* SoftFloat implementation for MIPS in GCC @ 2004-01-28 19:26 Rajesh Palani 2004-01-28 19:33 ` Daniel Jacobowitz 0 siblings, 1 reply; 5+ messages in thread From: Rajesh Palani @ 2004-01-28 19:26 UTC (permalink / raw) To: linux-mips [-- Attachment #1: Type: text/plain, Size: 719 bytes --] Hi, We are using a gcc 2.96 20000731 (Red Hat Linux 7.1 2.96-99.1) GCC cross-compiler with -msoftfloat to use software floating point routines. When we profied an application using the Linux Trace Toolkit, we observed that there were a lot of CpU (Co-processor unusable) exceptions. Some of the floating point routines ( eg. __floatdidf) expect values to be passed in floating point registers and take FP exceptions even though the application has been built with -msoftfloat. Is this a general MIPS/GCC issue? What is the status of softfloat for MIPS in GCC? Thanks in advance. Rajesh --------------------------------- Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it! [-- Attachment #2: Type: text/html, Size: 995 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: SoftFloat implementation for MIPS in GCC 2004-01-28 19:26 SoftFloat implementation for MIPS in GCC Rajesh Palani @ 2004-01-28 19:33 ` Daniel Jacobowitz 2004-01-28 19:53 ` Jun Sun 0 siblings, 1 reply; 5+ messages in thread From: Daniel Jacobowitz @ 2004-01-28 19:33 UTC (permalink / raw) To: Rajesh Palani; +Cc: linux-mips On Wed, Jan 28, 2004 at 11:26:36AM -0800, Rajesh Palani wrote: > Hi, > > We are using a gcc 2.96 20000731 (Red Hat Linux 7.1 2.96-99.1) GCC cross-compiler with -msoftfloat to use software floating point routines. > > When we profied an application using the Linux Trace Toolkit, we observed that there were a lot of CpU (Co-processor unusable) exceptions. Some of the floating point routines ( eg. __floatdidf) expect values to be passed in floating point registers and take FP exceptions even though the application has been built with -msoftfloat. Is this a general MIPS/GCC issue? What is the status of softfloat for MIPS in GCC? Try a more recent compiler, that one is ancient. If you configure correctly, you should get no references to the floating point registers at all. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: SoftFloat implementation for MIPS in GCC 2004-01-28 19:33 ` Daniel Jacobowitz @ 2004-01-28 19:53 ` Jun Sun 2004-01-28 19:57 ` David Daney 2004-01-28 20:00 ` Daniel Jacobowitz 0 siblings, 2 replies; 5+ messages in thread From: Jun Sun @ 2004-01-28 19:53 UTC (permalink / raw) To: Daniel Jacobowitz; +Cc: Rajesh Palani, linux-mips, jsun On Wed, Jan 28, 2004 at 02:33:55PM -0500, Daniel Jacobowitz wrote: > On Wed, Jan 28, 2004 at 11:26:36AM -0800, Rajesh Palani wrote: > > Hi, > > > > We are using a gcc 2.96 20000731 (Red Hat Linux 7.1 2.96-99.1) GCC cross-compiler with -msoftfloat to use software floating point routines. > > > > When we profied an application using the Linux Trace Toolkit, we observed that there were a lot of CpU (Co-processor unusable) exceptions. Some of the floating point routines ( eg. __floatdidf) expect values to be passed in floating point registers and take FP exceptions even though the application has been built with -msoftfloat. Is this a general MIPS/GCC issue? What is the status of softfloat for MIPS in GCC? > > Try a more recent compiler, that one is ancient. If you configure > correctly, you should get no references to the floating point registers > at all. > If glibc is not compiled with -msoftfloat, I think you will get a few FPU exceptions from glibc no matter how apps are compiled. Actually, will it be a problem if glibc and apps are compiled differently (such as in longjump, sig handling area)? Jun ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: SoftFloat implementation for MIPS in GCC 2004-01-28 19:53 ` Jun Sun @ 2004-01-28 19:57 ` David Daney 2004-01-28 20:00 ` Daniel Jacobowitz 1 sibling, 0 replies; 5+ messages in thread From: David Daney @ 2004-01-28 19:57 UTC (permalink / raw) To: Jun Sun; +Cc: Daniel Jacobowitz, Rajesh Palani, linux-mips Jun Sun wrote: >On Wed, Jan 28, 2004 at 02:33:55PM -0500, Daniel Jacobowitz wrote: > > >>On Wed, Jan 28, 2004 at 11:26:36AM -0800, Rajesh Palani wrote: >> >> >>>Hi, >>> >>> We are using a gcc 2.96 20000731 (Red Hat Linux 7.1 2.96-99.1) GCC cross-compiler with -msoftfloat to use software floating point routines. >>> >>> When we profied an application using the Linux Trace Toolkit, we observed that there were a lot of CpU (Co-processor unusable) exceptions. Some of the floating point routines ( eg. __floatdidf) expect values to be passed in floating point registers and take FP exceptions even though the application has been built with -msoftfloat. Is this a general MIPS/GCC issue? What is the status of softfloat for MIPS in GCC? >>> >>> >>Try a more recent compiler, that one is ancient. If you configure >>correctly, you should get no references to the floating point registers >>at all. >> >> >> > >If glibc is not compiled with -msoftfloat, I think you will get a few >FPU exceptions from glibc no matter how apps are compiled. > >Actually, will it be a problem if glibc and apps are compiled differently >(such as in longjump, sig handling area)? > > I have found that some versions of glibc (2.2.5 for example) have hard coded floating point code (in longjump handling IIRC) so no matter what you do you get the exceptions. David Daney. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: SoftFloat implementation for MIPS in GCC 2004-01-28 19:53 ` Jun Sun 2004-01-28 19:57 ` David Daney @ 2004-01-28 20:00 ` Daniel Jacobowitz 1 sibling, 0 replies; 5+ messages in thread From: Daniel Jacobowitz @ 2004-01-28 20:00 UTC (permalink / raw) To: Jun Sun; +Cc: Rajesh Palani, linux-mips On Wed, Jan 28, 2004 at 11:53:12AM -0800, Jun Sun wrote: > On Wed, Jan 28, 2004 at 02:33:55PM -0500, Daniel Jacobowitz wrote: > > On Wed, Jan 28, 2004 at 11:26:36AM -0800, Rajesh Palani wrote: > > > Hi, > > > > > > We are using a gcc 2.96 20000731 (Red Hat Linux 7.1 2.96-99.1) GCC cross-compiler with -msoftfloat to use software floating point routines. > > > > > > When we profied an application using the Linux Trace Toolkit, we observed that there were a lot of CpU (Co-processor unusable) exceptions. Some of the floating point routines ( eg. __floatdidf) expect values to be passed in floating point registers and take FP exceptions even though the application has been built with -msoftfloat. Is this a general MIPS/GCC issue? What is the status of softfloat for MIPS in GCC? > > > > Try a more recent compiler, that one is ancient. If you configure > > correctly, you should get no references to the floating point registers > > at all. > > > > If glibc is not compiled with -msoftfloat, I think you will get a few > FPU exceptions from glibc no matter how apps are compiled. > > Actually, will it be a problem if glibc and apps are compiled differently > (such as in longjump, sig handling area)? Yes, that will be a problem. Nothing that takes or returns a floating point value will work either. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2004-01-28 20:00 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2004-01-28 19:26 SoftFloat implementation for MIPS in GCC Rajesh Palani 2004-01-28 19:33 ` Daniel Jacobowitz 2004-01-28 19:53 ` Jun Sun 2004-01-28 19:57 ` David Daney 2004-01-28 20:00 ` Daniel Jacobowitz
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox