diff --git a/lib/msun/src/s_scalbn.c b/lib/msun/src/s_scalbn.c --- a/lib/msun/src/s_scalbn.c +++ b/lib/msun/src/s_scalbn.c @@ -1,63 +1,35 @@ -/* @(#)s_scalbn.c 5.1 93/09/24 */ -/* - * ==================================================== - * 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 +#include -#include -__FBSDID("$FreeBSD$"); - -/* - * scalbn (double x, int n) - * scalbn(x,n) returns x* 2**n computed by exponent - * manipulation rather than by actually performing an - * exponentiation or a multiplication. - */ - -#include - -#include "math.h" -#include "math_private.h" - -static const double -two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */ -twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */ -huge = 1.0e+300, -tiny = 1.0e-300; - -double -scalbn (double x, int n) +double scalbn(double x, int n) { - int32_t k,hx,lx; - EXTRACT_WORDS(hx,lx,x); - k = (hx&0x7ff00000)>>20; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ - x *= two54; - GET_HIGH_WORD(hx,x); - k = ((hx&0x7ff00000)>>20) - 54; - if (n< -50000) return tiny*x; /*underflow*/ - } - if (k==0x7ff) return x+x; /* NaN or Inf */ - k = k+n; - if (k > 0x7fe) return huge*copysign(huge,x); /* overflow */ - if (k > 0) /* normal result */ - {SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); return x;} - if (k <= -54) { - if (n > 50000) /* in case integer overflow in n+k */ - return huge*copysign(huge,x); /*overflow*/ - else - return tiny*copysign(tiny,x); /*underflow*/ + union {double f; uint64_t i;} u; + double_t y = x; + + if (n > 1023) { + y *= 0x1p1023; + n -= 1023; + if (n > 1023) { + y *= 0x1p1023; + n -= 1023; + if (n > 1023) + n = 1023; + } + } else if (n < -1022) { + /* make sure final n < -53 to avoid double + rounding in the subnormal range */ + y *= 0x1p-1022 * 0x1p53; + n += 1022 - 53; + if (n < -1022) { + y *= 0x1p-1022 * 0x1p53; + n += 1022 - 53; + if (n < -1022) + n = -1022; + } } - k += 54; /* subnormal result */ - SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); - return x*twom54; + u.i = (uint64_t)(0x3ff+n)<<52; + x = y * u.f; + return x; } #if (LDBL_MANT_DIG == 53) diff --git a/lib/msun/src/s_scalbnf.c b/lib/msun/src/s_scalbnf.c --- a/lib/msun/src/s_scalbnf.c +++ b/lib/msun/src/s_scalbnf.c @@ -1,57 +1,33 @@ -/* s_scalbnf.c -- float version of s_scalbn.c. - * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. - */ +#include +#include -/* - * ==================================================== - * 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 -__FBSDID("$FreeBSD$"); - -#include "math.h" -#include "math_private.h" - -static const float -two25 = 3.355443200e+07, /* 0x4c000000 */ -twom25 = 2.9802322388e-08, /* 0x33000000 */ -huge = 1.0e+30, -tiny = 1.0e-30; - -float -scalbnf (float x, int n) +float scalbnf(float x, int n) { - int32_t k,ix; - GET_FLOAT_WORD(ix,x); - k = (ix&0x7f800000)>>23; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((ix&0x7fffffff)==0) return x; /* +-0 */ - x *= two25; - GET_FLOAT_WORD(ix,x); - k = ((ix&0x7f800000)>>23) - 25; - if (n< -50000) return tiny*x; /*underflow*/ - } - if (k==0xff) return x+x; /* NaN or Inf */ - k = k+n; - if (k > 0xfe) return huge*copysignf(huge,x); /* overflow */ - if (k > 0) /* normal result */ - {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;} - if (k <= -25) { - if (n > 50000) /* in case integer overflow in n+k */ - return huge*copysignf(huge,x); /*overflow*/ - else - return tiny*copysignf(tiny,x); /*underflow*/ + union {float f; uint32_t i;} u; + float_t y = x; + + if (n > 127) { + y *= 0x1p127f; + n -= 127; + if (n > 127) { + y *= 0x1p127f; + n -= 127; + if (n > 127) + n = 127; + } + } else if (n < -126) { + y *= 0x1p-126f * 0x1p24f; + n += 126 - 24; + if (n < -126) { + y *= 0x1p-126f * 0x1p24f; + n += 126 - 24; + if (n < -126) + n = -126; + } } - k += 25; /* subnormal result */ - SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); - return x*twom25; + u.i = (uint32_t)(0x7f+n)<<23; + x = y * u.f; + return x; } __strong_reference(scalbnf, ldexpf); diff --git a/lib/msun/src/s_scalbnl.c b/lib/msun/src/s_scalbnl.c --- a/lib/msun/src/s_scalbnl.c +++ b/lib/msun/src/s_scalbnl.c @@ -1,18 +1,7 @@ -/* @(#)s_scalbn.c 5.1 93/09/24 */ -/* - * ==================================================== - * 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 -__FBSDID("$FreeBSD$"); - +#include +#include +#include "math_private.h" +#include "fpmath.h" /* * scalbnl (long double x, int n) * scalbnl(x,n) returns x* 2**n computed by exponent @@ -20,52 +9,39 @@ * exponentiation or a multiplication. */ -/* - * We assume that a long double has a 15-bit exponent. On systems - * where long double is the same as double, scalbnl() is an alias - * for scalbn(), so we don't use this routine. - */ - -#include -#include - -#include "fpmath.h" - -#if LDBL_MAX_EXP != 0x4000 -#error "Unsupported long double format" -#endif - -static const long double -huge = 0x1p16000L, -tiny = 0x1p-16000L; - -long double -scalbnl (long double x, int n) +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 +long double scalbnl(long double x, int n) +{ + return scalbn(x, n); +} +#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 +long double scalbnl(long double x, int n) { union IEEEl2bits u; - int k; - u.e = x; - k = u.bits.exp; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((u.bits.manh|u.bits.manl)==0) return x; /* +-0 */ - u.e *= 0x1p+128; - k = u.bits.exp - 128; - if (n< -50000) return tiny*x; /*underflow*/ - } - if (k==0x7fff) return x+x; /* NaN or Inf */ - k = k+n; - if (k >= 0x7fff) return huge*copysignl(huge,x); /* overflow */ - if (k > 0) /* normal result */ - {u.bits.exp = k; return u.e;} - if (k <= -128) { - if (n > 50000) /* in case integer overflow in n+k */ - return huge*copysign(huge,x); /*overflow*/ - else - return tiny*copysign(tiny,x); /*underflow*/ + + if (n > 16383) { + x *= 0x1p16383L; + n -= 16383; + if (n > 16383) { + x *= 0x1p16383L; + n -= 16383; + if (n > 16383) + n = 16383; + } + } else if (n < -16382) { + x *= 0x1p-16382L * 0x1p113L; + n += 16382 - 113; + if (n < -16382) { + x *= 0x1p-16382L * 0x1p113L; + n += 16382 - 113; + if (n < -16382) + n = -16382; + } } - k += 128; /* subnormal result */ - u.bits.exp = k; - return u.e*0x1p-128; + u.e = 1.0; + u.xbits.expsign = 0x3fff + n; + return x * u.e; } +#endif __strong_reference(scalbnl, ldexpl);