Bug 935789, part 2: Implement RotateLeft/RotateRight in MFBT and use them, r=Waldo.

--HG--
extra : rebase_source : efda8cfde4ec1b8cee007f528d682830f43f9111

gfx/thebes/gfxFontconfigUtils.h

@@ -8,11 +8,11 @@
 
 #include "gfxPlatform.h"
 
+#include "mozilla/MathAlgorithms.h"
 #include "nsAutoRef.h"
 #include "nsTArray.h"
 #include "nsTHashtable.h"
 #include "nsISupportsImpl.h"
-#include "prbit.h" // for PR_ROTATE_LEFT32
 
 #include <fontconfig/fontconfig.h>
 
@@ -165,7 +165,7 @@ protected:
         static PLDHashNumber HashKey(const FcChar8 *aKey) {
             uint32_t hash = 0;
             for (const FcChar8 *c = aKey; *c != '\0'; ++c) {
-                hash = PR_ROTATE_LEFT32(hash, 3) ^ FcToLower(*c);
+                hash = mozilla::RotateLeft(hash, 3) ^ FcToLower(*c);
             }
             return hash;
         }

mfbt/MathAlgorithms.h

@@ -451,6 +451,30 @@ RoundUpPow2(size_t x)
   return size_t(1) << CeilingLog2(x);
 }
 
+/**
+ * Rotates the bits of the given value left by the amount of the shift width.
+ */
+template<typename T>
+inline T
+RotateLeft(const T t, uint_fast8_t shift)
+{
+  MOZ_ASSERT(shift < sizeof(T) * CHAR_BIT, "Shift value is too large!");
+  static_assert(IsUnsigned<T>::value, "Rotates require unsigned values");
+  return (t << shift) | (t >> (sizeof(T) * CHAR_BIT - shift));
+}
+
+/**
+ * Rotates the bits of the given value right by the amount of the shift width.
+ */
+template<typename T>
+inline T
+RotateRight(const T t, uint_fast8_t shift)
+{
+  MOZ_ASSERT(shift < sizeof(T) * CHAR_BIT, "Shift value is too large!");
+  static_assert(IsUnsigned<T>::value, "Rotates require unsigned values");
+  return (t >> shift) | (t << (sizeof(T) * CHAR_BIT - shift));
+}
+
 } /* namespace mozilla */
 
 #endif /* mozilla_MathAlgorithms_h */

netwerk/protocol/websocket/WebSocketChannel.cpp

@@ -42,13 +42,13 @@
 #include "nsNetUtil.h"
 #include "mozilla/Atomics.h"
 #include "mozilla/Attributes.h"
+#include "mozilla/MathAlgorithms.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/TimeStamp.h"
 
 #include "plbase64.h"
 #include "prmem.h"
 #include "prnetdb.h"
-#include "prbit.h"
 #include "zlib.h"
 #include <algorithm>
 
@@ -1515,7 +1515,7 @@ WebSocketChannel::ApplyMask(uint32_t mask, uint8_t *data, uint64_t len)
 
   while (len && (reinterpret_cast<uintptr_t>(data) & 3)) {
     *data ^= mask >> 24;
-    mask = PR_ROTATE_LEFT32(mask, 8);
+    mask = RotateLeft(mask, 8);
     data++;
     len--;
   }
@@ -1536,7 +1536,7 @@ WebSocketChannel::ApplyMask(uint32_t mask, uint8_t *data, uint64_t len)
 
   while (len) {
     *data ^= mask >> 24;
-    mask = PR_ROTATE_LEFT32(mask, 8);
+    mask = RotateLeft(mask, 8);
     data++;
     len--;
   }
@@ -1779,7 +1779,7 @@ WebSocketChannel::PrimeNewOutgoingMessage()
 
   while (payload < (mOutHeader + mHdrOutToSend)) {
     *payload ^= mask >> 24;
-    mask = PR_ROTATE_LEFT32(mask, 8);
+    mask = RotateLeft(mask, 8);
     payload++;
   }