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 | |
| 27 | SmallVector<Value *, 4> Args; |
| 28 | // Reserve operand 0 for loop id self reference. |
| 29 | MDNode *TempNode = MDNode::getTemporary(Ctx, None); |
| 30 | Args.push_back(TempNode); |
| 31 | |
| 32 | // Setting vectorizer.width |
| 33 | if (Attrs.VectorizerWidth > 0) { |
Stephen Hines | c568f1e | 2014-07-21 00:47:37 -0700 | [diff] [blame] | 34 | Value *Vals[] = { MDString::get(Ctx, "llvm.loop.vectorize.width"), |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 35 | ConstantInt::get(Type::getInt32Ty(Ctx), |
| 36 | Attrs.VectorizerWidth) }; |
| 37 | Args.push_back(MDNode::get(Ctx, Vals)); |
| 38 | } |
| 39 | |
| 40 | // Setting vectorizer.unroll |
| 41 | if (Attrs.VectorizerUnroll > 0) { |
Stephen Hines | 176edba | 2014-12-01 14:53:08 -0800 | [diff] [blame] | 42 | Value *Vals[] = { MDString::get(Ctx, "llvm.loop.interleave.count"), |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 43 | ConstantInt::get(Type::getInt32Ty(Ctx), |
| 44 | Attrs.VectorizerUnroll) }; |
| 45 | Args.push_back(MDNode::get(Ctx, Vals)); |
| 46 | } |
| 47 | |
| 48 | // Setting vectorizer.enable |
| 49 | if (Attrs.VectorizerEnable != LoopAttributes::VecUnspecified) { |
Stephen Hines | c568f1e | 2014-07-21 00:47:37 -0700 | [diff] [blame] | 50 | Value *Vals[] = { MDString::get(Ctx, "llvm.loop.vectorize.enable"), |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 51 | ConstantInt::get(Type::getInt1Ty(Ctx), |
| 52 | (Attrs.VectorizerEnable == |
| 53 | LoopAttributes::VecEnable)) }; |
| 54 | Args.push_back(MDNode::get(Ctx, Vals)); |
| 55 | } |
| 56 | |
| 57 | MDNode *LoopID = MDNode::get(Ctx, Args); |
| 58 | assert(LoopID->use_empty() && "LoopID should not be used"); |
| 59 | |
| 60 | // Set the first operand to itself. |
| 61 | LoopID->replaceOperandWith(0, LoopID); |
| 62 | MDNode::deleteTemporary(TempNode); |
| 63 | return LoopID; |
| 64 | } |
| 65 | |
| 66 | LoopAttributes::LoopAttributes(bool IsParallel) |
| 67 | : IsParallel(IsParallel), VectorizerEnable(LoopAttributes::VecUnspecified), |
| 68 | VectorizerWidth(0), VectorizerUnroll(0) {} |
| 69 | |
| 70 | void LoopAttributes::clear() { |
| 71 | IsParallel = false; |
| 72 | VectorizerWidth = 0; |
| 73 | VectorizerUnroll = 0; |
| 74 | VectorizerEnable = LoopAttributes::VecUnspecified; |
| 75 | } |
| 76 | |
| 77 | LoopInfo::LoopInfo(BasicBlock *Header, const LoopAttributes &Attrs) |
| 78 | : LoopID(nullptr), Header(Header), Attrs(Attrs) { |
| 79 | LoopID = createMetadata(Header->getContext(), Attrs); |
| 80 | } |
| 81 | |
| 82 | void LoopInfoStack::push(BasicBlock *Header) { |
| 83 | Active.push_back(LoopInfo(Header, StagedAttrs)); |
| 84 | // Clear the attributes so nested loops do not inherit them. |
| 85 | StagedAttrs.clear(); |
| 86 | } |
| 87 | |
| 88 | void LoopInfoStack::pop() { |
| 89 | assert(!Active.empty() && "No active loops to pop"); |
| 90 | Active.pop_back(); |
| 91 | } |
| 92 | |
| 93 | void LoopInfoStack::InsertHelper(Instruction *I) const { |
| 94 | if (!hasInfo()) |
| 95 | return; |
| 96 | |
| 97 | const LoopInfo &L = getInfo(); |
| 98 | if (!L.getLoopID()) |
| 99 | return; |
| 100 | |
| 101 | if (TerminatorInst *TI = dyn_cast<TerminatorInst>(I)) { |
| 102 | for (unsigned i = 0, ie = TI->getNumSuccessors(); i < ie; ++i) |
| 103 | if (TI->getSuccessor(i) == L.getHeader()) { |
| 104 | TI->setMetadata("llvm.loop", L.getLoopID()); |
| 105 | break; |
| 106 | } |
| 107 | return; |
| 108 | } |
| 109 | |
| 110 | if (L.getAttributes().IsParallel && I->mayReadOrWriteMemory()) |
| 111 | I->setMetadata("llvm.mem.parallel_loop_access", L.getLoopID()); |
| 112 | } |