From 139f923bb4564fb021dce2b7ae460a3d8e3bb87d Mon Sep 17 00:00:00 2001 From: Jeff Johnston Date: Wed, 25 Mar 2009 19:13:24 +0000 Subject: 2009-03-25 Craig Howland * libc/include/math.h: (llround, llroundf): Declare. * libm/common/s_llround.c: New file, implementing llround(). * libm/common/sf_llround.c: New file, implementing llroundf(). * libm/common/sf_lround.c: Remove spurious cast in _DOUBLE_IS_32BITS version of function. * libm/common/sf_lrint.c: Ditto. * libm/common/sf_logb.c: Corrected return for subnormal argument by replacing existing function with a version created from sf_ilogb.c. * libm/common/s_logb.c: Ditto, except starting point s_ilogb.c. Also added documentation for logb() and logbf(). * libm/common/s_signbit.c: Add signbit() documentation. * libm/common/s_log2.c: Update return values to match what w_log2.c has, since log2 uses log(); add note about being derived instead of direct. * libm/common/sf_fma.c: Add casts to attempt to get correct results, as well as comments pointing out problems with the implementation. * libm/common/s_fma.c: Add fma() and fmaf() documentation. * libm/common/sf_remquo.c: Incorrect quotient returns for large values corrected by discarding existing function and replacing with Sun verion, with some enhancements. * libm/common/s_remquo.c: Ditto. Add remquo() and remquof() documentation. * libm/common/s_fmax.c: Add fmax() and fmaxf() documentation. * libm/common/s_fmin.c: Add fmin() and fminf() documentation. * libm/common/s_fdim.c: Return NAN for NAN arg, add fdim() and fdimf() documentation. * libm/common/sf_fdim.c: Return NAN for NAN arg, HUGE_VALF for inf arg. * libm/common/s_trunc.c: Add trunc() and truncf() documentation. * libm/common/s_rint.c: Add rint() and rintf() documentation. * libm/common/s_round.c: Add round() and roundf() documentation. * libm/common/s_scalbn.c: Add scalbln() and scalblnf() documentation. * libm/common/s_infinity.c: Add infinity() and infinityf() documentation. * libm/common/s_lround.c: Add lround(), lroundf(), llround(), and llroundf() documentation. * libm/common/s_lrint.c: Add lrint(), lrintf(), llrint(), and llrintf() documentation. * libm/common/isgreater.c: New file for documenting math.h function-like macros isgreater(), isgreaterequal(), isless(), islessequal(), islessgreater(), and isunordered(). * libm/common/s_isnan.c: Add documentation for function-like macros fpclassify(), isfinite(), isinf(), isnan(), and isnormal(). * libm/common/s_nearbyint.c: Add nearbyint() and nearbyintf() documentation. * libm/common/Makefile.am: Add s_llround.c (src); sf_llround.c (fsrc); s_fdim.def, s_fma.def, s_fmax.def, s_fmin.def, s_logb.def, s_lrint.def, s_lround.def, s_nearbyint.def, s_remquo.def, s_rint.def, s_round.def, s_signbit.def, s_trunc.def, and isgreater.def (chobj); re-name all existing chew files (chobj) to match source file base names (put in underscores), delete all special targets for chew files (leaving all to be generated by rule). * libm/common/Makefile.in: regenerate. * libm/math/w_exp2.c: Add "base 2" to documentation description (and delete TRAD_SYNOPSIS). * libm/math/w_gamma.c: Add tgamma() and tgammaf() documentation, along with some history behind the function names. * libm/math/math.tex: Add includes for newly-added documentation (see .def additions to common/Makefile.am and math/Makefile.am in this ChangeLog list), adjusted existing .def file names to match source file base names (added underscores); add mention of HUGE_VALF; rename "Version of library" section to "Error Handling" and add some text about floating-point exception; added section "Standards Compliance And Portability". * libm/math/Makefile.am: Add w_exp2.def (chobj); re-name all existing chew files (chobj) to match source file base names, delete all special targets for chew files (leaving all to be generated by rule). * libm/math/Makefile.in: regenerated * doc/makedoc.c: Change silent ignoring of commands < 5 characters to a failure when reading macro file for commands < 4 characters; add -v (verbose) option for printing some debugging information; get rid of spurious translation of "@*" to "*" (no source files used @*, so no existing doc pages were affected); clean up some compiler warnings. * doc/doc.str: add BUGS and SEEALSO sections (to match texi2pod.pl which has them); Remove ITEM command (redundant with makedoc built-in "o", not used in any present source file so nothing is lost, anyway). * HOWTO: New file to hold information for maintainers regarding how to do things. Initial sections on documentation and ELIX levels. --- newlib/libm/common/sf_logb.c | 46 +++++++++++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 16 deletions(-) (limited to 'newlib/libm/common/sf_logb.c') diff --git a/newlib/libm/common/sf_logb.c b/newlib/libm/common/sf_logb.c index f193f91f6..75336a1e0 100644 --- a/newlib/libm/common/sf_logb.c +++ b/newlib/libm/common/sf_logb.c @@ -1,7 +1,4 @@ -/* sf_logb.c -- float version of s_logb.c. - * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. - */ - +/* 2009 for Newlib: Sun's sf_ilogb.c converted to be sf_logb.c. */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. @@ -13,24 +10,41 @@ * ==================================================== */ +/* float logb(float x) + * return the binary exponent of non-zero x + * logbf(0) = -inf, raise divide-by-zero floating point exception + * logbf(+inf|-inf) = +inf (no signal is raised) + * logbf(NaN) = NaN (no signal is raised) + * Per C99 recommendation, a NaN argument is returned unchanged. + */ + #include "fdlibm.h" +float #ifdef __STDC__ - float logbf(float x) +logbf(float x) #else - float logbf(x) - float x; +logbf(x) +float x; #endif { - __int32_t ix; - GET_FLOAT_WORD(ix,x); - ix &= 0x7fffffff; /* high |x| */ - if(FLT_UWORD_IS_ZERO(ix)) return (float)-1.0/fabsf(x); - if(!FLT_UWORD_IS_FINITE(ix)) return x*x; - if((ix>>=23)==0) /* IEEE 754 logb */ - return -126.0; - else - return (float) (ix-127); + __int32_t hx,ix; + + GET_FLOAT_WORD(hx,x); + hx &= 0x7fffffff; + if(FLT_UWORD_IS_ZERO(hx)) { + float xx; + /* arg==0: return -inf and raise divide-by-zero exception */ + SET_FLOAT_WORD(xx,hx); /* +0.0 */ + return -1./xx; /* logbf(0) = -inf */ + } + if(FLT_UWORD_IS_SUBNORMAL(hx)) { + for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1; + return (float) ix; + } + else if (FLT_UWORD_IS_INFINITE(hx)) return HUGE_VALF; /* x==+|-inf */ + else if (FLT_UWORD_IS_NAN(hx)) return x; + else return (float) ((hx>>23)-127); } #ifdef _DOUBLE_IS_32BITS -- cgit v1.2.3