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    SubjectRe: [PATCH 01/12] x86_64: memset_user()
    On Fri, Dec 21, 2018 at 08:14:12PM +0200, Igor Stoppa wrote:
    > +unsigned long __memset_user(void __user *addr, int c, unsigned long size)
    > +{
    > + long __d0;
    > + unsigned long pattern = 0;
    > + int i;
    > +
    > + for (i = 0; i < 8; i++)
    > + pattern = (pattern << 8) | (0xFF & c);

    That's inefficient.

    pattern = (unsigned char)c;
    pattern |= pattern << 8;
    pattern |= pattern << 16;
    pattern |= pattern << 32;

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