1 files changed, 64 insertions, 0 deletions
diff --git a/libartbase/base/memory_region.cc b/libartbase/base/memory_region.cc
new file mode 100644
index 00000000000..862ff736396
--- /dev/null
+++ b/libartbase/base/memory_region.cc
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "memory_region.h"
+
+#include <stdint.h>
+#include <string.h>
+
+namespace art {
+
+void MemoryRegion::CopyFrom(size_t offset, const MemoryRegion& from) const {
+  CHECK(from.pointer() != nullptr);
+  CHECK_GT(from.size(), 0U);
+  CHECK_GE(this->size(), from.size());
+  CHECK_LE(offset, this->size() - from.size());
+  memmove(reinterpret_cast<void*>(begin() + offset), from.pointer(), from.size());
+}
+
+void MemoryRegion::StoreBits(uintptr_t bit_offset, uint32_t value, size_t length) {
+  DCHECK_LE(value, MaxInt<uint32_t>(length));
+  DCHECK_LE(length, BitSizeOf<uint32_t>());
+  DCHECK_LE(bit_offset + length, size_in_bits());
+  if (length == 0) {
+    return;
+  }
+  // Bits are stored in this order {7 6 5 4 3 2 1 0}.
+  // How many remaining bits in current byte is (bit_offset % kBitsPerByte) + 1.
+  uint8_t* out = ComputeInternalPointer<uint8_t>(bit_offset >> kBitsPerByteLog2);
+  size_t orig_len = length;
+  uint32_t orig_value = value;
+  uintptr_t bit_remainder = bit_offset % kBitsPerByte;
+  while (true) {
+    const uintptr_t remaining_bits = kBitsPerByte - bit_remainder;
+    if (length <= remaining_bits) {
+      // Length is smaller than all of remainder bits.
+      size_t mask = ((1 << length) - 1) << bit_remainder;
+      *out = (*out & ~mask) | (value << bit_remainder);
+      break;
+    }
+    // Copy remaining bits in current byte.
+    size_t value_mask = (1 << remaining_bits) - 1;
+    *out = (*out & ~(value_mask << bit_remainder)) | ((value & value_mask) << bit_remainder);
+    value >>= remaining_bits;
+    bit_remainder = 0;
+    length -= remaining_bits;
+    ++out;
+  }
+  DCHECK_EQ(LoadBits(bit_offset, orig_len), orig_value) << bit_offset << " " << orig_len;
+}
+
+}  // namespace art