More code clean up based on patch feedback.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84074 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2009-10-14 05:22:03 +00:00
parent 3dbe43b1b5
commit d83c2ca336

View File

@ -220,16 +220,16 @@ namespace {
private:
// VisitedPHIs - Track PHI nodes visited by a aliasCheck() call.
SmallSet<const Value*, 16> VisitedPHIs;
SmallSet<const PHINode*, 16> VisitedPHIs;
// aliasGEP - Provide a bunch of ad-hoc rules to disambiguate a GEP instruction
// against another.
AliasResult aliasGEP(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size);
// aliasGEP - Provide a bunch of ad-hoc rules to disambiguate a PHI instruction
// aliasPHI - Provide a bunch of ad-hoc rules to disambiguate a PHI instruction
// against another.
AliasResult aliasPHI(const Value *V1, unsigned V1Size,
AliasResult aliasPHI(const PHINode *PN, unsigned PNSize,
const Value *V2, unsigned V2Size);
AliasResult aliasCheck(const Value *V1, unsigned V1Size,
@ -477,18 +477,17 @@ BasicAliasAnalysis::aliasGEP(const Value *V1, unsigned V1Size,
return MayAlias;
}
// aliasGEP - Provide a bunch of ad-hoc rules to disambiguate a PHI instruction
// aliasPHI - Provide a bunch of ad-hoc rules to disambiguate a PHI instruction
// against another.
AliasAnalysis::AliasResult
BasicAliasAnalysis::aliasPHI(const Value *V1, unsigned V1Size,
BasicAliasAnalysis::aliasPHI(const PHINode *PN, unsigned PNSize,
const Value *V2, unsigned V2Size) {
// The PHI node has already been visited, avoid recursion any further.
if (!VisitedPHIs.insert(V1))
if (!VisitedPHIs.insert(PN))
return MayAlias;
SmallSet<Value*, 4> UniqueSrc;
SmallVector<Value*, 4> V1Srcs;
const PHINode *PN = cast<PHINode>(V1);
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *PV1 = PN->getIncomingValue(i);
if (isa<PHINode>(PV1))
@ -499,13 +498,18 @@ BasicAliasAnalysis::aliasPHI(const Value *V1, unsigned V1Size,
V1Srcs.push_back(PV1);
}
AliasResult Alias = aliasCheck(V1Srcs[0], PNSize, V2, V2Size);
// Early exit if the check of the first PHI source against V2 is MayAlias.
// Other results are not possible.
if (Alias == MayAlias)
return MayAlias;
// If all sources of the PHI node NoAlias or MustAlias V2, then returns
// NoAlias / MustAlias. Otherwise, returns MayAlias.
AliasResult Alias = aliasCheck(V1Srcs[0], V1Size, V2, V2Size);
for (unsigned i = 1, e = V1Srcs.size(); i != e; ++i) {
Value *V = V1Srcs[i];
AliasResult ThisAlias = aliasCheck(V, V1Size, V2, V2Size);
if (ThisAlias != Alias)
AliasResult ThisAlias = aliasCheck(V, PNSize, V2, V2Size);
if (ThisAlias != Alias || ThisAlias == MayAlias)
return MayAlias;
}
@ -577,8 +581,8 @@ BasicAliasAnalysis::aliasCheck(const Value *V1, unsigned V1Size,
std::swap(V1, V2);
std::swap(V1Size, V2Size);
}
if (isa<PHINode>(V1))
return aliasPHI(V1, V1Size, V2, V2Size);
if (const PHINode *PN = dyn_cast<PHINode>(V1))
return aliasPHI(PN, V1Size, V2, V2Size);
return MayAlias;
}