diff options
| -rw-r--r-- | lib/Analysis/LazyValueInfo.cpp | 51 |
1 files changed, 44 insertions, 7 deletions
diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp index e770ed4..7ec35cd 100644 --- a/lib/Analysis/LazyValueInfo.cpp +++ b/lib/Analysis/LazyValueInfo.cpp @@ -77,12 +77,18 @@ public: static LVILatticeVal get(Constant *C) { LVILatticeVal Res; - Res.markConstant(C); + if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) + Res.markConstantRange(ConstantRange(CI->getValue(), CI->getValue()+1)); + else if (!isa<UndefValue>(C)) + Res.markConstant(C); return Res; } static LVILatticeVal getNot(Constant *C) { LVILatticeVal Res; - Res.markNotConstant(C); + if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) + Res.markConstantRange(ConstantRange(CI->getValue()+1, CI->getValue())); + else + Res.markNotConstant(C); return Res; } @@ -154,8 +160,6 @@ public: if (NewR.isEmptySet()) return markOverdefined(); - assert(Range.contains(NewR) && - "Marking constant range with non-subset range!"); bool changed = Range == NewR; Range = NewR; return changed; @@ -202,8 +206,8 @@ public: if (RHS.isConstantRange()) { if (isConstantRange()) { - ConstantRange NewR = Range.intersectWith(RHS.getConstantRange()); - if (NewR.isEmptySet()) + ConstantRange NewR = Range.unionWith(RHS.getConstantRange()); + if (NewR.isFullSet()) return markOverdefined(); else return markConstantRange(NewR); @@ -498,7 +502,7 @@ LVILatticeVal LVIQuery::getEdgeValue(BasicBlock *BBFrom, BasicBlock *BBTo) { // it is. if (BI->getCondition() == Val) return LVILatticeVal::get(ConstantInt::get( - Type::getInt1Ty(Val->getContext()), isTrueDest)); + Type::getInt1Ty(Val->getContext()), isTrueDest)); // If the condition of the branch is an equality comparison, we may be // able to infer the value. @@ -679,6 +683,11 @@ Constant *LazyValueInfo::getConstantOnEdge(Value *V, BasicBlock *FromBB, if (Result.isConstant()) return Result.getConstant(); + else if (Result.isConstantRange()) { + ConstantRange CR = Result.getConstantRange(); + if (const APInt *SingleVal = CR.getSingleElement()) + return ConstantInt::get(V->getContext(), *SingleVal); + } return 0; } @@ -699,6 +708,34 @@ LazyValueInfo::getPredicateOnEdge(unsigned Pred, Value *V, Constant *C, return Unknown; } + if (Result.isConstantRange()) { + ConstantInt *CI = cast<ConstantInt>(C); + ConstantRange CR = Result.getConstantRange(); + if (Pred == ICmpInst::ICMP_EQ) { + if (!CR.contains(CI->getValue())) + return False; + + if (CR.isSingleElement() && CR.contains(CI->getValue())) + return True; + } else if (Pred == ICmpInst::ICMP_NE) { + if (!CR.contains(CI->getValue())) + return True; + + if (CR.isSingleElement() && CR.contains(CI->getValue())) + return False; + } + + // Handle more complex predicates. + ConstantRange RHS(CI->getValue(), CI->getValue()+1); + ConstantRange TrueValues = ConstantRange::makeICmpRegion(Pred, RHS); + if (CR.intersectWith(TrueValues).isEmptySet()) + return False; + else if (CR.intersectWith(TrueValues) == CR) + return True; + + return Unknown; + } + if (Result.isNotConstant()) { // If this is an equality comparison, we can try to fold it knowing that // "V != C1". |