Messages in this thread | | | Date | Fri, 21 Dec 2018 10:25:16 -0800 | From | Matthew Wilcox <> | Subject | Re: [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;
| |