From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nommos.sslcatacombnetworking.com (nommos.sslcatacombnetworking.com [67.18.224.114]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 0931EDDF95 for ; Sat, 13 Jan 2007 05:37:11 +1100 (EST) In-Reply-To: <32F3CC26D4DAC44E8ECD07155727A46E816A58@zch01exm20.fsl.freescale.net> References: <32F3CC26D4DAC44E8ECD07155727A46E816A58@zch01exm20.fsl.freescale.net> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=GB2312; delsp=yes; format=flowed Message-Id: <567FCA2A-22B1-4644-98D3-2E7431423307@kernel.crashing.org> From: Kumar Gala Subject: Re: [patch][0/5] powerpc: Add support to fully comply with IEEE-754 standard Date: Fri, 12 Jan 2007 12:36:19 -0600 To: "Zhu Ebony-r57400" Cc: linuxppc-dev@ozlabs.org, paulus@samba.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Jan 12, 2007, at 2:09 AM, Zhu Ebony-r57400 wrote: > Hi Kumar, > >> -----Original Message----- >> From: Kumar Gala [mailto:galak@kernel.crashing.org] >> Sent: 2007=C4=EA1=D4=C212=C8=D5 14:42 >> To: Zhu Ebony-r57400 >> Cc: paulus@samba.org; linuxppc-dev@ozlabs.org >> Subject: Re: [patch][0/5] powerpc: Add support to fully >> comply with IEEE-754 standard >> >> >> On Jan 11, 2007, at 11:19 PM, Zhu Ebony-r57400 wrote: >> >>> Hi Paul, >>> >>> This series of patch add support to fully comply with IEEE-754 >>> standard for E500/E500v2 core when hardware floating point >> compiling >>> is used. >>> >>> Ebony >> >> Here are some general comments: >> * We should be able to support math-emu (as it stands) and >> the fixup handling [you break math-emu] > > I don't think I break the math-emu. I think the codes I added have > no impact to the existing math-emu. This snippet of code breaks it from math-emu/sfp-machine.h >> +#ifdef CONFIG_SPE >> +#define __FPU_FPSCR (current->thread.spefscr) >> +#else >> #define __FPU_FPSCR (current->thread.fpscr.val) >> +#endif By doing this if I want 'classic FP' emulation as well as the IEEE =20 fixup my fpscr for classic emu will not be updated properly. > >> * Copyrights / header comments should give credit to the orig >> math- emu code > I'd like to do this, but in most handler codes, I can't find =20 > copyright information > of the orig authors. I think the math-emu code comes from glibc. In =20= > the > sigfpe_handler.c, I gave credit to the orig author. I think a comment is sufficient stating this is take from the math-=20 emu code. >> * Why isn't there any handling of SPEFloatingPointRound exceptions? > > I think the SPEFloatingPointRound exception is not necessary to =20 > handle if we > handle floating point exception this way. I dont believe this, you'll have to explain if this is really true. =20 But, I'm almost sure that if the RND mode is set to +/-inf and we do =20 an operation that is within the normal bounds that should round we =20 will NOT get one of the other exceptions. - k