-
Rasmus Villemoes authored
Since FORMAT_TYPE_INT is simply 1 more than FORMAT_TYPE_UINT, and similarly for BYTE/UBYTE, SHORT/USHORT, LONG/ULONG, we can eliminate a few instructions by making SIGN have the value 1 instead of 2, and then use arithmetic instead of branches for computing the right spec->type. It's a little hacky, but certainly in the same spirit as SMALL needing to have the value 0x20. For example for the spec->qualifier == 'l' case, gcc now generates 75e: 0f b6 53 01 movzbl 0x1(%rbx),%edx 762: 83 e2 01 and $0x1,%edx 765: 83 c2 09 add $0x9,%edx 768: 88 13 mov %dl,(%rbx) instead of 763: 0f b6 53 01 movzbl 0x1(%rbx),%edx 767: 83 e2 02 and $0x2,%edx 76a: 80 fa 01 cmp $0x1,%dl 76d: 19 d2 sbb %edx,%edx 76f: 83 c2 0a add $0xa,%edx 772: 88 13 mov %dl,(%rbx) Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
51be17df