Makefile uses new define

freelist/Makefile

@@ -1,7 +1,7 @@
 CC = gcc
 CFLAGS = -Wall -O2
 
-CFLAGS += -DFREELIST_NOALIGN
+CFLAGS += -DFREELIST_ALIGN
 
 TARGET = main.elf
 SRC = main.c freelist.c

freelist/freelist.h

@@ -5,27 +5,26 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-/* Fiddle these around according to your need. Delete or check makefile */
+/* Align to nearest multiple of align */
-#ifdef FREELIST_NOALIGN
+static inline size_t align_up_to(size_t n, size_t align) {
-#define ALIGN(x) (x)
+    return (n + align - 1) & ~(align - 1);
-#else // FREELIST_NOALIGN
-
-/* Align to nearest multiple of sizeof(void*) */
-static inline size_t align_up(size_t n) {
-    return (n + sizeof(void *) - 1) & ~(sizeof(void *) - 1);
 }
 
-#define ALIGN(x) (align_up(x))
+/* Fiddle these around according to your need. Delete or check makefile */
-#endif // FREELIST_NOALIGN
+#ifdef FREELIST_ALIGN
+#define ALIGN(x) (align_up_to(x, sizeof(void *)))
+#else
+#define ALIGN(x) (x)
+#endif
 
 typedef struct FreeListBlock FreeListBlock;
 
 typedef struct {
-    uintptr_t  start;
-    uintptr_t  end;
     FreeListBlock *free;
-    size_t     size;
+    uintptr_t      start;
-    size_t     allocated;
+    uintptr_t      end;
+    size_t         size;
+    size_t         allocated;
 } FreeList;
 
 int    fl_init(FreeList *fl, uintptr_t start, uintptr_t end, size_t itemsize);