[arm] Add support for SMMLA, SMMLS and SMMUL.

src/base/bits.h

 // Copyright 2014 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_BASE_BITS_H_
 #define V8_BASE_BITS_H_
 
 #include "include/v8stdint.h"
 #include "src/base/macros.h"
 #if V8_CC_MSVC
@@ skipping 169 matching lines @@
 inline bool SignedSubOverflow32(int32_t lhs, int32_t rhs, int32_t* val) {
 #if V8_HAS_BUILTIN_SSUB_OVERFLOW
   return __builtin_ssub_overflow(lhs, rhs, val);
 #else
   uint32_t res = static_cast<uint32_t>(lhs) - static_cast<uint32_t>(rhs);
   *val = bit_cast<int32_t>(res);
   return ((res ^ lhs) & (res ^ ~rhs) & (1U << 31)) != 0;
 #endif
 }
 
+
+// SignedMulHigh32(lhs, rhs) multiplies two signed 32-bit values |lhs| and
+// |rhs|, extracts the most significant 32 bits of the result, and returns
+// those.
+int32_t SignedMulHigh32(int32_t lhs, int32_t rhs);
+
+
+// SignedMulHighAndAdd32(lhs, rhs, acc) multiplies two signed 32-bit values
+// |lhs| and |rhs|, extracts the most significant 32 bits of the result, and
+// adds the accumulate value |acc|.
+int32_t SignedMulHighAndAdd32(int32_t lhs, int32_t rhs, int32_t acc);
+
+
+// SignedMulHighAndAdd32(lhs, rhs, acc) multiplies two signed 32-bit values
+// |lhs| and |rhs|, extracts the most significant 32 bits of the result, and
+// subtracts it from the accumulate value |acc|.
+int32_t SignedMulHighAndSub32(int32_t lhs, int32_t rhs, int32_t acc);
+
 }  // namespace bits
 }  // namespace base
 }  // namespace v8
 
 #endif  // V8_BASE_BITS_H_