Rename A64 port to ARM64 port

src/a64/utils-a64.cc

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#if V8_TARGET_ARCH_A64
-
-#include "a64/utils-a64.h"
-
-
-namespace v8 {
-namespace internal {
-
-#define __ assm->
-
-
-int CountLeadingZeros(uint64_t value, int width) {
-  // TODO(jbramley): Optimize this for A64 hosts.
-  ASSERT((width == 32) || (width == 64));
-  int count = 0;
-  uint64_t bit_test = 1UL << (width - 1);
-  while ((count < width) && ((bit_test & value) == 0)) {
-    count++;
-    bit_test >>= 1;
-  }
-  return count;
-}
-
-
-int CountLeadingSignBits(int64_t value, int width) {
-  // TODO(jbramley): Optimize this for A64 hosts.
-  ASSERT((width == 32) || (width == 64));
-  if (value >= 0) {
-    return CountLeadingZeros(value, width) - 1;
-  } else {
-    return CountLeadingZeros(~value, width) - 1;
-  }
-}
-
-
-int CountTrailingZeros(uint64_t value, int width) {
-  // TODO(jbramley): Optimize this for A64 hosts.
-  ASSERT((width == 32) || (width == 64));
-  int count = 0;
-  while ((count < width) && (((value >> count) & 1) == 0)) {
-    count++;
-  }
-  return count;
-}
-
-
-int CountSetBits(uint64_t value, int width) {
-  // TODO(jbramley): Would it be useful to allow other widths? The
-  // implementation already supports them.
-  ASSERT((width == 32) || (width == 64));
-
-  // Mask out unused bits to ensure that they are not counted.
-  value &= (0xffffffffffffffffUL >> (64-width));
-
-  // Add up the set bits.
-  // The algorithm works by adding pairs of bit fields together iteratively,
-  // where the size of each bit field doubles each time.
-  // An example for an 8-bit value:
-  // Bits:  h  g  f  e  d  c  b  a
-  //         \ |   \ |   \ |   \ |
-  // value = h+g   f+e   d+c   b+a
-  //            \    |      \    |
-  // value =   h+g+f+e     d+c+b+a
-  //                  \          |
-  // value =       h+g+f+e+d+c+b+a
-  value = ((value >> 1) & 0x5555555555555555) + (value & 0x5555555555555555);
-  value = ((value >> 2) & 0x3333333333333333) + (value & 0x3333333333333333);
-  value = ((value >> 4) & 0x0f0f0f0f0f0f0f0f) + (value & 0x0f0f0f0f0f0f0f0f);
-  value = ((value >> 8) & 0x00ff00ff00ff00ff) + (value & 0x00ff00ff00ff00ff);
-  value = ((value >> 16) & 0x0000ffff0000ffff) + (value & 0x0000ffff0000ffff);
-  value = ((value >> 32) & 0x00000000ffffffff) + (value & 0x00000000ffffffff);
-
-  return value;
-}
-
-
-int MaskToBit(uint64_t mask) {
-  ASSERT(CountSetBits(mask, 64) == 1);
-  return CountTrailingZeros(mask, 64);
-}
-
-
-} }  // namespace v8::internal
-
-#endif  // V8_TARGET_ARCH_A64