.TH "lib/real/scalbn.c" 3 "Tue Jan 24 2017" "Version 1.6.2" "amath" \" -*- nroff -*-
.ad l
.nh
.SH NAME
lib/real/scalbn.c \- 
.SH SYNOPSIS
.br
.PP
\fC#include 'prim\&.h'\fP
.br
\fC#include 'math\&.h'\fP
.br

.SS "Functions"

.in +1c
.ti -1c
.RI "double \fBscalbn\fP (double x, int n)"
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.in -1c
.SS "Variables"

.in +1c
.ti -1c
.RI "static const double \fBtwo54\fP = 1\&.80143985094819840000e+16"
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.ti -1c
.RI "static const double \fBtwom54\fP = 5\&.55111512312578270212e\-17"
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.ti -1c
.RI "static const double \fBhuge\fP = 1\&.0e+300"
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.ti -1c
.RI "static const double \fBtiny\fP = 1\&.0e\-300"
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.in -1c
.SH "Function Documentation"
.PP 
.SS "double scalbn (double x, int n)"

.PP
Definition at line 60 of file scalbn\&.c\&.
.PP
References huge, tiny, two54, and twom54\&.
.PP
Referenced by __kernel_rem_pio2(), and pow()\&.
.PP
.nf
61 {
62     sword  k,hx,lx;
63     EXTRACT_WORDS(hx,lx,x);
64     k = (hx&0x7ff00000)>>20;        /* extract exponent */
65     if (k==0) {             /* 0 or subnormal x */
66         if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
67         x *= two54;
68         GET_HIGH_WORD(hx,x);
69         k = ((hx&0x7ff00000)>>20) - 54;
70         if (n< -50000) return tiny*x;   /*underflow*/
71     }
72     if (k==0x7ff) return x+x;       /* NaN or Inf */
73     k = k+n;
74     if (k >  0x7fe) return huge*copysign(huge,x); /* overflow  */
75     if (k > 0)              /* normal result */
76     {
77         SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20));
78         return x;
79     }
80     if (k <= -54) {
81         if (n > 50000)      /* in case integer overflow in n+k */
82             return huge*copysign(huge,x);   /*overflow*/
83         else return tiny*copysign(tiny,x);  /*underflow*/
84     }
85     k += 54;                /* subnormal result */
86     SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20));
87     return x*twom54;
88 }
.fi
.SH "Variable Documentation"
.PP 
.SS "const double huge = 1\&.0e+300\fC [static]\fP"

.PP
Definition at line 57 of file scalbn\&.c\&.
.PP
Referenced by scalbn()\&.
.SS "const double tiny = 1\&.0e\-300\fC [static]\fP"

.PP
Definition at line 58 of file scalbn\&.c\&.
.PP
Referenced by scalbn()\&.
.SS "const double two54 = 1\&.80143985094819840000e+16\fC [static]\fP"

.PP
Definition at line 55 of file scalbn\&.c\&.
.PP
Referenced by scalbn()\&.
.SS "const double twom54 = 5\&.55111512312578270212e\-17\fC [static]\fP"

.PP
Definition at line 56 of file scalbn\&.c\&.
.PP
Referenced by scalbn()\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for amath from the source code\&.