[arm][arm64] Improve CountTrailingZero implementation.

src/compiler/machine-operator.h

 // Copyright 2013 the V8 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.
 
 #ifndef V8_COMPILER_MACHINE_OPERATOR_H_
 #define V8_COMPILER_MACHINE_OPERATOR_H_
 
 #include "src/base/flags.h"
 #include "src/machine-type.h"
 
@@ skipping 117 matching lines @@
     kFloat32RoundTiesEven = 1u << 10,
     kFloat64RoundTiesEven = 1u << 11,
     kFloat64RoundTiesAway = 1u << 12,
     kInt32DivIsSafe = 1u << 13,
     kUint32DivIsSafe = 1u << 14,
     kWord32ShiftIsSafe = 1u << 15,
     kWord32Ctz = 1u << 16,
     kWord64Ctz = 1u << 17,
     kWord32Popcnt = 1u << 18,
     kWord64Popcnt = 1u << 19,
+    kWord32ReverseBits = 1u << 20,
+    kWord64ReverseBits = 1u << 21,
     kAllOptionalOps = kFloat32Max | kFloat32Min | kFloat64Max | kFloat64Min |
                       kFloat32RoundDown | kFloat64RoundDown | kFloat32RoundUp |
                       kFloat64RoundUp | kFloat32RoundTruncate |
                       kFloat64RoundTruncate | kFloat64RoundTiesAway |
                       kFloat32RoundTiesEven | kFloat64RoundTiesEven |
-                      kWord32Ctz | kWord64Ctz | kWord32Popcnt | kWord64Popcnt
+                      kWord32Ctz | kWord64Ctz | kWord32Popcnt | kWord64Popcnt |
+                      kWord32ReverseBits | kWord64ReverseBits
   };
   typedef base::Flags<Flag, unsigned> Flags;
 
   explicit MachineOperatorBuilder(
       Zone* zone,
       MachineRepresentation word = MachineType::PointerRepresentation(),
       Flags supportedOperators = kNoFlags);
 
   const Operator* Word32And();
   const Operator* Word32Or();
   const Operator* Word32Xor();
   const Operator* Word32Shl();
   const Operator* Word32Shr();
   const Operator* Word32Sar();
   const Operator* Word32Ror();
   const Operator* Word32Equal();
   const Operator* Word32Clz();
   const OptionalOperator Word32Ctz();
   const OptionalOperator Word32Popcnt();
   const OptionalOperator Word64Popcnt();
+  const OptionalOperator Word32ReverseBits();
+  const OptionalOperator Word64ReverseBits();
   bool Word32ShiftIsSafe() const { return flags_ & kWord32ShiftIsSafe; }
 
   const Operator* Word64And();
   const Operator* Word64Or();
   const Operator* Word64Xor();
   const Operator* Word64Shl();
   const Operator* Word64Shr();
   const Operator* Word64Sar();
   const Operator* Word64Ror();
   const Operator* Word64Clz();
@@ skipping 188 matching lines @@
 };
 
 
 DEFINE_OPERATORS_FOR_FLAGS(MachineOperatorBuilder::Flags)
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_MACHINE_OPERATOR_H_