Index: fusl/src/malloc/memalign.c |
diff --git a/fusl/src/malloc/memalign.c b/fusl/src/malloc/memalign.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..006bd21c7673858a0206d8d131b9971a1d8bcad4 |
--- /dev/null |
+++ b/fusl/src/malloc/memalign.c |
@@ -0,0 +1,57 @@ |
+#include <stdlib.h> |
+#include <stdint.h> |
+#include <errno.h> |
+#include "libc.h" |
+ |
+/* This function should work with most dlmalloc-like chunk bookkeeping |
+ * systems, but it's only guaranteed to work with the native implementation |
+ * used in this library. */ |
+ |
+void *__memalign(size_t align, size_t len) |
+{ |
+ unsigned char *mem, *new, *end; |
+ size_t header, footer; |
+ |
+ if ((align & -align) != align) { |
+ errno = EINVAL; |
+ return NULL; |
+ } |
+ |
+ if (len > SIZE_MAX - align) { |
+ errno = ENOMEM; |
+ return NULL; |
+ } |
+ |
+ if (align <= 4*sizeof(size_t)) { |
+ if (!(mem = malloc(len))) |
+ return NULL; |
+ return mem; |
+ } |
+ |
+ if (!(mem = malloc(len + align-1))) |
+ return NULL; |
+ |
+ new = (void *)((uintptr_t)mem + align-1 & -align); |
+ if (new == mem) return mem; |
+ |
+ header = ((size_t *)mem)[-1]; |
+ |
+ if (!(header & 7)) { |
+ ((size_t *)new)[-2] = ((size_t *)mem)[-2] + (new-mem); |
+ ((size_t *)new)[-1] = ((size_t *)mem)[-1] - (new-mem); |
+ return new; |
+ } |
+ |
+ end = mem + (header & -8); |
+ footer = ((size_t *)end)[-2]; |
+ |
+ ((size_t *)mem)[-1] = header&7 | new-mem; |
+ ((size_t *)new)[-2] = footer&7 | new-mem; |
+ ((size_t *)new)[-1] = header&7 | end-new; |
+ ((size_t *)end)[-2] = footer&7 | end-new; |
+ |
+ free(mem); |
+ return new; |
+} |
+ |
+weak_alias(__memalign, memalign); |