1 files changed, 248 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGLoopInfo.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGLoopInfo.cpp
new file mode 100644
index 0000000..0afe7db
--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/CodeGen/CGLoopInfo.cpp
@@ -0,0 +1,248 @@
+//===---- CGLoopInfo.cpp - LLVM CodeGen for loop metadata -*- C++ -*-------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGLoopInfo.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Attr.h"
+#include "clang/Sema/LoopHint.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/InstrTypes.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Metadata.h"
+using namespace clang::CodeGen;
+using namespace llvm;
+
+static MDNode *createMetadata(LLVMContext &Ctx, const LoopAttributes &Attrs) {
+
+  if (!Attrs.IsParallel && Attrs.VectorizeWidth == 0 &&
+      Attrs.InterleaveCount == 0 && Attrs.UnrollCount == 0 &&
+      Attrs.VectorizeEnable == LoopAttributes::Unspecified &&
+      Attrs.UnrollEnable == LoopAttributes::Unspecified)
+    return nullptr;
+
+  SmallVector<Metadata *, 4> Args;
+  // Reserve operand 0 for loop id self reference.
+  auto TempNode = MDNode::getTemporary(Ctx, None);
+  Args.push_back(TempNode.get());
+
+  // Setting vectorize.width
+  if (Attrs.VectorizeWidth > 0) {
+    Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.vectorize.width"),
+                        ConstantAsMetadata::get(ConstantInt::get(
+                            Type::getInt32Ty(Ctx), Attrs.VectorizeWidth))};
+    Args.push_back(MDNode::get(Ctx, Vals));
+  }
+
+  // Setting interleave.count
+  if (Attrs.InterleaveCount > 0) {
+    Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.interleave.count"),
+                        ConstantAsMetadata::get(ConstantInt::get(
+                            Type::getInt32Ty(Ctx), Attrs.InterleaveCount))};
+    Args.push_back(MDNode::get(Ctx, Vals));
+  }
+
+  // Setting interleave.count
+  if (Attrs.UnrollCount > 0) {
+    Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.unroll.count"),
+                        ConstantAsMetadata::get(ConstantInt::get(
+                            Type::getInt32Ty(Ctx), Attrs.UnrollCount))};
+    Args.push_back(MDNode::get(Ctx, Vals));
+  }
+
+  // Setting vectorize.enable
+  if (Attrs.VectorizeEnable != LoopAttributes::Unspecified) {
+    Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.vectorize.enable"),
+                        ConstantAsMetadata::get(ConstantInt::get(
+                            Type::getInt1Ty(Ctx), (Attrs.VectorizeEnable ==
+                                                   LoopAttributes::Enable)))};
+    Args.push_back(MDNode::get(Ctx, Vals));
+  }
+
+  // Setting unroll.full or unroll.disable
+  if (Attrs.UnrollEnable != LoopAttributes::Unspecified) {
+    std::string Name;
+    if (Attrs.UnrollEnable == LoopAttributes::Enable)
+      Name = "llvm.loop.unroll.enable";
+    else if (Attrs.UnrollEnable == LoopAttributes::Full)
+      Name = "llvm.loop.unroll.full";
+    else
+      Name = "llvm.loop.unroll.disable";
+    Metadata *Vals[] = {MDString::get(Ctx, Name)};
+    Args.push_back(MDNode::get(Ctx, Vals));
+  }
+
+  // Set the first operand to itself.
+  MDNode *LoopID = MDNode::get(Ctx, Args);
+  LoopID->replaceOperandWith(0, LoopID);
+  return LoopID;
+}
+
+LoopAttributes::LoopAttributes(bool IsParallel)
+    : IsParallel(IsParallel), VectorizeEnable(LoopAttributes::Unspecified),
+      UnrollEnable(LoopAttributes::Unspecified), VectorizeWidth(0),
+      InterleaveCount(0), UnrollCount(0) {}
+
+void LoopAttributes::clear() {
+  IsParallel = false;
+  VectorizeWidth = 0;
+  InterleaveCount = 0;
+  UnrollCount = 0;
+  VectorizeEnable = LoopAttributes::Unspecified;
+  UnrollEnable = LoopAttributes::Unspecified;
+}
+
+LoopInfo::LoopInfo(BasicBlock *Header, const LoopAttributes &Attrs)
+    : LoopID(nullptr), Header(Header), Attrs(Attrs) {
+  LoopID = createMetadata(Header->getContext(), Attrs);
+}
+
+void LoopInfoStack::push(BasicBlock *Header) {
+  Active.push_back(LoopInfo(Header, StagedAttrs));
+  // Clear the attributes so nested loops do not inherit them.
+  StagedAttrs.clear();
+}
+
+void LoopInfoStack::push(BasicBlock *Header, clang::ASTContext &Ctx,
+                         ArrayRef<const clang::Attr *> Attrs) {
+
+  // Identify loop hint attributes from Attrs.
+  for (const auto *Attr : Attrs) {
+    const LoopHintAttr *LH = dyn_cast<LoopHintAttr>(Attr);
+
+    // Skip non loop hint attributes
+    if (!LH)
+      continue;
+
+    auto *ValueExpr = LH->getValue();
+    unsigned ValueInt = 1;
+    if (ValueExpr) {
+      llvm::APSInt ValueAPS = ValueExpr->EvaluateKnownConstInt(Ctx);
+      ValueInt = ValueAPS.getSExtValue();
+    }
+
+    LoopHintAttr::OptionType Option = LH->getOption();
+    LoopHintAttr::LoopHintState State = LH->getState();
+    switch (State) {
+    case LoopHintAttr::Disable:
+      switch (Option) {
+      case LoopHintAttr::Vectorize:
+        // Disable vectorization by specifying a width of 1.
+        setVectorizeWidth(1);
+        break;
+      case LoopHintAttr::Interleave:
+        // Disable interleaving by speciyfing a count of 1.
+        setInterleaveCount(1);
+        break;
+      case LoopHintAttr::Unroll:
+        setUnrollState(LoopAttributes::Disable);
+        break;
+      case LoopHintAttr::UnrollCount:
+      case LoopHintAttr::VectorizeWidth:
+      case LoopHintAttr::InterleaveCount:
+        llvm_unreachable("Options cannot be disabled.");
+        break;
+      }
+      break;
+    case LoopHintAttr::Enable:
+      switch (Option) {
+      case LoopHintAttr::Vectorize:
+      case LoopHintAttr::Interleave:
+        setVectorizeEnable(true);
+        break;
+      case LoopHintAttr::Unroll:
+        setUnrollState(LoopAttributes::Enable);
+        break;
+      case LoopHintAttr::UnrollCount:
+      case LoopHintAttr::VectorizeWidth:
+      case LoopHintAttr::InterleaveCount:
+        llvm_unreachable("Options cannot enabled.");
+        break;
+      }
+      break;
+    case LoopHintAttr::AssumeSafety:
+      switch (Option) {
+      case LoopHintAttr::Vectorize:
+      case LoopHintAttr::Interleave:
+        // Apply "llvm.mem.parallel_loop_access" metadata to load/stores.
+        setParallel(true);
+        setVectorizeEnable(true);
+        break;
+      case LoopHintAttr::Unroll:
+      case LoopHintAttr::UnrollCount:
+      case LoopHintAttr::VectorizeWidth:
+      case LoopHintAttr::InterleaveCount:
+        llvm_unreachable("Options cannot be used to assume mem safety.");
+        break;
+      }
+      break;
+    case LoopHintAttr::Full:
+      switch (Option) {
+      case LoopHintAttr::Unroll:
+        setUnrollState(LoopAttributes::Full);
+        break;
+      case LoopHintAttr::Vectorize:
+      case LoopHintAttr::Interleave:
+      case LoopHintAttr::UnrollCount:
+      case LoopHintAttr::VectorizeWidth:
+      case LoopHintAttr::InterleaveCount:
+        llvm_unreachable("Options cannot be used with 'full' hint.");
+        break;
+      }
+      break;
+    case LoopHintAttr::Numeric:
+      switch (Option) {
+      case LoopHintAttr::VectorizeWidth:
+        setVectorizeWidth(ValueInt);
+        break;
+      case LoopHintAttr::InterleaveCount:
+        setInterleaveCount(ValueInt);
+        break;
+      case LoopHintAttr::UnrollCount:
+        setUnrollCount(ValueInt);
+        break;
+      case LoopHintAttr::Unroll:
+      case LoopHintAttr::Vectorize:
+      case LoopHintAttr::Interleave:
+        llvm_unreachable("Options cannot be assigned a value.");
+        break;
+      }
+      break;
+    }
+  }
+
+  /// Stage the attributes.
+  push(Header);
+}
+
+void LoopInfoStack::pop() {
+  assert(!Active.empty() && "No active loops to pop");
+  Active.pop_back();
+}
+
+void LoopInfoStack::InsertHelper(Instruction *I) const {
+  if (!hasInfo())
+    return;
+
+  const LoopInfo &L = getInfo();
+  if (!L.getLoopID())
+    return;
+
+  if (TerminatorInst *TI = dyn_cast<TerminatorInst>(I)) {
+    for (unsigned i = 0, ie = TI->getNumSuccessors(); i < ie; ++i)
+      if (TI->getSuccessor(i) == L.getHeader()) {
+        TI->setMetadata("llvm.loop", L.getLoopID());
+        break;
+      }
+    return;
+  }
+
+  if (L.getAttributes().IsParallel && I->mayReadOrWriteMemory())
+    I->setMetadata("llvm.mem.parallel_loop_access", L.getLoopID());
+}