Date: Mon, 3 Aug 2015 17:34:34 +0800 From: Lei Zhang <zhanglei.april@...il.com> To: john-dev@...ts.openwall.com Subject: Re: JtR on ARM (NEON) > On Aug 3, 2015, at 10:58 AM, Solar Designer <solar@...nwall.com> wrote: > > On Mon, Aug 03, 2015 at 04:39:38AM +0200, magnum wrote: >> On 2015-07-31 10:35, Solar Designer wrote: >>>> From the figures above, MD4 and MD5 get 2x speedup; SHA1 and SHA256 >>>> have no speedup; SHA512 gets a lot slower. >>> >>> Yes. That's weird(...) Maybe unaligned accesses. >> >> How slow is NEON with unaligned scalar 32-bit? The raw formats' >> set_key() read the key (which may be unaligned) using 32-bit loads and >> places directly in the SIMD buffer. It might be a coincidence that >> MD4/MD5 happens to get aligned test vector keys and the others doesn't. >> Other than that I can't see what would be unaligned. > > I think we must not have any unaligned accesses on ARM at all. If we > currently do have any, let's fix that as a bug. > > While not completely unsupported, they are tricky: > > "How does the ARM Compiler support unaligned accesses?" > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15414.html > > http://www.heyrick.co.uk/armwiki/Unaligned_data_access I'm not very clear. Are you talking about unaligned vector load/stores or unaligned scalar load/stores? The links you posted discussed scalar load/stores. As we are not writing ARM assemblies in JtR, the compiler should be able to take care of scalar variables' alignment for us. Lei
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.