Add support for finding the dependencies of call and invoke instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@38497 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2007-07-10 17:59:22 +00:00
parent 5e2456c959
commit 5f32320797
2 changed files with 66 additions and 17 deletions

View File

@ -18,6 +18,7 @@
#define LLVM_ANALYSIS_MEMORY_DEPENDENCE_H
#include "llvm/Pass.h"
#include "llvm/Support/CallSite.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/Compiler.h"
#include <map>
@ -34,6 +35,7 @@ class MemoryDependenceAnalysis : public FunctionPass {
DenseMap<Instruction*, std::pair<Instruction*, bool> > depGraphLocal;
std::multimap<Instruction*, Instruction*> reverseDep;
Instruction* getCallSiteDependency(CallSite C, bool local = true);
public:
static Instruction* NonLocal;

View File

@ -40,6 +40,61 @@ void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequiredTransitive<TargetData>();
}
// Find the dependency of a CallSite
Instruction* MemoryDependenceAnalysis::getCallSiteDependency(CallSite C, bool local) {
assert(local && "Non-local memory dependence analysis not yet implemented");
AliasAnalysis& AA = getAnalysis<AliasAnalysis>();
TargetData& TD = getAnalysis<TargetData>();
BasicBlock::iterator blockBegin = C.getInstruction()->getParent()->begin();
BasicBlock::iterator QI = C.getInstruction();
while (QI != blockBegin) {
--QI;
// If this inst is a memory op, get the pointer it accessed
Value* pointer = 0;
uint64_t pointerSize = 0;
if (StoreInst* S = dyn_cast<StoreInst>(QI)) {
pointer = S->getPointerOperand();
pointerSize = TD.getTypeSize(S->getOperand(0)->getType());
} else if (LoadInst* L = dyn_cast<LoadInst>(QI)) {
pointer = L->getPointerOperand();
pointerSize = TD.getTypeSize(L->getType());
} else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) {
pointer = AI;
if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize()))
pointerSize = C->getZExtValue();
else
pointerSize = ~0UL;
} else if (FreeInst* F = dyn_cast<FreeInst>(QI)) {
pointer = F->getPointerOperand();
// FreeInsts erase the entire structure
pointerSize = ~0UL;
} else if (CallSite::get(QI).getInstruction() != 0) {
if (AA.getModRefInfo(C, CallSite::get(QI)) != AliasAnalysis::NoModRef) {
depGraphLocal.insert(std::make_pair(C.getInstruction(), std::make_pair(QI, true)));
reverseDep.insert(std::make_pair(QI, C.getInstruction()));
return QI;
} else {
continue;
}
}
if (AA.getModRefInfo(C, pointer, pointerSize) != AliasAnalysis::NoModRef) {
depGraphLocal.insert(std::make_pair(C.getInstruction(), std::make_pair(QI, true)));
reverseDep.insert(std::make_pair(QI, C.getInstruction()));
return QI;
}
}
// No dependence found
depGraphLocal.insert(std::make_pair(C.getInstruction(), std::make_pair(NonLocal, true)));
reverseDep.insert(std::make_pair(NonLocal, C.getInstruction()));
return NonLocal;
}
/// getDependency - Return the instruction on which a memory operation
/// depends. The local paramter indicates if the query should only
/// evaluate dependencies within the same basic block.
@ -77,13 +132,13 @@ Instruction* MemoryDependenceAnalysis::getDependency(Instruction* query,
// FreeInsts erase the entire structure, not just a field
dependeeSize = ~0UL;
} else if (isa<AllocationInst>(query))
} else if (CallSite::get(QI).getInstruction() != 0)
return getCallSiteDependency(CallSite::get(QI));
else if (isa<AllocationInst>(query))
return None;
else
// FIXME: Call/InvokeInsts need proper handling
return None;
BasicBlock::iterator blockBegin = query->getParent()->begin();
while (QI != blockBegin) {
@ -109,21 +164,13 @@ Instruction* MemoryDependenceAnalysis::getDependency(Instruction* query,
// FreeInsts erase the entire structure
pointerSize = ~0UL;
} else if (CallInst* C = dyn_cast<CallInst>(QI)) {
} else if (CallSite::get(QI).getInstruction() != 0) {
// Call insts need special handling. Check is they can modify our pointer
if (AA.getModRefInfo(C, dependee, dependeeSize) != AliasAnalysis::NoModRef) {
depGraphLocal.insert(std::make_pair(query, std::make_pair(C, true)));
reverseDep.insert(std::make_pair(C, query));
return C;
} else {
continue;
}
} else if (InvokeInst* I = dyn_cast<InvokeInst>(QI)) {
// Invoke insts need special handling. Check is they can modify our pointer
if (AA.getModRefInfo(I, dependee, dependeeSize) != AliasAnalysis::NoModRef) {
depGraphLocal.insert(std::make_pair(query, std::make_pair(I, true)));
reverseDep.insert(std::make_pair(I, query));
return I;
if (AA.getModRefInfo(CallSite::get(QI), dependee, dependeeSize) !=
AliasAnalysis::NoModRef) {
depGraphLocal.insert(std::make_pair(query, std::make_pair(QI, true)));
reverseDep.insert(std::make_pair(QI, query));
return QI;
} else {
continue;
}