X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fmacro.h;h=6a5742824479165f846e2df2f32c69d935998d9d;hb=da054c3782f25b3b18243f6c76dcfcf90ba70274;hp=9f5e4552b49ed16b2ae86723ad3f3bfdd7115f69;hpb=fed1e721fd0c81e60c77120539f34e16c2585634;p=elogind.git

diff --git a/src/shared/macro.h b/src/shared/macro.h
index 9f5e4552b..6a5742824 100644
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -95,15 +95,15 @@
 #error "Wut? Pointers are neither 4 nor 8 bytes long?"
 #endif
 
-#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
-#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
-#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
+#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
+#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
+#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
 
 static inline size_t ALIGN_TO(size_t l, size_t ali) {
         return ((l + ali - 1) & ~(ali - 1));
 }
 
-#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p, ali))
+#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
 
 /* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
 static inline unsigned long ALIGN_POWER2(unsigned long u) {
@@ -197,6 +197,17 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
                                         UNIQ_T(X,xq);                   \
         })
 
+/* [(x + y - 1) / y] suffers from an integer overflow, even though the
+ * computation should be possible in the given type. Therefore, we use
+ * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
+ * quotient and the remainder, so both should be equally fast. */
+#define DIV_ROUND_UP(_x, _y)                                            \
+        __extension__ ({                                                \
+                const typeof(_x) __x = (_x);                            \
+                const typeof(_y) __y = (_y);                            \
+                (__x / __y + !!(__x % __y));                            \
+        })
+
 #define assert_se(expr)                                                 \
         do {                                                            \
                 if (_unlikely_(!(expr)))                                \