diff options
Diffstat (limited to 'libquadmath/math/scalblnq.c')
-rw-r--r-- | libquadmath/math/scalblnq.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/libquadmath/math/scalblnq.c b/libquadmath/math/scalblnq.c new file mode 100644 index 000000000..75997f688 --- /dev/null +++ b/libquadmath/math/scalblnq.c @@ -0,0 +1,48 @@ +/* s_scalblnl.c -- long double version of s_scalbn.c. + * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. + */ + +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "quadmath-imp.h" + +static const __float128 +two114 = 2.0769187434139310514121985316880384E+34Q, /* 0x4071000000000000, 0 */ +twom114 = 4.8148248609680896326399448564623183E-35Q, /* 0x3F8D000000000000, 0 */ +huge = 1.0E+4900Q, +tiny = 1.0E-4900Q; + +__float128 +scalblnq (__float128 x, long int n) +{ + int64_t k,hx,lx; + GET_FLT128_WORDS64(hx,lx,x); + k = (hx>>48)&0x7fff; /* extract exponent */ + if (k==0) { /* 0 or subnormal x */ + if ((lx|(hx&0x7fffffffffffffffULL))==0) return x; /* +-0 */ + x *= two114; + GET_FLT128_MSW64(hx,x); + k = ((hx>>48)&0x7fff) - 114; + } + if (k==0x7fff) return x+x; /* NaN or Inf */ + k = k+n; + if (n> 50000 || k > 0x7ffe) + return huge*copysignq(huge,x); /* overflow */ + if (n< -50000) return tiny*copysignq(tiny,x); /*underflow*/ + if (k > 0) /* normal result */ + {SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); return x;} + if (k <= -114) + return tiny*copysignq(tiny,x); /*underflow*/ + k += 114; /* subnormal result */ + SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); + return x*twom114; +} |