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 | |
Chris Lattner | d216e8b | 2006-12-19 22:17:40 +0000 | [diff] [blame] | 15 | #define DEBUG_TYPE "mem2reg" |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 16 | #include "llvm/Transforms/Scalar.h" |
| 17 | #include "llvm/Transforms/Utils/PromoteMemToReg.h" |
Chris Lattner | 8d89e7b | 2006-05-09 04:13:41 +0000 | [diff] [blame] | 18 | #include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h" |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 19 | #include "llvm/Analysis/Dominators.h" |
Misha Brukman | 47b14a4 | 2004-07-29 17:30:56 +0000 | [diff] [blame] | 20 | #include "llvm/Instructions.h" |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 21 | #include "llvm/Function.h" |
Reid Spencer | 551ccae | 2004-09-01 22:55:40 +0000 | [diff] [blame] | 22 | #include "llvm/ADT/Statistic.h" |
Chris Lattner | a4f0b3a | 2006-08-27 12:54:02 +0000 | [diff] [blame] | 23 | #include "llvm/Support/Compiler.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 | d216e8b | 2006-12-19 22:17:40 +0000 | [diff] [blame] | 26 | STATISTIC(NumPromoted, "Number of alloca's promoted"); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 27 | |
Chris Lattner | d216e8b | 2006-12-19 22:17:40 +0000 | [diff] [blame] | 28 | namespace { |
Chris Lattner | f4b5461 | 2006-06-28 22:08:15 +0000 | [diff] [blame] | 29 | struct VISIBILITY_HIDDEN PromotePass : public FunctionPass { |
Devang Patel | 1997473 | 2007-05-03 01:11:54 +0000 | [diff] [blame^] | 30 | static char ID; // Pass identifcation, replacement for typeid |
Devang Patel | 794fd75 | 2007-05-01 21:15:47 +0000 | [diff] [blame] | 31 | PromotePass() : FunctionPass((intptr_t)&ID) {} |
| 32 | |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 33 | // runOnFunction - To run this pass, first we calculate the alloca |
| 34 | // instructions that are safe for promotion, then we promote each one. |
| 35 | // |
| 36 | virtual bool runOnFunction(Function &F); |
| 37 | |
| 38 | // getAnalysisUsage - We need dominance frontiers |
| 39 | // |
| 40 | virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
Owen Anderson | df07335 | 2007-04-20 06:27:13 +0000 | [diff] [blame] | 41 | AU.addRequired<ETForest>(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 42 | AU.addRequired<DominanceFrontier>(); |
| 43 | AU.setPreservesCFG(); |
Anton Korobeynikov | bed2946 | 2007-04-16 18:10:23 +0000 | [diff] [blame] | 44 | // This is a cluster of orthogonal Transforms |
Chris Lattner | 8d89e7b | 2006-05-09 04:13:41 +0000 | [diff] [blame] | 45 | AU.addPreserved<UnifyFunctionExitNodes>(); |
| 46 | AU.addPreservedID(LowerSelectID); |
| 47 | AU.addPreservedID(LowerSwitchID); |
Chris Lattner | ed96fe8 | 2006-05-17 21:05:27 +0000 | [diff] [blame] | 48 | AU.addPreservedID(LowerInvokePassID); |
| 49 | AU.addPreservedID(LowerAllocationsID); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 50 | } |
| 51 | }; |
| 52 | |
Devang Patel | 1997473 | 2007-05-03 01:11:54 +0000 | [diff] [blame^] | 53 | char PromotePass::ID = 0; |
Chris Lattner | 7f8897f | 2006-08-27 22:42:52 +0000 | [diff] [blame] | 54 | RegisterPass<PromotePass> X("mem2reg", "Promote Memory to Register"); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 55 | } // end of anonymous namespace |
| 56 | |
| 57 | bool PromotePass::runOnFunction(Function &F) { |
| 58 | std::vector<AllocaInst*> Allocas; |
| 59 | |
Chris Lattner | 02a3be0 | 2003-09-20 14:39:18 +0000 | [diff] [blame] | 60 | BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 61 | |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 62 | bool Changed = false; |
Chris Lattner | 43f820d | 2003-10-05 21:20:13 +0000 | [diff] [blame] | 63 | |
Owen Anderson | df07335 | 2007-04-20 06:27:13 +0000 | [diff] [blame] | 64 | ETForest &ET = getAnalysis<ETForest>(); |
Chris Lattner | 43f820d | 2003-10-05 21:20:13 +0000 | [diff] [blame] | 65 | DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 66 | |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 67 | while (1) { |
| 68 | Allocas.clear(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 69 | |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 70 | // Find allocas that are safe to promote, by looking at all instructions in |
| 71 | // the entry node |
| 72 | for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) |
| 73 | if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? |
Devang Patel | 41968df | 2007-04-25 17:15:20 +0000 | [diff] [blame] | 74 | if (isAllocaPromotable(AI)) |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 75 | Allocas.push_back(AI); |
| 76 | |
| 77 | if (Allocas.empty()) break; |
| 78 | |
Devang Patel | 68c01b3 | 2007-04-25 18:32:35 +0000 | [diff] [blame] | 79 | PromoteMemToReg(Allocas, ET, DF); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 80 | NumPromoted += Allocas.size(); |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 81 | Changed = true; |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 82 | } |
Chris Lattner | 83c39d2 | 2003-06-25 14:58:56 +0000 | [diff] [blame] | 83 | |
| 84 | return Changed; |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 85 | } |
| 86 | |
Chris Lattner | b3674e4 | 2006-05-02 04:24:36 +0000 | [diff] [blame] | 87 | // Publically exposed interface to pass... |
| 88 | const PassInfo *llvm::PromoteMemoryToRegisterID = X.getPassInfo(); |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 89 | // createPromoteMemoryToRegister - Provide an entry point to create this pass. |
| 90 | // |
Alkis Evlogimenos | ab7ada3 | 2005-03-28 02:01:12 +0000 | [diff] [blame] | 91 | FunctionPass *llvm::createPromoteMemoryToRegisterPass() { |
Chris Lattner | d99bf49 | 2003-02-22 23:57:48 +0000 | [diff] [blame] | 92 | return new PromotePass(); |
| 93 | } |