There is no easy way to do this, as far as I can tell. Crypto++ doesn't actually use GAS directly. It contains inline assembly, which GCC mixes with assembly code that it generates, and then passes on to the assembler. The code that GCC generates is in AT&T syntax, which NASM doesn't support, I think.
BTW, apparently someone is working on getting the latest GAS to work on Mac OS X. See http://gcc.gnu.org/ml/gcc/2009-09/msg00146.html. -------------------------------------------------- From: "Mouse" <[email protected]> Sent: Wednesday, November 18, 2009 4:38 AM To: "Crypto++ Users" <[email protected]> Subject: Re: Performance in Mac OS X > Is it possible to configure Crypto++ to use NASM instead of GAS? If so > - any guidance? > > I'll post 64-bit Mac OS X numbers later on. > > On Nov 17, 2009, at 17:27 , Wei Dai wrote: > >> I'm pretty sure GPLv3 came out way after GNU AS >> supported .intel_syntax. I >> suspect that Apple doesn't want to upgrade because they've made too >> many >> changes to the assembler and don't want to port those changes to a >> later >> version of GNU AS. >> >> I guess it wouldn't hurt to ask Apple directly. Does anyone know if >> they >> have an open source outreach/liason person? >> >> BTW, on 64-bit Mac OS X, the performance difference should be much >> smaller, >> if you compile Crypto++ into a 64-bit binary. (I don't remember if >> that >> happens automatically, or if you have to set some compiler flags.) >> >> -------------------------------------------------- >> From: "Zooko Wilcox-O'Hearn" <[email protected]> >> Sent: Tuesday, November 17, 2009 2:09 PM >> To: "Wei Dai" <[email protected]> >> Cc: "Jose Cisneros" <[email protected]>; "Crypto++ Users" >> <[email protected]> >> Subject: Re: Performance in Mac OS X >> >>> On Tuesday, 2009-11-17, at 13:47 , Wei Dai wrote: >>> >>>> That's because the assembler in Mac OS X is based on a very old >>>> version >>>> of GNU AS, which doesn't support .intel_syntax. The assembly code >>>> in >>>> Crypto++ is written in Intel syntax to be compatible with Microsoft >>>> compilers/assemblers. >>> >>> >>> It is indeed a very old version. It calls itself "v1.38". GNU AS >>> v1.38 >>> was released so long ago that I can't figure out when it was. It >>> was >>> released before 1996, and probably many years before 1996. >>> >>> I think that Apple refuses to upgrade to the new GNU assembler >>> because >>> the new one is under GPLv3 and Apple doesn't like that. >>> >>> So, I don't know if or how this situation is ever going to be >>> improved. >>> Apple will patch its ancient version of as to do the new syntax? >>> Wei Dai >>> will write old-style-syntax variants of all his assembly just for >>> Mac OS >>> X? Apple will give up and accept GPLv3- licensed assembler? All >>> Apple >>> users will instead install some open source operating system on >>> their >>> machines? >>> >>> I guess what will happen is Crypto++ will continue to be much >>> slower on >>> Mac OS X than on other systems. Maybe this doesn't matter in >>> practice. >>> Just how slow is it? Slow enough that it diminishes your battery >>> life? >>> Slow enough that it worsens the user experience? >>> >>> Maybe someone who cares about this issue should write to Apple and >>> request that their assembler support Intel syntax. >>> >>> Regards, >>> >>> Zooko >>> >> >> -- >> You received this message because you are subscribed to the "Crypto+ >> + Users" Google Group. >> To unsubscribe, send an email to >> [email protected] >> . >> More information about Crypto++ and this group is available at >> http://www.cryptopp.com >> . > > -- > You received this message because you are subscribed to the "Crypto++ > Users" Google Group. > To unsubscribe, send an email to > [email protected]. > More information about Crypto++ and this group is available at > http://www.cryptopp.com. > -- You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to [email protected]. More information about Crypto++ and this group is available at http://www.cryptopp.com.
