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50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
/* frexpq.c -- __float128 version of s_frexp.c.
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* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* for non-zero x
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* x = frexpq(arg,&exp);
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* return a __float128 fp quantity x such that 0.5 <= |x| <1.0
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* and the corresponding binary exponent "exp". That is
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* arg = x*2^exp.
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* If arg is inf, 0.0, or NaN, then frexpq(arg,&exp) returns arg
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* with *exp=0.
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*/
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#include "quadmath-imp.h"
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static const __float128
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two114 = 2.0769187434139310514121985316880384E+34Q; /* 0x4071000000000000, 0 */
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__float128
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frexpq (__float128 x, int *eptr)
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{
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uint64_t hx, lx, ix;
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GET_FLT128_WORDS64(hx,lx,x);
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ix = 0x7fffffffffffffffULL&hx;
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*eptr = 0;
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if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x; /* 0,inf,nan */
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if (ix<0x0001000000000000ULL) { /* subnormal */
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x *= two114;
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GET_FLT128_MSW64(hx,x);
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ix = hx&0x7fffffffffffffffULL;
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*eptr = -114;
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}
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*eptr += (ix>>48)-16382;
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hx = (hx&0x8000ffffffffffffULL) | 0x3ffe000000000000ULL;
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SET_FLT128_MSW64(x,hx);
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return x;
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}
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