libwebp: update to v0.5.1

third_party/libwebp/utils/bit_reader.c

Index: third_party/libwebp/utils/bit_reader.c
diff --git a/third_party/libwebp/utils/bit_reader.c b/third_party/libwebp/utils/bit_reader.c
index 45198e15368d6cf3e79958e1c131f0bb741709c1..50ffb74f9c8b9016e2ee9986ace64ae1c0d66392 100644
--- a/third_party/libwebp/utils/bit_reader.c
+++ b/third_party/libwebp/utils/bit_reader.c
@@ -16,6 +16,7 @@
 #endif
 
 #include "./bit_reader_inl.h"
+#include "../utils/utils.h"
 
 //------------------------------------------------------------------------------
 // VP8BitReader
@@ -119,11 +120,10 @@ int32_t VP8GetSignedValue(VP8BitReader* const br, int bits) {
 
 #define VP8L_LOG8_WBITS 4  // Number of bytes needed to store VP8L_WBITS bits.
 
-#if !defined(WEBP_FORCE_ALIGNED) && \
-    (defined(__arm__) || defined(_M_ARM) || defined(__aarch64__) || \
-     defined(__i386__) || defined(_M_IX86) || \
-     defined(__x86_64__) || defined(_M_X64))
-#define VP8L_USE_UNALIGNED_LOAD
+#if defined(__arm__) || defined(_M_ARM) || defined(__aarch64__) || \
+    defined(__i386__) || defined(_M_IX86) || \
+    defined(__x86_64__) || defined(_M_X64)
+#define VP8L_USE_FAST_LOAD
 #endif
 
 static const uint32_t kBitMask[VP8L_MAX_NUM_BIT_READ + 1] = {
@@ -191,15 +191,11 @@ static void ShiftBytes(VP8LBitReader* const br) {
 
 void VP8LDoFillBitWindow(VP8LBitReader* const br) {
   assert(br->bit_pos_ >= VP8L_WBITS);
-  // TODO(jzern): given the fixed read size it may be possible to force
-  //              alignment in this block.
-#if defined(VP8L_USE_UNALIGNED_LOAD)
+#if defined(VP8L_USE_FAST_LOAD)
   if (br->pos_ + sizeof(br->val_) < br->len_) {
     br->val_ >>= VP8L_WBITS;
     br->bit_pos_ -= VP8L_WBITS;
-    // The expression below needs a little-endian arch to work correctly.
-    // This gives a large speedup for decoding speed.
-    br->val_ |= (vp8l_val_t)WebPMemToUint32(br->buf_ + br->pos_) <<
+    br->val_ |= (vp8l_val_t)HToLE32(WebPMemToUint32(br->buf_ + br->pos_)) <<
                 (VP8L_LBITS - VP8L_WBITS);
     br->pos_ += VP8L_LOG8_WBITS;
     return;