b_width_log2 and b_height_log2 lookups

    Replace case statement with lookup.
    Small speed gain at low speed settings but at speed 2+ where the
    number of motion searches etc. falls the impact rises to ~3-4%.

    Change-Id: Idff639b7b302ee65e042b7bf836943ac0a06fad8

Change-Id: I5940719a4a161f8c26ac9a6753f1678494cec644

3 files changed, 39 insertions, 35 deletions

diff --git a/vp9/common/vp9_blockd.h b/vp9/common/vp9_blockd.h
index 550794218..8c5827663 100644
--- a/vp9/common/vp9_blockd.h
+++ b/vp9/common/vp9_blockd.h
@@ -20,6 +20,7 @@
 #include "vpx_ports/mem.h"
 #include "vp9/common/vp9_common.h"
 #include "vp9/common/vp9_enums.h"
+#include "vp9/common/vp9_common_data.h"
 
 #define BLOCK_SIZE_GROUPS   4
 #define MAX_MB_SEGMENTS     8
@@ -141,43 +142,10 @@ typedef enum {
 } MV_REFERENCE_FRAME;
 
 static INLINE int b_width_log2(BLOCK_SIZE_TYPE sb_type) {
-  switch (sb_type) {
-    case BLOCK_SIZE_SB4X8:
-    case BLOCK_SIZE_AB4X4: return 0;
-    case BLOCK_SIZE_SB8X4:
-    case BLOCK_SIZE_SB8X8:
-    case BLOCK_SIZE_SB8X16: return 1;
-    case BLOCK_SIZE_SB16X8:
-    case BLOCK_SIZE_MB16X16:
-    case BLOCK_SIZE_SB16X32: return 2;
-    case BLOCK_SIZE_SB32X16:
-    case BLOCK_SIZE_SB32X32:
-    case BLOCK_SIZE_SB32X64: return 3;
-    case BLOCK_SIZE_SB64X32:
-    case BLOCK_SIZE_SB64X64: return 4;
-    default: assert(0);
-      return -1;
-  }
+  return b_width_log2_lookup[sb_type];
 }
-
 static INLINE int b_height_log2(BLOCK_SIZE_TYPE sb_type) {
-  switch (sb_type) {
-    case BLOCK_SIZE_SB8X4:
-    case BLOCK_SIZE_AB4X4: return 0;
-    case BLOCK_SIZE_SB4X8:
-    case BLOCK_SIZE_SB8X8:
-    case BLOCK_SIZE_SB16X8: return 1;
-    case BLOCK_SIZE_SB8X16:
-    case BLOCK_SIZE_MB16X16:
-    case BLOCK_SIZE_SB32X16: return 2;
-    case BLOCK_SIZE_SB16X32:
-    case BLOCK_SIZE_SB32X32:
-    case BLOCK_SIZE_SB64X32: return 3;
-    case BLOCK_SIZE_SB32X64:
-    case BLOCK_SIZE_SB64X64: return 4;
-    default: assert(0);
-      return -1;
-  }
+  return b_height_log2_lookup[sb_type];
 }
 
 static INLINE int mi_width_log2(BLOCK_SIZE_TYPE sb_type) {
diff --git a/vp9/common/vp9_common_data.c b/vp9/common/vp9_common_data.c
new file mode 100644
index 000000000..feb107e13
--- /dev/null
+++ b/vp9/common/vp9_common_data.c
@@ -0,0 +1,17 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "vp9/common/vp9_common_data.h"
+
+// Log 2 conversion lookup tables for block width and height
+const int b_width_log2_lookup[BLOCK_SIZE_TYPES] =
+  {0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4};
+const int b_height_log2_lookup[BLOCK_SIZE_TYPES] =
+  {0, 1, 0, 1, 2, 1, 2, 3, 2, 3, 4, 3, 4};
diff --git a/vp9/common/vp9_common_data.h b/vp9/common/vp9_common_data.h
new file mode 100644
index 000000000..f080fddc7
--- /dev/null
+++ b/vp9/common/vp9_common_data.h
@@ -0,0 +1,19 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef VP9_COMMON_VP9_COMMON_DATA_H_
+#define VP9_COMMON_VP9_COMMON_DATA_H_
+
+#include "vp9/common/vp9_enums.h"
+
+extern const int b_width_log2_lookup[BLOCK_SIZE_TYPES];
+extern const int b_height_log2_lookup[BLOCK_SIZE_TYPES];
+
+#endif    // VP9_COMMON_VP9_COMMON_DATA_H