Date: Thu, 7 Mar 2019 16:22:45 -0800 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Bruce Evans <brde@optusnet.com.au> Cc: freebsd-numerics@freebsd.org Subject: Re: Update ENTERI() macro Message-ID: <20190308002245.GA26338@troutmask.apl.washington.edu> In-Reply-To: <20190306214233.GA23159@troutmask.apl.washington.edu> References: <20190227201214.V1823@besplex.bde.org> <20190227161906.GA77785@troutmask.apl.washington.edu> <20190228060920.R4413@besplex.bde.org> <20190304212159.GA12587@troutmask.apl.washington.edu> <20190305153243.Y1349@besplex.bde.org> <20190306055201.GA40298@troutmask.apl.washington.edu> <20190306225811.P2731@besplex.bde.org> <20190306184829.GA44023@troutmask.apl.washington.edu> <20190307061214.R4911@besplex.bde.org> <20190306214233.GA23159@troutmask.apl.washington.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Mar 06, 2019 at 01:42:33PM -0800, Steve Kargl wrote: > On Thu, Mar 07, 2019 at 06:30:42AM +1100, Bruce Evans wrote: > > On Wed, 6 Mar 2019, Steve Kargl wrote: > > > > > On Wed, Mar 06, 2019 at 11:56:23PM +1100, Bruce Evans wrote: > > >> On Tue, 5 Mar 2019, Steve Kargl wrote: > > > > > >>> a similar k_cexpl.c. Yes, I added the 'c' in the name to avoid > > >>> confusion in ld80/. In particular, I have no idea how he found > > >>> his scaling value 'k'. Any insights? > > >> > > >> bde already wrote __ldexp_cexpl() in ld*/k_expl.h, and kargl committed > > >> it in r260066. Does it not work? :-). > > >> > > >> Well, it hasn't been tested, and it indeed cannot work since it spells > > >> cosl(y) as cos(y). > > > > > > Taking long breaks from pecking at libm issues seems to be > > > conducive to memory loss. I'll go review k_expl.h. I simply > > > remember it as having a kernel for expl(). > > > > I now see that you implemented 2 more versions of __ldexpl_cexpl() by > > cloning the old double precision version. Apparently the includes > > are to unpolluted for the compiler to see the multiple versions :-). > > > > Using the version in k_expl.h almost forces inlining of expl()'s kernel > > and its large tables, just like for hyperbolic functions. This wastes > > a lot of space, especially for duplicating the tables. It is only a > > small optimization for time. It is done for the hyperbolic functions > > to get this optimization, and for __ldexpl_cexpl() just for convenience. > > The version in k_expl.h has 2 bugs. You note the first (cos instead > of cosl). The second is > > In file included from /data/kargl/trunk/math/libm/msun/ld80/s_cexpl.c:43: > /data/kargl/trunk/math/libm/msun/ld80/k_expl.h:288:22: error: magnitude of > floating-point constant too large for type 'double'; maximum is > 1.7976931348623157E+308 [-Werror,-Wliteral-range] > exp_x = (lo + hi) * 0x1p16382; > ^ Make that 3 bugs. Index: ld80/k_expl.h =================================================================== --- ld80/k_expl.h (revision 344600) +++ ld80/k_expl.h (working copy) @@ -285,7 +285,7 @@ y = cimagl(z); __k_expl(x, &hi, &lo, &k); - exp_x = (lo + hi) * 0x1p16382; + exp_x = (lo + hi) * 0x1p16382L; expt += k - 16382; scale1 = 1; @@ -292,9 +292,9 @@ half_expt = expt / 2; SET_LDBL_EXPSIGN(scale1, BIAS + half_expt); scale2 = 1; - SET_LDBL_EXPSIGN(scale1, BIAS + expt - half_expt); + SET_LDBL_EXPSIGN(scale2, BIAS + expt - half_expt); - return (CMPLXL(cos(y) * exp_x * scale1 * scale2, + return (CMPLXL(cosl(y) * exp_x * scale1 * scale2, sinl(y) * exp_x * scale1 * scale2)); } #endif /* _COMPLEX_H */ -- Steve
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20190308002245.GA26338>