { /* |x|>=1 */ + t = Math.expm1(2.0 * Math.abs(x)); + z = 1.00000000000000000000e+00 - 2.0 / (t + 2.0); + } else { + t = Math.expm1(-2.0 * Math.abs(x)); + z = -t / (t + 2.0); + } + /* |x| > 22, return +-1 */ + } else { + z = 1.00000000000000000000e+00 - TINY; /* raised inexact flag */ + } + return (jx >= 0) ? z : -z; + } /** * Returns the measure in degrees of the supplied radian angle. The result @@ -922,6 +1852,7 @@ public final class StrictMath { /** * Returns a double with the given magnitude and the sign of {@code sign}. * If {@code sign} is NaN, the sign of the result is positive. + * * @since 1.6 */ public static double copySign(double magnitude, double sign) { @@ -932,13 +1863,15 @@ public final class StrictMath { // (Tested on a Nexus One.) long magnitudeBits = Double.doubleToRawLongBits(magnitude); long signBits = Double.doubleToRawLongBits((sign != sign) ? 1.0 : sign); - magnitudeBits = (magnitudeBits & ~Double.SIGN_MASK) | (signBits & Double.SIGN_MASK); + magnitudeBits = (magnitudeBits & ~Double.SIGN_MASK) + | (signBits & Double.SIGN_MASK); return Double.longBitsToDouble(magnitudeBits); } /** - * Returns a float with the given magnitude and the sign of {@code sign}. - * If {@code sign} is NaN, the sign of the result is positive. + * Returns a float with the given magnitude and the sign of {@code sign}. If + * {@code sign} is NaN, the sign of the result is positive. + * * @since 1.6 */ public static float copySign(float magnitude, float sign) { @@ -949,12 +1882,14 @@ public final class StrictMath { // (Tested on a Nexus One.) int magnitudeBits = Float.floatToRawIntBits(magnitude); int signBits = Float.floatToRawIntBits((sign != sign) ? 1.0f : sign); - magnitudeBits = (magnitudeBits & ~Float.SIGN_MASK) | (signBits & Float.SIGN_MASK); + magnitudeBits = (magnitudeBits & ~Float.SIGN_MASK) + | (signBits & Float.SIGN_MASK); return Float.intBitsToFloat(magnitudeBits); } /** * Returns the exponent of float {@code f}. + * * @since 1.6 */ public static int getExponent(float f) { @@ -963,14 +1898,17 @@ public final class StrictMath { /** * Returns the exponent of double {@code d}. + * * @since 1.6 */ - public static int getExponent(double d){ + public static int getExponent(double d) { return Math.getExponent(d); } /** - * Returns the next double after {@code start} in the given {@code direction}. + * Returns the next double after {@code start} in the given + * {@code direction}. + * * @since 1.6 */ public static double nextAfter(double start, double direction) { @@ -981,7 +1919,9 @@ public final class StrictMath { } /** - * Returns the next float after {@code start} in the given {@code direction}. + * Returns the next float after {@code start} in the given {@code direction} + * . + * * @since 1.6 */ public static float nextAfter(float start, double direction) { @@ -990,6 +1930,7 @@ public final class StrictMath { /** * Returns the next double larger than {@code d}. + * * @since 1.6 */ public static double nextUp(double d) { @@ -998,6 +1939,7 @@ public final class StrictMath { /** * Returns the next float larger than {@code f}. + * * @since 1.6 */ public static float nextUp(float f) { @@ -1006,6 +1948,7 @@ public final class StrictMath { /** * Returns {@code d} * 2^{@code scaleFactor}. The result may be rounded. + * * @since 1.6 */ public static double scalb(double d, int scaleFactor) { @@ -1049,12 +1992,10 @@ public final class StrictMath { } else { if (Math.abs(d) >= Double.MIN_NORMAL) { // common situation - result = ((factor + Double.EXPONENT_BIAS) << Double.MANTISSA_BITS) - | (bits & Double.MANTISSA_MASK); + result = ((factor + Double.EXPONENT_BIAS) << Double.MANTISSA_BITS) | (bits & Double.MANTISSA_MASK); } else { // origin d is sub-normal, change mantissa to normal style - result = ((factor + Double.EXPONENT_BIAS) << Double.MANTISSA_BITS) - | ((bits << (subNormalFactor + 1)) & Double.MANTISSA_MASK); + result = ((factor + Double.EXPONENT_BIAS) << Double.MANTISSA_BITS) | ((bits << (subNormalFactor + 1)) & Double.MANTISSA_MASK); } } return Double.longBitsToDouble(result | sign); @@ -1062,6 +2003,7 @@ public final class StrictMath { /** * Returns {@code d} * 2^{@code scaleFactor}. The result may be rounded. + * * @since 1.6 */ public static float scalb(float d, int scaleFactor) { @@ -1073,8 +2015,7 @@ public final class StrictMath { int factor = ((bits & Float.EXPONENT_MASK) >> Float.MANTISSA_BITS) - Float.EXPONENT_BIAS + scaleFactor; // calculates the factor of sub-normal values - int subNormalFactor = Integer.numberOfLeadingZeros(bits & ~Float.SIGN_MASK) - - Float.EXPONENT_BITS; + int subNormalFactor = Integer.numberOfLeadingZeros(bits & ~Float.SIGN_MASK) - Float.EXPONENT_BITS; if (subNormalFactor < 0) { // not sub-normal values subNormalFactor = 0; @@ -1105,8 +2046,9 @@ public final class StrictMath { | (bits & Float.MANTISSA_MASK); } else { // origin d is sub-normal, change mantissa to normal style - result = ((factor + Float.EXPONENT_BIAS) << Float.MANTISSA_BITS) - | ((bits << (subNormalFactor + 1)) & Float.MANTISSA_MASK); + result = ((factor + Float.EXPONENT_BIAS) + << Float.MANTISSA_BITS) | ( + (bits << (subNormalFactor + 1)) & Float.MANTISSA_MASK); } } return Float.intBitsToFloat(result | sign); @@ -1120,10 +2062,10 @@ public final class StrictMath { } // change it to positive int absDigits = -digits; - if (Integer.numberOfLeadingZeros(bits & ~Float.SIGN_MASK) <= (32 - absDigits)) { + if (Integer.numberOfLeadingZeros(bits & ~Float.SIGN_MASK) + <= (32 - absDigits)) { // some bits will remain after shifting, calculates its carry - if ((((bits >> (absDigits - 1)) & 0x1) == 0) - || Integer.numberOfTrailingZeros(bits) == (absDigits - 1)) { + if ((((bits >> (absDigits - 1)) & 0x1) == 0) || Integer.numberOfTrailingZeros(bits) == (absDigits - 1)) { return bits >> absDigits; } return ((bits >> absDigits) + 1); @@ -1139,10 +2081,10 @@ public final class StrictMath { } // change it to positive long absDigits = -digits; - if (Long.numberOfLeadingZeros(bits & ~Double.SIGN_MASK) <= (64 - absDigits)) { + if (Long.numberOfLeadingZeros(bits & ~Double.SIGN_MASK) + <= (64 - absDigits)) { // some bits will remain after shifting, calculates its carry - if ((((bits >> (absDigits - 1)) & 0x1) == 0) - || Long.numberOfTrailingZeros(bits) == (absDigits - 1)) { + if ((((bits >> (absDigits - 1)) & 0x1) == 0) || Long.numberOfTrailingZeros(bits) == (absDigits - 1)) { return bits >> absDigits; } return ((bits >> absDigits) + 1); diff --git a/luni/src/main/native/java_lang_StrictMath.cpp b/luni/src/main/native/java_lang_StrictMath.cpp index cfe375e..e8c6dfb 100644 --- a/luni/src/main/native/java_lang_StrictMath.cpp +++ b/luni/src/main/native/java_lang_StrictMath.cpp @@ -34,26 +34,6 @@ static jdouble StrictMath_tan(JNIEnv*, jclass, jdouble a) { return ieee_tan(a); } -static jdouble StrictMath_asin(JNIEnv*, jclass, jdouble a) { - return ieee_asin(a); -} - -static jdouble StrictMath_acos(JNIEnv*, jclass, jdouble a) { - return ieee_acos(a); -} - -static jdouble StrictMath_atan(JNIEnv*, jclass, jdouble a) { - return ieee_atan(a); -} - -static jdouble StrictMath_exp(JNIEnv*, jclass, jdouble a) { - return ieee_exp(a); -} - -static jdouble StrictMath_log(JNIEnv*, jclass, jdouble a) { - return ieee_log(a); -} - static jdouble StrictMath_sqrt(JNIEnv*, jclass, jdouble a) { return ieee_sqrt(a); } @@ -74,75 +54,30 @@ static jdouble StrictMath_rint(JNIEnv*, jclass, jdouble a) { return ieee_rint(a); } -static jdouble StrictMath_atan2(JNIEnv*, jclass, jdouble a, jdouble b) { - return ieee_atan2(a, b); -} - static jdouble StrictMath_pow(JNIEnv*, jclass, jdouble a, jdouble b) { return ieee_pow(a,b); } -static jdouble StrictMath_sinh(JNIEnv*, jclass, jdouble a) { - return ieee_sinh(a); -} - -static jdouble StrictMath_tanh(JNIEnv*, jclass, jdouble a) { - return ieee_tanh(a); -} - -static jdouble StrictMath_cosh(JNIEnv*, jclass, jdouble a) { - return ieee_cosh(a); -} - -static jdouble StrictMath_log10(JNIEnv*, jclass, jdouble a) { - return ieee_log10(a); -} - -static jdouble StrictMath_cbrt(JNIEnv*, jclass, jdouble a) { - return ieee_cbrt(a); -} - -static jdouble StrictMath_expm1(JNIEnv*, jclass, jdouble a) { - return ieee_expm1(a); -} - static jdouble StrictMath_hypot(JNIEnv*, jclass, jdouble a, jdouble b) { return ieee_hypot(a, b); } -static jdouble StrictMath_log1p(JNIEnv*, jclass, jdouble a) { - return ieee_log1p(a); -} - static jdouble StrictMath_nextafter(JNIEnv*, jclass, jdouble a, jdouble b) { return ieee_nextafter(a, b); } static JNINativeMethod gMethods[] = { NATIVE_METHOD(StrictMath, IEEEremainder, "!(DD)D"), - NATIVE_METHOD(StrictMath, acos, "!(D)D"), - NATIVE_METHOD(StrictMath, asin, "!(D)D"), - NATIVE_METHOD(StrictMath, atan, "!(D)D"), - NATIVE_METHOD(StrictMath, atan2, "!(DD)D"), - NATIVE_METHOD(StrictMath, cbrt, "!(D)D"), NATIVE_METHOD(StrictMath, ceil, "!(D)D"), NATIVE_METHOD(StrictMath, cos, "!(D)D"), - NATIVE_METHOD(StrictMath, cosh, "!(D)D"), - NATIVE_METHOD(StrictMath, exp, "!(D)D"), - NATIVE_METHOD(StrictMath, expm1, "!(D)D"), NATIVE_METHOD(StrictMath, floor, "!(D)D"), NATIVE_METHOD(StrictMath, hypot, "!(DD)D"), - NATIVE_METHOD(StrictMath, log, "!(D)D"), - NATIVE_METHOD(StrictMath, log10, "!(D)D"), - NATIVE_METHOD(StrictMath, log1p, "!(D)D"), NATIVE_METHOD(StrictMath, nextafter, "!(DD)D"), NATIVE_METHOD(StrictMath, pow, "!(DD)D"), NATIVE_METHOD(StrictMath, rint, "!(D)D"), NATIVE_METHOD(StrictMath, sin, "!(D)D"), - NATIVE_METHOD(StrictMath, sinh, "!(D)D"), NATIVE_METHOD(StrictMath, sqrt, "!(D)D"), NATIVE_METHOD(StrictMath, tan, "!(D)D"), - NATIVE_METHOD(StrictMath, tanh, "!(D)D"), }; void register_java_lang_StrictMath(JNIEnv* env) { jniRegisterNativeMethods(env, "java/lang/StrictMath", gMethods, NELEM(gMethods)); |