diff options
Diffstat (limited to 'src/fundamental')
| -rw-r--r-- | src/fundamental/macro-fundamental.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/fundamental/macro-fundamental.h b/src/fundamental/macro-fundamental.h index 940b661b0e..36d759ea1d 100644 --- a/src/fundamental/macro-fundamental.h +++ b/src/fundamental/macro-fundamental.h @@ -5,6 +5,7 @@ #include <assert.h> #endif +#include <limits.h> #include "type.h" #define _align_(x) __attribute__((__aligned__(x))) @@ -273,3 +274,34 @@ free(memory); \ (typeof(memory)) NULL; \ }) + +static inline size_t ALIGN_TO(size_t l, size_t ali) { + /* sd-boot uses UINTN for size_t, let's make sure SIZE_MAX is correct. */ + assert_cc(SIZE_MAX == ~(size_t)0); + + /* Check that alignment is exponent of 2 */ +#if SIZE_MAX == UINT_MAX + assert(__builtin_popcount(ali) == 1); +#elif SIZE_MAX == ULONG_MAX + assert(__builtin_popcountl(ali) == 1); +#elif SIZE_MAX == ULLONG_MAX + assert(__builtin_popcountll(ali) == 1); +#else + #error "Unexpected size_t" +#endif + + if (l > SIZE_MAX - (ali - 1)) + return SIZE_MAX; /* indicate overflow */ + + return ((l + ali - 1) & ~(ali - 1)); +} + +/* Same as ALIGN_TO but callable in constant contexts. */ +#define CONST_ALIGN_TO(l, ali) \ + __builtin_choose_expr( \ + __builtin_constant_p(l) && \ + __builtin_constant_p(ali) && \ + __builtin_popcountll(ali) == 1 && /* is power of 2? */ \ + (l <= SIZE_MAX - (ali - 1)), /* overflow? */ \ + ((l) + (ali) - 1) & ~((ali) - 1), \ + VOID_0) |