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//===---- 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.
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Compiler.h"
namespace llvm {
class BasicBlock;
class Instruction;
class MDNode;
} // end namespace llvm
namespace clang {
class Attr;
class ASTContext;
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 State of loop vectorization or unrolling.
enum LVEnableState { Unspecified, Enable, Disable, Full };
/// \brief Value for llvm.loop.vectorize.enable metadata.
LVEnableState VectorizeEnable;
/// \brief Value for llvm.loop.unroll.* metadata (enable, disable, or full).
LVEnableState UnrollEnable;
/// \brief Value for llvm.loop.vectorize.width metadata.
unsigned VectorizeWidth;
/// \brief Value for llvm.loop.interleave.count metadata.
unsigned InterleaveCount;
/// \brief llvm.unroll.
unsigned UnrollCount;
/// \brief Value for llvm.loop.distribute.enable metadata.
LVEnableState DistributeEnable;
/// \brief Information used when generating a structured loop.
class LoopInfo {
/// \brief Construct a new LoopInfo for the loop with entry Header.
LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs,
const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc);
/// \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; }
/// \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 &) = delete;
void operator=(const LoopInfoStack &) = delete;
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, const llvm::DebugLoc &StartLoc,
const llvm::DebugLoc &EndLoc);
/// \brief Begin a new structured loop. Stage attributes from the Attrs list.
/// The staged attributes are applied to the loop and then cleared.
void push(llvm::BasicBlock *Header, clang::ASTContext &Ctx,
llvm::ArrayRef<const Attr *> Attrs, const llvm::DebugLoc &StartLoc,
const llvm::DebugLoc &EndLoc);
/// \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 'vectorize.enable'
void setVectorizeEnable(bool Enable = true) {
StagedAttrs.VectorizeEnable =
Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
/// \brief Set the next pushed loop as a distribution candidate.
void setDistributeState(bool Enable = true) {
StagedAttrs.DistributeEnable =
Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
/// \brief Set the next pushed loop unroll state.
void setUnrollState(const LoopAttributes::LVEnableState &State) {
StagedAttrs.UnrollEnable = State;
/// \brief Set the vectorize width for the next loop pushed.
void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; }
/// \brief Set the interleave count for the next loop pushed.
void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; }
/// \brief Set the unroll count for the next loop pushed.
void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; }
/// \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