Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 1 | //===---- CGLoopInfo.cpp - LLVM CodeGen for loop metadata -*- C++ -*-------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | |
| 10 | #include "CGLoopInfo.h" |
| 11 | #include "llvm/IR/BasicBlock.h" |
| 12 | #include "llvm/IR/Constants.h" |
| 13 | #include "llvm/IR/InstrTypes.h" |
| 14 | #include "llvm/IR/Instructions.h" |
| 15 | #include "llvm/IR/Metadata.h" |
| 16 | using namespace clang; |
| 17 | using namespace CodeGen; |
| 18 | using namespace llvm; |
| 19 | |
| 20 | static MDNode *createMetadata(LLVMContext &Ctx, const LoopAttributes &Attrs) { |
| 21 | |
| 22 | if (!Attrs.IsParallel && Attrs.VectorizerWidth == 0 && |
| 23 | Attrs.VectorizerUnroll == 0 && |
| 24 | Attrs.VectorizerEnable == LoopAttributes::VecUnspecified) |
| 25 | return nullptr; |
| 26 | |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame^] | 27 | SmallVector<Metadata *, 4> Args; |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 28 | // Reserve operand 0 for loop id self reference. |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame^] | 29 | auto TempNode = MDNode::getTemporary(Ctx, None); |
| 30 | Args.push_back(TempNode.get()); |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 31 | |
| 32 | // Setting vectorizer.width |
| 33 | if (Attrs.VectorizerWidth > 0) { |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame^] | 34 | Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.vectorize.width"), |
| 35 | ConstantAsMetadata::get(ConstantInt::get( |
| 36 | Type::getInt32Ty(Ctx), Attrs.VectorizerWidth))}; |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 37 | Args.push_back(MDNode::get(Ctx, Vals)); |
| 38 | } |
| 39 | |
| 40 | // Setting vectorizer.unroll |
| 41 | if (Attrs.VectorizerUnroll > 0) { |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame^] | 42 | Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.interleave.count"), |
| 43 | ConstantAsMetadata::get(ConstantInt::get( |
| 44 | Type::getInt32Ty(Ctx), Attrs.VectorizerUnroll))}; |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 45 | Args.push_back(MDNode::get(Ctx, Vals)); |
| 46 | } |
| 47 | |
| 48 | // Setting vectorizer.enable |
| 49 | if (Attrs.VectorizerEnable != LoopAttributes::VecUnspecified) { |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame^] | 50 | Metadata *Vals[] = { |
| 51 | MDString::get(Ctx, "llvm.loop.vectorize.enable"), |
| 52 | ConstantAsMetadata::get(ConstantInt::get( |
| 53 | Type::getInt1Ty(Ctx), |
| 54 | (Attrs.VectorizerEnable == LoopAttributes::VecEnable)))}; |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 55 | Args.push_back(MDNode::get(Ctx, Vals)); |
| 56 | } |
| 57 | |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 58 | // Set the first operand to itself. |
Stephen Hines | 0e2c34f | 2015-03-23 12:09:02 -0700 | [diff] [blame^] | 59 | MDNode *LoopID = MDNode::get(Ctx, Args); |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 60 | LoopID->replaceOperandWith(0, LoopID); |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 61 | return LoopID; |
| 62 | } |
| 63 | |
| 64 | LoopAttributes::LoopAttributes(bool IsParallel) |
| 65 | : IsParallel(IsParallel), VectorizerEnable(LoopAttributes::VecUnspecified), |
| 66 | VectorizerWidth(0), VectorizerUnroll(0) {} |
| 67 | |
| 68 | void LoopAttributes::clear() { |
| 69 | IsParallel = false; |
| 70 | VectorizerWidth = 0; |
| 71 | VectorizerUnroll = 0; |
| 72 | VectorizerEnable = LoopAttributes::VecUnspecified; |
| 73 | } |
| 74 | |
| 75 | LoopInfo::LoopInfo(BasicBlock *Header, const LoopAttributes &Attrs) |
| 76 | : LoopID(nullptr), Header(Header), Attrs(Attrs) { |
| 77 | LoopID = createMetadata(Header->getContext(), Attrs); |
| 78 | } |
| 79 | |
| 80 | void LoopInfoStack::push(BasicBlock *Header) { |
| 81 | Active.push_back(LoopInfo(Header, StagedAttrs)); |
| 82 | // Clear the attributes so nested loops do not inherit them. |
| 83 | StagedAttrs.clear(); |
| 84 | } |
| 85 | |
| 86 | void LoopInfoStack::pop() { |
| 87 | assert(!Active.empty() && "No active loops to pop"); |
| 88 | Active.pop_back(); |
| 89 | } |
| 90 | |
| 91 | void LoopInfoStack::InsertHelper(Instruction *I) const { |
| 92 | if (!hasInfo()) |
| 93 | return; |
| 94 | |
| 95 | const LoopInfo &L = getInfo(); |
| 96 | if (!L.getLoopID()) |
| 97 | return; |
| 98 | |
| 99 | if (TerminatorInst *TI = dyn_cast<TerminatorInst>(I)) { |
| 100 | for (unsigned i = 0, ie = TI->getNumSuccessors(); i < ie; ++i) |
| 101 | if (TI->getSuccessor(i) == L.getHeader()) { |
| 102 | TI->setMetadata("llvm.loop", L.getLoopID()); |
| 103 | break; |
| 104 | } |
| 105 | return; |
| 106 | } |
| 107 | |
| 108 | if (L.getAttributes().IsParallel && I->mayReadOrWriteMemory()) |
| 109 | I->setMetadata("llvm.mem.parallel_loop_access", L.getLoopID()); |
| 110 | } |