Don't bother counting alias results, allow the AliasAnalysisCounter to do that.

llvm-svn: 5505
This commit is contained in:
Chris Lattner 2003-02-07 20:39:48 +00:00
parent 9a734b6c24
commit fdc902e6f2
2 changed files with 8 additions and 37 deletions

View File

@ -25,14 +25,10 @@
#include "llvm/Constants.h"
#include "llvm/GlobalValue.h"
#include "llvm/DerivedTypes.h"
#include "Support/Statistic.h"
// Register the AliasAnalysis interface, providing a nice name to refer to.
namespace {
RegisterAnalysisGroup<AliasAnalysis> Z("Alias Analysis");
Statistic<> NumNoAlias ("basic-aa", "Number of 'no alias' replies");
Statistic<> NumMayAlias ("basic-aa", "Number of 'may alias' replies");
Statistic<> NumMustAlias("basic-aa", "Number of 'must alias' replies");
}
// CanModify - Define a little visitor class that is used to check to see if
@ -145,20 +141,6 @@ static const Value *getUnderlyingObject(const Value *V) {
return 0;
}
static inline AliasAnalysis::Result MustAlias() {
++NumMustAlias;
return AliasAnalysis::MustAlias;
}
static inline AliasAnalysis::Result MayAlias() {
++NumMayAlias;
return AliasAnalysis::MayAlias;
}
static inline AliasAnalysis::Result NoAlias() {
++NumNoAlias;
return AliasAnalysis::NoAlias;
}
// alias - Provide a bunch of ad-hoc rules to disambiguate in common cases, such
// as array references. Note that this function is heavily tail recursive.
@ -173,11 +155,11 @@ AliasAnalysis::Result BasicAliasAnalysis::alias(const Value *V1,
V2 = CPR->getValue();
// Are we checking for alias of the same value?
if (V1 == V2) return ::MustAlias();
if (V1 == V2) return MustAlias;
if ((!isa<PointerType>(V1->getType()) || !isa<PointerType>(V2->getType())) &&
V1->getType() != Type::LongTy && V2->getType() != Type::LongTy)
return ::NoAlias(); // Scalars cannot alias each other
return NoAlias; // Scalars cannot alias each other
// Strip off cast instructions...
if (const Instruction *I = dyn_cast<CastInst>(V1))
@ -216,7 +198,7 @@ AliasAnalysis::Result BasicAliasAnalysis::alias(const Value *V1,
//
if (AllConstant &&
alias(GEP1->getOperand(0), GEP2->getOperand(1)) != MayAlias)
return ::NoAlias();
return NoAlias;
}
// Figure out what objects these things are pointing to if we can...
@ -226,16 +208,16 @@ AliasAnalysis::Result BasicAliasAnalysis::alias(const Value *V1,
// Pointing at a discernable object?
if (O1 && O2) {
// If they are two different objects, we know that we have no alias...
if (O1 != O2) return ::NoAlias();
if (O1 != O2) return NoAlias;
// If they are the same object, they we can look at the indexes. If they
// index off of the object is the same for both pointers, they must alias.
// If they are provably different, they must not alias. Otherwise, we can't
// tell anything.
} else if (O1 && isa<ConstantPointerNull>(V2)) {
return ::NoAlias(); // Unique values don't alias null
return NoAlias; // Unique values don't alias null
} else if (O2 && isa<ConstantPointerNull>(V1)) {
return ::NoAlias(); // Unique values don't alias null
return NoAlias; // Unique values don't alias null
}
return MayAlias;

View File

@ -9,12 +9,6 @@
#include "llvm/Analysis/DSGraph.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Module.h"
#include "Support/Statistic.h"
namespace {
Statistic<> NumNoAlias ("ds-aa", "Number of 'no alias' replies");
Statistic<> NumMayAlias ("ds-aa", "Number of 'may alias' replies");
};
namespace {
class DSAA : public Pass, public AliasAnalysis {
@ -104,18 +98,14 @@ AliasAnalysis::Result DSAA::alias(const Value *V1, const Value *V2) {
if (I->second.getNode() != J->second.getNode()) {
// Return noalias if one of the nodes is complete...
if ((~I->second.getNode()->NodeType | ~J->second.getNode()->NodeType)
& DSNode::Incomplete) {
++NumNoAlias;
& DSNode::Incomplete)
return NoAlias;
}
// both are incomplete, they may alias...
} else {
// Both point to the same node, see if they point to different
// offsets... FIXME: This needs to know the size of the alias query
if (I->second.getOffset() != J->second.getOffset()) {
++NumNoAlias;
if (I->second.getOffset() != J->second.getOffset())
return NoAlias;
}
}
}
}
@ -123,6 +113,5 @@ AliasAnalysis::Result DSAA::alias(const Value *V1, const Value *V2) {
// FIXME: we could improve on this by checking the globals graph for aliased
// global queries...
++NumMayAlias;
return getAnalysis<AliasAnalysis>().alias(V1, V2);
}