> From: Will Deacon [mailto:will.deacon@xxxxxxx] > Sent: Thursday, October 30, 2014 8:01 PM > To: Wang, Yalin > Cc: 'Rob Herring'; 'Joe Perches'; 'Russell King - ARM Linux'; 'linux- > kernel@xxxxxxxxxxxxxxx'; 'akinobu.mita@xxxxxxxxx'; 'linux-mm@xxxxxxxxx'; > 'linux-arm-kernel@xxxxxxxxxxxxxxxxxxx' > Subject: Re: [RFC V5 3/3] arm64:add bitrev.h file to support rbit > instruction > > > +static __always_inline __attribute_const__ u32 __arch_bitrev32(u32 x) > > +{ > > + if (__builtin_constant_p(x)) { > > + x = (x >> 16) | (x << 16); > > + x = ((x & 0xFF00FF00) >> 8) | ((x & 0x00FF00FF) << 8); > > + x = ((x & 0xF0F0F0F0) >> 4) | ((x & 0x0F0F0F0F) << 4); > > + x = ((x & 0xCCCCCCCC) >> 2) | ((x & 0x33333333) << 2); > > + return ((x & 0xAAAAAAAA) >> 1) | ((x & 0x55555555) << 1); > > Shouldn't this part be in the generic code? Good idea, I will change this part into linux/bitrev.h . Thanks -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href