From: Damjan Marion <damarion@cisco.com>
Date: Mon, 25 Jun 2018 23:29:55 +0000 (+0200)
Subject: SIMD optimized linear search in clib_bitmap_first_set
X-Git-Tag: v18.07-rc1~112
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F12%2F13212%2F3;p=vpp.git

SIMD optimized linear search in clib_bitmap_first_set

Change-Id: Ib3a55598a83cc99485b40e38e7c406ecb126fd42
Signed-off-by: Damjan Marion <damarion@cisco.com>
---

diff --git a/src/vppinfra/bitmap.h b/src/vppinfra/bitmap.h
index dbf9eeb2232..9418b1fcced 100644
--- a/src/vppinfra/bitmap.h
+++ b/src/vppinfra/bitmap.h
@@ -384,8 +384,29 @@ do {									\
 always_inline uword
 clib_bitmap_first_set (uword * ai)
 {
-  uword i;
-  for (i = 0; i < vec_len (ai); i++)
+  uword i = 0;
+#if uword_bits == 64
+#if defined (CLIB_HAVE_VEC256)
+  while (i + 7 < vec_len (ai))
+    {
+      u64x4 v;
+      v = u64x4_load_unaligned (ai + i) | u64x4_load_unaligned (ai + i + 4);
+      if (!u64x4_is_all_zero (v))
+	break;
+      i += 8;
+    }
+#elif defined (CLIB_HAVE_VEC128)
+  while (i + 3 < vec_len (ai))
+    {
+      u64x2 v;
+      v = u64x2_load_unaligned (ai + i) | u64x2_load_unaligned (ai + i + 2);
+      if (!u64x2_is_all_zero (v))
+	break;
+      i += 4;
+    }
+#endif
+#endif
+  for (; i < vec_len (ai); i++)
     {
       uword x = ai[i];
       if (x != 0)