It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/Mem2Reg.cpp b/lib/Transforms/Utils/Mem2Reg.cpp
new file mode 100644
index 0000000..d67b3de
--- /dev/null
+++ b/lib/Transforms/Utils/Mem2Reg.cpp
@@ -0,0 +1,93 @@
+//===- Mem2Reg.cpp - The -mem2reg pass, a wrapper around the Utils lib ----===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and 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/Transforms/Utils/UnifyFunctionExitNodes.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Instructions.h"
+#include "llvm/Function.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Compiler.h"
+using namespace llvm;
+
+STATISTIC(NumPromoted, "Number of alloca's promoted");
+
+namespace {
+ struct VISIBILITY_HIDDEN PromotePass : public FunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ PromotePass() : FunctionPass((intptr_t)&ID) {}
+
+ // 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<DominatorTree>();
+ AU.addRequired<DominanceFrontier>();
+ AU.setPreservesCFG();
+ // This is a cluster of orthogonal Transforms
+ AU.addPreserved<UnifyFunctionExitNodes>();
+ AU.addPreservedID(LowerSelectID);
+ AU.addPreservedID(LowerSwitchID);
+ AU.addPreservedID(LowerInvokePassID);
+ AU.addPreservedID(LowerAllocationsID);
+ }
+ };
+
+ char PromotePass::ID = 0;
+ RegisterPass<PromotePass> X("mem2reg", "Promote Memory to Register");
+} // end of anonymous namespace
+
+bool PromotePass::runOnFunction(Function &F) {
+ std::vector<AllocaInst*> Allocas;
+
+ BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function
+
+ bool Changed = false;
+
+ DominatorTree &DT = getAnalysis<DominatorTree>();
+ DominanceFrontier &DF = getAnalysis<DominanceFrontier>();
+
+ while (1) {
+ Allocas.clear();
+
+ // 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();
+ Changed = true;
+ }
+
+ return Changed;
+}
+
+// Publically exposed interface to pass...
+const PassInfo *llvm::PromoteMemoryToRegisterID = X.getPassInfo();
+// createPromoteMemoryToRegister - Provide an entry point to create this pass.
+//
+FunctionPass *llvm::createPromoteMemoryToRegisterPass() {
+ return new PromotePass();
+}