1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "verifier/dex_gc_map.h"
18 
19 #include "base/logging.h"
20 
21 namespace art {
22 namespace verifier {
23 
FindBitMap(uint16_t dex_pc,bool error_if_not_present) const24 const uint8_t* DexPcToReferenceMap::FindBitMap(uint16_t dex_pc, bool error_if_not_present) const {
25   size_t num_entries = NumEntries();
26   // Do linear or binary search?
27   static const size_t kSearchThreshold = 8;
28   if (num_entries < kSearchThreshold) {
29     for (size_t i = 0; i < num_entries; i++)  {
30       if (GetDexPc(i) == dex_pc) {
31         return GetBitMap(i);
32       }
33     }
34   } else {
35     int lo = 0;
36     int hi = num_entries -1;
37     while (hi >= lo) {
38       int mid = (hi + lo) / 2;
39       int mid_pc = GetDexPc(mid);
40       if (dex_pc > mid_pc) {
41         lo = mid + 1;
42       } else if (dex_pc < mid_pc) {
43         hi = mid - 1;
44       } else {
45         return GetBitMap(mid);
46       }
47     }
48   }
49   if (error_if_not_present) {
50     LOG(ERROR) << "Didn't find reference bit map for dex_pc " << dex_pc;
51   }
52   return NULL;
53 }
54 
55 }  // namespace verifier
56 }  // namespace art
57