#include "llvm/Pass.h"
#include "llvm/Function.h"
#include "llvm/BasicBlock.h"
-#include "llvm/ConstantVals.h"
+#include "llvm/Constant.h"
-using namespace std;
+using std::vector;
+using std::map;
+using std::set;
namespace {
+ struct PromotePass : public FunctionPass {
+ vector<AllocaInst*> Allocas; // the alloca instruction..
+ map<Instruction*, unsigned> AllocaLookup; // reverse mapping of above
+
+ vector<vector<BasicBlock*> > PhiNodes; // index corresponds to Allocas
+
+ // List of instructions to remove at end of pass
+ vector<Instruction *> KillList;
+
+ map<BasicBlock*,vector<PHINode*> > NewPhiNodes; // the PhiNodes we're adding
-// instance of the promoter -- to keep all the local function data.
-// gets re-created for each function processed
-class PromoteInstance {
-protected:
- vector<AllocaInst*> Allocas; // the alloca instruction..
- map<Instruction*, unsigned> AllocaLookup; // reverse mapping of above
-
- vector<vector<BasicBlock*> > PhiNodes; // index corresponds to Allocas
-
- //list of instructions to remove at end of pass :)
- vector<Instruction *> KillList;
-
- map<BasicBlock*, vector<PHINode*> > NewPhiNodes; // the phinodes we're adding
-
- bool didchange;
-
- void traverse(BasicBlock *BB, BasicBlock *Pred, vector<Value*> &IncVals,
- set<BasicBlock*> &Visited);
- bool PromoteFunction(Function *F, DominanceFrontier &DF);
- bool QueuePhiNode(BasicBlock *bb, unsigned alloca_index);
- void findSafeAllocas(Function *M);
-public:
- // I do this so that I can force the deconstruction of the local variables
- PromoteInstance(Function *F, DominanceFrontier &DF) {
- didchange = PromoteFunction(F, DF);
- }
- //This returns whether the pass changes anything
- operator bool () { return didchange; }
-};
+ public:
+ const char *getPassName() const { return "Promote Memory to Register"; }
+
+ // runOnFunction - To run this pass, first we calculate the alloca
+ // instructions that are safe for promotion, then we promote each one.
+ //
+ virtual bool runOnFunction(Function *F);
+
+ // getAnalysisUsage - We need dominance frontiers
+ //
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired(DominanceFrontier::ID);
+ AU.preservesCFG();
+ }
+
+ private:
+ void Traverse(BasicBlock *BB, BasicBlock *Pred, vector<Value*> &IncVals,
+ set<BasicBlock*> &Visited);
+ bool QueuePhiNode(BasicBlock *BB, unsigned AllocaIdx);
+ void FindSafeAllocas(Function *F);
+ };
} // end of anonymous namespace
static inline bool isSafeAlloca(const AllocaInst *AI) {
if (AI->isArrayAllocation()) return false;
- for (Value::use_iterator UI = AI->use_begin(), UE = AI->use_end();
+ for (Value::use_const_iterator UI = AI->use_begin(), UE = AI->use_end();
UI != UE; ++UI) { // Loop over all of the uses of the alloca
// Only allow nonindexed memory access instructions...
if (MAI->hasIndices()) { // indexed?
// Allow the access if there is only one index and the index is
// zero.
- if (*MAI->idx_begin() != ConstantUInt::get(Type::UIntTy, 0) ||
+ if (*MAI->idx_begin() != Constant::getNullValue(Type::UIntTy) ||
MAI->idx_begin()+1 != MAI->idx_end())
return false;
}
return false; // Not a load or store?
}
}
+
+ return true;
}
-// findSafeAllocas - Find allocas that are safe to promote
+// FindSafeAllocas - Find allocas that are safe to promote
//
-void PromoteInstance::findSafeAllocas(Function *F) {
+void PromotePass::FindSafeAllocas(Function *F) {
BasicBlock *BB = F->getEntryNode(); // Get the entry node for the function
// Look at all instructions in the entry node
-bool PromoteInstance::PromoteFunction(Function *F, DominanceFrontier &DF) {
+bool PromotePass::runOnFunction(Function *F) {
// Calculate the set of safe allocas
- findSafeAllocas(F);
+ FindSafeAllocas(F);
+
+ // If there is nothing to do, bail out...
+ if (Allocas.empty()) return false;
// Add each alloca to the KillList. Note: KillList is destroyed MOST recently
// added to least recently.
WriteSets[i].push_back(SI->getParent());
}
+ // Get dominance frontier information...
+ DominanceFrontier &DF = getAnalysis<DominanceFrontier>();
+
// Compute the locations where PhiNodes need to be inserted. Look at the
// dominance frontier of EACH basic-block we have a write in
//
// and inserting the phi nodes we marked as necessary
//
set<BasicBlock*> Visited; // The basic blocks we've already visited
- traverse(F->front(), 0, Values, Visited);
+ Traverse(F->front(), 0, Values, Visited);
// Remove all instructions marked by being placed in the KillList...
//
Instruction *I = KillList.back();
KillList.pop_back();
- //now go find..
I->getParent()->getInstList().remove(I);
delete I;
}
- return !Allocas.empty();
+ // Purge data structurse so they are available the next iteration...
+ Allocas.clear();
+ AllocaLookup.clear();
+ PhiNodes.clear();
+ NewPhiNodes.clear();
+ return true;
}
// QueuePhiNode - queues a phi-node to be added to a basic-block for a specific
// Alloca returns true if there wasn't already a phi-node for that variable
//
-bool PromoteInstance::QueuePhiNode(BasicBlock *BB, unsigned AllocaNo) {
+bool PromotePass::QueuePhiNode(BasicBlock *BB, unsigned AllocaNo) {
// Look up the basic-block in question
vector<PHINode*> &BBPNs = NewPhiNodes[BB];
if (BBPNs.empty()) BBPNs.resize(Allocas.size());
// If the BB already has a phi node added for the i'th alloca then we're done!
if (BBPNs[AllocaNo]) return false;
- // Create a phi-node using the dereferenced type...
+ // Create a PhiNode using the dereferenced type...
PHINode *PN = new PHINode(Allocas[AllocaNo]->getType()->getElementType(),
Allocas[AllocaNo]->getName()+".mem2reg");
BBPNs[AllocaNo] = PN;
return true;
}
-void PromoteInstance::traverse(BasicBlock *BB, BasicBlock *Pred,
- vector<Value*> &IncomingVals,
- set<BasicBlock*> &Visited) {
+void PromotePass::Traverse(BasicBlock *BB, BasicBlock *Pred,
+ vector<Value*> &IncomingVals,
+ set<BasicBlock*> &Visited) {
// If this is a BB needing a phi node, lookup/create the phinode for each
// variable we need phinodes for.
vector<PHINode *> &BBPNs = NewPhiNodes[BB];
// Recurse across our successors
for (unsigned i = 0; i != TI->getNumSuccessors(); i++) {
vector<Value*> OutgoingVals(IncomingVals);
- traverse(TI->getSuccessor(i), BB, OutgoingVals, Visited);
+ Traverse(TI->getSuccessor(i), BB, OutgoingVals, Visited);
}
}
}
}
-namespace {
- struct PromotePass : public FunctionPass {
-
- // runOnFunction - To run this pass, first we calculate the alloca
- // instructions that are safe for promotion, then we promote each one.
- //
- virtual bool runOnFunction(Function *F) {
- return (bool)PromoteInstance(F, getAnalysis<DominanceFrontier>());
- }
-
- // getAnalysisUsage - We need dominance frontiers
- //
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired(DominanceFrontier::ID);
- }
- };
-}
-
-
// createPromoteMemoryToRegister - Provide an entry point to create this pass.
//
Pass *createPromoteMemoryToRegister() {
projects / oota-llvm.git / blobdiff