vppinfra: improve clib_array_mask_u32

Type: improvement
Change-Id: Ibdb79a0a1c3ba56f9b2f0f2536aafcdeda5cb6d6
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 52 insertions, 33 deletions

diff --git a/src/vppinfra/vector/array_mask.h b/src/vppinfra/vector/array_mask.h
index 778ed3e638f..fa427a6f1a9 100644
--- a/src/vppinfra/vector/array_mask.h
+++ b/src/vppinfra/vector/array_mask.h
@@ -17,61 +17,80 @@
 static_always_inline void
 clib_array_mask_u32 (u32 *src, u32 mask, u32 n_elts)
 {
-  u32 i;
 #if defined(CLIB_HAVE_VEC512)
   u32x16 mask16 = u32x16_splat (mask);
-
-  for (i = 0; i + 16 <= n_elts; i += 16)
-    *((u32x16u *) (src + i)) &= mask16;
-  n_elts -= i;
-  if (n_elts)
+  if (n_elts <= 16)
     {
-      u16 m = pow2_mask (n_elts);
-      u32x16_mask_store (u32x16_mask_load_zero (src + i, m) & mask16, src + i,
-			 m);
+      u32 m = pow2_mask (n_elts);
+      u32x16 r = u32x16_mask_load_zero (src, m);
+      u32x16_mask_store (r & mask16, src, m);
+      return;
     }
-  return;
+  for (int i = 0; i < n_elts; i += 16)
+    *((u32x16u *) (src + i)) &= mask16;
+  *((u32x16u *) (src + n_elts - 16)) &= mask16;
 #elif defined(CLIB_HAVE_VEC256)
   u32x8 mask8 = u32x8_splat (mask);
-
-  for (i = 0; i + 8 <= n_elts; i += 8)
-    *((u32x8u *) (src + i)) &= mask8;
-  n_elts -= i;
-  src += i;
 #if defined(CLIB_HAVE_VEC256_MASK_LOAD_STORE)
-  if (n_elts)
+  if (n_elts <= 8)
     {
-      u8 m = pow2_mask (n_elts);
-      u32x8_mask_store (u32x8_mask_load_zero (src, m) & mask8, src, m);
+      u32 m = pow2_mask (n_elts);
+      u32x8 r = u32x8_mask_load_zero (src, m);
+      u32x8_mask_store (r & mask8, src, m);
+      return;
+    }
+#else
+  if (PREDICT_FALSE (n_elts < 4))
+    {
+      if (n_elts & 2)
+	{
+	  src[0] &= mask;
+	  src[1] &= mask;
+	  src += 2;
+	}
+      if (n_elts & 1)
+	src[0] &= mask;
+      return;
+    }
+  if (n_elts <= 8)
+    {
+      u32x4 mask4 = u32x4_splat (mask);
+      *(u32x4u *) src &= mask4;
+      *(u32x4u *) (src + n_elts - 4) &= mask4;
     }
-  return;
 #endif
+
+  for (int i = 0; i < n_elts; i += 8)
+    *((u32x8u *) (src + i)) &= mask8;
+  *((u32x8u *) (src + n_elts - 8)) &= mask8;
 #elif defined(CLIB_HAVE_VEC128)
   u32x4 mask4 = u32x4_splat (mask);
 
-  for (i = 0; i + 4 <= n_elts; i += 4)
-    *((u32x4u *) (src + i)) &= mask4;
-  n_elts -= i;
-  src += i;
-  switch (n_elts)
+  if (PREDICT_FALSE (n_elts < 4))
     {
-    case 3:
-      src[2] &= mask;
-    case 2:
-      src[1] &= mask;
-    case 1:
-      src[0] &= mask;
-    case 0:
-    default:;
+      if (n_elts & 2)
+	{
+	  src[0] &= mask;
+	  src[1] &= mask;
+	  src += 2;
+	}
+      if (n_elts & 1)
+	src[0] &= mask;
+      return;
     }
+
+  for (int i = 0; i < n_elts; i += 4)
+    *((u32x4u *) (src + i)) &= mask4;
+  *((u32x4u *) (src + n_elts - 4)) &= mask4;
   return;
-#endif
+#else
   while (n_elts > 0)
     {
       src[0] &= mask;
       src++;
       n_elts--;
     }
+#endif
 }
 
 #endif