//===- Mem2Reg.cpp - The -mem2reg pass, a wrapper around the Utils lib ----===//
//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
// This pass is a simple pass wrapper around the PromoteMemToReg function call
// exposed by the Utils library.
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "mem2reg"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
-#include "llvm/Analysis/Dominators.h"
-#include "llvm/iMemory.h"
+#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
+#include "llvm/Analysis/DominanceFrontier.h"
+#include "llvm/Instructions.h"
#include "llvm/Function.h"
-#include "llvm/Target/TargetData.h"
-#include "Support/Statistic.h"
+#include "llvm/ADT/Statistic.h"
+using namespace llvm;
-namespace {
- Statistic<> NumPromoted("mem2reg", "Number of alloca's promoted");
+STATISTIC(NumPromoted, "Number of alloca's promoted");
+namespace {
struct PromotePass : public FunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ PromotePass() : FunctionPass(ID) {
+ initializePromotePassPass(*PassRegistry::getPassRegistry());
+ }
+
// runOnFunction - To run this pass, first we calculate the alloca
// instructions that are safe for promotion, then we promote each one.
//
// getAnalysisUsage - We need dominance frontiers
//
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<DominatorTree>();
AU.addRequired<DominanceFrontier>();
- AU.addRequired<TargetData>();
AU.setPreservesCFG();
+ // This is a cluster of orthogonal Transforms
+ AU.addPreserved<UnifyFunctionExitNodes>();
+ AU.addPreservedID(LowerSwitchID);
+ AU.addPreservedID(LowerInvokePassID);
}
};
-
- RegisterOpt<PromotePass> X("mem2reg", "Promote Memory to Register");
} // end of anonymous namespace
+char PromotePass::ID = 0;
+INITIALIZE_PASS_BEGIN(PromotePass, "mem2reg", "Promote Memory to Register",
+ false, false)
+INITIALIZE_PASS_DEPENDENCY(DominatorTree)
+INITIALIZE_PASS_DEPENDENCY(DominanceFrontier)
+INITIALIZE_PASS_END(PromotePass, "mem2reg", "Promote Memory to Register",
+ false, false)
+
bool PromotePass::runOnFunction(Function &F) {
std::vector<AllocaInst*> Allocas;
- const TargetData &TD = getAnalysis<TargetData>();
- BasicBlock &BB = F.getEntryNode(); // Get the entry node for the function
+ BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function
+
+ bool Changed = false;
+
+ DominatorTree &DT = getAnalysis<DominatorTree>();
+ DominanceFrontier &DF = getAnalysis<DominanceFrontier>();
- // Find allocas that are safe to promote, by looking at all instructions in
- // the entry node
- for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I)
- if (AllocaInst *AI = dyn_cast<AllocaInst>(&*I)) // Is it an alloca?
- if (isAllocaPromotable(AI, TD))
- Allocas.push_back(AI);
+ while (1) {
+ Allocas.clear();
- if (!Allocas.empty()) {
- PromoteMemToReg(Allocas, getAnalysis<DominanceFrontier>(), TD);
+ // Find allocas that are safe to promote, by looking at all instructions in
+ // the entry node
+ for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I)
+ if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca?
+ if (isAllocaPromotable(AI))
+ Allocas.push_back(AI);
+
+ if (Allocas.empty()) break;
+
+ PromoteMemToReg(Allocas, DT, DF);
NumPromoted += Allocas.size();
- return true;
+ Changed = true;
}
- return false;
+
+ return Changed;
}
// createPromoteMemoryToRegister - Provide an entry point to create this pass.
//
-Pass *createPromoteMemoryToRegister() {
+FunctionPass *llvm::createPromoteMemoryToRegisterPass() {
return new PromotePass();
}