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2011-12-05x86/div64: Add a micro-optimization shortcut if base is power of twoSebastian Andrzej Siewior1-8/+14
In the target code I have a do_div(x, PAGE_SIZE). The x86-64 version of it was doing a shift and a mask which is clever. The 32bit version of it had a div operation in it which made me think. After digging I noticed that x86 has an optimized version of it. This patch adds this shift and mask optimization if base is constant so we don't have any runtime "checking" overhead since most users use a power of ten. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1322649814-544-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-22x86: Fix ASM_X86__ header guardsH. Peter Anvin1-3/+3
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since: a. the double underscore is ugly and pointless. b. no leading underscore violates namespace constraints. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22x86, um: ... and asm-x86 moveAl Viro1-0/+60
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>