lzx.h: Align 'struct lzx_lru_queue' on x86_64
authorEric Biggers <ebiggers3@gmail.com>
Thu, 12 Jun 2014 03:34:33 +0000 (22:34 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Thu, 12 Jun 2014 04:20:56 +0000 (23:20 -0500)
include/wimlib/lzx.h

index 50d80f620de6333510004947cefc2c42eb77c9a7..ae1c6a9c696ec28bedae3fca69675d48776ac302 100644 (file)
@@ -6,6 +6,7 @@
  * */
 
 #include "wimlib/assert.h"
+#include "wimlib/compiler.h"
 #include "wimlib/util.h"
 #include "wimlib/types.h"
 
@@ -142,7 +143,13 @@ extern unsigned lzx_get_num_main_syms(u32 window_size);
 /* Least-recently used queue for match offsets.  */
 struct lzx_lru_queue {
        u32 R[LZX_NUM_RECENT_OFFSETS];
-};
+}
+#ifdef __x86_64__
+_aligned_attribute(8)  /* Improves performance of LZX compression by 1% - 2%;
+                         specifically, this speeds up
+                         lzx_get_near_optimal_match().  */
+#endif
+;
 
 /* In the LZX format, an offset of n bytes is actually encoded
  * as (n + LZX_OFFSET_OFFSET).  */