Update V8 to r6101 as required by WebKit r74534

Change-Id: I7f84af8dd732f11898fd644b2c2b1538914cb78d
diff --git a/src/safepoint-table.cc b/src/safepoint-table.cc
new file mode 100644
index 0000000..b9468a5
--- /dev/null
+++ b/src/safepoint-table.cc
@@ -0,0 +1,210 @@
+// Copyright 2010 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.
+
+#include "safepoint-table.h"
+#include "disasm.h"
+
+namespace v8 {
+namespace internal {
+
+SafepointTable::SafepointTable(Code* code) {
+  ASSERT(code->kind() == Code::OPTIMIZED_FUNCTION);
+  code_ = code;
+  Address header = code->instruction_start() + code->safepoint_table_start();
+  length_ = Memory::uint32_at(header + kLengthOffset);
+  entry_size_ = Memory::uint32_at(header + kEntrySizeOffset);
+  pc_and_deoptimization_indexes_ = header + kHeaderSize;
+  entries_ = pc_and_deoptimization_indexes_ +
+            (length_ * kPcAndDeoptimizationIndexSize);
+  ASSERT(entry_size_ > 0);
+  ASSERT_EQ(DeoptimizationIndexField::max(), Safepoint::kNoDeoptimizationIndex);
+}
+
+
+bool SafepointTable::HasRegisters(uint8_t* entry) {
+  ASSERT(IsAligned(kNumSafepointRegisters, kBitsPerByte));
+  const int num_reg_bytes = kNumSafepointRegisters >> kBitsPerByteLog2;
+  for (int i = 0; i < num_reg_bytes; i++) {
+    if (entry[i] != kNoRegisters) return true;
+  }
+  return false;
+}
+
+
+bool SafepointTable::HasRegisterAt(uint8_t* entry, int reg_index) {
+  ASSERT(reg_index >= 0 && reg_index < kNumSafepointRegisters);
+  int byte_index = reg_index >> kBitsPerByteLog2;
+  int bit_index = reg_index & (kBitsPerByte - 1);
+  return (entry[byte_index] & (1 << bit_index)) != 0;
+}
+
+
+void SafepointTable::PrintEntry(unsigned index) const {
+  disasm::NameConverter converter;
+  uint8_t* entry = GetEntry(index);
+
+  // Print the stack slot bits.
+  if (entry_size_ > 0) {
+    ASSERT(IsAligned(kNumSafepointRegisters, kBitsPerByte));
+    const int first = kNumSafepointRegisters >> kBitsPerByteLog2;
+    int last = entry_size_ - 1;
+    for (int i = first; i < last; i++) PrintBits(entry[i], kBitsPerByte);
+    int last_bits = code_->stack_slots() - ((last - first) * kBitsPerByte);
+    PrintBits(entry[last], last_bits);
+
+    // Print the registers (if any).
+    if (!HasRegisters(entry)) return;
+    for (int j = 0; j < kNumSafepointRegisters; j++) {
+      if (HasRegisterAt(entry, j)) {
+        PrintF(" | %s", converter.NameOfCPURegister(j));
+      }
+    }
+  }
+}
+
+
+void SafepointTable::PrintBits(uint8_t byte, int digits) {
+  ASSERT(digits >= 0 && digits <= kBitsPerByte);
+  for (int i = 0; i < digits; i++) {
+    PrintF("%c", ((byte & (1 << i)) == 0) ? '0' : '1');
+  }
+}
+
+
+Safepoint SafepointTableBuilder::DefineSafepoint(Assembler* assembler,
+                                                 int deoptimization_index) {
+  ASSERT(deoptimization_index != -1);
+  DeoptimizationInfo pc_and_deoptimization_index;
+  pc_and_deoptimization_index.pc = assembler->pc_offset();
+  pc_and_deoptimization_index.deoptimization_index = deoptimization_index;
+  pc_and_deoptimization_index.pc_after_gap = assembler->pc_offset();
+  deoptimization_info_.Add(pc_and_deoptimization_index);
+  indexes_.Add(new ZoneList<int>(8));
+  registers_.Add(NULL);
+  return Safepoint(indexes_.last(), registers_.last());
+}
+
+
+Safepoint SafepointTableBuilder::DefineSafepointWithRegisters(
+    Assembler* assembler, int arguments, int deoptimization_index) {
+  ASSERT(deoptimization_index != -1);
+  ASSERT(arguments == 0);  // Only case that works for now.
+  DeoptimizationInfo pc_and_deoptimization_index;
+  pc_and_deoptimization_index.pc = assembler->pc_offset();
+  pc_and_deoptimization_index.deoptimization_index = deoptimization_index;
+  pc_and_deoptimization_index.pc_after_gap = assembler->pc_offset();
+  deoptimization_info_.Add(pc_and_deoptimization_index);
+  indexes_.Add(new ZoneList<int>(8));
+  registers_.Add(new ZoneList<int>(4));
+  return Safepoint(indexes_.last(), registers_.last());
+}
+
+
+unsigned SafepointTableBuilder::GetCodeOffset() const {
+  ASSERT(emitted_);
+  return offset_;
+}
+
+
+void SafepointTableBuilder::Emit(Assembler* assembler, int bits_per_entry) {
+  // Make sure the safepoint table is properly aligned. Pad with nops.
+  assembler->Align(kIntSize);
+  assembler->RecordComment(";;; Safepoint table.");
+  offset_ = assembler->pc_offset();
+
+  // Take the register bits into account.
+  bits_per_entry += kNumSafepointRegisters;
+
+  // Compute the number of bytes per safepoint entry.
+  int bytes_per_entry =
+      RoundUp(bits_per_entry, kBitsPerByte) >> kBitsPerByteLog2;
+
+  // Emit the table header.
+  int length = deoptimization_info_.length();
+  assembler->dd(length);
+  assembler->dd(bytes_per_entry);
+
+  // Emit sorted table of pc offsets together with deoptimization indexes and
+  // pc after gap information.
+  for (int i = 0; i < length; i++) {
+    assembler->dd(deoptimization_info_[i].pc);
+    assembler->dd(EncodeDeoptimizationIndexAndGap(deoptimization_info_[i]));
+  }
+
+  // Emit table of bitmaps.
+  ZoneList<uint8_t> bits(bytes_per_entry);
+  for (int i = 0; i < length; i++) {
+    ZoneList<int>* indexes = indexes_[i];
+    ZoneList<int>* registers = registers_[i];
+    bits.Clear();
+    bits.AddBlock(0, bytes_per_entry);
+
+    // Run through the registers (if any).
+    ASSERT(IsAligned(kNumSafepointRegisters, kBitsPerByte));
+    if (registers == NULL) {
+      const int num_reg_bytes = kNumSafepointRegisters >> kBitsPerByteLog2;
+      for (int j = 0; j < num_reg_bytes; j++) {
+        bits[j] = SafepointTable::kNoRegisters;
+      }
+    } else {
+      for (int j = 0; j < registers->length(); j++) {
+        int index = registers->at(j);
+        ASSERT(index >= 0 && index < kNumSafepointRegisters);
+        int byte_index = index >> kBitsPerByteLog2;
+        int bit_index = index & (kBitsPerByte - 1);
+        bits[byte_index] |= (1 << bit_index);
+      }
+    }
+
+    // Run through the indexes and build a bitmap.
+    for (int j = 0; j < indexes->length(); j++) {
+      int index = bits_per_entry - 1 - indexes->at(j);
+      int byte_index = index >> kBitsPerByteLog2;
+      int bit_index = index & (kBitsPerByte - 1);
+      bits[byte_index] |= (1U << bit_index);
+    }
+
+    // Emit the bitmap for the current entry.
+    for (int k = 0; k < bytes_per_entry; k++) {
+      assembler->db(bits[k]);
+    }
+  }
+  emitted_ = true;
+}
+
+
+uint32_t SafepointTableBuilder::EncodeDeoptimizationIndexAndGap(
+    DeoptimizationInfo info) {
+  unsigned index = info.deoptimization_index;
+  unsigned gap_size = info.pc_after_gap - info.pc;
+  uint32_t encoding = SafepointTable::DeoptimizationIndexField::encode(index);
+  encoding |= SafepointTable::GapCodeSizeField::encode(gap_size);
+  return encoding;
+}
+
+
+} }  // namespace v8::internal