Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 1 | //===- Mem2Reg.cpp - The -mem2reg pass, a wrapper around the Utils lib ----===// |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 2 | // |
John Criswell | b576c94 | 2003-10-20 19:43:21 +0000 | [diff] [blame] | 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file was developed by the LLVM research group and is distributed under |
| 6 | // the University of Illinois Open Source License. See LICENSE.TXT for details. |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 7 | // |
John Criswell | b576c94 | 2003-10-20 19:43:21 +0000 | [diff] [blame] | 8 | //===----------------------------------------------------------------------===// |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 9 | // |
| 10 | // This pass is a simple pass wrapper around the PromoteMemToReg function call |
| 11 | // exposed by the Utils library. |
| 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "llvm/Transforms/Scalar.h" |
| 16 | #include "llvm/Transforms/Utils/PromoteMemToReg.h" |
Chris Lattner | 8d89e7b | 2006-05-09 04:13:41 +0000 | [diff] [blame] | 17 | #include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h" |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 18 | #include "llvm/Analysis/Dominators.h" |
Misha Brukman | 47b14a4 | 2004-07-29 17:30:56 +0000 | [diff] [blame] | 19 | #include "llvm/Instructions.h" |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 20 | #include "llvm/Function.h" |
Chris Lattner | fb743a9 | 2003-03-03 17:25:18 +0000 | [diff] [blame] | 21 | #include "llvm/Target/TargetData.h" |
Reid Spencer | 551ccae | 2004-09-01 22:55:40 +0000 | [diff] [blame] | 22 | #include "llvm/ADT/Statistic.h" |
Chris Lattner | f4b5461 | 2006-06-28 22:08:15 +0000 | [diff] [blame^] | 23 | #include "llvm/Support/Visibility.h" |
Chris Lattner | d745602 | 2004-01-09 06:02:20 +0000 | [diff] [blame] | 24 | using namespace llvm; |
Brian Gaeke | d0fde30 | 2003-11-11 22:41:34 +0000 | [diff] [blame] | 25 | |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 26 | namespace { |
| 27 | Statistic<> NumPromoted("mem2reg", "Number of alloca's promoted"); |
| 28 | |
Chris Lattner | f4b5461 | 2006-06-28 22:08:15 +0000 | [diff] [blame^] | 29 | struct VISIBILITY_HIDDEN PromotePass : public FunctionPass { |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 30 | // runOnFunction - To run this pass, first we calculate the alloca |
| 31 | // instructions that are safe for promotion, then we promote each one. |
| 32 | // |
| 33 | virtual bool runOnFunction(Function &F); |
| 34 | |
| 35 | // getAnalysisUsage - We need dominance frontiers |
| 36 | // |
| 37 | virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
Chris Lattner | 43f820d | 2003-10-05 21:20:13 +0000 | [diff] [blame] | 38 | AU.addRequired<DominatorTree>(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 39 | AU.addRequired<DominanceFrontier>(); |
Chris Lattner | fb743a9 | 2003-03-03 17:25:18 +0000 | [diff] [blame] | 40 | AU.addRequired<TargetData>(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 41 | AU.setPreservesCFG(); |
Chris Lattner | ed96fe8 | 2006-05-17 21:05:27 +0000 | [diff] [blame] | 42 | // This is a cluster of orthogonal Transforms |
Chris Lattner | 8d89e7b | 2006-05-09 04:13:41 +0000 | [diff] [blame] | 43 | AU.addPreserved<UnifyFunctionExitNodes>(); |
| 44 | AU.addPreservedID(LowerSelectID); |
| 45 | AU.addPreservedID(LowerSwitchID); |
Chris Lattner | ed96fe8 | 2006-05-17 21:05:27 +0000 | [diff] [blame] | 46 | AU.addPreservedID(LowerInvokePassID); |
| 47 | AU.addPreservedID(LowerAllocationsID); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 48 | } |
| 49 | }; |
| 50 | |
| 51 | RegisterOpt<PromotePass> X("mem2reg", "Promote Memory to Register"); |
| 52 | } // end of anonymous namespace |
| 53 | |
| 54 | bool PromotePass::runOnFunction(Function &F) { |
| 55 | std::vector<AllocaInst*> Allocas; |
Chris Lattner | fb743a9 | 2003-03-03 17:25:18 +0000 | [diff] [blame] | 56 | const TargetData &TD = getAnalysis<TargetData>(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 57 | |
Chris Lattner | 02a3be0 | 2003-09-20 14:39:18 +0000 | [diff] [blame] | 58 | BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 59 | |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 60 | bool Changed = false; |
Chris Lattner | 43f820d | 2003-10-05 21:20:13 +0000 | [diff] [blame] | 61 | |
| 62 | DominatorTree &DT = getAnalysis<DominatorTree>(); |
| 63 | DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 64 | |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 65 | while (1) { |
| 66 | Allocas.clear(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 67 | |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 68 | // Find allocas that are safe to promote, by looking at all instructions in |
| 69 | // the entry node |
| 70 | for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) |
| 71 | if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? |
| 72 | if (isAllocaPromotable(AI, TD)) |
| 73 | Allocas.push_back(AI); |
| 74 | |
| 75 | if (Allocas.empty()) break; |
| 76 | |
Chris Lattner | 43f820d | 2003-10-05 21:20:13 +0000 | [diff] [blame] | 77 | PromoteMemToReg(Allocas, DT, DF, TD); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 78 | NumPromoted += Allocas.size(); |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 79 | Changed = true; |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 80 | } |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 81 | |
| 82 | return Changed; |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 83 | } |
| 84 | |
Chris Lattner | b3674e4 | 2006-05-02 04:24:36 +0000 | [diff] [blame] | 85 | // Publically exposed interface to pass... |
| 86 | const PassInfo *llvm::PromoteMemoryToRegisterID = X.getPassInfo(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 87 | // createPromoteMemoryToRegister - Provide an entry point to create this pass. |
| 88 | // |
Alkis Evlogimenos | ab7ada3 | 2005-03-28 02:01:12 +0000 | [diff] [blame] | 89 | FunctionPass *llvm::createPromoteMemoryToRegisterPass() { |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 90 | return new PromotePass(); |
| 91 | } |