annotate src/share/vm/runtime/sharedRuntimeTrans.cpp @ 18096:ca6d25be853b jdk8u25-b13

8044269: Analysis of archive files. Summary: Add checksum verification. Reviewed-by: iklam, dholmes, mschoene
author jiangli
date Tue, 12 Aug 2014 17:46:16 -0400
parents bdd155477289
children 8a9bb7821e28 631c3a4ea10c
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1 /*
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2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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20 * or visit www.oracle.com if you need additional information or have any
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21 * questions.
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22 *
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23 */
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24
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25 #include "precompiled.hpp"
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26 #include "prims/jni.h"
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27 #include "runtime/interfaceSupport.hpp"
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28 #include "runtime/sharedRuntime.hpp"
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29
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30 // This file contains copies of the fdlibm routines used by
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31 // StrictMath. It turns out that it is almost always required to use
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32 // these runtime routines; the Intel CPU doesn't meet the Java
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33 // specification for sin/cos outside a certain limited argument range,
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34 // and the SPARC CPU doesn't appear to have sin/cos instructions. It
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35 // also turns out that avoiding the indirect call through function
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36 // pointer out to libjava.so in SharedRuntime speeds these routines up
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37 // by roughly 15% on both Win32/x86 and Solaris/SPARC.
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38
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39 // Enabling optimizations in this file causes incorrect code to be
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40 // generated; can not figure out how to turn down optimization for one
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41 // file in the IDE on Windows
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42 #ifdef WIN32
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43 # pragma optimize ( "", off )
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44 #endif
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45
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46 #include <math.h>
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47
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48 // VM_LITTLE_ENDIAN is #defined appropriately in the Makefiles
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49 // [jk] this is not 100% correct because the float word order may different
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50 // from the byte order (e.g. on ARM)
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51 #ifdef VM_LITTLE_ENDIAN
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52 # define __HI(x) *(1+(int*)&x)
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53 # define __LO(x) *(int*)&x
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54 #else
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55 # define __HI(x) *(int*)&x
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56 # define __LO(x) *(1+(int*)&x)
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57 #endif
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58
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59 #if !defined(AIX)
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60 double copysign(double x, double y) {
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61 __HI(x) = (__HI(x)&0x7fffffff)|(__HI(y)&0x80000000);
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62 return x;
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63 }
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64 #endif
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65
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66 /*
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67 * ====================================================
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68 * Copyright (c) 1998 Oracle and/or its affiliates. All rights reserved.
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69 *
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70 * Developed at SunSoft, a Sun Microsystems, Inc. business.
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71 * Permission to use, copy, modify, and distribute this
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72 * software is freely granted, provided that this notice
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73 * is preserved.
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74 * ====================================================
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75 */
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76
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77 /*
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78 * scalbn (double x, int n)
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79 * scalbn(x,n) returns x* 2**n computed by exponent
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80 * manipulation rather than by actually performing an
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81 * exponentiation or a multiplication.
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82 */
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83
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84 static const double
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85 two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
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86 twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
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87 hugeX = 1.0e+300,
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88 tiny = 1.0e-300;
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89
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90 #if !defined(AIX)
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91 double scalbn (double x, int n) {
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92 int k,hx,lx;
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93 hx = __HI(x);
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94 lx = __LO(x);
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95 k = (hx&0x7ff00000)>>20; /* extract exponent */
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96 if (k==0) { /* 0 or subnormal x */
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97 if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
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98 x *= two54;
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99 hx = __HI(x);
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100 k = ((hx&0x7ff00000)>>20) - 54;
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101 if (n< -50000) return tiny*x; /*underflow*/
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102 }
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103 if (k==0x7ff) return x+x; /* NaN or Inf */
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104 k = k+n;
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105 if (k > 0x7fe) return hugeX*copysign(hugeX,x); /* overflow */
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106 if (k > 0) /* normal result */
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107 {__HI(x) = (hx&0x800fffff)|(k<<20); return x;}
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108 if (k <= -54) {
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109 if (n > 50000) /* in case integer overflow in n+k */
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110 return hugeX*copysign(hugeX,x); /*overflow*/
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111 else return tiny*copysign(tiny,x); /*underflow*/
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112 }
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113 k += 54; /* subnormal result */
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114 __HI(x) = (hx&0x800fffff)|(k<<20);
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115 return x*twom54;
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116 }
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117 #endif
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118
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119 /* __ieee754_log(x)
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120 * Return the logrithm of x
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121 *
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122 * Method :
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123 * 1. Argument Reduction: find k and f such that
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124 * x = 2^k * (1+f),
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125 * where sqrt(2)/2 < 1+f < sqrt(2) .
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126 *
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127 * 2. Approximation of log(1+f).
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128 * Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
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129 * = 2s + 2/3 s**3 + 2/5 s**5 + .....,
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130 * = 2s + s*R
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131 * We use a special Reme algorithm on [0,0.1716] to generate
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132 * a polynomial of degree 14 to approximate R The maximum error
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133 * of this polynomial approximation is bounded by 2**-58.45. In
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134 * other words,
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135 * 2 4 6 8 10 12 14
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136 * R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s +Lg6*s +Lg7*s
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137 * (the values of Lg1 to Lg7 are listed in the program)
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138 * and
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139 * | 2 14 | -58.45
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140 * | Lg1*s +...+Lg7*s - R(z) | <= 2
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141 * | |
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142 * Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2.
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143 * In order to guarantee error in log below 1ulp, we compute log
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144 * by
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145 * log(1+f) = f - s*(f - R) (if f is not too large)
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146 * log(1+f) = f - (hfsq - s*(hfsq+R)). (better accuracy)
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147 *
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148 * 3. Finally, log(x) = k*ln2 + log(1+f).
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149 * = k*ln2_hi+(f-(hfsq-(s*(hfsq+R)+k*ln2_lo)))
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150 * Here ln2 is split into two floating point number:
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151 * ln2_hi + ln2_lo,
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152 * where n*ln2_hi is always exact for |n| < 2000.
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153 *
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154 * Special cases:
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155 * log(x) is NaN with signal if x < 0 (including -INF) ;
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156 * log(+INF) is +INF; log(0) is -INF with signal;
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157 * log(NaN) is that NaN with no signal.
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158 *
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159 * Accuracy:
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160 * according to an error analysis, the error is always less than
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161 * 1 ulp (unit in the last place).
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162 *
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163 * Constants:
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164 * The hexadecimal values are the intended ones for the following
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165 * constants. The decimal values may be used, provided that the
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166 * compiler will convert from decimal to binary accurately enough
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167 * to produce the hexadecimal values shown.
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168 */
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169
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170 static const double
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171 ln2_hi = 6.93147180369123816490e-01, /* 3fe62e42 fee00000 */
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172 ln2_lo = 1.90821492927058770002e-10, /* 3dea39ef 35793c76 */
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173 Lg1 = 6.666666666666735130e-01, /* 3FE55555 55555593 */
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174 Lg2 = 3.999999999940941908e-01, /* 3FD99999 9997FA04 */
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175 Lg3 = 2.857142874366239149e-01, /* 3FD24924 94229359 */
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176 Lg4 = 2.222219843214978396e-01, /* 3FCC71C5 1D8E78AF */
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177 Lg5 = 1.818357216161805012e-01, /* 3FC74664 96CB03DE */
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178 Lg6 = 1.531383769920937332e-01, /* 3FC39A09 D078C69F */
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179 Lg7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */
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180
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181 static double zero = 0.0;
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182
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183 static double __ieee754_log(double x) {
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184 double hfsq,f,s,z,R,w,t1,t2,dk;
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185 int k,hx,i,j;
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186 unsigned lx;
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187
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188 hx = __HI(x); /* high word of x */
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189 lx = __LO(x); /* low word of x */
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190
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191 k=0;
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192 if (hx < 0x00100000) { /* x < 2**-1022 */
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193 if (((hx&0x7fffffff)|lx)==0)
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194 return -two54/zero; /* log(+-0)=-inf */
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195 if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
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196 k -= 54; x *= two54; /* subnormal number, scale up x */
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197 hx = __HI(x); /* high word of x */
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198 }
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199 if (hx >= 0x7ff00000) return x+x;
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200 k += (hx>>20)-1023;
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201 hx &= 0x000fffff;
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202 i = (hx+0x95f64)&0x100000;
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203 __HI(x) = hx|(i^0x3ff00000); /* normalize x or x/2 */
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204 k += (i>>20);
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205 f = x-1.0;
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206 if((0x000fffff&(2+hx))<3) { /* |f| < 2**-20 */
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207 if(f==zero) {
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208 if (k==0) return zero;
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209 else {dk=(double)k; return dk*ln2_hi+dk*ln2_lo;}
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210 }
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211 R = f*f*(0.5-0.33333333333333333*f);
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212 if(k==0) return f-R; else {dk=(double)k;
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213 return dk*ln2_hi-((R-dk*ln2_lo)-f);}
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214 }
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215 s = f/(2.0+f);
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216 dk = (double)k;
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217 z = s*s;
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218 i = hx-0x6147a;
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219 w = z*z;
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220 j = 0x6b851-hx;
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221 t1= w*(Lg2+w*(Lg4+w*Lg6));
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222 t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7)));
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223 i |= j;
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224 R = t2+t1;
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225 if(i>0) {
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226 hfsq=0.5*f*f;
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227 if(k==0) return f-(hfsq-s*(hfsq+R)); else
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228 return dk*ln2_hi-((hfsq-(s*(hfsq+R)+dk*ln2_lo))-f);
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229 } else {
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230 if(k==0) return f-s*(f-R); else
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231 return dk*ln2_hi-((s*(f-R)-dk*ln2_lo)-f);
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232 }
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233 }
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234
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235 JRT_LEAF(jdouble, SharedRuntime::dlog(jdouble x))
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236 return __ieee754_log(x);
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237 JRT_END
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238
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239 /* __ieee754_log10(x)
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240 * Return the base 10 logarithm of x
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241 *
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242 * Method :
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243 * Let log10_2hi = leading 40 bits of log10(2) and
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244 * log10_2lo = log10(2) - log10_2hi,
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245 * ivln10 = 1/log(10) rounded.
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246 * Then
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247 * n = ilogb(x),
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248 * if(n<0) n = n+1;
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249 * x = scalbn(x,-n);
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250 * log10(x) := n*log10_2hi + (n*log10_2lo + ivln10*log(x))
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251 *
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252 * Note 1:
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253 * To guarantee log10(10**n)=n, where 10**n is normal, the rounding
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254 * mode must set to Round-to-Nearest.
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255 * Note 2:
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256 * [1/log(10)] rounded to 53 bits has error .198 ulps;
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257 * log10 is monotonic at all binary break points.
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258 *
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259 * Special cases:
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260 * log10(x) is NaN with signal if x < 0;
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261 * log10(+INF) is +INF with no signal; log10(0) is -INF with signal;
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262 * log10(NaN) is that NaN with no signal;
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263 * log10(10**N) = N for N=0,1,...,22.
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264 *
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265 * Constants:
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266 * The hexadecimal values are the intended ones for the following constants.
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267 * The decimal values may be used, provided that the compiler will convert
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268 * from decimal to binary accurately enough to produce the hexadecimal values
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269 * shown.
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270 */
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271
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272 static const double
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273 ivln10 = 4.34294481903251816668e-01, /* 0x3FDBCB7B, 0x1526E50E */
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274 log10_2hi = 3.01029995663611771306e-01, /* 0x3FD34413, 0x509F6000 */
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275 log10_2lo = 3.69423907715893078616e-13; /* 0x3D59FEF3, 0x11F12B36 */
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276
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277 static double __ieee754_log10(double x) {
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278 double y,z;
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279 int i,k,hx;
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280 unsigned lx;
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281
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282 hx = __HI(x); /* high word of x */
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283 lx = __LO(x); /* low word of x */
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284
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285 k=0;
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286 if (hx < 0x00100000) { /* x < 2**-1022 */
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287 if (((hx&0x7fffffff)|lx)==0)
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288 return -two54/zero; /* log(+-0)=-inf */
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289 if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
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290 k -= 54; x *= two54; /* subnormal number, scale up x */
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291 hx = __HI(x); /* high word of x */
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292 }
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293 if (hx >= 0x7ff00000) return x+x;
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294 k += (hx>>20)-1023;
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295 i = ((unsigned)k&0x80000000)>>31;
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296 hx = (hx&0x000fffff)|((0x3ff-i)<<20);
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297 y = (double)(k+i);
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298 __HI(x) = hx;
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299 z = y*log10_2lo + ivln10*__ieee754_log(x);
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300 return z+y*log10_2hi;
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301 }
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302
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303 JRT_LEAF(jdouble, SharedRuntime::dlog10(jdouble x))
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304 return __ieee754_log10(x);
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305 JRT_END
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306
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307
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308 /* __ieee754_exp(x)
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309 * Returns the exponential of x.
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310 *
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311 * Method
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312 * 1. Argument reduction:
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313 * Reduce x to an r so that |r| <= 0.5*ln2 ~ 0.34658.
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314 * Given x, find r and integer k such that
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315 *
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316 * x = k*ln2 + r, |r| <= 0.5*ln2.
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317 *
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318 * Here r will be represented as r = hi-lo for better
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319 * accuracy.
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320 *
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321 * 2. Approximation of exp(r) by a special rational function on
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322 * the interval [0,0.34658]:
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323 * Write
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324 * R(r**2) = r*(exp(r)+1)/(exp(r)-1) = 2 + r*r/6 - r**4/360 + ...
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325 * We use a special Reme algorithm on [0,0.34658] to generate
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326 * a polynomial of degree 5 to approximate R. The maximum error
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327 * of this polynomial approximation is bounded by 2**-59. In
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328 * other words,
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329 * R(z) ~ 2.0 + P1*z + P2*z**2 + P3*z**3 + P4*z**4 + P5*z**5
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330 * (where z=r*r, and the values of P1 to P5 are listed below)
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331 * and
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332 * | 5 | -59
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333 * | 2.0+P1*z+...+P5*z - R(z) | <= 2
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334 * | |
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335 * The computation of exp(r) thus becomes
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336 * 2*r
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337 * exp(r) = 1 + -------
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338 * R - r
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339 * r*R1(r)
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340 * = 1 + r + ----------- (for better accuracy)
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341 * 2 - R1(r)
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342 * where
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343 * 2 4 10
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344 * R1(r) = r - (P1*r + P2*r + ... + P5*r ).
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345 *
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346 * 3. Scale back to obtain exp(x):
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347 * From step 1, we have
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348 * exp(x) = 2^k * exp(r)
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349 *
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350 * Special cases:
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351 * exp(INF) is INF, exp(NaN) is NaN;
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352 * exp(-INF) is 0, and
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353 * for finite argument, only exp(0)=1 is exact.
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354 *
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355 * Accuracy:
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356 * according to an error analysis, the error is always less than
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357 * 1 ulp (unit in the last place).
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358 *
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359 * Misc. info.
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360 * For IEEE double
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361 * if x > 7.09782712893383973096e+02 then exp(x) overflow
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362 * if x < -7.45133219101941108420e+02 then exp(x) underflow
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363 *
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364 * Constants:
a61af66fc99e Initial load
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parents:
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365 * The hexadecimal values are the intended ones for the following
a61af66fc99e Initial load
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parents:
diff changeset
366 * constants. The decimal values may be used, provided that the
a61af66fc99e Initial load
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parents:
diff changeset
367 * compiler will convert from decimal to binary accurately enough
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diff changeset
368 * to produce the hexadecimal values shown.
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parents:
diff changeset
369 */
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370
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371 static const double
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372 one = 1.0,
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373 halF[2] = {0.5,-0.5,},
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374 twom1000= 9.33263618503218878990e-302, /* 2**-1000=0x01700000,0*/
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375 o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
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376 u_threshold= -7.45133219101941108420e+02, /* 0xc0874910, 0xD52D3051 */
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377 ln2HI[2] ={ 6.93147180369123816490e-01, /* 0x3fe62e42, 0xfee00000 */
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378 -6.93147180369123816490e-01,},/* 0xbfe62e42, 0xfee00000 */
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379 ln2LO[2] ={ 1.90821492927058770002e-10, /* 0x3dea39ef, 0x35793c76 */
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380 -1.90821492927058770002e-10,},/* 0xbdea39ef, 0x35793c76 */
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381 invln2 = 1.44269504088896338700e+00, /* 0x3ff71547, 0x652b82fe */
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382 P1 = 1.66666666666666019037e-01, /* 0x3FC55555, 0x5555553E */
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383 P2 = -2.77777777770155933842e-03, /* 0xBF66C16C, 0x16BEBD93 */
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diff changeset
384 P3 = 6.61375632143793436117e-05, /* 0x3F11566A, 0xAF25DE2C */
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385 P4 = -1.65339022054652515390e-06, /* 0xBEBBBD41, 0xC5D26BF1 */
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386 P5 = 4.13813679705723846039e-08; /* 0x3E663769, 0x72BEA4D0 */
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387
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diff changeset
388 static double __ieee754_exp(double x) {
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389 double y,hi=0,lo=0,c,t;
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390 int k=0,xsb;
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diff changeset
391 unsigned hx;
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392
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393 hx = __HI(x); /* high word of x */
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parents:
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394 xsb = (hx>>31)&1; /* sign bit of x */
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395 hx &= 0x7fffffff; /* high word of |x| */
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396
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parents:
diff changeset
397 /* filter out non-finite argument */
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parents:
diff changeset
398 if(hx >= 0x40862E42) { /* if |x|>=709.78... */
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parents:
diff changeset
399 if(hx>=0x7ff00000) {
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parents:
diff changeset
400 if(((hx&0xfffff)|__LO(x))!=0)
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parents:
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401 return x+x; /* NaN */
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402 else return (xsb==0)? x:0.0; /* exp(+-inf)={inf,0} */
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403 }
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404 if(x > o_threshold) return hugeX*hugeX; /* overflow */
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parents:
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405 if(x < u_threshold) return twom1000*twom1000; /* underflow */
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parents:
diff changeset
406 }
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parents:
diff changeset
407
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parents:
diff changeset
408 /* argument reduction */
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parents:
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409 if(hx > 0x3fd62e42) { /* if |x| > 0.5 ln2 */
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diff changeset
410 if(hx < 0x3FF0A2B2) { /* and |x| < 1.5 ln2 */
a61af66fc99e Initial load
duke
parents:
diff changeset
411 hi = x-ln2HI[xsb]; lo=ln2LO[xsb]; k = 1-xsb-xsb;
a61af66fc99e Initial load
duke
parents:
diff changeset
412 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
413 k = (int)(invln2*x+halF[xsb]);
a61af66fc99e Initial load
duke
parents:
diff changeset
414 t = k;
a61af66fc99e Initial load
duke
parents:
diff changeset
415 hi = x - t*ln2HI[0]; /* t*ln2HI is exact here */
a61af66fc99e Initial load
duke
parents:
diff changeset
416 lo = t*ln2LO[0];
a61af66fc99e Initial load
duke
parents:
diff changeset
417 }
a61af66fc99e Initial load
duke
parents:
diff changeset
418 x = hi - lo;
a61af66fc99e Initial load
duke
parents:
diff changeset
419 }
a61af66fc99e Initial load
duke
parents:
diff changeset
420 else if(hx < 0x3e300000) { /* when |x|<2**-28 */
a61af66fc99e Initial load
duke
parents:
diff changeset
421 if(hugeX+x>one) return one+x;/* trigger inexact */
a61af66fc99e Initial load
duke
parents:
diff changeset
422 }
a61af66fc99e Initial load
duke
parents:
diff changeset
423 else k = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
424
a61af66fc99e Initial load
duke
parents:
diff changeset
425 /* x is now in primary range */
a61af66fc99e Initial load
duke
parents:
diff changeset
426 t = x*x;
a61af66fc99e Initial load
duke
parents:
diff changeset
427 c = x - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
a61af66fc99e Initial load
duke
parents:
diff changeset
428 if(k==0) return one-((x*c)/(c-2.0)-x);
a61af66fc99e Initial load
duke
parents:
diff changeset
429 else y = one-((lo-(x*c)/(2.0-c))-hi);
a61af66fc99e Initial load
duke
parents:
diff changeset
430 if(k >= -1021) {
a61af66fc99e Initial load
duke
parents:
diff changeset
431 __HI(y) += (k<<20); /* add k to y's exponent */
a61af66fc99e Initial load
duke
parents:
diff changeset
432 return y;
a61af66fc99e Initial load
duke
parents:
diff changeset
433 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
434 __HI(y) += ((k+1000)<<20);/* add k to y's exponent */
a61af66fc99e Initial load
duke
parents:
diff changeset
435 return y*twom1000;
a61af66fc99e Initial load
duke
parents:
diff changeset
436 }
a61af66fc99e Initial load
duke
parents:
diff changeset
437 }
a61af66fc99e Initial load
duke
parents:
diff changeset
438
a61af66fc99e Initial load
duke
parents:
diff changeset
439 JRT_LEAF(jdouble, SharedRuntime::dexp(jdouble x))
a61af66fc99e Initial load
duke
parents:
diff changeset
440 return __ieee754_exp(x);
a61af66fc99e Initial load
duke
parents:
diff changeset
441 JRT_END
a61af66fc99e Initial load
duke
parents:
diff changeset
442
a61af66fc99e Initial load
duke
parents:
diff changeset
443 /* __ieee754_pow(x,y) return x**y
a61af66fc99e Initial load
duke
parents:
diff changeset
444 *
a61af66fc99e Initial load
duke
parents:
diff changeset
445 * n
a61af66fc99e Initial load
duke
parents:
diff changeset
446 * Method: Let x = 2 * (1+f)
a61af66fc99e Initial load
duke
parents:
diff changeset
447 * 1. Compute and return log2(x) in two pieces:
a61af66fc99e Initial load
duke
parents:
diff changeset
448 * log2(x) = w1 + w2,
a61af66fc99e Initial load
duke
parents:
diff changeset
449 * where w1 has 53-24 = 29 bit trailing zeros.
a61af66fc99e Initial load
duke
parents:
diff changeset
450 * 2. Perform y*log2(x) = n+y' by simulating muti-precision
a61af66fc99e Initial load
duke
parents:
diff changeset
451 * arithmetic, where |y'|<=0.5.
a61af66fc99e Initial load
duke
parents:
diff changeset
452 * 3. Return x**y = 2**n*exp(y'*log2)
a61af66fc99e Initial load
duke
parents:
diff changeset
453 *
a61af66fc99e Initial load
duke
parents:
diff changeset
454 * Special cases:
a61af66fc99e Initial load
duke
parents:
diff changeset
455 * 1. (anything) ** 0 is 1
a61af66fc99e Initial load
duke
parents:
diff changeset
456 * 2. (anything) ** 1 is itself
a61af66fc99e Initial load
duke
parents:
diff changeset
457 * 3. (anything) ** NAN is NAN
a61af66fc99e Initial load
duke
parents:
diff changeset
458 * 4. NAN ** (anything except 0) is NAN
a61af66fc99e Initial load
duke
parents:
diff changeset
459 * 5. +-(|x| > 1) ** +INF is +INF
a61af66fc99e Initial load
duke
parents:
diff changeset
460 * 6. +-(|x| > 1) ** -INF is +0
a61af66fc99e Initial load
duke
parents:
diff changeset
461 * 7. +-(|x| < 1) ** +INF is +0
a61af66fc99e Initial load
duke
parents:
diff changeset
462 * 8. +-(|x| < 1) ** -INF is +INF
a61af66fc99e Initial load
duke
parents:
diff changeset
463 * 9. +-1 ** +-INF is NAN
a61af66fc99e Initial load
duke
parents:
diff changeset
464 * 10. +0 ** (+anything except 0, NAN) is +0
a61af66fc99e Initial load
duke
parents:
diff changeset
465 * 11. -0 ** (+anything except 0, NAN, odd integer) is +0
a61af66fc99e Initial load
duke
parents:
diff changeset
466 * 12. +0 ** (-anything except 0, NAN) is +INF
a61af66fc99e Initial load
duke
parents:
diff changeset
467 * 13. -0 ** (-anything except 0, NAN, odd integer) is +INF
a61af66fc99e Initial load
duke
parents:
diff changeset
468 * 14. -0 ** (odd integer) = -( +0 ** (odd integer) )
a61af66fc99e Initial load
duke
parents:
diff changeset
469 * 15. +INF ** (+anything except 0,NAN) is +INF
a61af66fc99e Initial load
duke
parents:
diff changeset
470 * 16. +INF ** (-anything except 0,NAN) is +0
a61af66fc99e Initial load
duke
parents:
diff changeset
471 * 17. -INF ** (anything) = -0 ** (-anything)
a61af66fc99e Initial load
duke
parents:
diff changeset
472 * 18. (-anything) ** (integer) is (-1)**(integer)*(+anything**integer)
a61af66fc99e Initial load
duke
parents:
diff changeset
473 * 19. (-anything except 0 and inf) ** (non-integer) is NAN
a61af66fc99e Initial load
duke
parents:
diff changeset
474 *
a61af66fc99e Initial load
duke
parents:
diff changeset
475 * Accuracy:
a61af66fc99e Initial load
duke
parents:
diff changeset
476 * pow(x,y) returns x**y nearly rounded. In particular
a61af66fc99e Initial load
duke
parents:
diff changeset
477 * pow(integer,integer)
a61af66fc99e Initial load
duke
parents:
diff changeset
478 * always returns the correct integer provided it is
a61af66fc99e Initial load
duke
parents:
diff changeset
479 * representable.
a61af66fc99e Initial load
duke
parents:
diff changeset
480 *
a61af66fc99e Initial load
duke
parents:
diff changeset
481 * Constants :
a61af66fc99e Initial load
duke
parents:
diff changeset
482 * The hexadecimal values are the intended ones for the following
a61af66fc99e Initial load
duke
parents:
diff changeset
483 * constants. The decimal values may be used, provided that the
a61af66fc99e Initial load
duke
parents:
diff changeset
484 * compiler will convert from decimal to binary accurately enough
a61af66fc99e Initial load
duke
parents:
diff changeset
485 * to produce the hexadecimal values shown.
a61af66fc99e Initial load
duke
parents:
diff changeset
486 */
a61af66fc99e Initial load
duke
parents:
diff changeset
487
a61af66fc99e Initial load
duke
parents:
diff changeset
488 static const double
a61af66fc99e Initial load
duke
parents:
diff changeset
489 bp[] = {1.0, 1.5,},
a61af66fc99e Initial load
duke
parents:
diff changeset
490 dp_h[] = { 0.0, 5.84962487220764160156e-01,}, /* 0x3FE2B803, 0x40000000 */
a61af66fc99e Initial load
duke
parents:
diff changeset
491 dp_l[] = { 0.0, 1.35003920212974897128e-08,}, /* 0x3E4CFDEB, 0x43CFD006 */
a61af66fc99e Initial load
duke
parents:
diff changeset
492 zeroX = 0.0,
a61af66fc99e Initial load
duke
parents:
diff changeset
493 two = 2.0,
a61af66fc99e Initial load
duke
parents:
diff changeset
494 two53 = 9007199254740992.0, /* 0x43400000, 0x00000000 */
a61af66fc99e Initial load
duke
parents:
diff changeset
495 /* poly coefs for (3/2)*(log(x)-2s-2/3*s**3 */
a61af66fc99e Initial load
duke
parents:
diff changeset
496 L1X = 5.99999999999994648725e-01, /* 0x3FE33333, 0x33333303 */
a61af66fc99e Initial load
duke
parents:
diff changeset
497 L2X = 4.28571428578550184252e-01, /* 0x3FDB6DB6, 0xDB6FABFF */
a61af66fc99e Initial load
duke
parents:
diff changeset
498 L3X = 3.33333329818377432918e-01, /* 0x3FD55555, 0x518F264D */
a61af66fc99e Initial load
duke
parents:
diff changeset
499 L4X = 2.72728123808534006489e-01, /* 0x3FD17460, 0xA91D4101 */
a61af66fc99e Initial load
duke
parents:
diff changeset
500 L5X = 2.30660745775561754067e-01, /* 0x3FCD864A, 0x93C9DB65 */
a61af66fc99e Initial load
duke
parents:
diff changeset
501 L6X = 2.06975017800338417784e-01, /* 0x3FCA7E28, 0x4A454EEF */
a61af66fc99e Initial load
duke
parents:
diff changeset
502 lg2 = 6.93147180559945286227e-01, /* 0x3FE62E42, 0xFEFA39EF */
a61af66fc99e Initial load
duke
parents:
diff changeset
503 lg2_h = 6.93147182464599609375e-01, /* 0x3FE62E43, 0x00000000 */
a61af66fc99e Initial load
duke
parents:
diff changeset
504 lg2_l = -1.90465429995776804525e-09, /* 0xBE205C61, 0x0CA86C39 */
a61af66fc99e Initial load
duke
parents:
diff changeset
505 ovt = 8.0085662595372944372e-0017, /* -(1024-log2(ovfl+.5ulp)) */
a61af66fc99e Initial load
duke
parents:
diff changeset
506 cp = 9.61796693925975554329e-01, /* 0x3FEEC709, 0xDC3A03FD =2/(3ln2) */
a61af66fc99e Initial load
duke
parents:
diff changeset
507 cp_h = 9.61796700954437255859e-01, /* 0x3FEEC709, 0xE0000000 =(float)cp */
a61af66fc99e Initial load
duke
parents:
diff changeset
508 cp_l = -7.02846165095275826516e-09, /* 0xBE3E2FE0, 0x145B01F5 =tail of cp_h*/
a61af66fc99e Initial load
duke
parents:
diff changeset
509 ivln2 = 1.44269504088896338700e+00, /* 0x3FF71547, 0x652B82FE =1/ln2 */
a61af66fc99e Initial load
duke
parents:
diff changeset
510 ivln2_h = 1.44269502162933349609e+00, /* 0x3FF71547, 0x60000000 =24b 1/ln2*/
a61af66fc99e Initial load
duke
parents:
diff changeset
511 ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/
a61af66fc99e Initial load
duke
parents:
diff changeset
512
a61af66fc99e Initial load
duke
parents:
diff changeset
513 double __ieee754_pow(double x, double y) {
a61af66fc99e Initial load
duke
parents:
diff changeset
514 double z,ax,z_h,z_l,p_h,p_l;
a61af66fc99e Initial load
duke
parents:
diff changeset
515 double y1,t1,t2,r,s,t,u,v,w;
a61af66fc99e Initial load
duke
parents:
diff changeset
516 int i0,i1,i,j,k,yisint,n;
a61af66fc99e Initial load
duke
parents:
diff changeset
517 int hx,hy,ix,iy;
a61af66fc99e Initial load
duke
parents:
diff changeset
518 unsigned lx,ly;
a61af66fc99e Initial load
duke
parents:
diff changeset
519
a61af66fc99e Initial load
duke
parents:
diff changeset
520 i0 = ((*(int*)&one)>>29)^1; i1=1-i0;
a61af66fc99e Initial load
duke
parents:
diff changeset
521 hx = __HI(x); lx = __LO(x);
a61af66fc99e Initial load
duke
parents:
diff changeset
522 hy = __HI(y); ly = __LO(y);
a61af66fc99e Initial load
duke
parents:
diff changeset
523 ix = hx&0x7fffffff; iy = hy&0x7fffffff;
a61af66fc99e Initial load
duke
parents:
diff changeset
524
a61af66fc99e Initial load
duke
parents:
diff changeset
525 /* y==zero: x**0 = 1 */
a61af66fc99e Initial load
duke
parents:
diff changeset
526 if((iy|ly)==0) return one;
a61af66fc99e Initial load
duke
parents:
diff changeset
527
a61af66fc99e Initial load
duke
parents:
diff changeset
528 /* +-NaN return x+y */
a61af66fc99e Initial load
duke
parents:
diff changeset
529 if(ix > 0x7ff00000 || ((ix==0x7ff00000)&&(lx!=0)) ||
a61af66fc99e Initial load
duke
parents:
diff changeset
530 iy > 0x7ff00000 || ((iy==0x7ff00000)&&(ly!=0)))
a61af66fc99e Initial load
duke
parents:
diff changeset
531 return x+y;
a61af66fc99e Initial load
duke
parents:
diff changeset
532
a61af66fc99e Initial load
duke
parents:
diff changeset
533 /* determine if y is an odd int when x < 0
a61af66fc99e Initial load
duke
parents:
diff changeset
534 * yisint = 0 ... y is not an integer
a61af66fc99e Initial load
duke
parents:
diff changeset
535 * yisint = 1 ... y is an odd int
a61af66fc99e Initial load
duke
parents:
diff changeset
536 * yisint = 2 ... y is an even int
a61af66fc99e Initial load
duke
parents:
diff changeset
537 */
a61af66fc99e Initial load
duke
parents:
diff changeset
538 yisint = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
539 if(hx<0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
540 if(iy>=0x43400000) yisint = 2; /* even integer y */
a61af66fc99e Initial load
duke
parents:
diff changeset
541 else if(iy>=0x3ff00000) {
a61af66fc99e Initial load
duke
parents:
diff changeset
542 k = (iy>>20)-0x3ff; /* exponent */
a61af66fc99e Initial load
duke
parents:
diff changeset
543 if(k>20) {
a61af66fc99e Initial load
duke
parents:
diff changeset
544 j = ly>>(52-k);
a61af66fc99e Initial load
duke
parents:
diff changeset
545 if((unsigned)(j<<(52-k))==ly) yisint = 2-(j&1);
a61af66fc99e Initial load
duke
parents:
diff changeset
546 } else if(ly==0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
547 j = iy>>(20-k);
a61af66fc99e Initial load
duke
parents:
diff changeset
548 if((j<<(20-k))==iy) yisint = 2-(j&1);
a61af66fc99e Initial load
duke
parents:
diff changeset
549 }
a61af66fc99e Initial load
duke
parents:
diff changeset
550 }
a61af66fc99e Initial load
duke
parents:
diff changeset
551 }
a61af66fc99e Initial load
duke
parents:
diff changeset
552
a61af66fc99e Initial load
duke
parents:
diff changeset
553 /* special value of y */
a61af66fc99e Initial load
duke
parents:
diff changeset
554 if(ly==0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
555 if (iy==0x7ff00000) { /* y is +-inf */
a61af66fc99e Initial load
duke
parents:
diff changeset
556 if(((ix-0x3ff00000)|lx)==0)
a61af66fc99e Initial load
duke
parents:
diff changeset
557 return y - y; /* inf**+-1 is NaN */
a61af66fc99e Initial load
duke
parents:
diff changeset
558 else if (ix >= 0x3ff00000)/* (|x|>1)**+-inf = inf,0 */
a61af66fc99e Initial load
duke
parents:
diff changeset
559 return (hy>=0)? y: zeroX;
a61af66fc99e Initial load
duke
parents:
diff changeset
560 else /* (|x|<1)**-,+inf = inf,0 */
a61af66fc99e Initial load
duke
parents:
diff changeset
561 return (hy<0)?-y: zeroX;
a61af66fc99e Initial load
duke
parents:
diff changeset
562 }
a61af66fc99e Initial load
duke
parents:
diff changeset
563 if(iy==0x3ff00000) { /* y is +-1 */
a61af66fc99e Initial load
duke
parents:
diff changeset
564 if(hy<0) return one/x; else return x;
a61af66fc99e Initial load
duke
parents:
diff changeset
565 }
a61af66fc99e Initial load
duke
parents:
diff changeset
566 if(hy==0x40000000) return x*x; /* y is 2 */
a61af66fc99e Initial load
duke
parents:
diff changeset
567 if(hy==0x3fe00000) { /* y is 0.5 */
a61af66fc99e Initial load
duke
parents:
diff changeset
568 if(hx>=0) /* x >= +0 */
a61af66fc99e Initial load
duke
parents:
diff changeset
569 return sqrt(x);
a61af66fc99e Initial load
duke
parents:
diff changeset
570 }
a61af66fc99e Initial load
duke
parents:
diff changeset
571 }
a61af66fc99e Initial load
duke
parents:
diff changeset
572
a61af66fc99e Initial load
duke
parents:
diff changeset
573 ax = fabsd(x);
a61af66fc99e Initial load
duke
parents:
diff changeset
574 /* special value of x */
a61af66fc99e Initial load
duke
parents:
diff changeset
575 if(lx==0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
576 if(ix==0x7ff00000||ix==0||ix==0x3ff00000){
a61af66fc99e Initial load
duke
parents:
diff changeset
577 z = ax; /*x is +-0,+-inf,+-1*/
a61af66fc99e Initial load
duke
parents:
diff changeset
578 if(hy<0) z = one/z; /* z = (1/|x|) */
a61af66fc99e Initial load
duke
parents:
diff changeset
579 if(hx<0) {
a61af66fc99e Initial load
duke
parents:
diff changeset
580 if(((ix-0x3ff00000)|yisint)==0) {
1681
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
581 #ifdef CAN_USE_NAN_DEFINE
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
582 z = NAN;
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
583 #else
0
a61af66fc99e Initial load
duke
parents:
diff changeset
584 z = (z-z)/(z-z); /* (-1)**non-int is NaN */
1681
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
585 #endif
0
a61af66fc99e Initial load
duke
parents:
diff changeset
586 } else if(yisint==1)
a61af66fc99e Initial load
duke
parents:
diff changeset
587 z = -1.0*z; /* (x<0)**odd = -(|x|**odd) */
a61af66fc99e Initial load
duke
parents:
diff changeset
588 }
a61af66fc99e Initial load
duke
parents:
diff changeset
589 return z;
a61af66fc99e Initial load
duke
parents:
diff changeset
590 }
a61af66fc99e Initial load
duke
parents:
diff changeset
591 }
a61af66fc99e Initial load
duke
parents:
diff changeset
592
a61af66fc99e Initial load
duke
parents:
diff changeset
593 n = (hx>>31)+1;
a61af66fc99e Initial load
duke
parents:
diff changeset
594
a61af66fc99e Initial load
duke
parents:
diff changeset
595 /* (x<0)**(non-int) is NaN */
1681
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
596 if((n|yisint)==0)
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
597 #ifdef CAN_USE_NAN_DEFINE
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
598 return NAN;
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
599 #else
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
600 return (x-x)/(x-x);
126ea7725993 6953477: Increase portability and flexibility of building Hotspot
bobv
parents: 1552
diff changeset
601 #endif
0
a61af66fc99e Initial load
duke
parents:
diff changeset
602
a61af66fc99e Initial load
duke
parents:
diff changeset
603 s = one; /* s (sign of result -ve**odd) = -1 else = 1 */
a61af66fc99e Initial load
duke
parents:
diff changeset
604 if((n|(yisint-1))==0) s = -one;/* (-ve)**(odd int) */
a61af66fc99e Initial load
duke
parents:
diff changeset
605
a61af66fc99e Initial load
duke
parents:
diff changeset
606 /* |y| is huge */
a61af66fc99e Initial load
duke
parents:
diff changeset
607 if(iy>0x41e00000) { /* if |y| > 2**31 */
a61af66fc99e Initial load
duke
parents:
diff changeset
608 if(iy>0x43f00000){ /* if |y| > 2**64, must o/uflow */
a61af66fc99e Initial load
duke
parents:
diff changeset
609 if(ix<=0x3fefffff) return (hy<0)? hugeX*hugeX:tiny*tiny;
a61af66fc99e Initial load
duke
parents:
diff changeset
610 if(ix>=0x3ff00000) return (hy>0)? hugeX*hugeX:tiny*tiny;
a61af66fc99e Initial load
duke
parents:
diff changeset
611 }
a61af66fc99e Initial load
duke
parents:
diff changeset
612 /* over/underflow if x is not close to one */
a61af66fc99e Initial load
duke
parents:
diff changeset
613 if(ix<0x3fefffff) return (hy<0)? s*hugeX*hugeX:s*tiny*tiny;
a61af66fc99e Initial load
duke
parents:
diff changeset
614 if(ix>0x3ff00000) return (hy>0)? s*hugeX*hugeX:s*tiny*tiny;
a61af66fc99e Initial load
duke
parents:
diff changeset
615 /* now |1-x| is tiny <= 2**-20, suffice to compute
a61af66fc99e Initial load
duke
parents:
diff changeset
616 log(x) by x-x^2/2+x^3/3-x^4/4 */
a61af66fc99e Initial load
duke
parents:
diff changeset
617 t = ax-one; /* t has 20 trailing zeros */
a61af66fc99e Initial load
duke
parents:
diff changeset
618 w = (t*t)*(0.5-t*(0.3333333333333333333333-t*0.25));
a61af66fc99e Initial load
duke
parents:
diff changeset
619 u = ivln2_h*t; /* ivln2_h has 21 sig. bits */
a61af66fc99e Initial load
duke
parents:
diff changeset
620 v = t*ivln2_l-w*ivln2;
a61af66fc99e Initial load
duke
parents:
diff changeset
621 t1 = u+v;
a61af66fc99e Initial load
duke
parents:
diff changeset
622 __LO(t1) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
623 t2 = v-(t1-u);
a61af66fc99e Initial load
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parents:
diff changeset
624 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
625 double ss,s2,s_h,s_l,t_h,t_l;
a61af66fc99e Initial load
duke
parents:
diff changeset
626 n = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
627 /* take care subnormal number */
a61af66fc99e Initial load
duke
parents:
diff changeset
628 if(ix<0x00100000)
a61af66fc99e Initial load
duke
parents:
diff changeset
629 {ax *= two53; n -= 53; ix = __HI(ax); }
a61af66fc99e Initial load
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parents:
diff changeset
630 n += ((ix)>>20)-0x3ff;
a61af66fc99e Initial load
duke
parents:
diff changeset
631 j = ix&0x000fffff;
a61af66fc99e Initial load
duke
parents:
diff changeset
632 /* determine interval */
a61af66fc99e Initial load
duke
parents:
diff changeset
633 ix = j|0x3ff00000; /* normalize ix */
a61af66fc99e Initial load
duke
parents:
diff changeset
634 if(j<=0x3988E) k=0; /* |x|<sqrt(3/2) */
a61af66fc99e Initial load
duke
parents:
diff changeset
635 else if(j<0xBB67A) k=1; /* |x|<sqrt(3) */
a61af66fc99e Initial load
duke
parents:
diff changeset
636 else {k=0;n+=1;ix -= 0x00100000;}
a61af66fc99e Initial load
duke
parents:
diff changeset
637 __HI(ax) = ix;
a61af66fc99e Initial load
duke
parents:
diff changeset
638
a61af66fc99e Initial load
duke
parents:
diff changeset
639 /* compute ss = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */
a61af66fc99e Initial load
duke
parents:
diff changeset
640 u = ax-bp[k]; /* bp[0]=1.0, bp[1]=1.5 */
a61af66fc99e Initial load
duke
parents:
diff changeset
641 v = one/(ax+bp[k]);
a61af66fc99e Initial load
duke
parents:
diff changeset
642 ss = u*v;
a61af66fc99e Initial load
duke
parents:
diff changeset
643 s_h = ss;
a61af66fc99e Initial load
duke
parents:
diff changeset
644 __LO(s_h) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
645 /* t_h=ax+bp[k] High */
a61af66fc99e Initial load
duke
parents:
diff changeset
646 t_h = zeroX;
a61af66fc99e Initial load
duke
parents:
diff changeset
647 __HI(t_h)=((ix>>1)|0x20000000)+0x00080000+(k<<18);
a61af66fc99e Initial load
duke
parents:
diff changeset
648 t_l = ax - (t_h-bp[k]);
a61af66fc99e Initial load
duke
parents:
diff changeset
649 s_l = v*((u-s_h*t_h)-s_h*t_l);
a61af66fc99e Initial load
duke
parents:
diff changeset
650 /* compute log(ax) */
a61af66fc99e Initial load
duke
parents:
diff changeset
651 s2 = ss*ss;
a61af66fc99e Initial load
duke
parents:
diff changeset
652 r = s2*s2*(L1X+s2*(L2X+s2*(L3X+s2*(L4X+s2*(L5X+s2*L6X)))));
a61af66fc99e Initial load
duke
parents:
diff changeset
653 r += s_l*(s_h+ss);
a61af66fc99e Initial load
duke
parents:
diff changeset
654 s2 = s_h*s_h;
a61af66fc99e Initial load
duke
parents:
diff changeset
655 t_h = 3.0+s2+r;
a61af66fc99e Initial load
duke
parents:
diff changeset
656 __LO(t_h) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
657 t_l = r-((t_h-3.0)-s2);
a61af66fc99e Initial load
duke
parents:
diff changeset
658 /* u+v = ss*(1+...) */
a61af66fc99e Initial load
duke
parents:
diff changeset
659 u = s_h*t_h;
a61af66fc99e Initial load
duke
parents:
diff changeset
660 v = s_l*t_h+t_l*ss;
a61af66fc99e Initial load
duke
parents:
diff changeset
661 /* 2/(3log2)*(ss+...) */
a61af66fc99e Initial load
duke
parents:
diff changeset
662 p_h = u+v;
a61af66fc99e Initial load
duke
parents:
diff changeset
663 __LO(p_h) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
664 p_l = v-(p_h-u);
a61af66fc99e Initial load
duke
parents:
diff changeset
665 z_h = cp_h*p_h; /* cp_h+cp_l = 2/(3*log2) */
a61af66fc99e Initial load
duke
parents:
diff changeset
666 z_l = cp_l*p_h+p_l*cp+dp_l[k];
a61af66fc99e Initial load
duke
parents:
diff changeset
667 /* log2(ax) = (ss+..)*2/(3*log2) = n + dp_h + z_h + z_l */
a61af66fc99e Initial load
duke
parents:
diff changeset
668 t = (double)n;
a61af66fc99e Initial load
duke
parents:
diff changeset
669 t1 = (((z_h+z_l)+dp_h[k])+t);
a61af66fc99e Initial load
duke
parents:
diff changeset
670 __LO(t1) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
671 t2 = z_l-(((t1-t)-dp_h[k])-z_h);
a61af66fc99e Initial load
duke
parents:
diff changeset
672 }
a61af66fc99e Initial load
duke
parents:
diff changeset
673
a61af66fc99e Initial load
duke
parents:
diff changeset
674 /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */
a61af66fc99e Initial load
duke
parents:
diff changeset
675 y1 = y;
a61af66fc99e Initial load
duke
parents:
diff changeset
676 __LO(y1) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
677 p_l = (y-y1)*t1+y*t2;
a61af66fc99e Initial load
duke
parents:
diff changeset
678 p_h = y1*t1;
a61af66fc99e Initial load
duke
parents:
diff changeset
679 z = p_l+p_h;
a61af66fc99e Initial load
duke
parents:
diff changeset
680 j = __HI(z);
a61af66fc99e Initial load
duke
parents:
diff changeset
681 i = __LO(z);
a61af66fc99e Initial load
duke
parents:
diff changeset
682 if (j>=0x40900000) { /* z >= 1024 */
a61af66fc99e Initial load
duke
parents:
diff changeset
683 if(((j-0x40900000)|i)!=0) /* if z > 1024 */
a61af66fc99e Initial load
duke
parents:
diff changeset
684 return s*hugeX*hugeX; /* overflow */
a61af66fc99e Initial load
duke
parents:
diff changeset
685 else {
a61af66fc99e Initial load
duke
parents:
diff changeset
686 if(p_l+ovt>z-p_h) return s*hugeX*hugeX; /* overflow */
a61af66fc99e Initial load
duke
parents:
diff changeset
687 }
a61af66fc99e Initial load
duke
parents:
diff changeset
688 } else if((j&0x7fffffff)>=0x4090cc00 ) { /* z <= -1075 */
a61af66fc99e Initial load
duke
parents:
diff changeset
689 if(((j-0xc090cc00)|i)!=0) /* z < -1075 */
a61af66fc99e Initial load
duke
parents:
diff changeset
690 return s*tiny*tiny; /* underflow */
a61af66fc99e Initial load
duke
parents:
diff changeset
691 else {
a61af66fc99e Initial load
duke
parents:
diff changeset
692 if(p_l<=z-p_h) return s*tiny*tiny; /* underflow */
a61af66fc99e Initial load
duke
parents:
diff changeset
693 }
a61af66fc99e Initial load
duke
parents:
diff changeset
694 }
a61af66fc99e Initial load
duke
parents:
diff changeset
695 /*
a61af66fc99e Initial load
duke
parents:
diff changeset
696 * compute 2**(p_h+p_l)
a61af66fc99e Initial load
duke
parents:
diff changeset
697 */
a61af66fc99e Initial load
duke
parents:
diff changeset
698 i = j&0x7fffffff;
a61af66fc99e Initial load
duke
parents:
diff changeset
699 k = (i>>20)-0x3ff;
a61af66fc99e Initial load
duke
parents:
diff changeset
700 n = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
701 if(i>0x3fe00000) { /* if |z| > 0.5, set n = [z+0.5] */
a61af66fc99e Initial load
duke
parents:
diff changeset
702 n = j+(0x00100000>>(k+1));
a61af66fc99e Initial load
duke
parents:
diff changeset
703 k = ((n&0x7fffffff)>>20)-0x3ff; /* new k for n */
a61af66fc99e Initial load
duke
parents:
diff changeset
704 t = zeroX;
a61af66fc99e Initial load
duke
parents:
diff changeset
705 __HI(t) = (n&~(0x000fffff>>k));
a61af66fc99e Initial load
duke
parents:
diff changeset
706 n = ((n&0x000fffff)|0x00100000)>>(20-k);
a61af66fc99e Initial load
duke
parents:
diff changeset
707 if(j<0) n = -n;
a61af66fc99e Initial load
duke
parents:
diff changeset
708 p_h -= t;
a61af66fc99e Initial load
duke
parents:
diff changeset
709 }
a61af66fc99e Initial load
duke
parents:
diff changeset
710 t = p_l+p_h;
a61af66fc99e Initial load
duke
parents:
diff changeset
711 __LO(t) = 0;
a61af66fc99e Initial load
duke
parents:
diff changeset
712 u = t*lg2_h;
a61af66fc99e Initial load
duke
parents:
diff changeset
713 v = (p_l-(t-p_h))*lg2+t*lg2_l;
a61af66fc99e Initial load
duke
parents:
diff changeset
714 z = u+v;
a61af66fc99e Initial load
duke
parents:
diff changeset
715 w = v-(z-u);
a61af66fc99e Initial load
duke
parents:
diff changeset
716 t = z*z;
a61af66fc99e Initial load
duke
parents:
diff changeset
717 t1 = z - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
a61af66fc99e Initial load
duke
parents:
diff changeset
718 r = (z*t1)/(t1-two)-(w+z*w);
a61af66fc99e Initial load
duke
parents:
diff changeset
719 z = one-(r-z);
a61af66fc99e Initial load
duke
parents:
diff changeset
720 j = __HI(z);
a61af66fc99e Initial load
duke
parents:
diff changeset
721 j += (n<<20);
a61af66fc99e Initial load
duke
parents:
diff changeset
722 if((j>>20)<=0) z = scalbn(z,n); /* subnormal output */
a61af66fc99e Initial load
duke
parents:
diff changeset
723 else __HI(z) += (n<<20);
a61af66fc99e Initial load
duke
parents:
diff changeset
724 return s*z;
a61af66fc99e Initial load
duke
parents:
diff changeset
725 }
a61af66fc99e Initial load
duke
parents:
diff changeset
726
a61af66fc99e Initial load
duke
parents:
diff changeset
727
a61af66fc99e Initial load
duke
parents:
diff changeset
728 JRT_LEAF(jdouble, SharedRuntime::dpow(jdouble x, jdouble y))
a61af66fc99e Initial load
duke
parents:
diff changeset
729 return __ieee754_pow(x, y);
a61af66fc99e Initial load
duke
parents:
diff changeset
730 JRT_END
a61af66fc99e Initial load
duke
parents:
diff changeset
731
a61af66fc99e Initial load
duke
parents:
diff changeset
732 #ifdef WIN32
a61af66fc99e Initial load
duke
parents:
diff changeset
733 # pragma optimize ( "", on )
a61af66fc99e Initial load
duke
parents:
diff changeset
734 #endif