0058967bb0
2006-01-31 Richard Guenther <rguenther@suse.de> Paolo Bonzini <bonzini@gnu.org> * Makefile.def (target_modules): Add libgcc-math target module. * configure.in (target_libraries): Add libgcc-math target library. (--enable-libgcc-math): New configure switch. * Makefile.in: Re-generate. * configure: Re-generate. * libgcc-math: New toplevel directory. * doc/install.texi (--disable-libgcc-math): Document. libgcc-math/ * configure.ac: New file. * Makefile.am: Likewise. * configure: New generated file. * Makefile.in: Likewise. * aclocal.m4: Likewise. * libtool-version: New file. * include/ieee754.h: New file. * include/libc-symbols.h: Likewise. * include/math_private.h: Likewise. * i386/Makefile.am: New file. * i386/Makefile.in: New generated file. * i386/sse2.h: New file. * i386/endian.h: Likewise. * i386/sse2.map: Linker script for SSE2 ABI math intrinsics. * flt-32/: Import from glibc. * dbl-64/: Likewise. Co-Authored-By: Paolo Bonzini <bonzini@gnu.org> From-SVN: r110434
71 lines
2.0 KiB
C
71 lines
2.0 KiB
C
/* @(#)s_scalbn.c 5.1 93/09/24 */
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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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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: s_scalbn.c,v 1.8 1995/05/10 20:48:08 jtc Exp $";
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#endif
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/*
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* scalbn (double x, int n)
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* scalbn(x,n) returns x* 2**n computed by exponent
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* manipulation rather than by actually performing an
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* exponentiation or a multiplication.
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*/
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const double
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#else
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static double
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#endif
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two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
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twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
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huge = 1.0e+300,
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tiny = 1.0e-300;
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#ifdef __STDC__
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double __scalbn (double x, int n)
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#else
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double __scalbn (x,n)
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double x; int n;
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#endif
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{
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int32_t k,hx,lx;
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EXTRACT_WORDS(hx,lx,x);
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k = (hx&0x7ff00000)>>20; /* extract exponent */
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if (k==0) { /* 0 or subnormal x */
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if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
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x *= two54;
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GET_HIGH_WORD(hx,x);
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k = ((hx&0x7ff00000)>>20) - 54;
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}
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if (k==0x7ff) return x+x; /* NaN or Inf */
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k = k+n;
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if (n> 50000 || k > 0x7fe)
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return huge*__builtin_copysign(huge,x); /* overflow */
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if (n< -50000) return tiny*__builtin_copysign(tiny,x); /*underflow*/
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if (k > 0) /* normal result */
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{SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); return x;}
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if (k <= -54)
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return tiny*__builtin_copysign(tiny,x); /*underflow*/
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k += 54; /* subnormal result */
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SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20));
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return x*twom54;
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}
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weak_alias (__scalbn, scalbn)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__scalbn, __scalbnl)
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weak_alias (__scalbn, scalbnl)
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#endif
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