On 05/30/2014 08:48 AM, Andy Lutomirski wrote: > This adds a macro GET(x) to convert x from big-endian to > little-endian. Hopefully I put it everywhere it needs to go and got > all the cases needed for everyone's linux/elf.h. > > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > --- > arch/x86/vdso/vdso2c.c | 15 ++++++++++++ > arch/x86/vdso/vdso2c.h | 63 ++++++++++++++++++++++++++++---------------------- > 2 files changed, 50 insertions(+), 28 deletions(-) A couple of observations: 1. We shouldn't use double-underscore in host C code. 2. It would be nice if we can take these sort of things (host-build helper macros) and move them to some common file in the Linux kernel eventually, so it would be a good thing to make the naming a little less general. 3. Even though it isn't necessary, making it work on 8-bit values so one doesn't have to worry about the type would seem like a good thing. I came up with the following, it seems like a reasonable simplification: > #define _LE(x, bits, ifnot) \ > __builtin_choose_expr( \ > (sizeof(x) == bits/8), \ > (__typeof__(x))le##bits##toh(x), ifnot) > > extern void bad_le(uint64_t); > #define _LAST_LE(x) \ > __builtin_choose_expr(sizeof(x) == 1, (x), bad_le(x)) > > #define LE(x) \ > _LE(x, 64, _LE(x, 32, _LE(x, 16, _LAST_LE(x)))) What do you think? -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
