[libfuzzer] Refactoring coverage state-management code.
It is now less state-dependent and will allow easier comparing of
coverages of different units.
Differential Revision: http://reviews.llvm.org/D20085
llvm-svn: 269140
diff --git a/llvm/lib/Fuzzer/FuzzerTracePC.cpp b/llvm/lib/Fuzzer/FuzzerTracePC.cpp
index 1afd6e3..250deef 100644
--- a/llvm/lib/Fuzzer/FuzzerTracePC.cpp
+++ b/llvm/lib/Fuzzer/FuzzerTracePC.cpp
@@ -15,39 +15,43 @@
#include "FuzzerInternal.h"
namespace fuzzer {
-static const size_t kMapSizeInBits = 65371; // Prime.
-static const size_t kMapSizeInBitsAligned = 65536; // 2^16
-static const size_t kBitsInWord =(sizeof(uintptr_t) * 8);
-static const size_t kMapSizeInWords = kMapSizeInBitsAligned / kBitsInWord;
-static uintptr_t CurrentMap[kMapSizeInWords] __attribute__((aligned(512)));
-static uintptr_t CombinedMap[kMapSizeInWords] __attribute__((aligned(512)));
-static size_t CombinedMapSize;
+
+void PcCoverageMap::Reset() { memset(Map, 0, sizeof(Map)); }
+
+void PcCoverageMap::Update(uintptr_t Addr) {
+ uintptr_t Idx = Addr % kMapSizeInBits;
+ uintptr_t WordIdx = Idx / kBitsInWord;
+ uintptr_t BitIdx = Idx % kBitsInWord;
+ Map[WordIdx] |= 1UL << BitIdx;
+}
+
+size_t PcCoverageMap::MergeFrom(const PcCoverageMap &Other) {
+ uintptr_t Res = 0;
+ for (size_t i = 0; i < kMapSizeInWords; i++)
+ Res += __builtin_popcountl(Map[i] |= Other.Map[i]);
+ return Res;
+}
+
+static PcCoverageMap CurrentMap;
static thread_local uintptr_t Prev;
void PcMapResetCurrent() {
if (Prev) {
Prev = 0;
- memset(CurrentMap, 0, sizeof(CurrentMap));
+ CurrentMap.Reset();
}
}
-void PcMapMergeCurrentToCombined() {
- if (!Prev) return;
- uintptr_t Res = 0;
- for (size_t i = 0; i < kMapSizeInWords; i++)
- Res += __builtin_popcountl(CombinedMap[i] |= CurrentMap[i]);
- CombinedMapSize = Res;
+size_t PcMapMergeInto(PcCoverageMap *Map) {
+ if (!Prev)
+ return 0;
+ return Map->MergeFrom(CurrentMap);
}
-size_t PcMapCombinedSize() { return CombinedMapSize; }
-
static void HandlePC(uint32_t PC) {
// We take 12 bits of PC and mix it with the previous PCs.
uintptr_t Next = (Prev << 5) ^ (PC & 4095);
- uintptr_t Idx = Next % kMapSizeInBits;
- uintptr_t WordIdx = Idx / kBitsInWord;
- uintptr_t BitIdx = Idx % kBitsInWord;
- CurrentMap[WordIdx] |= 1UL << BitIdx;
+ CurrentMap.Update(Next);
Prev = Next;
}