Commit Graph

5 Commits

Author SHA1 Message Date
Ma Ling
3b4b682bec x86, mem: Optimize memmove for small size and unaligned cases
movs instruction will combine data to accelerate moving data,
however we need to concern two cases about it.

1. movs instruction need long lantency to startup,
   so here we use general mov instruction to copy data.
2. movs instruction is not good for unaligned case,
   even if src offset is 0x10, dest offset is 0x0,
   we avoid and handle the case by general mov instruction.

Signed-off-by: Ma Ling <ling.ma@intel.com>
LKML-Reference: <1284664360-6138-1-git-send-email-ling.ma@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-09-24 18:57:11 -07:00
Ma, Ling
fdf4289679 x86, mem: Don't implement forward memmove() as memcpy()
memmove() allow source and destination address to be overlap, but
there is no such limitation for memcpy().  Therefore, explicitly
implement memmove() in both the forwards and backward directions, to
give us the ability to optimize memcpy().

Signed-off-by: Ma Ling <ling.ma@intel.com>
LKML-Reference: <C10D3FB0CD45994C8A51FEC1227CE22F0E483AD86A@shsmsx502.ccr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-08-23 14:14:27 -07:00
Paolo Ciarrocchi
e940659788 x86: coding style fixes to arch/x86/lib/memmove_64.c
After the patch:

  total: 0 errors, 0 warnings, 21 lines checked

no code changed:

arch/x86/lib/memmove_64.o:
   text    data     bss     dec     hex filename
    116       0       0     116      74 memmove_64.o.before
    116       0       0     116      74 memmove_64.o.after
md5:
2d6b0951cafb86a11a222cdd70f6104f  memmove_64.o.before.asm
2d6b0951cafb86a11a222cdd70f6104f  memmove_64.o.after.asm

Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 17:40:48 +02:00
Jan Engelhardt
ade1af7712 x86: remove unneded casts
x86: remove unneeded casts

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:23 +01:00
Thomas Gleixner
185f3d3890 x86_64: move lib
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:17:08 +02:00