Hello!

This patch enables setting of default 80387 precision control at link
time. When executable is built, the gcc driver links correct object
file, and there the PC field of 80387 is set to selected precision
(similar to ifort's -pcX flag) when executable is started.

This patch speeds up iterative FP operations (division, sqrt...) when
80 bit precision is not needed.

Patch was bootstrapped on i686-pc-linux-gnu and manually checked via
debugger that really affects the computations. I have to bootstrap
this patch on x86_64 to check that everything is OK there, too. OK for
mainline, if it passes?

2007-04-02  Uros Bizjak  <ubizjak@gmail.com>

	* config.gcc (i[34567]86-*-linux*): Add i386/t-crtpc to tm-file.
	(x86_64-*-linux*): Ditto.

	* config/i386/i386.opt (mpc): New option.
	* config/i386/i386.c (overrride_options): Handle
	ix87_precision_string.

        * config/i386/crtprec.c: New file.
	* config/i386/t-crtpc: Ditto.

	* config/i386/linux.h (ENDFILE_SPEC): Add handling of -mpcN options.
	* config/i386/linux64.h (ENDFILE_SPEC): Ditto.

	* config/i386/t-linux64 (EXTRA_MULTILIB_PARTS): Add
	crtprec32.o, crtprec64.o and crtprec80.o.

libgcc/ChangeLog:

	* config.host (i[34567]86-*-linux*): Add i386/t-crtpc to tm-file.
	(x86_64-*-linux*): Ditto.

Uros.