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    SubjectRe: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions
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    On 21 November 2015 20:39:58 GMT+00:00, Arnd Bergmann <arnd@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.
    >
    > Arnd

    The ARM ARM says anything with virt has idiv, lpae doesn't matter. ARMv7-R also has idiv. I've no idea if anyone runs Linux on those though.
    --
    Måns Rullgård


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