}
};
-// A passport for a CMP site. We want to keep track of where the given CMP is
-// and how many times it is evaluated to true or false.
-struct CmpSitePassport {
- uintptr_t PC;
- size_t Counter[2];
-
- bool IsInterestingCmpTarget() {
- static const size_t kRareEnough = 50;
- size_t C0 = Counter[0];
- size_t C1 = Counter[1];
- return C0 > kRareEnough * (C1 + 1) || C1 > kRareEnough * (C0 + 1);
- }
-};
-
-// For now, just keep a simple imprecise hash table PC => CmpSitePassport.
-// Potentially, will need to have a compiler support to have a precise mapping
-// and also thread-safety.
-struct CmpSitePassportTable {
- static const size_t kSize = 99991; // Prime.
- CmpSitePassport Passports[kSize];
-
- CmpSitePassport *GetPassport(uintptr_t PC) {
- uintptr_t Idx = PC & kSize;
- CmpSitePassport *Res = &Passports[Idx];
- if (Res->PC == 0) // Not thread safe.
- Res->PC = PC;
- return Res->PC == PC ? Res : nullptr;
- }
-};
-
-static CmpSitePassportTable CSPTable; // Zero initialized.
-
// For now, very simple: put Size bytes of Data at position Pos.
struct TraceBasedMutation {
size_t Pos;
uint64_t Arg1, uint64_t Arg2) {
if (!RecordingTraces) return;
int Added = 0;
- CmpSitePassport *CSP = CSPTable.GetPassport(PC);
- if (!CSP) return;
- CSP->Counter[ComputeCmp(CmpSize, CmpType, Arg1, Arg2)]++;
- size_t C0 = CSP->Counter[0];
- size_t C1 = CSP->Counter[1];
- // FIXME: is this a good idea or a bad?
- // if (!CSP->IsInterestingCmpTarget())
- // return;
if (Options.Verbosity >= 3)
- Printf("TraceCmp: %p %zd/%zd; %zd %zd\n", CSP->PC, C0, C1, Arg1, Arg2);
+ Printf("TraceCmp %zd/%zd: %p %zd %zd\n", CmpSize, CmpType, PC, Arg1, Arg2);
Added += TryToAddDesiredData(Arg1, Arg2, CmpSize);
Added += TryToAddDesiredData(Arg2, Arg1, CmpSize);
if (!Added && CmpSize == 4 && IsTwoByteData(Arg1) && IsTwoByteData(Arg2)) {