This patch adds a helper class (CGLoopInfo) for marking memory instructions with llvm.mem.parallel_loop_access metadata.

It also adds a simple initial version of codegen for pragma omp simd (it will change in the future to support all the clauses).

Differential revision: http://reviews.llvm.org/D3644



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209411 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 136 insertions, 0 deletions

diff --git a/lib/CodeGen/CGLoopInfo.h b/lib/CodeGen/CGLoopInfo.h
new file mode 100644
index 0000000000..f4a8dcae69
--- /dev/null
+++ b/lib/CodeGen/CGLoopInfo.h
@@ -0,0 +1,136 @@
+//===---- CGLoopInfo.h - 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the internal state used for llvm translation for loop statement
+// metadata.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CODEGEN_CGLOOPINFO_H
+#define CLANG_CODEGEN_CGLOOPINFO_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/Value.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+class BasicBlock;
+class Instruction;
+class MDNode;
+} // end namespace llvm
+
+namespace clang {
+namespace CodeGen {
+
+/// \brief Attributes that may be specified on loops.
+struct LoopAttributes {
+  explicit LoopAttributes(bool IsParallel = false);
+  void clear();
+
+  /// \brief Generate llvm.loop.parallel metadata for loads and stores.
+  bool IsParallel;
+
+  /// \brief Values of llvm.vectorizer.enable metadata.
+  enum LVEnableState { VecUnspecified, VecEnable, VecDisable };
+
+  /// \brief llvm.vectorizer.enable
+  LVEnableState VectorizerEnable;
+
+  /// \brief llvm.vectorizer.width
+  unsigned VectorizerWidth;
+
+  /// \brief llvm.vectorizer.unroll
+  unsigned VectorizerUnroll;
+};
+
+/// \brief Information used when generating a structured loop.
+class LoopInfo {
+public:
+  /// \brief Construct a new LoopInfo for the loop with entry Header.
+  LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs);
+
+  /// \brief Get the loop id metadata for this loop.
+  llvm::MDNode *getLoopID() const { return LoopID; }
+
+  /// \brief Get the header block of this loop.
+  llvm::BasicBlock *getHeader() const { return Header; }
+
+  /// \brief Get the set of attributes active for this loop.
+  const LoopAttributes &getAttributes() const { return Attrs; }
+
+private:
+  /// \brief Loop ID metadata.
+  llvm::MDNode *LoopID;
+  /// \brief Header block of this loop.
+  llvm::BasicBlock *Header;
+  /// \brief The attributes for this loop.
+  LoopAttributes Attrs;
+};
+
+/// \brief A stack of loop information corresponding to loop nesting levels.
+/// This stack can be used to prepare attributes which are applied when a loop
+/// is emitted.
+class LoopInfoStack {
+  LoopInfoStack(const LoopInfoStack &) LLVM_DELETED_FUNCTION;
+  void operator=(const LoopInfoStack &) LLVM_DELETED_FUNCTION;
+
+public:
+  LoopInfoStack() {}
+
+  /// \brief Begin a new structured loop. The set of staged attributes will be
+  /// applied to the loop and then cleared.
+  void push(llvm::BasicBlock *Header);
+
+  /// \brief End the current loop.
+  void pop();
+
+  /// \brief Return the top loop id metadata.
+  llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); }
+
+  /// \brief Return true if the top loop is parallel.
+  bool getCurLoopParallel() const {
+    return hasInfo() ? getInfo().getAttributes().IsParallel : false;
+  }
+
+  /// \brief Function called by the CodeGenFunction when an instruction is
+  /// created.
+  void InsertHelper(llvm::Instruction *I) const;
+
+  /// \brief Set the next pushed loop as parallel.
+  void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; }
+
+  /// \brief Set the next pushed loop 'vectorizer.enable'
+  void setVectorizerEnable(bool Enable = true) {
+    StagedAttrs.VectorizerEnable =
+        Enable ? LoopAttributes::VecEnable : LoopAttributes::VecDisable;
+  }
+
+  /// \brief Set the vectorizer width for the next loop pushed.
+  void setVectorizerWidth(unsigned W) { StagedAttrs.VectorizerWidth = W; }
+
+  /// \brief Set the vectorizer unroll for the next loop pushed.
+  void setVectorizerUnroll(unsigned U) { StagedAttrs.VectorizerUnroll = U; }
+
+private:
+  /// \brief Returns true if there is LoopInfo on the stack.
+  bool hasInfo() const { return !Active.empty(); }
+  /// \brief Return the LoopInfo for the current loop. HasInfo should be called
+  /// first to ensure LoopInfo is present.
+  const LoopInfo &getInfo() const { return Active.back(); }
+  /// \brief The set of attributes that will be applied to the next pushed loop.
+  LoopAttributes StagedAttrs;
+  /// \brief Stack of active loops.
+  llvm::SmallVector<LoopInfo, 4> Active;
+};
+
+} // end namespace CodeGen
+} // end namespace clang
+
+#endif // CLANG_CODEGEN_CGLOOPINFO_H