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H A D | super.c | 3e68fbb5 Sun May 14 18:49:43 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Don't pack on-medium structures, because GCC emits crappy code
If we use __attribute__((packed)), GCC will _also_ assume that the structures aren't sensibly aligned, and it'll emit code to cope with that instead of straight word load/save. This can be _very_ suboptimal on architectures like ARM.
Ideally, we want an attribute which just tells GCC not to do any padding, without the alignment side-effects. In the absense of that, we'll just drop the 'packed' attribute and hope that everything stays as it was (which to be fair is fairly much what we expect). And add some paranoia checks in the initialisation code, which should be optimised away completely in the normal case.
Signed-off-by: David Woodhouse <dwmw2@infradead.org> 3e68fbb5 Sun May 14 18:49:43 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Don't pack on-medium structures, because GCC emits crappy code If we use __attribute__((packed)), GCC will _also_ assume that the structures aren't sensibly aligned, and it'll emit code to cope with that instead of straight word load/save. This can be _very_ suboptimal on architectures like ARM. Ideally, we want an attribute which just tells GCC not to do any padding, without the alignment side-effects. In the absense of that, we'll just drop the 'packed' attribute and hope that everything stays as it was (which to be fair is fairly much what we expect). And add some paranoia checks in the initialisation code, which should be optimised away completely in the normal case. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
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