[v3] Return of the son of fp printing.

Phil Edwards phil@codesourcery.com
Mon Aug 30 00:07:00 GMT 2004

On Sun, Aug 29, 2004 at 07:11:41PM -0400, Jerry Quinn wrote:
> Glibc uses a version of GMP under the
> covers for its printing and it seemed like too much work and licensing hassle
> to bring it over.

It's already required to build F95, and there's increased pressure to
import it into the GCC tree.  So this may not be so far away as you think.

> It seems to have been successful.  The fp printing performance test shows:
> before:
> ofstream_insert_float.cc 	precision 6              	6964r 6534u   79s        0mem    0pf 
> ofstream_insert_float.cc 	precision 12             	6836r 6470u   68s        0mem    0pf 
> after:
> ofstream_insert_float.cc 	precision 6              	2914r 2703u   80s        0mem    0pf 
> ofstream_insert_float.cc 	precision 12             	3710r 3281u   58s        0mem    0pf 


> The biggest issue with this patch is that I don't know if adding the exported
> symbols to 3.4.2 is the right thing to do.  Wiser heads, let me know.

Mark froze the branch a couple hours ago, so we'll pretend you wrote 3.4.x
instead.  :-)

There are formatting and naming issues with the patch (stuff goes past 80
characters in several places, there look to be a couple of tabs embedded in
a few lines, and stuff in floatconv.cc is going to have to be uglified), but
those can be dealt with before checkin.

> +++ include/bits/locale_facets.tcc	29 Aug 2004 22:22:27 -0000
> @@ -36,6 +36,7 @@
>  #pragma GCC system_header
>  #include <limits>		// For numeric_limits
> +#include <cmath>		// For log10

Is there no easier (yet safe) way to get log10 than by pulling in the entire
math header?  (I don't know, it's an honest question.)


Religion and science have always been matters of faith in something.  It is
the same something.
    - Master Ash, "Citadel of the Autarch" by Gene Wolfe

More information about the Gcc-patches mailing list