Mercurial > hg > CbC > CbC_gcc

comparison libquadmath/math/scalblnq.c @ 111:04ced10e8804

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents 561a7518be6b
children 1830386684a0
comparison
equal deleted inserted replaced
68:561a7518be6b 111:04ced10e8804
1 /* s_scalblnl.c -- long double version of s_scalbn.c. 1 /* scalblnq.c -- __float128 version of s_scalbn.c.
2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. 2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
3 */ 3 */
4 4
5 /* 5 /*
6 * ==================================================== 6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 * 8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business. 9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this 10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice 11 * software is freely granted, provided that this notice
12 * is preserved. 12 * is preserved.
13 * ==================================================== 13 * ====================================================
14 */
15
16 /*
17 * scalblnq (_float128 x, long int n)
18 * scalblnq(x,n) returns x* 2**n computed by exponent
19 * manipulation rather than by actually performing an
20 * exponentiation or a multiplication.
14 */ 21 */
15 22
16 #include "quadmath-imp.h" 23 #include "quadmath-imp.h"
17 24
18 static const __float128 25 static const __float128
32 x *= two114; 39 x *= two114;
33 GET_FLT128_MSW64(hx,x); 40 GET_FLT128_MSW64(hx,x);
34 k = ((hx>>48)&0x7fff) - 114; 41 k = ((hx>>48)&0x7fff) - 114;
35 } 42 }
36 if (k==0x7fff) return x+x; /* NaN or Inf */ 43 if (k==0x7fff) return x+x; /* NaN or Inf */
44 if (n< -50000) return tiny*copysignq(tiny,x); /*underflow*/
45 if (n> 50000 || k+n > 0x7ffe)
46 return huge*copysignq(huge,x); /* overflow */
47 /* Now k and n are bounded we know that k = k+n does not
48 overflow. */
37 k = k+n; 49 k = k+n;
38 if (n> 50000 || k > 0x7ffe)
39 return huge*copysignq(huge,x); /* overflow */
40 if (n< -50000) return tiny*copysignq(tiny,x); /*underflow*/
41 if (k > 0) /* normal result */ 50 if (k > 0) /* normal result */
42 {SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); return x;} 51 {SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); return x;}
43 if (k <= -114) 52 if (k <= -114)
44 return tiny*copysignq(tiny,x); /*underflow*/ 53 return tiny*copysignq(tiny,x); /*underflow*/
45 k += 114; /* subnormal result */ 54 k += 114; /* subnormal result */