Nikos Mavrogiannopoulos <n...@redhat.com> writes: > #define ALIGN16(x) \ > ((void *)(((ptrdiff_t)(x)+(ptrdiff_t)0x0f)&~((ptrdiff_t)0x0f)))
I think I'd prefer allocating a uint64_t array (largest type used in nettle context structs), and leave to the compiler to figure out what alignment is needed and how to get it. > What about this macros (untested, just idea demo): > > #if defined(HAVE_ALLOCA) > # define TMP_DECL_ALLOC(name, type, max, size) type *name = > alloca(sizeof (*name) * (size))) > #else if __STDC_VERSION__ >= 199901L > # define TMP_DECL_ALLOC(name, type, max, size) \ > type _tmp##name[size+16]; \ > type *name = ALIGN16(_tmp##name) > #else /* fallback for pre-C99 and pre-alloca() times > # define TMP_DECL_ALLOC(name, type, max, size) \ > type _tmp##name[max+16]; \ > type *name = ALIGN16(_tmp##name); \ > assert(size <= max) > #endif Not so nice with number of cases increased from two to three. But as you suggest, maybe we don't need the third case. But I wonder if we can get down to just one case. Which relevant compilers don't support variable length arrays? I'd guess this could be expeted mainly for embedded platforms with either older compilers, or c11 compilers taking advantage of variable-length arrays being optional. Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid 368C6677. Internet email is subject to wholesale government surveillance. _______________________________________________ nettle-bugs mailing list nettle-bugs@lists.lysator.liu.se http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
