Merge a few A64 utils into the CompilerIntrinsics.

src/compiler-intrinsics.cc

-// Copyright 2013 the V8 project authors. All rights reserved.
+// Copyright 2006-2013 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"
-
+#include "compiler-intrinsics.h"
 
 namespace v8 {
 namespace internal {
 
-#define __ assm->
-
-
-int CountLeadingZeros(uint64_t value, int width) {
-  // TODO(jbramley): Optimize this for A64 hosts.
+int C_CountRedundantLeadingSignBits(int64_t value, int width) {
   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;
+  uint64_t val = static_cast<uint64_t>((value >= 0) ? value : ~value);
+  return CountLeadingZeros(val, width) - 1;
 }
 
 
-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));
-
+int C_CountSetBits(uint64_t value, int width) {
   // Mask out unused bits to ensure that they are not counted.
-  value &= (0xffffffffffffffffUL >> (64-width));
+  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