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Add statistics to basicAA pass

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5480 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-02-03 21:16:17 +00:00
parent 1e88369afe
commit dc1ad196e1
1 changed files with 28 additions and 7 deletions
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35
lib/Analysis/AliasAnalysis.cpp
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@ -25,9 +25,15 @@
#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.
static RegisterAnalysisGroup<AliasAnalysis> X("Alias Analysis");
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
// arbitrary chunks of code can modify a specified pointer.
@ -139,6 +145,21 @@ 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.
// Hopefully we have a smart C++ compiler. :)
@ -152,11 +173,11 @@ 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))
@ -195,7 +216,7 @@ 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...
@ -205,16 +226,16 @@ 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;