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linux/arch/m68k/lib/memmove.c

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m68knommu: add optimize memmove() function Add an m68k/coldfire optimized memmove() function for the m68knommu arch. This is the same function as used by m68k. Simple speed tests show this is faster once buffers are larger than 4 bytes, and significantly faster on much larger buffers (4 times faster above about 100 bytes). This also goes part of the way to fixing a regression caused by commit ea61bc461d09e8d331a307916530aaae808c72a2 ("m68k/m68knommu: merge MMU and non-MMU string.h"), which breaks non-coldfire non-mmu builds (which is the 68x328 and 68360 families). They currently have no memmove() fucntion defined, since there was none in the m68knommu/lib functions. Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-02-03 21:58:39 +10:00
m68k: nommu: fix memmove() with differently aligned src and dest for 68000 68000 has different alignment needs to 68020+. memcpy() checks if the destination is aligned and does a smaller copy to fix the alignment and then critically for 68000 it checks if the source is still unaligned and if it is reverts to smaller copies. memmove() does not currently do the second part and malfunctions if one of the pointers is aligned and the other isn't. This is apparently getting triggered by printk. If I put breakpoints into the new checks added by this commit the first hit looks like this: memmove (n=205, src=0x2f3971 <printk_shared_pbufs+205>, dest=0x2f3980 <printk_shared_pbufs+220>) at arch/m68k/lib/memmove.c:82 Signed-off-by: Daniel Palmer <daniel@thingy.jp> Signed-off-by: Greg Ungerer <gerg@kernel.org>
2025-12-13 21:04:01 +09:00
m68knommu: add optimize memmove() function Add an m68k/coldfire optimized memmove() function for the m68knommu arch. This is the same function as used by m68k. Simple speed tests show this is faster once buffers are larger than 4 bytes, and significantly faster on much larger buffers (4 times faster above about 100 bytes). This also goes part of the way to fixing a regression caused by commit ea61bc461d09e8d331a307916530aaae808c72a2 ("m68k/m68knommu: merge MMU and non-MMU string.h"), which breaks non-coldfire non-mmu builds (which is the 68x328 and 68360 families). They currently have no memmove() fucntion defined, since there was none in the m68knommu/lib functions. Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-02-03 21:58:39 +10:00
m68k: nommu: fix memmove() with differently aligned src and dest for 68000 68000 has different alignment needs to 68020+. memcpy() checks if the destination is aligned and does a smaller copy to fix the alignment and then critically for 68000 it checks if the source is still unaligned and if it is reverts to smaller copies. memmove() does not currently do the second part and malfunctions if one of the pointers is aligned and the other isn't. This is apparently getting triggered by printk. If I put breakpoints into the new checks added by this commit the first hit looks like this: memmove (n=205, src=0x2f3971 <printk_shared_pbufs+205>, dest=0x2f3980 <printk_shared_pbufs+220>) at arch/m68k/lib/memmove.c:82 Signed-off-by: Daniel Palmer <daniel@thingy.jp> Signed-off-by: Greg Ungerer <gerg@kernel.org>
2025-12-13 21:04:01 +09:00
m68knommu: add optimize memmove() function Add an m68k/coldfire optimized memmove() function for the m68knommu arch. This is the same function as used by m68k. Simple speed tests show this is faster once buffers are larger than 4 bytes, and significantly faster on much larger buffers (4 times faster above about 100 bytes). This also goes part of the way to fixing a regression caused by commit ea61bc461d09e8d331a307916530aaae808c72a2 ("m68k/m68knommu: merge MMU and non-MMU string.h"), which breaks non-coldfire non-mmu builds (which is the 68x328 and 68360 families). They currently have no memmove() fucntion defined, since there was none in the m68knommu/lib functions. Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-02-03 21:58:39 +10:00