This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: sparc, ia64: Compute cos(M_PI_2l) for your 128-bit long double please.
- From: Rich Felker <dalias at aerifal dot cx>
- To: Andreas Schwab <schwab at suse dot de>
- Cc: David Miller <davem at davemloft dot net>, carlos at redhat dot com, vapier at gentoo dot org, brooks_moses at mentor dot com, libc-alpha at sourceware dot org, joseph at codesourcery dot com, aj at suse dot com, thomas at codesourcery dot com
- Date: Thu, 11 Apr 2013 09:09:44 -0400
- Subject: Re: sparc, ia64: Compute cos(M_PI_2l) for your 128-bit long double please.
- References: <5164D25B dot 9090406 at redhat dot com> <m2fvyyjp82 dot fsf at igel dot home> <5165CFDE dot 6020709 at redhat dot com> <20130410 dot 233850 dot 1096713545971361798 dot davem at davemloft dot net> <20130411123902 dot GF20323 at brightrain dot aerifal dot cx> <mvm7gk9xllk dot fsf at hawking dot suse dot de>
On Thu, Apr 11, 2013 at 03:06:47PM +0200, Andreas Schwab wrote:
> Rich Felker <dalias@aerifal.cx> writes:
>
> > I would just use something like "%.100000g\n".
>
> If you use %g you need at most DECIMAL_DIG digits.
No, that's wrong. DECIMAL_DIG is sufficient if you want to round-trip
the value back. But here we want to print the exact value in order to
use an external tool to apply cos() to that value.
Rich