From ba25c9d14ad6de05f13d3ebb1fa9242eebf34266 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Thu, 17 Sep 2009 15:12:34 -0700 Subject: [PATCH] util: Add comments. --- lib/util.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/util.h b/lib/util.h index dad7b7c4..962bad2f 100644 --- a/lib/util.h +++ b/lib/util.h @@ -52,10 +52,19 @@ extern const char *program_name; +/* Returns the number of elements in ARRAY. */ #define ARRAY_SIZE(ARRAY) (sizeof ARRAY / sizeof *ARRAY) + +/* Returns X / Y, rounding up. X must be nonnegative to round correctly. */ #define DIV_ROUND_UP(X, Y) (((X) + ((Y) - 1)) / (Y)) + +/* Returns X rounded up to the nearest multiple of Y. */ #define ROUND_UP(X, Y) (DIV_ROUND_UP(X, Y) * (Y)) + +/* Returns X rounded down to the nearest multiple of Y. */ #define ROUND_DOWN(X, Y) ((X) / (Y) * (Y)) + +/* Returns true if X is a power of 2, otherwise false. */ #define IS_POW2(X) ((X) && !((X) & ((X) - 1))) #ifndef MIN -- 2.30.2