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src/share/vm/runtime/sharedRuntimeMath.hpp@631c3a4ea10c
src/share/vm/runtime/sharedRuntimeMath.hpp
Thu, 22 May 2014 11:36:23 -0400
- author
- lfoltan
- date
- Thu, 22 May 2014 11:36:23 -0400
- changeset 7000
- 631c3a4ea10c
- child 7002
- a073be2ce5c2
- permissions
- -rw-r--r--
8043301: Duplicate definitions in vm/runtime/sharedRuntimeTrans.cpp versus math.h in VS2013
Summary: Factor out definitions of copysignA and scalbnA into new file sharedRuntimeMath.hpp
Reviewed-by: kvn
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 */
25 #ifndef SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP
26 #define SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP
28 #include <math.h>
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
41 static double copysignA(double x, double y) {
42 __HI(x) = (__HI(x)&0x7fffffff)|(__HI(y)&0x80000000);
43 return x;
44 }
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 */
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 */
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;
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 }
97 #endif // SHARE_VM_RUNTIME_SHAREDRUNTIMEMATH_HPP
