From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Denk Date: Sun, 20 Feb 2011 11:20:07 +0100 Subject: [U-Boot] [PATCH] ARM: Add comments why -msoft-float is used. In-Reply-To: <4D60E16E.1060406@ahsoftware.de> References: <1298171532-5296-1-git-send-email-holler@ahsoftware.de> <20110220084242.B9AC11468BF@gemini.denx.de> <4D60E16E.1060406@ahsoftware.de> Message-ID: <20110220102007.CD20E14F31A@gemini.denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Alexander Holler, In message <4D60E16E.1060406@ahsoftware.de> you wrote: > > I don't know how other the compiler behaves for other architectures and > if those are having the need to save fp-contexts for irqs. I thought I had explained this again in recent postings, not to mention the times I did that before; you probably can find this in the archives. > # -msoft-float forces the compiler to avoid any fp-related instructions > for optimizations. > > Would that be better? No, not at all, because the only additional information about what -msoft-float does (not using FP instructions) in the "for optimizations" part - but that does not help much if you don;t have the background we discussed here again. So if you want to document this, then please provide a more complete explanation about the reasons for using -msoft-float, summarizing the recent discussion. Keep in mind that it does not only apply to ARM Makefiles, but to all other architectures as well. And instead of adding it to all ~30 affected files (which also gives no guarantee that it will be documented in any newly created config.mk files), please add it to some central doc file - either to the README, or feel free to create a doc/README.toolchain or similar that can then also be used to document things like linker options, information about known issues, etc. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de Remember, an int is not always 16 bits. I'm not sure, but if the 80386 is one step closer to Intel's slugfest with the CPU curve that is aymptotically approaching a real machine, perhaps an int has been implemented as 32 bits by some Unix vendors...? - Derek Terveer