Arnd Bergmann <a...@arndb.de> writes: > On Saturday 21 November 2015 20:45:38 Måns Rullgård wrote: >> On 21 November 2015 20:39:58 GMT+00:00, Arnd Bergmann <a...@arndb.de> wrote: >> >On Friday 20 November 2015 17:23:14 Stephen Boyd wrote: >> >> This is a respin of a patch series from about a year ago[1]. I >> >realized >> >> that we already had most of the code in recordmcount to figure out >> >> where we make calls to particular functions, so recording where >> >> we make calls to the integer division functions should be easy enough >> >> to add support for in the same codepaths. Looking back on the thread >> >> it seems like Mans was thinking along the same lines, although it >> >wasn't >> >> obvious to me back then or even over the last few days when I wrote >> >this. >> > >> >Shouldn't we start by allowing to build the kernel for -march=armv7ve >> >on platforms that allow it? That would seem like a simpler change >> >and likely generate better code for most people, except when you >> >actually >> >care about running the same binary kernel on older platforms. >> > >> >I tried to get a complete list of CPU cores with idiv, lpae and >> >virtualization support at some point, but I don't remember the >> >details for all Qualcomm and Marvell cores any more, to create the >> >complete configuration matrix. IIRC, all CPUs that support >> >virtualization also do lpae (they have to) and all CPUs that >> >do lpae also do idiv, but the opposite is not true. >> > >> >> The ARM ARM says anything with virt has idiv, lpae doesn't matter. > > Ok, and anything with virt also has lpae by definition. The question is > whether we care about using idiv on cores that do not have lpae, or that > have neither lpae nor virt.
The question is, are there any such cores? GCC doesn't know of any, but then it's missing most non-ARM designs. -- Måns Rullgård m...@mansr.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
