#ifndef _WIMLIB_LZ_SARRAY_H
#define _WIMLIB_LZ_SARRAY_H
-#include "wimlib/compiler.h" /* must define '_always_inline_attribute' */
+#include "wimlib/compiler.h" /* must define '_always_inline_attribute',
+ 'likely()', and 'prefetch()'. */
#include "wimlib/lz.h" /* must define 'struct raw_match' and LZ_ASSERT() */
#include "wimlib/types.h" /* must define 'bool', 'u8', 'u16, and 'u32' */
/* Prepare for searching the current position. */
lz_sarray_update_salink(r, link);
+#if 1
+ /* Prefetch next position in SA and link.
+ *
+ * This can improve performance on large windows since the locations in
+ * SA and link at which each successive search begins are in general
+ * randomly distributed. */
+ if (likely(i + 1 < mf->window_size)) {
+ const lz_sarray_pos_t next_r = ISA[i + 1];
+ prefetch(&SA[next_r]);
+ prefetch(&link[next_r]);
+ }
+#endif
+
/* L = rank of next suffix to the left;
* R = rank of next suffix to the right;
* lenL = length of match between current position and the suffix with rank L;
}
}
- /* Here we have lenL < lenR. Extend right, unless the
- * minimum match length would be underrun. */
- if (lenR == 0)
- return nmatches;
+ /* Here we have lenL < lenR. Extend right.
+ * (No check for whether the minimum match length has
+ * been underrun is needed, provided that such lengths
+ * are marked as 0.) */
goto extend_right;
}
}