From 601d294296e1de9fc423700db00bccc04a2bf50d Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 6 Jun 2001 12:55:46 +0000 Subject: Update. 2001-06-04 Bruno Haible * iconv/loop.c (UNICODE_TAG_HANDLER): New macro. * iconv/gconv_simple.c (__gconv_transform_internal_ascii): Invoke UNICODE_TAG_HANDLER. (__gconv_transform_internal_ucs2): Likewise. (__gconv_transform_internal_ucs2reverse): Likewise. * iconvdata/8bit-gap.c (BODY for TO_LOOP): Invoke UNICODE_TAG_HANDLER. * iconvdata/8bit-generic.c (BODY for TO_LOOP): Likewise. * iconvdata/ansi_x3.110.c (BODY for TO_LOOP): Likewise. * iconvdata/big5.c (BODY for TO_LOOP): Likewise. * iconvdata/big5hkscs.c (BODY for TO_LOOP): Likewise. * iconvdata/cp1255.c (BODY for TO_LOOP): Likewise. * iconvdata/cp1258.c (BODY for TO_LOOP): Likewise. * iconvdata/euc-cn.c (BODY for TO_LOOP): Likewise. * iconvdata/euc-jp.c (BODY for TO_LOOP): Likewise. * iconvdata/euc-kr.c (BODY for TO_LOOP): Likewise. * iconvdata/euc-tw.c (BODY for TO_LOOP): Likewise. * iconvdata/gbk.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm930.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm932.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm933.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm935.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm937.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm939.c (BODY for TO_LOOP): Likewise. * iconvdata/ibm943.c (BODY for TO_LOOP): Likewise. * iconvdata/iso646.c (BODY for TO_LOOP): Likewise. * iconvdata/iso8859-1.c (BODY for TO_LOOP): Likewise. * iconvdata/iso_6937.c (BODY for TO_LOOP): Likewise. * iconvdata/iso_6937-2.c (BODY for TO_LOOP): Likewise. * iconvdata/iso-2022-cn.c (BODY for TO_LOOP): Likewise. * iconvdata/iso-2022-cn-ext.c (BODY for TO_LOOP): Likewise. * iconvdata/iso-2022-kr.c (BODY for TO_LOOP): Likewise. * iconvdata/johab.c (BODY for TO_LOOP): Likewise. * iconvdata/sjis.c (BODY for TO_LOOP): Likewise. * iconvdata/t.61.c (BODY for TO_LOOP): Likewise. * iconvdata/uhc.c (BODY for TO_LOOP): Likewise. * iconvdata/unicode.c (BODY for TO_LOOP): Likewise. * iconvdata/iso-2022-jp.c (TAG_none, TAG_language, TAG_language_j, TAG_language_ja, TAG_language_k, TAG_language_ko, TAG_language_z, TAG_language_zh, CURRENT_TAG_MASK): New enum values. (EMIT_SHIFT_TO_INIT): Don't emit an escape sequence if ASCII_set is already selected but set2 or tag are set. (conversion): New enum type. (cvlist_t): New type. (CVLIST, CVLIST_FIRST, CVLIST_REST): New macros. (conversion_lists): New array. (BODY for TO_LOOP): Keep track of Unicode 3.1 language tag. If "ja", prefer conversion to Japanese character sets. If "zh", prefer conversion to GB2312. If "ko", prefer conversion to KSC5601. Small optimizations. (INIT_PARAMS): Add tag. (UPDATE_PARAMS): Add tag. 2001-06-04 Bruno Haible * locale/programs/locfile.c (write_locale_data): Before creat(), unlink the file, to avoid crashing the processes that mmap it. Change a double slash to a single slash. Free fname in case of error return. 2001-06-02 Jakub Jelinek * sysdeps/i386/fpu/s_frexpl.S (__frexpl): Mostly revert 2000-12-03 changes, do the special handling for denormal numbers, not for normalized numbers (patch by ). * math/test-misc.c (main): Test frexpl with denormal arguments. 2001-06-04 Jakub Jelinek * math/libm-test.inc (llround_test): Add two new llround tests. * sysdeps/ieee754/ldbl-96/s_llroundl.c (__llroundl): Don't allow overflow when rounding away from zero. 2001-06-04 Jakub Jelinek * math/Makefile (libm-calls): Add e_log2, w_log2, remove s_log2. * math/math_private.h (__ieee754_log2, __ieee754_log2f, __ieee754_log2l): New prototypes. * sysdeps/generic/w_log2.c: New file. * sysdeps/generic/w_log2f.c: New file. * sysdeps/generic/w_log2l.c: New file. * sysdeps/generic/s_log2l.c: Move... * sysdeps/generic/e_log2l.c: ...to here. Rename to __ieee754_log2l. * sysdeps/ieee754/k_standard.c (__kernel_standard): Handle log2(0) and log2(x < 0). * sysdeps/i386/fpu/s_log2.S: Move... * sysdeps/i386/fpu/e_log2.S: ...to here. Rename to __ieee754_log2. * sysdeps/i386/fpu/s_log2f.S: Move... * sysdeps/i386/fpu/e_log2f.S: ...to here. Rename to __ieee754_log2f. * sysdeps/i386/fpu/s_log2l.S: Move... * sysdeps/i386/fpu/e_log2l.S: ...to here. Rename to __ieee754_log2l. * sysdeps/m68k/fpu/s_log2.S: Move... * sysdeps/m68k/fpu/e_log2.S: ...to here. Rename to __ieee754_log2. * sysdeps/m68k/fpu/s_log2f.S: Move... * sysdeps/m68k/fpu/e_log2f.S: ...to here. Rename to __ieee754_log2f. * sysdeps/m68k/fpu/s_log2l.S: Move... * sysdeps/m68k/fpu/e_log2l.S: ...to here. Rename to __ieee754_log2l. * sysdeps/ieee754/dbl-64/s_log2.c: Move... * sysdeps/ieee754/dbl-64/e_log2.c: ...to here. Rename to __ieee754_log2. * sysdeps/ieee754/flt-32/s_log2f.c: Move... * sysdeps/ieee754/flt-32/e_log2f.c: ...to here. Rename to __ieee754_log2f. 2001-06-04 Jakub Jelinek * sysdeps/generic/w_exp2.c (u_threshold): Lower threshold so that even arguments which result in denormalized exp2 are accepted. (__exp2): Arguments equal to u_threshold already result into underflow. * sysdeps/generic/w_exp2f.c (u_threshold, __exp2f): Likewise. * sysdeps/generic/w_exp2l.c (u_threshold, __exp2l): Likewise. * sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Lomark was too low, with corrected lowmark use greaterequal, not greater. * sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise. 2001-06-04 Jakub Jelinek * math/libm-test.inc (ilogb_test): Test that ilogb(+-Inf) == INT_MAX. * sysdeps/i386/fpu/s_ilogb.S (__ilogb): Return INT_MAX for +-Inf. * sysdeps/i386/fpu/s_ilogbf.S (__ilogbf): Likewise. * sysdeps/i386/fpu/s_ilogbl.S (__ilogbl): Likewise. * sysdeps/ieee754/dbl-64/s_ilogb.c (__ilogb): Likewise. * sysdeps/ieee754/flt-32/s_ilogbf.c (__ilogbf): Likewise. * sysdeps/ieee754/ldbl-128/s_ilogbl.c (__ilogbl): Likewise. * sysdeps/ieee754/ldbl-96/s_ilogbl.c (__ilogbl): Likewise. 2001-06-04 Jakub Jelinek * sysdeps/generic/w_coshl.c (__coshl): Test if finite argument gave non-finite result instead of using constant in generic version. * sysdeps/generic/w_coshf.c (__coshf): Likewise. * sysdeps/generic/w_cosh.c (__cosh): Likewise. * sysdeps/generic/w_exp10.c (o_threshold, u_threshold): Remove. (__exp10): Test if finite argument gave non-finite result. * sysdeps/generic/w_exp10f.c (o_threshold, u_threshold, __exp10f): Likewise. * sysdeps/generic/w_exp10l.c (o_threshold, u_threshold, __exp10l): Likewise. 2001-06-04 Jakub Jelinek * sysdeps/ieee754/ldbl-96/e_coshl.c (__ieee754_coshl): Fix overflow threshold constant (log(LDBL_MAX)+M_LN2l). 2001-05-29 Bruno Haible * locale/programs/ld-ctype.c (idx_table): New struct type. (idx_table_init, idx_table_get, idx_table_add): New functions. (MAX_CHARNAMES_IDX): Remove macro. (locale_ctype_t): Change type of charnames_idx field. (ctype_startup): Change initialization of charnames_idx field. (find_idx): Use idx_table_get and idx_table_add for speed. * locale/programs/charmap.c (charmap_new_char): Fix ucs4 value computation of characters in a range. 2001-05-29 Bruno Haible * iconvdata/gb18030.c (__fourbyte_to_ucs1): Add mappings for , . (__ucs_to_gb18030_tab1): Likewise. (BODY for FROM_LOOP): Add mapping for ... (BODY for TO_LOOP): Likewise. * iconvdata/tst-table-charmap.sh: Update for charmaps containing syntax. * iconvdata/tst-table-from.c (bmp_only): New variable. (utf8_decode): If bmp_only, don't return characters outside Unicode plane 0. (main): When testing UTF-8 or GB18030, set bmp_only to 1. Don't print a conversion line if utf8_decode returns NULL. * iconvdata/tst-table-to.c (main): When testing encodings other than UTF-8 and GB18030, loop upto U+30000 instead of U+10000. Use UTF-8 instead of UCS-2 as input. * iconvdata/tst-table.sh: For GB18030, use only the part < 0x10000 of the charmap. 2001-05-29 Bruno Haible * iconvdata/cns11643l1.c: Update to Unicode 3.1. (__cns11643l1_to_ucs4_tab): Regenerated. (__cns11643l1_from_ucs4_tab12): Regenerated. * iconvdata/cns11643.c: Update to Unicode 3.1. (__cns11643l14_to_ucs4_tab): Remove array. (__cns11643l3_to_ucs4_tab, __cns11643l4_to_ucs4_tab, __cns11643l5_to_ucs4_tab, __cns11643l6_to_ucs4_tab, __cns11643l7_to_ucs4_tab, __cns11643l15_to_ucs4_tab): New arrays. (__cns11643_from_ucs4p0_tab): Renamed from __cns11643_from_ucs4_tab. (__cns11643_from_ucs4p2_tab): New array. * iconvdata/cns11643.h (__cns11643l14_to_ucs4_tab): Remove declaration. (__cns11643l3_to_ucs4_tab, __cns11643l4_to_ucs4_tab, __cns11643l5_to_ucs4_tab, __cns11643l6_to_ucs4_tab, __cns11643l7_to_ucs4_tab, __cns11643l15_to_ucs4_tab): New declarations. (cns11643_to_ucs4): Treat planes 3, 4, 5, 6, 7, 15 instead of 14. (__cns11643_from_ucs4_tab): Remove declaration. (__cns11643_from_ucs4p0_tab, __cns11643_from_ucs4p2_tab): New declarations. (ucs4_to_cns11643): Update for new arrays. Treat U+3400..U+4DFF and U+20000..U+2A6D6. * iconvdata/cns11643l2.h (__cns11643_from_ucs4_tab): Remove declaration. (__cns11643_from_ucs4p0_tab): New declaration. (ucs4_to_cns11643l2): Update for new arrays. * iconvdata/iso-2022-cn-ext.c (BODY for FROM_LOOP): Handle planes 3 to 7. (BODY for TO_LOOP): Handle planes 3 to 7, instead of plane 14. * iconvdata/EUC-TW.irreversible: New file. * iconvdata/tst-table.sh: Use it. * iconvdata/Makefile (distribute): Add CP1255.irreversible, CP1258.irreversible, EUC-TW.irreversible. 2001-05-29 Bruno Haible * locale/C-translit.h.in: Add transliterations for new Unicode 3.1 mathematical symbols. --- sysdeps/ieee754/dbl-64/e_exp2.c | 6 +- sysdeps/ieee754/dbl-64/e_log2.c | 130 +++++++++++++++++++++++++++++++++++++ sysdeps/ieee754/dbl-64/s_ilogb.c | 14 +++- sysdeps/ieee754/dbl-64/s_log2.c | 136 --------------------------------------- 4 files changed, 144 insertions(+), 142 deletions(-) create mode 100644 sysdeps/ieee754/dbl-64/e_log2.c delete mode 100644 sysdeps/ieee754/dbl-64/s_log2.c (limited to 'sysdeps/ieee754/dbl-64') diff --git a/sysdeps/ieee754/dbl-64/e_exp2.c b/sysdeps/ieee754/dbl-64/e_exp2.c index d02af15..699f44e 100644 --- a/sysdeps/ieee754/dbl-64/e_exp2.c +++ b/sysdeps/ieee754/dbl-64/e_exp2.c @@ -1,5 +1,5 @@ /* Double-precision floating point 2^x. - Copyright (C) 1997, 1998, 2000 Free Software Foundation, Inc. + Copyright (C) 1997, 1998, 2000, 2001 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Geoffrey Keating @@ -44,10 +44,10 @@ double __ieee754_exp2 (double x) { static const double himark = (double) DBL_MAX_EXP; - static const double lomark = (double) (DBL_MIN_EXP - DBL_MANT_DIG - 1) - 1.0; + static const double lomark = (double) (DBL_MIN_EXP - DBL_MANT_DIG - 1); /* Check for usual case. */ - if (isless (x, himark) && isgreater (x, lomark)) + if (isless (x, himark) && isgreaterequal (x, lomark)) { static const double THREEp42 = 13194139533312.0; int tval, unsafe; diff --git a/sysdeps/ieee754/dbl-64/e_log2.c b/sysdeps/ieee754/dbl-64/e_log2.c new file mode 100644 index 0000000..f05d0ce --- /dev/null +++ b/sysdeps/ieee754/dbl-64/e_log2.c @@ -0,0 +1,130 @@ +/* Adapted for log2 by Ulrich Drepper . */ +/* + * ==================================================== + * 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. + * ==================================================== + */ + +/* __ieee754_log2(x) + * Return the logarithm to base 2 of x + * + * Method : + * 1. Argument Reduction: find k and f such that + * x = 2^k * (1+f), + * where sqrt(2)/2 < 1+f < sqrt(2) . + * + * 2. Approximation of log(1+f). + * Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s) + * = 2s + 2/3 s**3 + 2/5 s**5 + ....., + * = 2s + s*R + * We use a special Reme algorithm on [0,0.1716] to generate + * a polynomial of degree 14 to approximate R The maximum error + * of this polynomial approximation is bounded by 2**-58.45. In + * other words, + * 2 4 6 8 10 12 14 + * R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s +Lg6*s +Lg7*s + * (the values of Lg1 to Lg7 are listed in the program) + * and + * | 2 14 | -58.45 + * | Lg1*s +...+Lg7*s - R(z) | <= 2 + * | | + * Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2. + * In order to guarantee error in log below 1ulp, we compute log + * by + * log(1+f) = f - s*(f - R) (if f is not too large) + * log(1+f) = f - (hfsq - s*(hfsq+R)). (better accuracy) + * + * 3. Finally, log(x) = k + log(1+f). + * = k+(f-(hfsq-(s*(hfsq+R)))) + * + * Special cases: + * log2(x) is NaN with signal if x < 0 (including -INF) ; + * log2(+INF) is +INF; log(0) is -INF with signal; + * log2(NaN) is that NaN with no signal. + * + * Constants: + * The hexadecimal values are the intended ones for the following + * constants. The decimal values may be used, provided that the + * compiler will convert from decimal to binary accurately enough + * to produce the hexadecimal values shown. + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const double +#else +static double +#endif +ln2 = 0.69314718055994530942, +two54 = 1.80143985094819840000e+16, /* 43500000 00000000 */ +Lg1 = 6.666666666666735130e-01, /* 3FE55555 55555593 */ +Lg2 = 3.999999999940941908e-01, /* 3FD99999 9997FA04 */ +Lg3 = 2.857142874366239149e-01, /* 3FD24924 94229359 */ +Lg4 = 2.222219843214978396e-01, /* 3FCC71C5 1D8E78AF */ +Lg5 = 1.818357216161805012e-01, /* 3FC74664 96CB03DE */ +Lg6 = 1.531383769920937332e-01, /* 3FC39A09 D078C69F */ +Lg7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */ + +#ifdef __STDC__ +static const double zero = 0.0; +#else +static double zero = 0.0; +#endif + +#ifdef __STDC__ + double __ieee754_log2(double x) +#else + double __ieee754_log2(x) + double x; +#endif +{ + double hfsq,f,s,z,R,w,t1,t2,dk; + int32_t k,hx,i,j; + u_int32_t lx; + + EXTRACT_WORDS(hx,lx,x); + + k=0; + if (hx < 0x00100000) { /* x < 2**-1022 */ + if (((hx&0x7fffffff)|lx)==0) + return -two54/(x-x); /* log(+-0)=-inf */ + if (hx<0) return (x-x)/(x-x); /* log(-#) = NaN */ + k -= 54; x *= two54; /* subnormal number, scale up x */ + GET_HIGH_WORD(hx,x); + } + if (hx >= 0x7ff00000) return x+x; + k += (hx>>20)-1023; + hx &= 0x000fffff; + i = (hx+0x95f64)&0x100000; + SET_HIGH_WORD(x,hx|(i^0x3ff00000)); /* normalize x or x/2 */ + k += (i>>20); + dk = (double) k; + f = x-1.0; + if((0x000fffff&(2+hx))<3) { /* |f| < 2**-20 */ + if(f==zero) return dk; + R = f*f*(0.5-0.33333333333333333*f); + return dk-(R-f)/ln2; + } + s = f/(2.0+f); + z = s*s; + i = hx-0x6147a; + w = z*z; + j = 0x6b851-hx; + t1= w*(Lg2+w*(Lg4+w*Lg6)); + t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7))); + i |= j; + R = t2+t1; + if(i>0) { + hfsq=0.5*f*f; + return dk-((hfsq-(s*(hfsq+R)))-f)/ln2; + } else { + return dk-((s*(f-R))-f)/ln2; + } +} diff --git a/sysdeps/ieee754/dbl-64/s_ilogb.c b/sysdeps/ieee754/dbl-64/s_ilogb.c index 820f01c..89a8337 100644 --- a/sysdeps/ieee754/dbl-64/s_ilogb.c +++ b/sysdeps/ieee754/dbl-64/s_ilogb.c @@ -16,10 +16,12 @@ static char rcsid[] = "$NetBSD: s_ilogb.c,v 1.9 1995/05/10 20:47:28 jtc Exp $"; /* ilogb(double x) * return the binary exponent of non-zero x - * ilogb(0) = 0x80000001 - * ilogb(inf/NaN) = 0x7fffffff (no signal is raised) + * ilogb(0) = FP_ILOGB0 + * ilogb(NaN) = FP_ILOGBNAN (no signal is raised) + * ilogb(+-Inf) = INT_MAX (no signal is raised) */ +#include #include "math.h" #include "math_private.h" @@ -47,7 +49,13 @@ static char rcsid[] = "$NetBSD: s_ilogb.c,v 1.9 1995/05/10 20:47:28 jtc Exp $"; return ix; } else if (hx<0x7ff00000) return (hx>>20)-1023; - else return FP_ILOGBNAN; + else if (FP_ILOGBNAN != INT_MAX) { + /* ISO C99 requires ilogb(+-Inf) == INT_MAX. */ + GET_LOW_WORD(lx,x); + if(((hx^0x7ff00000)|lx) == 0) + return INT_MAX; + } + return FP_ILOGBNAN; } weak_alias (__ilogb, ilogb) #ifdef NO_LONG_DOUBLE diff --git a/sysdeps/ieee754/dbl-64/s_log2.c b/sysdeps/ieee754/dbl-64/s_log2.c deleted file mode 100644 index 7379ce8..0000000 --- a/sysdeps/ieee754/dbl-64/s_log2.c +++ /dev/null @@ -1,136 +0,0 @@ -/* Adapted for log2 by Ulrich Drepper . */ -/* - * ==================================================== - * 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. - * ==================================================== - */ - -/* __log2(x) - * Return the logarithm to base 2 of x - * - * Method : - * 1. Argument Reduction: find k and f such that - * x = 2^k * (1+f), - * where sqrt(2)/2 < 1+f < sqrt(2) . - * - * 2. Approximation of log(1+f). - * Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s) - * = 2s + 2/3 s**3 + 2/5 s**5 + ....., - * = 2s + s*R - * We use a special Reme algorithm on [0,0.1716] to generate - * a polynomial of degree 14 to approximate R The maximum error - * of this polynomial approximation is bounded by 2**-58.45. In - * other words, - * 2 4 6 8 10 12 14 - * R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s +Lg6*s +Lg7*s - * (the values of Lg1 to Lg7 are listed in the program) - * and - * | 2 14 | -58.45 - * | Lg1*s +...+Lg7*s - R(z) | <= 2 - * | | - * Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2. - * In order to guarantee error in log below 1ulp, we compute log - * by - * log(1+f) = f - s*(f - R) (if f is not too large) - * log(1+f) = f - (hfsq - s*(hfsq+R)). (better accuracy) - * - * 3. Finally, log(x) = k + log(1+f). - * = k+(f-(hfsq-(s*(hfsq+R)))) - * - * Special cases: - * log2(x) is NaN with signal if x < 0 (including -INF) ; - * log2(+INF) is +INF; log(0) is -INF with signal; - * log2(NaN) is that NaN with no signal. - * - * Constants: - * The hexadecimal values are the intended ones for the following - * constants. The decimal values may be used, provided that the - * compiler will convert from decimal to binary accurately enough - * to produce the hexadecimal values shown. - */ - -#include "math.h" -#include "math_private.h" - -#ifdef __STDC__ -static const double -#else -static double -#endif -ln2 = 0.69314718055994530942, -two54 = 1.80143985094819840000e+16, /* 43500000 00000000 */ -Lg1 = 6.666666666666735130e-01, /* 3FE55555 55555593 */ -Lg2 = 3.999999999940941908e-01, /* 3FD99999 9997FA04 */ -Lg3 = 2.857142874366239149e-01, /* 3FD24924 94229359 */ -Lg4 = 2.222219843214978396e-01, /* 3FCC71C5 1D8E78AF */ -Lg5 = 1.818357216161805012e-01, /* 3FC74664 96CB03DE */ -Lg6 = 1.531383769920937332e-01, /* 3FC39A09 D078C69F */ -Lg7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */ - -#ifdef __STDC__ -static const double zero = 0.0; -#else -static double zero = 0.0; -#endif - -#ifdef __STDC__ - double __log2(double x) -#else - double __log2(x) - double x; -#endif -{ - double hfsq,f,s,z,R,w,t1,t2,dk; - int32_t k,hx,i,j; - u_int32_t lx; - - EXTRACT_WORDS(hx,lx,x); - - k=0; - if (hx < 0x00100000) { /* x < 2**-1022 */ - if (((hx&0x7fffffff)|lx)==0) - return -two54/(x-x); /* log(+-0)=-inf */ - if (hx<0) return (x-x)/(x-x); /* log(-#) = NaN */ - k -= 54; x *= two54; /* subnormal number, scale up x */ - GET_HIGH_WORD(hx,x); - } - if (hx >= 0x7ff00000) return x+x; - k += (hx>>20)-1023; - hx &= 0x000fffff; - i = (hx+0x95f64)&0x100000; - SET_HIGH_WORD(x,hx|(i^0x3ff00000)); /* normalize x or x/2 */ - k += (i>>20); - dk = (double) k; - f = x-1.0; - if((0x000fffff&(2+hx))<3) { /* |f| < 2**-20 */ - if(f==zero) return dk; - R = f*f*(0.5-0.33333333333333333*f); - return dk-(R-f)/ln2; - } - s = f/(2.0+f); - z = s*s; - i = hx-0x6147a; - w = z*z; - j = 0x6b851-hx; - t1= w*(Lg2+w*(Lg4+w*Lg6)); - t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7))); - i |= j; - R = t2+t1; - if(i>0) { - hfsq=0.5*f*f; - return dk-((hfsq-(s*(hfsq+R)))-f)/ln2; - } else { - return dk-((s*(f-R))-f)/ln2; - } -} - -weak_alias (__log2, log2) -#ifdef NO_LONG_DOUBLE -strong_alias (__log2, __log2l) -weak_alias (__log2, log2l) -#endif -- cgit v1.1