| /* |
| * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP |
| #define SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP |
| |
| #include <math.h> |
| |
| // Used to access the lower/higher 32 bits of a double |
| typedef union { |
| double d; |
| struct { |
| #ifdef VM_LITTLE_ENDIAN |
| int lo; |
| int hi; |
| #else |
| int hi; |
| int lo; |
| #endif |
| } split; |
| } DoubleIntConv; |
| |
| static inline int high(double d) { |
| DoubleIntConv x; |
| x.d = d; |
| return x.split.hi; |
| } |
| |
| static inline int low(double d) { |
| DoubleIntConv x; |
| x.d = d; |
| return x.split.lo; |
| } |
| |
| static inline void set_high(double* d, int high) { |
| DoubleIntConv conv; |
| conv.d = *d; |
| conv.split.hi = high; |
| *d = conv.d; |
| } |
| |
| static inline void set_low(double* d, int low) { |
| DoubleIntConv conv; |
| conv.d = *d; |
| conv.split.lo = low; |
| *d = conv.d; |
| } |
| |
| static double copysignA(double x, double y) { |
| DoubleIntConv convX; |
| convX.d = x; |
| convX.split.hi = (convX.split.hi & 0x7fffffff) | (high(y) & 0x80000000); |
| return convX.d; |
| } |
| |
| /* |
| * ==================================================== |
| * Copyright (c) 1998 Oracle and/or its affiliates. All rights reserved. |
| * |
| * Developed at SunSoft, a Sun Microsystems, Inc. business. |
| * Permission to use, copy, modify, and distribute this |
| * software is freely granted, provided that this notice |
| * is preserved. |
| * ==================================================== |
| */ |
| |
| /* |
| * scalbn (double x, int n) |
| * scalbn(x,n) returns x* 2**n computed by exponent |
| * manipulation rather than by actually performing an |
| * exponentiation or a multiplication. |
| */ |
| |
| static const double |
| two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */ |
| twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */ |
| hugeX = 1.0e+300, |
| tiny = 1.0e-300; |
| |
| static double scalbnA(double x, int n) { |
| int k,hx,lx; |
| hx = high(x); |
| lx = low(x); |
| k = (hx&0x7ff00000)>>20; /* extract exponent */ |
| if (k==0) { /* 0 or subnormal x */ |
| if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ |
| x *= two54; |
| hx = high(x); |
| k = ((hx&0x7ff00000)>>20) - 54; |
| if (n< -50000) return tiny*x; /*underflow*/ |
| } |
| if (k==0x7ff) return x+x; /* NaN or Inf */ |
| k = k+n; |
| if (k > 0x7fe) return hugeX*copysignA(hugeX,x); /* overflow */ |
| if (k > 0) { /* normal result */ |
| set_high(&x, (hx&0x800fffff)|(k<<20)); |
| return x; |
| } |
| if (k <= -54) { |
| if (n > 50000) /* in case integer overflow in n+k */ |
| return hugeX*copysignA(hugeX,x); /*overflow*/ |
| else return tiny*copysignA(tiny,x); /*underflow*/ |
| } |
| k += 54; /* subnormal result */ |
| set_high(&x, (hx&0x800fffff)|(k<<20)); |
| return x*twom54; |
| } |
| |
| #endif // SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP |