martong added inline comments.
================
Comment at: clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp:51
+ ProgramStateRef StFalse = assume(State, Cond, false);
+ if (!StFalse) { // both infeasible
+ ProgramStateRef Infeasible = State->cloneAsInfeasible();
----------------
martong wrote:
> martong wrote:
> > martong wrote:
> > > steakhal wrote:
> > > > Should we mark this `LLVM_UNLIKELY(cond)`?
> > > > I would expect this function to be quite hot, and infeasible states
> > > > rare.
> > > >
> > > > Could we measure this one?
> > > Yes, it could be.
> > >
> > > Let me come back with some measurement results soon. I am going to use
> > > llvm statistics macros to measure this, but that makes sense on top of
> > > D124758
> > This is what I use for the measurement, stay tuned for the results.
> > ```
> > diff --git a/clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp
> > b/clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp
> > index ef98ed7d36e9..82097d67ec0f 100644
> > --- a/clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp
> > +++ b/clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp
> > @@ -16,10 +16,16 @@
> > #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
> > #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
> > #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
> > +#include "llvm/ADT/Statistic.h"
> >
> > using namespace clang;
> > using namespace ento;
> >
> > +#define DEBUG_TYPE "CoreEngine"
> > +
> > +STATISTIC(NumInfeasible, "The # of infeasible states");
> > +STATISTIC(NumFeasible, "The # of feasible states");
> > +
> > ConstraintManager::~ConstraintManager() = default;
> >
> > static DefinedSVal getLocFromSymbol(const ProgramStateRef &State,
> > @@ -51,16 +57,20 @@ ConstraintManager::assumeDual(ProgramStateRef State,
> > DefinedSVal Cond) {
> > if (!StFalse) { // both infeasible
> > ProgramStateRef Infeasible = State->cloneAsInfeasible();
> > assert(Infeasible->isInfeasible());
> > + ++NumInfeasible;
> > return ProgramStatePair(Infeasible, Infeasible);
> > }
> > + ++NumFeasible;
> > return ProgramStatePair(nullptr, StFalse);
> > }
> >
> > ProgramStateRef StFalse = assumeInternal(State, Cond, false);
> > if (!StFalse) {
> > + ++NumFeasible;
> > return ProgramStatePair(StTrue, nullptr);
> > }
> >
> > + ++NumFeasible;
> > return ProgramStatePair(StTrue, StFalse);
> > }
> > ```
> Ups, the purpose of the measure is to determine if UNLIKELY is justified, so
> this diff seems better, restarted the measurement with it.
> ```
> --- a/clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp
> +++ b/clang/lib/StaticAnalyzer/Core/ConstraintManager.cpp
> @@ -16,10 +16,16 @@
> #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
> #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
> #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
> +#include "llvm/ADT/Statistic.h"
>
> using namespace clang;
> using namespace ento;
>
> +#define DEBUG_TYPE "CoreEngine"
> +
> +STATISTIC(NumInfeasible, "The # of infeasible states");
> +STATISTIC(NumFeasible, "The # of feasible states");
> +
> ConstraintManager::~ConstraintManager() = default;
>
> static DefinedSVal getLocFromSymbol(const ProgramStateRef &State,
> @@ -51,8 +57,10 @@ ConstraintManager::assumeDual(ProgramStateRef State,
> DefinedSVal Cond) {
> if (!StFalse) { // both infeasible
> ProgramStateRef Infeasible = State->cloneAsInfeasible();
> assert(Infeasible->isInfeasible());
> + ++NumInfeasible;
> return ProgramStatePair(Infeasible, Infeasible);
> }
> + ++NumFeasible;
> return ProgramStatePair(nullptr, StFalse);
> }
>
> ```
This is indeed UNLIKELY. Seems like a good upper-bound for the ratio's order of
magnitude is around 1000 / 10 million i.e. 0.0001.
{F22964634}
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D124674/new/
https://reviews.llvm.org/D124674
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
