Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/runtime/sharedRuntimeMath.hpp
src/share/vm/runtime/sharedRuntimeMath.hpp
- changeset 7000
- 631c3a4ea10c
- child 7002
- a073be2ce5c2
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| 6999:cabe05c85665 | 7000:631c3a4ea10c |
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| 1 /* | |
| 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. | |
| 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
| 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 20 * or visit www.oracle.com if you need additional information or have any | |
| 21 * questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 #ifndef SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP | |
| 26 #define SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP | |
| 27 | |
| 28 #include <math.h> | |
| 29 | |
| 30 // VM_LITTLE_ENDIAN is #defined appropriately in the Makefiles | |
| 31 // [jk] this is not 100% correct because the float word order may different | |
| 32 // from the byte order (e.g. on ARM FPA) | |
| 33 #ifdef VM_LITTLE_ENDIAN | |
| 34 # define __HI(x) *(1+(int*)&x) | |
| 35 # define __LO(x) *(int*)&x | |
| 36 #else | |
| 37 # define __HI(x) *(int*)&x | |
| 38 # define __LO(x) *(1+(int*)&x) | |
| 39 #endif | |
| 40 | |
| 41 static double copysignA(double x, double y) { | |
| 42 __HI(x) = (__HI(x)&0x7fffffff)|(__HI(y)&0x80000000); | |
| 43 return x; | |
| 44 } | |
| 45 | |
| 46 /* | |
| 47 * ==================================================== | |
| 48 * Copyright (c) 1998 Oracle and/or its affiliates. All rights reserved. | |
| 49 * | |
| 50 * Developed at SunSoft, a Sun Microsystems, Inc. business. | |
| 51 * Permission to use, copy, modify, and distribute this | |
| 52 * software is freely granted, provided that this notice | |
| 53 * is preserved. | |
| 54 * ==================================================== | |
| 55 */ | |
| 56 | |
| 57 /* | |
| 58 * scalbn (double x, int n) | |
| 59 * scalbn(x,n) returns x* 2**n computed by exponent | |
| 60 * manipulation rather than by actually performing an | |
| 61 * exponentiation or a multiplication. | |
| 62 */ | |
| 63 | |
| 64 static const double | |
| 65 two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */ | |
| 66 twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */ | |
| 67 hugeX = 1.0e+300, | |
| 68 tiny = 1.0e-300; | |
| 69 | |
| 70 static double scalbnA (double x, int n) { | |
| 71 int k,hx,lx; | |
| 72 hx = __HI(x); | |
| 73 lx = __LO(x); | |
| 74 k = (hx&0x7ff00000)>>20; /* extract exponent */ | |
| 75 if (k==0) { /* 0 or subnormal x */ | |
| 76 if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ | |
| 77 x *= two54; | |
| 78 hx = __HI(x); | |
| 79 k = ((hx&0x7ff00000)>>20) - 54; | |
| 80 if (n< -50000) return tiny*x; /*underflow*/ | |
| 81 } | |
| 82 if (k==0x7ff) return x+x; /* NaN or Inf */ | |
| 83 k = k+n; | |
| 84 if (k > 0x7fe) return hugeX*copysignA(hugeX,x); /* overflow */ | |
| 85 if (k > 0) /* normal result */ | |
| 86 {__HI(x) = (hx&0x800fffff)|(k<<20); return x;} | |
| 87 if (k <= -54) { | |
| 88 if (n > 50000) /* in case integer overflow in n+k */ | |
| 89 return hugeX*copysignA(hugeX,x); /*overflow*/ | |
| 90 else return tiny*copysignA(tiny,x); /*underflow*/ | |
| 91 } | |
| 92 k += 54; /* subnormal result */ | |
| 93 __HI(x) = (hx&0x800fffff)|(k<<20); | |
| 94 return x*twom54; | |
| 95 } | |
| 96 | |
| 97 #endif // SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP |
