[llvm] r297081 - [Outliner] Fixed Asan bot failure in r296418
Evgenii Stepanov via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 7 11:22:58 PST 2017
Hi,
there are still memory leaks in the outliner tests:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/3273/steps/check-llvm%20asan/logs/stdio
On Mon, Mar 6, 2017 at 1:31 PM, Jessica Paquette via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: paquette
> Date: Mon Mar 6 15:31:18 2017
> New Revision: 297081
>
> URL: http://llvm.org/viewvc/llvm-project?rev=297081&view=rev
> Log:
> [Outliner] Fixed Asan bot failure in r296418
>
> Fixed the asan bot failure which led to the last commit of the outliner being reverted.
> The change is in lib/CodeGen/MachineOutliner.cpp in the SuffixTree's constructor. LeafVector
> is no longer initialized using reserve but just a standard constructor.
>
>
> Added:
> llvm/trunk/lib/CodeGen/MachineOutliner.cpp
> llvm/trunk/test/CodeGen/X86/machine-outliner-debuginfo.ll
> llvm/trunk/test/CodeGen/X86/machine-outliner.ll
> Modified:
> llvm/trunk/include/llvm/CodeGen/Passes.h
> llvm/trunk/include/llvm/InitializePasses.h
> llvm/trunk/include/llvm/Target/TargetInstrInfo.h
> llvm/trunk/lib/CodeGen/CMakeLists.txt
> llvm/trunk/lib/CodeGen/CodeGen.cpp
> llvm/trunk/lib/CodeGen/TargetPassConfig.cpp
> llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
> llvm/trunk/lib/Target/X86/X86InstrInfo.h
>
> Modified: llvm/trunk/include/llvm/CodeGen/Passes.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/Passes.h?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/CodeGen/Passes.h (original)
> +++ llvm/trunk/include/llvm/CodeGen/Passes.h Mon Mar 6 15:31:18 2017
> @@ -405,6 +405,11 @@ namespace llvm {
>
> /// This pass combine basic blocks guarded by the same branch.
> extern char &BranchCoalescingID;
> +
> + /// This pass performs outlining on machine instructions directly before
> + /// printing assembly.
> + ModulePass *createMachineOutlinerPass();
> +
> } // End llvm namespace
>
> /// Target machine pass initializer for passes with dependencies. Use with
>
> Modified: llvm/trunk/include/llvm/InitializePasses.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InitializePasses.h?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/InitializePasses.h (original)
> +++ llvm/trunk/include/llvm/InitializePasses.h Mon Mar 6 15:31:18 2017
> @@ -237,6 +237,7 @@ void initializeMachineLICMPass(PassRegis
> void initializeMachineLoopInfoPass(PassRegistry&);
> void initializeMachineModuleInfoPass(PassRegistry&);
> void initializeMachineOptimizationRemarkEmitterPassPass(PassRegistry&);
> +void initializeMachineOutlinerPass(PassRegistry&);
> void initializeMachinePipelinerPass(PassRegistry&);
> void initializeMachinePostDominatorTreePass(PassRegistry&);
> void initializeMachineRegionInfoPassPass(PassRegistry&);
>
> Modified: llvm/trunk/include/llvm/Target/TargetInstrInfo.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetInstrInfo.h?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Target/TargetInstrInfo.h (original)
> +++ llvm/trunk/include/llvm/Target/TargetInstrInfo.h Mon Mar 6 15:31:18 2017
> @@ -1508,6 +1508,63 @@ public:
> return false;
> }
>
> + /// \brief Return how many instructions would be saved by outlining a
> + /// sequence containing \p SequenceSize instructions that appears
> + /// \p Occurrences times in a module.
> + virtual unsigned getOutliningBenefit(size_t SequenceSize, size_t Occurrences)
> + const {
> + llvm_unreachable(
> + "Target didn't implement TargetInstrInfo::getOutliningBenefit!");
> + }
> +
> + /// Represents how an instruction should be mapped by the outliner.
> + /// \p Legal instructions are those which are safe to outline.
> + /// \p Illegal instructions are those which cannot be outlined.
> + /// \p Invisible instructions are instructions which can be outlined, but
> + /// shouldn't actually impact the outlining result.
> + enum MachineOutlinerInstrType {Legal, Illegal, Invisible};
> +
> + /// Return true if the instruction is legal to outline.
> + virtual MachineOutlinerInstrType getOutliningType(MachineInstr &MI) const {
> + llvm_unreachable(
> + "Target didn't implement TargetInstrInfo::getOutliningType!");
> + }
> +
> + /// Insert a custom epilogue for outlined functions.
> + /// This may be empty, in which case no epilogue or return statement will be
> + /// emitted.
> + virtual void insertOutlinerEpilogue(MachineBasicBlock &MBB,
> + MachineFunction &MF) const {
> + llvm_unreachable(
> + "Target didn't implement TargetInstrInfo::insertOutlinerEpilogue!");
> + }
> +
> + /// Insert a call to an outlined function into the program.
> + /// Returns an iterator to the spot where we inserted the call. This must be
> + /// implemented by the target.
> + virtual MachineBasicBlock::iterator
> + insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
> + MachineBasicBlock::iterator &It, MachineFunction &MF)
> + const {
> + llvm_unreachable(
> + "Target didn't implement TargetInstrInfo::insertOutlinedCall!");
> + }
> +
> + /// Insert a custom prologue for outlined functions.
> + /// This may be empty, in which case no prologue will be emitted.
> + virtual void insertOutlinerPrologue(MachineBasicBlock &MBB,
> + MachineFunction &MF) const {
> + llvm_unreachable(
> + "Target didn't implement TargetInstrInfo::insertOutlinerPrologue!");
> + }
> +
> + /// Return true if the function can safely be outlined from.
> + /// By default, this means that the function has no red zone.
> + virtual bool isFunctionSafeToOutlineFrom(MachineFunction &F) const {
> + llvm_unreachable("Target didn't implement "
> + "TargetInstrInfo::isFunctionSafeToOutlineFrom!");
> + }
> +
> private:
> unsigned CallFrameSetupOpcode, CallFrameDestroyOpcode;
> unsigned CatchRetOpcode;
>
> Modified: llvm/trunk/lib/CodeGen/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CMakeLists.txt?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/CMakeLists.txt (original)
> +++ llvm/trunk/lib/CodeGen/CMakeLists.txt Mon Mar 6 15:31:18 2017
> @@ -75,6 +75,7 @@ add_llvm_library(LLVMCodeGen
> MachineModuleInfo.cpp
> MachineModuleInfoImpls.cpp
> MachineOptimizationRemarkEmitter.cpp
> + MachineOutliner.cpp
> MachinePassRegistry.cpp
> MachinePipeliner.cpp
> MachinePostDominators.cpp
>
> Modified: llvm/trunk/lib/CodeGen/CodeGen.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGen.cpp?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/CodeGen.cpp (original)
> +++ llvm/trunk/lib/CodeGen/CodeGen.cpp Mon Mar 6 15:31:18 2017
> @@ -58,6 +58,7 @@ void llvm::initializeCodeGen(PassRegistr
> initializeMachineLoopInfoPass(Registry);
> initializeMachineModuleInfoPass(Registry);
> initializeMachineOptimizationRemarkEmitterPassPass(Registry);
> + initializeMachineOutlinerPass(Registry);
> initializeMachinePipelinerPass(Registry);
> initializeMachinePostDominatorTreePass(Registry);
> initializeMachineRegionInfoPassPass(Registry);
>
> Added: llvm/trunk/lib/CodeGen/MachineOutliner.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineOutliner.cpp?rev=297081&view=auto
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/MachineOutliner.cpp (added)
> +++ llvm/trunk/lib/CodeGen/MachineOutliner.cpp Mon Mar 6 15:31:18 2017
> @@ -0,0 +1,1399 @@
> +//===---- MachineOutliner.cpp - Outline instructions -----------*- C++ -*-===//
> +//
> +// The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +///
> +/// \file
> +/// Replaces repeated sequences of instructions with function calls.
> +///
> +/// This works by placing every instruction from every basic block in a
> +/// suffix tree, and repeatedly querying that tree for repeated sequences of
> +/// instructions. If a sequence of instructions appears often, then it ought
> +/// to be beneficial to pull out into a function.
> +///
> +/// This was originally presented at the 2016 LLVM Developers' Meeting in the
> +/// talk "Reducing Code Size Using Outlining". For a high-level overview of
> +/// how this pass works, the talk is available on YouTube at
> +///
> +/// https://www.youtube.com/watch?v=yorld-WSOeU
> +///
> +/// The slides for the talk are available at
> +///
> +/// http://www.llvm.org/devmtg/2016-11/Slides/Paquette-Outliner.pdf
> +///
> +/// The talk provides an overview of how the outliner finds candidates and
> +/// ultimately outlines them. It describes how the main data structure for this
> +/// pass, the suffix tree, is queried and purged for candidates. It also gives
> +/// a simplified suffix tree construction algorithm for suffix trees based off
> +/// of the algorithm actually used here, Ukkonen's algorithm.
> +///
> +/// For the original RFC for this pass, please see
> +///
> +/// http://lists.llvm.org/pipermail/llvm-dev/2016-August/104170.html
> +///
> +/// For more information on the suffix tree data structure, please see
> +/// https://www.cs.helsinki.fi/u/ukkonen/SuffixT1withFigs.pdf
> +///
> +//===----------------------------------------------------------------------===//
> +#include "llvm/ADT/DenseMap.h"
> +#include "llvm/ADT/Statistic.h"
> +#include "llvm/ADT/Twine.h"
> +#include "llvm/CodeGen/MachineFrameInfo.h"
> +#include "llvm/CodeGen/MachineFunction.h"
> +#include "llvm/CodeGen/MachineInstrBuilder.h"
> +#include "llvm/CodeGen/MachineModuleInfo.h"
> +#include "llvm/CodeGen/Passes.h"
> +#include "llvm/IR/IRBuilder.h"
> +#include "llvm/Support/Allocator.h"
> +#include "llvm/Support/Debug.h"
> +#include "llvm/Support/raw_ostream.h"
> +#include "llvm/Target/TargetInstrInfo.h"
> +#include "llvm/Target/TargetMachine.h"
> +#include "llvm/Target/TargetRegisterInfo.h"
> +#include "llvm/Target/TargetSubtargetInfo.h"
> +#include <functional>
> +#include <map>
> +#include <sstream>
> +#include <tuple>
> +#include <vector>
> +
> +#define DEBUG_TYPE "machine-outliner"
> +
> +using namespace llvm;
> +
> +STATISTIC(NumOutlined, "Number of candidates outlined");
> +STATISTIC(FunctionsCreated, "Number of functions created");
> +
> +namespace {
> +
> +/// Represents an undefined index in the suffix tree.
> +const size_t EmptyIdx = -1;
> +
> +/// A node in a suffix tree which represents a substring or suffix.
> +///
> +/// Each node has either no children or at least two children, with the root
> +/// being a exception in the empty tree.
> +///
> +/// Children are represented as a map between unsigned integers and nodes. If
> +/// a node N has a child M on unsigned integer k, then the mapping represented
> +/// by N is a proper prefix of the mapping represented by M. Note that this,
> +/// although similar to a trie is somewhat different: each node stores a full
> +/// substring of the full mapping rather than a single character state.
> +///
> +/// Each internal node contains a pointer to the internal node representing
> +/// the same string, but with the first character chopped off. This is stored
> +/// in \p Link. Each leaf node stores the start index of its respective
> +/// suffix in \p SuffixIdx.
> +struct SuffixTreeNode {
> +
> + /// The children of this node.
> + ///
> + /// A child existing on an unsigned integer implies that from the mapping
> + /// represented by the current node, there is a way to reach another
> + /// mapping by tacking that character on the end of the current string.
> + DenseMap<unsigned, SuffixTreeNode *> Children;
> +
> + /// A flag set to false if the node has been pruned from the tree.
> + bool IsInTree = true;
> +
> + /// The start index of this node's substring in the main string.
> + size_t StartIdx = EmptyIdx;
> +
> + /// The end index of this node's substring in the main string.
> + ///
> + /// Every leaf node must have its \p EndIdx incremented at the end of every
> + /// step in the construction algorithm. To avoid having to update O(N)
> + /// nodes individually at the end of every step, the end index is stored
> + /// as a pointer.
> + size_t *EndIdx = nullptr;
> +
> + /// For leaves, the start index of the suffix represented by this node.
> + ///
> + /// For all other nodes, this is ignored.
> + size_t SuffixIdx = EmptyIdx;
> +
> + /// \brief For internal nodes, a pointer to the internal node representing
> + /// the same sequence with the first character chopped off.
> + ///
> + /// This has two major purposes in the suffix tree. The first is as a
> + /// shortcut in Ukkonen's construction algorithm. One of the things that
> + /// Ukkonen's algorithm does to achieve linear-time construction is
> + /// keep track of which node the next insert should be at. This makes each
> + /// insert O(1), and there are a total of O(N) inserts. The suffix link
> + /// helps with inserting children of internal nodes.
> + ///
> + /// Say we add a child to an internal node with associated mapping S. The
> + /// next insertion must be at the node representing S - its first character.
> + /// This is given by the way that we iteratively build the tree in Ukkonen's
> + /// algorithm. The main idea is to look at the suffixes of each prefix in the
> + /// string, starting with the longest suffix of the prefix, and ending with
> + /// the shortest. Therefore, if we keep pointers between such nodes, we can
> + /// move to the next insertion point in O(1) time. If we don't, then we'd
> + /// have to query from the root, which takes O(N) time. This would make the
> + /// construction algorithm O(N^2) rather than O(N).
> + ///
> + /// The suffix link is also used during the tree pruning process to let us
> + /// quickly throw out a bunch of potential overlaps. Say we have a sequence
> + /// S we want to outline. Then each of its suffixes contribute to at least
> + /// one overlapping case. Therefore, we can follow the suffix links
> + /// starting at the node associated with S to the root and "delete" those
> + /// nodes, save for the root. For each candidate, this removes
> + /// O(|candidate|) overlaps from the search space. We don't actually
> + /// completely invalidate these nodes though; doing that is far too
> + /// aggressive. Consider the following pathological string:
> + ///
> + /// 1 2 3 1 2 3 2 3 2 3 2 3 2 3 2 3 2 3
> + ///
> + /// If we, for the sake of example, outlined 1 2 3, then we would throw
> + /// out all instances of 2 3. This isn't desirable. To get around this,
> + /// when we visit a link node, we decrement its occurrence count by the
> + /// number of sequences we outlined in the current step. In the pathological
> + /// example, the 2 3 node would have an occurrence count of 8, while the
> + /// 1 2 3 node would have an occurrence count of 2. Thus, the 2 3 node
> + /// would survive to the next round allowing us to outline the extra
> + /// instances of 2 3.
> + SuffixTreeNode *Link = nullptr;
> +
> + /// The parent of this node. Every node except for the root has a parent.
> + SuffixTreeNode *Parent = nullptr;
> +
> + /// The number of times this node's string appears in the tree.
> + ///
> + /// This is equal to the number of leaf children of the string. It represents
> + /// the number of suffixes that the node's string is a prefix of.
> + size_t OccurrenceCount = 0;
> +
> + /// Returns true if this node is a leaf.
> + bool isLeaf() const { return SuffixIdx != EmptyIdx; }
> +
> + /// Returns true if this node is the root of its owning \p SuffixTree.
> + bool isRoot() const { return StartIdx == EmptyIdx; }
> +
> + /// Return the number of elements in the substring associated with this node.
> + size_t size() const {
> +
> + // Is it the root? If so, it's the empty string so return 0.
> + if (isRoot())
> + return 0;
> +
> + assert(*EndIdx != EmptyIdx && "EndIdx is undefined!");
> +
> + // Size = the number of elements in the string.
> + // For example, [0 1 2 3] has length 4, not 3. 3-0 = 3, so we have 3-0+1.
> + return *EndIdx - StartIdx + 1;
> + }
> +
> + SuffixTreeNode(size_t StartIdx, size_t *EndIdx, SuffixTreeNode *Link,
> + SuffixTreeNode *Parent)
> + : StartIdx(StartIdx), EndIdx(EndIdx), Link(Link), Parent(Parent) {}
> +
> + SuffixTreeNode() {}
> +};
> +
> +/// A data structure for fast substring queries.
> +///
> +/// Suffix trees represent the suffixes of their input strings in their leaves.
> +/// A suffix tree is a type of compressed trie structure where each node
> +/// represents an entire substring rather than a single character. Each leaf
> +/// of the tree is a suffix.
> +///
> +/// A suffix tree can be seen as a type of state machine where each state is a
> +/// substring of the full string. The tree is structured so that, for a string
> +/// of length N, there are exactly N leaves in the tree. This structure allows
> +/// us to quickly find repeated substrings of the input string.
> +///
> +/// In this implementation, a "string" is a vector of unsigned integers.
> +/// These integers may result from hashing some data type. A suffix tree can
> +/// contain 1 or many strings, which can then be queried as one large string.
> +///
> +/// The suffix tree is implemented using Ukkonen's algorithm for linear-time
> +/// suffix tree construction. Ukkonen's algorithm is explained in more detail
> +/// in the paper by Esko Ukkonen "On-line construction of suffix trees. The
> +/// paper is available at
> +///
> +/// https://www.cs.helsinki.fi/u/ukkonen/SuffixT1withFigs.pdf
> +class SuffixTree {
> +private:
> + /// Each element is an integer representing an instruction in the module.
> + ArrayRef<unsigned> Str;
> +
> + /// Maintains each node in the tree.
> + BumpPtrAllocator NodeAllocator;
> +
> + /// The root of the suffix tree.
> + ///
> + /// The root represents the empty string. It is maintained by the
> + /// \p NodeAllocator like every other node in the tree.
> + SuffixTreeNode *Root = nullptr;
> +
> + /// Stores each leaf in the tree for better pruning.
> + std::vector<SuffixTreeNode *> LeafVector;
> +
> + /// Maintains the end indices of the internal nodes in the tree.
> + ///
> + /// Each internal node is guaranteed to never have its end index change
> + /// during the construction algorithm; however, leaves must be updated at
> + /// every step. Therefore, we need to store leaf end indices by reference
> + /// to avoid updating O(N) leaves at every step of construction. Thus,
> + /// every internal node must be allocated its own end index.
> + BumpPtrAllocator InternalEndIdxAllocator;
> +
> + /// The end index of each leaf in the tree.
> + size_t LeafEndIdx = -1;
> +
> + /// \brief Helper struct which keeps track of the next insertion point in
> + /// Ukkonen's algorithm.
> + struct ActiveState {
> + /// The next node to insert at.
> + SuffixTreeNode *Node;
> +
> + /// The index of the first character in the substring currently being added.
> + size_t Idx = EmptyIdx;
> +
> + /// The length of the substring we have to add at the current step.
> + size_t Len = 0;
> + };
> +
> + /// \brief The point the next insertion will take place at in the
> + /// construction algorithm.
> + ActiveState Active;
> +
> + /// Allocate a leaf node and add it to the tree.
> + ///
> + /// \param Parent The parent of this node.
> + /// \param StartIdx The start index of this node's associated string.
> + /// \param Edge The label on the edge leaving \p Parent to this node.
> + ///
> + /// \returns A pointer to the allocated leaf node.
> + SuffixTreeNode *insertLeaf(SuffixTreeNode &Parent, size_t StartIdx,
> + unsigned Edge) {
> +
> + assert(StartIdx <= LeafEndIdx && "String can't start after it ends!");
> +
> + SuffixTreeNode *N = new (NodeAllocator) SuffixTreeNode(StartIdx,
> + &LeafEndIdx,
> + nullptr,
> + &Parent);
> + Parent.Children[Edge] = N;
> +
> + return N;
> + }
> +
> + /// Allocate an internal node and add it to the tree.
> + ///
> + /// \param Parent The parent of this node. Only null when allocating the root.
> + /// \param StartIdx The start index of this node's associated string.
> + /// \param EndIdx The end index of this node's associated string.
> + /// \param Edge The label on the edge leaving \p Parent to this node.
> + ///
> + /// \returns A pointer to the allocated internal node.
> + SuffixTreeNode *insertInternalNode(SuffixTreeNode *Parent, size_t StartIdx,
> + size_t EndIdx, unsigned Edge) {
> +
> + assert(StartIdx <= EndIdx && "String can't start after it ends!");
> + assert(!(!Parent && StartIdx != EmptyIdx) &&
> + "Non-root internal nodes must have parents!");
> +
> + size_t *E = new (InternalEndIdxAllocator) size_t(EndIdx);
> + SuffixTreeNode *N = new (NodeAllocator) SuffixTreeNode(StartIdx,
> + E,
> + Root,
> + Parent);
> + if (Parent)
> + Parent->Children[Edge] = N;
> +
> + return N;
> + }
> +
> + /// \brief Set the suffix indices of the leaves to the start indices of their
> + /// respective suffixes. Also stores each leaf in \p LeafVector at its
> + /// respective suffix index.
> + ///
> + /// \param[in] CurrNode The node currently being visited.
> + /// \param CurrIdx The current index of the string being visited.
> + void setSuffixIndices(SuffixTreeNode &CurrNode, size_t CurrIdx) {
> +
> + bool IsLeaf = CurrNode.Children.size() == 0 && !CurrNode.isRoot();
> +
> + // Traverse the tree depth-first.
> + for (auto &ChildPair : CurrNode.Children) {
> + assert(ChildPair.second && "Node had a null child!");
> + setSuffixIndices(*ChildPair.second,
> + CurrIdx + ChildPair.second->size());
> + }
> +
> + // Is this node a leaf?
> + if (IsLeaf) {
> + // If yes, give it a suffix index and bump its parent's occurrence count.
> + CurrNode.SuffixIdx = Str.size() - CurrIdx;
> + assert(CurrNode.Parent && "CurrNode had no parent!");
> + CurrNode.Parent->OccurrenceCount++;
> +
> + // Store the leaf in the leaf vector for pruning later.
> + LeafVector[CurrNode.SuffixIdx] = &CurrNode;
> + }
> + }
> +
> + /// \brief Construct the suffix tree for the prefix of the input ending at
> + /// \p EndIdx.
> + ///
> + /// Used to construct the full suffix tree iteratively. At the end of each
> + /// step, the constructed suffix tree is either a valid suffix tree, or a
> + /// suffix tree with implicit suffixes. At the end of the final step, the
> + /// suffix tree is a valid tree.
> + ///
> + /// \param EndIdx The end index of the current prefix in the main string.
> + /// \param SuffixesToAdd The number of suffixes that must be added
> + /// to complete the suffix tree at the current phase.
> + ///
> + /// \returns The number of suffixes that have not been added at the end of
> + /// this step.
> + unsigned extend(size_t EndIdx, size_t SuffixesToAdd) {
> + SuffixTreeNode *NeedsLink = nullptr;
> +
> + while (SuffixesToAdd > 0) {
> +
> + // Are we waiting to add anything other than just the last character?
> + if (Active.Len == 0) {
> + // If not, then say the active index is the end index.
> + Active.Idx = EndIdx;
> + }
> +
> + assert(Active.Idx <= EndIdx && "Start index can't be after end index!");
> +
> + // The first character in the current substring we're looking at.
> + unsigned FirstChar = Str[Active.Idx];
> +
> + // Have we inserted anything starting with FirstChar at the current node?
> + if (Active.Node->Children.count(FirstChar) == 0) {
> + // If not, then we can just insert a leaf and move too the next step.
> + insertLeaf(*Active.Node, EndIdx, FirstChar);
> +
> + // The active node is an internal node, and we visited it, so it must
> + // need a link if it doesn't have one.
> + if (NeedsLink) {
> + NeedsLink->Link = Active.Node;
> + NeedsLink = nullptr;
> + }
> + } else {
> + // There's a match with FirstChar, so look for the point in the tree to
> + // insert a new node.
> + SuffixTreeNode *NextNode = Active.Node->Children[FirstChar];
> +
> + size_t SubstringLen = NextNode->size();
> +
> + // Is the current suffix we're trying to insert longer than the size of
> + // the child we want to move to?
> + if (Active.Len >= SubstringLen) {
> + // If yes, then consume the characters we've seen and move to the next
> + // node.
> + Active.Idx += SubstringLen;
> + Active.Len -= SubstringLen;
> + Active.Node = NextNode;
> + continue;
> + }
> +
> + // Otherwise, the suffix we're trying to insert must be contained in the
> + // next node we want to move to.
> + unsigned LastChar = Str[EndIdx];
> +
> + // Is the string we're trying to insert a substring of the next node?
> + if (Str[NextNode->StartIdx + Active.Len] == LastChar) {
> + // If yes, then we're done for this step. Remember our insertion point
> + // and move to the next end index. At this point, we have an implicit
> + // suffix tree.
> + if (NeedsLink && !Active.Node->isRoot()) {
> + NeedsLink->Link = Active.Node;
> + NeedsLink = nullptr;
> + }
> +
> + Active.Len++;
> + break;
> + }
> +
> + // The string we're trying to insert isn't a substring of the next node,
> + // but matches up to a point. Split the node.
> + //
> + // For example, say we ended our search at a node n and we're trying to
> + // insert ABD. Then we'll create a new node s for AB, reduce n to just
> + // representing C, and insert a new leaf node l to represent d. This
> + // allows us to ensure that if n was a leaf, it remains a leaf.
> + //
> + // | ABC ---split---> | AB
> + // n s
> + // C / \ D
> + // n l
> +
> + // The node s from the diagram
> + SuffixTreeNode *SplitNode =
> + insertInternalNode(Active.Node,
> + NextNode->StartIdx,
> + NextNode->StartIdx + Active.Len - 1,
> + FirstChar);
> +
> + // Insert the new node representing the new substring into the tree as
> + // a child of the split node. This is the node l from the diagram.
> + insertLeaf(*SplitNode, EndIdx, LastChar);
> +
> + // Make the old node a child of the split node and update its start
> + // index. This is the node n from the diagram.
> + NextNode->StartIdx += Active.Len;
> + NextNode->Parent = SplitNode;
> + SplitNode->Children[Str[NextNode->StartIdx]] = NextNode;
> +
> + // SplitNode is an internal node, update the suffix link.
> + if (NeedsLink)
> + NeedsLink->Link = SplitNode;
> +
> + NeedsLink = SplitNode;
> + }
> +
> + // We've added something new to the tree, so there's one less suffix to
> + // add.
> + SuffixesToAdd--;
> +
> + if (Active.Node->isRoot()) {
> + if (Active.Len > 0) {
> + Active.Len--;
> + Active.Idx = EndIdx - SuffixesToAdd + 1;
> + }
> + } else {
> + // Start the next phase at the next smallest suffix.
> + Active.Node = Active.Node->Link;
> + }
> + }
> +
> + return SuffixesToAdd;
> + }
> +
> + /// \brief Return the start index and length of a string which maximizes a
> + /// benefit function by traversing the tree depth-first.
> + ///
> + /// Helper function for \p bestRepeatedSubstring.
> + ///
> + /// \param CurrNode The node currently being visited.
> + /// \param CurrLen Length of the current string.
> + /// \param[out] BestLen Length of the most beneficial substring.
> + /// \param[out] MaxBenefit Benefit of the most beneficial substring.
> + /// \param[out] BestStartIdx Start index of the most beneficial substring.
> + /// \param BenefitFn The function the query should return a maximum string
> + /// for.
> + void findBest(SuffixTreeNode &CurrNode, size_t CurrLen, size_t &BestLen,
> + size_t &MaxBenefit, size_t &BestStartIdx,
> + const std::function<unsigned(SuffixTreeNode &, size_t CurrLen)>
> + &BenefitFn) {
> +
> + if (!CurrNode.IsInTree)
> + return;
> +
> + // Can we traverse further down the tree?
> + if (!CurrNode.isLeaf()) {
> + // If yes, continue the traversal.
> + for (auto &ChildPair : CurrNode.Children) {
> + if (ChildPair.second && ChildPair.second->IsInTree)
> + findBest(*ChildPair.second, CurrLen + ChildPair.second->size(),
> + BestLen, MaxBenefit, BestStartIdx, BenefitFn);
> + }
> + } else {
> + // We hit a leaf.
> + size_t StringLen = CurrLen - CurrNode.size();
> + unsigned Benefit = BenefitFn(CurrNode, StringLen);
> +
> + // Did we do better than in the last step?
> + if (Benefit <= MaxBenefit)
> + return;
> +
> + // We did better, so update the best string.
> + MaxBenefit = Benefit;
> + BestStartIdx = CurrNode.SuffixIdx;
> + BestLen = StringLen;
> + }
> + }
> +
> +public:
> +
> + /// \brief Return a substring of the tree with maximum benefit if such a
> + /// substring exists.
> + ///
> + /// Clears the input vector and fills it with a maximum substring or empty.
> + ///
> + /// \param[in,out] Best The most beneficial substring in the tree. Empty
> + /// if it does not exist.
> + /// \param BenefitFn The function the query should return a maximum string
> + /// for.
> + void bestRepeatedSubstring(std::vector<unsigned> &Best,
> + const std::function<unsigned(SuffixTreeNode &, size_t CurrLen)>
> + &BenefitFn) {
> + Best.clear();
> + size_t Length = 0; // Becomes the length of the best substring.
> + size_t Benefit = 0; // Becomes the benefit of the best substring.
> + size_t StartIdx = 0; // Becomes the start index of the best substring.
> + findBest(*Root, 0, Length, Benefit, StartIdx, BenefitFn);
> +
> + for (size_t Idx = 0; Idx < Length; Idx++)
> + Best.push_back(Str[Idx + StartIdx]);
> + }
> +
> + /// Perform a depth-first search for \p QueryString on the suffix tree.
> + ///
> + /// \param QueryString The string to search for.
> + /// \param CurrIdx The current index in \p QueryString that is being matched
> + /// against.
> + /// \param CurrNode The suffix tree node being searched in.
> + ///
> + /// \returns A \p SuffixTreeNode that \p QueryString appears in if such a
> + /// node exists, and \p nullptr otherwise.
> + SuffixTreeNode *findString(const std::vector<unsigned> &QueryString,
> + size_t &CurrIdx, SuffixTreeNode *CurrNode) {
> +
> + // The search ended at a nonexistent or pruned node. Quit.
> + if (!CurrNode || !CurrNode->IsInTree)
> + return nullptr;
> +
> + unsigned Edge = QueryString[CurrIdx]; // The edge we want to move on.
> + SuffixTreeNode *NextNode = CurrNode->Children[Edge]; // Next node in query.
> +
> + if (CurrNode->isRoot()) {
> + // If we're at the root we have to check if there's a child, and move to
> + // that child. Don't consume the character since \p Root represents the
> + // empty string.
> + if (NextNode && NextNode->IsInTree)
> + return findString(QueryString, CurrIdx, NextNode);
> + return nullptr;
> + }
> +
> + size_t StrIdx = CurrNode->StartIdx;
> + size_t MaxIdx = QueryString.size();
> + bool ContinueSearching = false;
> +
> + // Match as far as possible into the string. If there's a mismatch, quit.
> + for (; CurrIdx < MaxIdx; CurrIdx++, StrIdx++) {
> + Edge = QueryString[CurrIdx];
> +
> + // We matched perfectly, but still have a remainder to search.
> + if (StrIdx > *(CurrNode->EndIdx)) {
> + ContinueSearching = true;
> + break;
> + }
> +
> + if (Edge != Str[StrIdx])
> + return nullptr;
> + }
> +
> + NextNode = CurrNode->Children[Edge];
> +
> + // Move to the node which matches what we're looking for and continue
> + // searching.
> + if (ContinueSearching)
> + return findString(QueryString, CurrIdx, NextNode);
> +
> + // We matched perfectly so we're done.
> + return CurrNode;
> + }
> +
> + /// \brief Remove a node from a tree and all nodes representing proper
> + /// suffixes of that node's string.
> + ///
> + /// This is used in the outlining algorithm to reduce the number of
> + /// overlapping candidates
> + ///
> + /// \param N The suffix tree node to start pruning from.
> + /// \param Len The length of the string to be pruned.
> + ///
> + /// \returns True if this candidate didn't overlap with a previously chosen
> + /// candidate.
> + bool prune(SuffixTreeNode *N, size_t Len) {
> +
> + bool NoOverlap = true;
> + std::vector<unsigned> IndicesToPrune;
> +
> + // Look at each of N's children.
> + for (auto &ChildPair : N->Children) {
> + SuffixTreeNode *M = ChildPair.second;
> +
> + // Is this a leaf child?
> + if (M && M->IsInTree && M->isLeaf()) {
> + // Save each leaf child's suffix indices and remove them from the tree.
> + IndicesToPrune.push_back(M->SuffixIdx);
> + M->IsInTree = false;
> + }
> + }
> +
> + // Remove each suffix we have to prune from the tree. Each of these will be
> + // I + some offset for I in IndicesToPrune and some offset < Len.
> + unsigned Offset = 1;
> + for (unsigned CurrentSuffix = 1; CurrentSuffix < Len; CurrentSuffix++) {
> + for (unsigned I : IndicesToPrune) {
> +
> + unsigned PruneIdx = I + Offset;
> +
> + // Is this index actually in the string?
> + if (PruneIdx < LeafVector.size()) {
> + // If yes, we have to try and prune it.
> + // Was the current leaf already pruned by another candidate?
> + if (LeafVector[PruneIdx]->IsInTree) {
> + // If not, prune it.
> + LeafVector[PruneIdx]->IsInTree = false;
> + } else {
> + // If yes, signify that we've found an overlap, but keep pruning.
> + NoOverlap = false;
> + }
> +
> + // Update the parent of the current leaf's occurrence count.
> + SuffixTreeNode *Parent = LeafVector[PruneIdx]->Parent;
> +
> + // Is the parent still in the tree?
> + if (Parent->OccurrenceCount > 0) {
> + Parent->OccurrenceCount--;
> + Parent->IsInTree = (Parent->OccurrenceCount > 1);
> + }
> + }
> + }
> +
> + // Move to the next character in the string.
> + Offset++;
> + }
> +
> + // We know we can never outline anything which starts one index back from
> + // the indices we want to outline. This is because our minimum outlining
> + // length is always 2.
> + for (unsigned I : IndicesToPrune) {
> + if (I > 0) {
> +
> + unsigned PruneIdx = I-1;
> + SuffixTreeNode *Parent = LeafVector[PruneIdx]->Parent;
> +
> + // Was the leaf one index back from I already pruned?
> + if (LeafVector[PruneIdx]->IsInTree) {
> + // If not, prune it.
> + LeafVector[PruneIdx]->IsInTree = false;
> + } else {
> + // If yes, signify that we've found an overlap, but keep pruning.
> + NoOverlap = false;
> + }
> +
> + // Update the parent of the current leaf's occurrence count.
> + if (Parent->OccurrenceCount > 0) {
> + Parent->OccurrenceCount--;
> + Parent->IsInTree = (Parent->OccurrenceCount > 1);
> + }
> + }
> + }
> +
> + // Finally, remove N from the tree and set its occurrence count to 0.
> + N->IsInTree = false;
> + N->OccurrenceCount = 0;
> +
> + return NoOverlap;
> + }
> +
> + /// \brief Find each occurrence of of a string in \p QueryString and prune
> + /// their nodes.
> + ///
> + /// \param QueryString The string to search for.
> + /// \param[out] Occurrences The start indices of each occurrence.
> + ///
> + /// \returns Whether or not the occurrence overlaps with a previous candidate.
> + bool findOccurrencesAndPrune(const std::vector<unsigned> &QueryString,
> + std::vector<size_t> &Occurrences) {
> + size_t Dummy = 0;
> + SuffixTreeNode *N = findString(QueryString, Dummy, Root);
> +
> + if (!N || !N->IsInTree)
> + return false;
> +
> + // If this is an internal node, occurrences are the number of leaf children
> + // of the node.
> + for (auto &ChildPair : N->Children) {
> + SuffixTreeNode *M = ChildPair.second;
> +
> + // Is it a leaf? If so, we have an occurrence.
> + if (M && M->IsInTree && M->isLeaf())
> + Occurrences.push_back(M->SuffixIdx);
> + }
> +
> + // If we're in a leaf, then this node is the only occurrence.
> + if (N->isLeaf())
> + Occurrences.push_back(N->SuffixIdx);
> +
> + return prune(N, QueryString.size());
> + }
> +
> + /// Construct a suffix tree from a sequence of unsigned integers.
> + ///
> + /// \param Str The string to construct the suffix tree for.
> + SuffixTree(const std::vector<unsigned> &Str) : Str(Str) {
> + Root = insertInternalNode(nullptr, EmptyIdx, EmptyIdx, 0);
> + Root->IsInTree = true;
> + Active.Node = Root;
> + LeafVector = std::vector<SuffixTreeNode*>(Str.size());
> +
> + // Keep track of the number of suffixes we have to add of the current
> + // prefix.
> + size_t SuffixesToAdd = 0;
> + Active.Node = Root;
> +
> + // Construct the suffix tree iteratively on each prefix of the string.
> + // PfxEndIdx is the end index of the current prefix.
> + // End is one past the last element in the string.
> + for (size_t PfxEndIdx = 0, End = Str.size(); PfxEndIdx < End; PfxEndIdx++) {
> + SuffixesToAdd++;
> + LeafEndIdx = PfxEndIdx; // Extend each of the leaves.
> + SuffixesToAdd = extend(PfxEndIdx, SuffixesToAdd);
> + }
> +
> + // Set the suffix indices of each leaf.
> + assert(Root && "Root node can't be nullptr!");
> + setSuffixIndices(*Root, 0);
> + }
> +};
> +
> +/// \brief An individual sequence of instructions to be replaced with a call to
> +/// an outlined function.
> +struct Candidate {
> +
> + /// Set to false if the candidate overlapped with another candidate.
> + bool InCandidateList = true;
> +
> + /// The start index of this \p Candidate.
> + size_t StartIdx;
> +
> + /// The number of instructions in this \p Candidate.
> + size_t Len;
> +
> + /// The index of this \p Candidate's \p OutlinedFunction in the list of
> + /// \p OutlinedFunctions.
> + size_t FunctionIdx;
> +
> + Candidate(size_t StartIdx, size_t Len, size_t FunctionIdx)
> + : StartIdx(StartIdx), Len(Len), FunctionIdx(FunctionIdx) {}
> +
> + Candidate() {}
> +
> + /// \brief Used to ensure that \p Candidates are outlined in an order that
> + /// preserves the start and end indices of other \p Candidates.
> + bool operator<(const Candidate &RHS) const { return StartIdx > RHS.StartIdx; }
> +};
> +
> +/// \brief The information necessary to create an outlined function for some
> +/// class of candidate.
> +struct OutlinedFunction {
> +
> + /// The actual outlined function created.
> + /// This is initialized after we go through and create the actual function.
> + MachineFunction *MF = nullptr;
> +
> + /// A number assigned to this function which appears at the end of its name.
> + size_t Name;
> +
> + /// The number of times that this function has appeared.
> + size_t OccurrenceCount = 0;
> +
> + /// \brief The sequence of integers corresponding to the instructions in this
> + /// function.
> + std::vector<unsigned> Sequence;
> +
> + /// The number of instructions this function would save.
> + unsigned Benefit = 0;
> +
> + OutlinedFunction(size_t Name, size_t OccurrenceCount,
> + const std::vector<unsigned> &Sequence,
> + unsigned Benefit)
> + : Name(Name), OccurrenceCount(OccurrenceCount), Sequence(Sequence),
> + Benefit(Benefit)
> + {}
> +};
> +
> +/// \brief Maps \p MachineInstrs to unsigned integers and stores the mappings.
> +struct InstructionMapper {
> +
> + /// \brief The next available integer to assign to a \p MachineInstr that
> + /// cannot be outlined.
> + ///
> + /// Set to -3 for compatability with \p DenseMapInfo<unsigned>.
> + unsigned IllegalInstrNumber = -3;
> +
> + /// \brief The next available integer to assign to a \p MachineInstr that can
> + /// be outlined.
> + unsigned LegalInstrNumber = 0;
> +
> + /// Correspondence from \p MachineInstrs to unsigned integers.
> + DenseMap<MachineInstr *, unsigned, MachineInstrExpressionTrait>
> + InstructionIntegerMap;
> +
> + /// Corresponcence from unsigned integers to \p MachineInstrs.
> + /// Inverse of \p InstructionIntegerMap.
> + DenseMap<unsigned, MachineInstr *> IntegerInstructionMap;
> +
> + /// The vector of unsigned integers that the module is mapped to.
> + std::vector<unsigned> UnsignedVec;
> +
> + /// \brief Stores the location of the instruction associated with the integer
> + /// at index i in \p UnsignedVec for each index i.
> + std::vector<MachineBasicBlock::iterator> InstrList;
> +
> + /// \brief Maps \p *It to a legal integer.
> + ///
> + /// Updates \p InstrList, \p UnsignedVec, \p InstructionIntegerMap,
> + /// \p IntegerInstructionMap, and \p LegalInstrNumber.
> + ///
> + /// \returns The integer that \p *It was mapped to.
> + unsigned mapToLegalUnsigned(MachineBasicBlock::iterator &It) {
> +
> + // Get the integer for this instruction or give it the current
> + // LegalInstrNumber.
> + InstrList.push_back(It);
> + MachineInstr &MI = *It;
> + bool WasInserted;
> + DenseMap<MachineInstr *, unsigned, MachineInstrExpressionTrait>::iterator
> + ResultIt;
> + std::tie(ResultIt, WasInserted) =
> + InstructionIntegerMap.insert(std::make_pair(&MI, LegalInstrNumber));
> + unsigned MINumber = ResultIt->second;
> +
> + // There was an insertion.
> + if (WasInserted) {
> + LegalInstrNumber++;
> + IntegerInstructionMap.insert(std::make_pair(MINumber, &MI));
> + }
> +
> + UnsignedVec.push_back(MINumber);
> +
> + // Make sure we don't overflow or use any integers reserved by the DenseMap.
> + if (LegalInstrNumber >= IllegalInstrNumber)
> + report_fatal_error("Instruction mapping overflow!");
> +
> + assert(LegalInstrNumber != DenseMapInfo<unsigned>::getEmptyKey()
> + && "Tried to assign DenseMap tombstone or empty key to instruction.");
> + assert(LegalInstrNumber != DenseMapInfo<unsigned>::getTombstoneKey()
> + && "Tried to assign DenseMap tombstone or empty key to instruction.");
> +
> + return MINumber;
> + }
> +
> + /// Maps \p *It to an illegal integer.
> + ///
> + /// Updates \p InstrList, \p UnsignedVec, and \p IllegalInstrNumber.
> + ///
> + /// \returns The integer that \p *It was mapped to.
> + unsigned mapToIllegalUnsigned(MachineBasicBlock::iterator &It) {
> + unsigned MINumber = IllegalInstrNumber;
> +
> + InstrList.push_back(It);
> + UnsignedVec.push_back(IllegalInstrNumber);
> + IllegalInstrNumber--;
> +
> + assert(LegalInstrNumber < IllegalInstrNumber &&
> + "Instruction mapping overflow!");
> +
> + assert(IllegalInstrNumber !=
> + DenseMapInfo<unsigned>::getEmptyKey() &&
> + "IllegalInstrNumber cannot be DenseMap tombstone or empty key!");
> +
> + assert(IllegalInstrNumber !=
> + DenseMapInfo<unsigned>::getTombstoneKey() &&
> + "IllegalInstrNumber cannot be DenseMap tombstone or empty key!");
> +
> + return MINumber;
> + }
> +
> + /// \brief Transforms a \p MachineBasicBlock into a \p vector of \p unsigneds
> + /// and appends it to \p UnsignedVec and \p InstrList.
> + ///
> + /// Two instructions are assigned the same integer if they are identical.
> + /// If an instruction is deemed unsafe to outline, then it will be assigned an
> + /// unique integer. The resulting mapping is placed into a suffix tree and
> + /// queried for candidates.
> + ///
> + /// \param MBB The \p MachineBasicBlock to be translated into integers.
> + /// \param TRI \p TargetRegisterInfo for the module.
> + /// \param TII \p TargetInstrInfo for the module.
> + void convertToUnsignedVec(MachineBasicBlock &MBB,
> + const TargetRegisterInfo &TRI,
> + const TargetInstrInfo &TII) {
> + for (MachineBasicBlock::iterator It = MBB.begin(), Et = MBB.end(); It != Et;
> + It++) {
> +
> + // Keep track of where this instruction is in the module.
> + switch(TII.getOutliningType(*It)) {
> + case TargetInstrInfo::MachineOutlinerInstrType::Illegal:
> + mapToIllegalUnsigned(It);
> + break;
> +
> + case TargetInstrInfo::MachineOutlinerInstrType::Legal:
> + mapToLegalUnsigned(It);
> + break;
> +
> + case TargetInstrInfo::MachineOutlinerInstrType::Invisible:
> + break;
> + }
> + }
> +
> + // After we're done every insertion, uniquely terminate this part of the
> + // "string". This makes sure we won't match across basic block or function
> + // boundaries since the "end" is encoded uniquely and thus appears in no
> + // repeated substring.
> + InstrList.push_back(MBB.end());
> + UnsignedVec.push_back(IllegalInstrNumber);
> + IllegalInstrNumber--;
> + }
> +
> + InstructionMapper() {
> + // Make sure that the implementation of DenseMapInfo<unsigned> hasn't
> + // changed.
> + assert(DenseMapInfo<unsigned>::getEmptyKey() == (unsigned)-1 &&
> + "DenseMapInfo<unsigned>'s empty key isn't -1!");
> + assert(DenseMapInfo<unsigned>::getTombstoneKey() == (unsigned)-2 &&
> + "DenseMapInfo<unsigned>'s tombstone key isn't -2!");
> + }
> +};
> +
> +/// \brief An interprocedural pass which finds repeated sequences of
> +/// instructions and replaces them with calls to functions.
> +///
> +/// Each instruction is mapped to an unsigned integer and placed in a string.
> +/// The resulting mapping is then placed in a \p SuffixTree. The \p SuffixTree
> +/// is then repeatedly queried for repeated sequences of instructions. Each
> +/// non-overlapping repeated sequence is then placed in its own
> +/// \p MachineFunction and each instance is then replaced with a call to that
> +/// function.
> +struct MachineOutliner : public ModulePass {
> +
> + static char ID;
> +
> + StringRef getPassName() const override { return "Machine Outliner"; }
> +
> + void getAnalysisUsage(AnalysisUsage &AU) const override {
> + AU.addRequired<MachineModuleInfo>();
> + AU.addPreserved<MachineModuleInfo>();
> + AU.setPreservesAll();
> + ModulePass::getAnalysisUsage(AU);
> + }
> +
> + MachineOutliner() : ModulePass(ID) {
> + initializeMachineOutlinerPass(*PassRegistry::getPassRegistry());
> + }
> +
> + /// \brief Replace the sequences of instructions represented by the
> + /// \p Candidates in \p CandidateList with calls to \p MachineFunctions
> + /// described in \p FunctionList.
> + ///
> + /// \param M The module we are outlining from.
> + /// \param CandidateList A list of candidates to be outlined.
> + /// \param FunctionList A list of functions to be inserted into the module.
> + /// \param Mapper Contains the instruction mappings for the module.
> + bool outline(Module &M, const ArrayRef<Candidate> &CandidateList,
> + std::vector<OutlinedFunction> &FunctionList,
> + InstructionMapper &Mapper);
> +
> + /// Creates a function for \p OF and inserts it into the module.
> + MachineFunction *createOutlinedFunction(Module &M, const OutlinedFunction &OF,
> + InstructionMapper &Mapper);
> +
> + /// Find potential outlining candidates and store them in \p CandidateList.
> + ///
> + /// For each type of potential candidate, also build an \p OutlinedFunction
> + /// struct containing the information to build the function for that
> + /// candidate.
> + ///
> + /// \param[out] CandidateList Filled with outlining candidates for the module.
> + /// \param[out] FunctionList Filled with functions corresponding to each type
> + /// of \p Candidate.
> + /// \param ST The suffix tree for the module.
> + /// \param TII TargetInstrInfo for the module.
> + ///
> + /// \returns The length of the longest candidate found. 0 if there are none.
> + unsigned buildCandidateList(std::vector<Candidate> &CandidateList,
> + std::vector<OutlinedFunction> &FunctionList,
> + SuffixTree &ST, const TargetInstrInfo &TII);
> +
> + /// \brief Remove any overlapping candidates that weren't handled by the
> + /// suffix tree's pruning method.
> + ///
> + /// Pruning from the suffix tree doesn't necessarily remove all overlaps.
> + /// If a short candidate is chosen for outlining, then a longer candidate
> + /// which has that short candidate as a suffix is chosen, the tree's pruning
> + /// method will not find it. Thus, we need to prune before outlining as well.
> + ///
> + /// \param[in,out] CandidateList A list of outlining candidates.
> + /// \param[in,out] FunctionList A list of functions to be outlined.
> + /// \param MaxCandidateLen The length of the longest candidate.
> + /// \param TII TargetInstrInfo for the module.
> + void pruneOverlaps(std::vector<Candidate> &CandidateList,
> + std::vector<OutlinedFunction> &FunctionList,
> + unsigned MaxCandidateLen,
> + const TargetInstrInfo &TII);
> +
> + /// Construct a suffix tree on the instructions in \p M and outline repeated
> + /// strings from that tree.
> + bool runOnModule(Module &M) override;
> +};
> +
> +} // Anonymous namespace.
> +
> +char MachineOutliner::ID = 0;
> +
> +namespace llvm {
> +ModulePass *createMachineOutlinerPass() { return new MachineOutliner(); }
> +}
> +
> +INITIALIZE_PASS(MachineOutliner, "machine-outliner",
> + "Machine Function Outliner", false, false)
> +
> +void MachineOutliner::pruneOverlaps(std::vector<Candidate> &CandidateList,
> + std::vector<OutlinedFunction> &FunctionList,
> + unsigned MaxCandidateLen,
> + const TargetInstrInfo &TII) {
> +
> + // Check for overlaps in the range. This is O(n^2) worst case, but we can
> + // alleviate that somewhat by bounding our search space using the start
> + // index of our first candidate and the maximum distance an overlapping
> + // candidate could have from the first candidate.
> + for (auto It = CandidateList.begin(), Et = CandidateList.end(); It != Et;
> + It++) {
> + Candidate &C1 = *It;
> + OutlinedFunction &F1 = FunctionList[C1.FunctionIdx];
> +
> + // If we removed this candidate, skip it.
> + if (!C1.InCandidateList)
> + continue;
> +
> + // If the candidate's function isn't good to outline anymore, then
> + // remove the candidate and skip it.
> + if (F1.OccurrenceCount < 2 || F1.Benefit < 1) {
> + C1.InCandidateList = false;
> + continue;
> + }
> +
> + // The minimum start index of any candidate that could overlap with this
> + // one.
> + unsigned FarthestPossibleIdx = 0;
> +
> + // Either the index is 0, or it's at most MaxCandidateLen indices away.
> + if (C1.StartIdx > MaxCandidateLen)
> + FarthestPossibleIdx = C1.StartIdx - MaxCandidateLen;
> +
> + // Compare against the other candidates in the list.
> + // This is at most MaxCandidateLen/2 other candidates.
> + // This is because each candidate has to be at least 2 indices away.
> + // = O(n * MaxCandidateLen/2) comparisons
> + //
> + // On average, the maximum length of a candidate is quite small; a fraction
> + // of the total module length in terms of instructions. If the maximum
> + // candidate length is large, then there are fewer possible candidates to
> + // compare against in the first place.
> + for (auto Sit = It + 1; Sit != Et; Sit++) {
> + Candidate &C2 = *Sit;
> + OutlinedFunction &F2 = FunctionList[C2.FunctionIdx];
> +
> + // Is this candidate too far away to overlap?
> + // NOTE: This will be true in
> + // O(max(FarthestPossibleIdx/2, #Candidates remaining)) steps
> + // for every candidate.
> + if (C2.StartIdx < FarthestPossibleIdx)
> + break;
> +
> + // Did we already remove this candidate in a previous step?
> + if (!C2.InCandidateList)
> + continue;
> +
> + // Is the function beneficial to outline?
> + if (F2.OccurrenceCount < 2 || F2.Benefit < 1) {
> + // If not, remove this candidate and move to the next one.
> + C2.InCandidateList = false;
> + continue;
> + }
> +
> + size_t C2End = C2.StartIdx + C2.Len - 1;
> +
> + // Do C1 and C2 overlap?
> + //
> + // Not overlapping:
> + // High indices... [C1End ... C1Start][C2End ... C2Start] ...Low indices
> + //
> + // We sorted our candidate list so C2Start <= C1Start. We know that
> + // C2End > C2Start since each candidate has length >= 2. Therefore, all we
> + // have to check is C2End < C2Start to see if we overlap.
> + if (C2End < C1.StartIdx)
> + continue;
> +
> + // C2 overlaps with C1. Because we pruned the tree already, the only way
> + // this can happen is if C1 is a proper suffix of C2. Thus, we must have
> + // found C1 first during our query, so it must have benefit greater or
> + // equal to C2. Greedily pick C1 as the candidate to keep and toss out C2.
> + DEBUG (
> + size_t C1End = C1.StartIdx + C1.Len - 1;
> + dbgs() << "- Found an overlap to purge.\n";
> + dbgs() << "--- C1 :[" << C1.StartIdx << ", " << C1End << "]\n";
> + dbgs() << "--- C2 :[" << C2.StartIdx << ", " << C2End << "]\n";
> + );
> +
> + // Update the function's occurrence count and benefit to reflec that C2
> + // is being removed.
> + F2.OccurrenceCount--;
> + F2.Benefit = TII.getOutliningBenefit(F2.Sequence.size(),
> + F2.OccurrenceCount
> + );
> +
> + // Mark C2 as not in the list.
> + C2.InCandidateList = false;
> +
> + DEBUG (
> + dbgs() << "- Removed C2. \n";
> + dbgs() << "--- Num fns left for C2: " << F2.OccurrenceCount << "\n";
> + dbgs() << "--- C2's benefit: " << F2.Benefit << "\n";
> + );
> + }
> + }
> +}
> +
> +unsigned
> +MachineOutliner::buildCandidateList(std::vector<Candidate> &CandidateList,
> + std::vector<OutlinedFunction> &FunctionList,
> + SuffixTree &ST,
> + const TargetInstrInfo &TII) {
> +
> + std::vector<unsigned> CandidateSequence; // Current outlining candidate.
> + unsigned MaxCandidateLen = 0; // Length of the longest candidate.
> +
> + // Function for maximizing query in the suffix tree.
> + // This allows us to define more fine-grained types of things to outline in
> + // the target without putting target-specific info in the suffix tree.
> + auto BenefitFn = [&TII](const SuffixTreeNode &Curr, size_t StringLen) {
> +
> + // Any leaf whose parent is the root only has one occurrence.
> + if (Curr.Parent->isRoot())
> + return 0u;
> +
> + // Anything with length < 2 will never be beneficial on any target.
> + if (StringLen < 2)
> + return 0u;
> +
> + size_t Occurrences = Curr.Parent->OccurrenceCount;
> +
> + // Anything with fewer than 2 occurrences will never be beneficial on any
> + // target.
> + if (Occurrences < 2)
> + return 0u;
> +
> + return TII.getOutliningBenefit(StringLen, Occurrences);
> + };
> +
> + // Repeatedly query the suffix tree for the substring that maximizes
> + // BenefitFn. Find the occurrences of that string, prune the tree, and store
> + // each occurrence as a candidate.
> + for (ST.bestRepeatedSubstring(CandidateSequence, BenefitFn);
> + CandidateSequence.size() > 1;
> + ST.bestRepeatedSubstring(CandidateSequence, BenefitFn)) {
> +
> + std::vector<size_t> Occurrences;
> +
> + bool GotNonOverlappingCandidate =
> + ST.findOccurrencesAndPrune(CandidateSequence, Occurrences);
> +
> + // Is the candidate we found known to overlap with something we already
> + // outlined?
> + if (!GotNonOverlappingCandidate)
> + continue;
> +
> + // Is this candidate the longest so far?
> + if (CandidateSequence.size() > MaxCandidateLen)
> + MaxCandidateLen = CandidateSequence.size();
> +
> + // Keep track of the benefit of outlining this candidate in its
> + // OutlinedFunction.
> + unsigned FnBenefit = TII.getOutliningBenefit(CandidateSequence.size(),
> + Occurrences.size()
> + );
> +
> + assert(FnBenefit > 0 && "Function cannot be unbeneficial!");
> +
> + // Save an OutlinedFunction for this candidate.
> + FunctionList.emplace_back(
> + FunctionList.size(), // Number of this function.
> + Occurrences.size(), // Number of occurrences.
> + CandidateSequence, // Sequence to outline.
> + FnBenefit // Instructions saved by outlining this function.
> + );
> +
> + // Save each of the occurrences of the candidate so we can outline them.
> + for (size_t &Occ : Occurrences)
> + CandidateList.emplace_back(
> + Occ, // Starting idx in that MBB.
> + CandidateSequence.size(), // Candidate length.
> + FunctionList.size() - 1 // Idx of the corresponding function.
> + );
> +
> + FunctionsCreated++;
> + }
> +
> + // Sort the candidates in decending order. This will simplify the outlining
> + // process when we have to remove the candidates from the mapping by
> + // allowing us to cut them out without keeping track of an offset.
> + std::stable_sort(CandidateList.begin(), CandidateList.end());
> +
> + return MaxCandidateLen;
> +}
> +
> +MachineFunction *
> +MachineOutliner::createOutlinedFunction(Module &M, const OutlinedFunction &OF,
> + InstructionMapper &Mapper) {
> +
> + // Create the function name. This should be unique. For now, just hash the
> + // module name and include it in the function name plus the number of this
> + // function.
> + std::ostringstream NameStream;
> + NameStream << "OUTLINED_FUNCTION" << "_" << OF.Name;
> +
> + // Create the function using an IR-level function.
> + LLVMContext &C = M.getContext();
> + Function *F = dyn_cast<Function>(
> + M.getOrInsertFunction(NameStream.str(), Type::getVoidTy(C), NULL));
> + assert(F && "Function was null!");
> +
> + // NOTE: If this is linkonceodr, then we can take advantage of linker deduping
> + // which gives us better results when we outline from linkonceodr functions.
> + F->setLinkage(GlobalValue::PrivateLinkage);
> + F->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
> +
> + BasicBlock *EntryBB = BasicBlock::Create(C, "entry", F);
> + IRBuilder<> Builder(EntryBB);
> + Builder.CreateRetVoid();
> +
> + MachineModuleInfo &MMI = getAnalysis<MachineModuleInfo>();
> + MachineFunction &MF = MMI.getMachineFunction(*F);
> + MachineBasicBlock &MBB = *MF.CreateMachineBasicBlock();
> + const TargetSubtargetInfo &STI = MF.getSubtarget();
> + const TargetInstrInfo &TII = *STI.getInstrInfo();
> +
> + // Insert the new function into the module.
> + MF.insert(MF.begin(), &MBB);
> +
> + TII.insertOutlinerPrologue(MBB, MF);
> +
> + // Copy over the instructions for the function using the integer mappings in
> + // its sequence.
> + for (unsigned Str : OF.Sequence) {
> + MachineInstr *NewMI =
> + MF.CloneMachineInstr(Mapper.IntegerInstructionMap.find(Str)->second);
> + NewMI->dropMemRefs();
> +
> + // Don't keep debug information for outlined instructions.
> + // FIXME: This means outlined functions are currently undebuggable.
> + NewMI->setDebugLoc(DebugLoc());
> + MBB.insert(MBB.end(), NewMI);
> + }
> +
> + TII.insertOutlinerEpilogue(MBB, MF);
> +
> + return &MF;
> +}
> +
> +bool MachineOutliner::outline(Module &M,
> + const ArrayRef<Candidate> &CandidateList,
> + std::vector<OutlinedFunction> &FunctionList,
> + InstructionMapper &Mapper) {
> +
> + bool OutlinedSomething = false;
> +
> + // Replace the candidates with calls to their respective outlined functions.
> + for (const Candidate &C : CandidateList) {
> +
> + // Was the candidate removed during pruneOverlaps?
> + if (!C.InCandidateList)
> + continue;
> +
> + // If not, then look at its OutlinedFunction.
> + OutlinedFunction &OF = FunctionList[C.FunctionIdx];
> +
> + // Was its OutlinedFunction made unbeneficial during pruneOverlaps?
> + if (OF.OccurrenceCount < 2 || OF.Benefit < 1)
> + continue;
> +
> + // If not, then outline it.
> + assert(C.StartIdx < Mapper.InstrList.size() && "Candidate out of bounds!");
> + MachineBasicBlock *MBB = (*Mapper.InstrList[C.StartIdx]).getParent();
> + MachineBasicBlock::iterator StartIt = Mapper.InstrList[C.StartIdx];
> + unsigned EndIdx = C.StartIdx + C.Len - 1;
> +
> + assert(EndIdx < Mapper.InstrList.size() && "Candidate out of bounds!");
> + MachineBasicBlock::iterator EndIt = Mapper.InstrList[EndIdx];
> + assert(EndIt != MBB->end() && "EndIt out of bounds!");
> +
> + EndIt++; // Erase needs one past the end index.
> +
> + // Does this candidate have a function yet?
> + if (!OF.MF)
> + OF.MF = createOutlinedFunction(M, OF, Mapper);
> +
> + MachineFunction *MF = OF.MF;
> + const TargetSubtargetInfo &STI = MF->getSubtarget();
> + const TargetInstrInfo &TII = *STI.getInstrInfo();
> +
> + // Insert a call to the new function and erase the old sequence.
> + TII.insertOutlinedCall(M, *MBB, StartIt, *MF);
> + StartIt = Mapper.InstrList[C.StartIdx];
> + MBB->erase(StartIt, EndIt);
> +
> + OutlinedSomething = true;
> +
> + // Statistics.
> + NumOutlined++;
> + }
> +
> + DEBUG (
> + dbgs() << "OutlinedSomething = " << OutlinedSomething << "\n";
> + );
> +
> + return OutlinedSomething;
> +}
> +
> +bool MachineOutliner::runOnModule(Module &M) {
> +
> + // Is there anything in the module at all?
> + if (M.empty())
> + return false;
> +
> + MachineModuleInfo &MMI = getAnalysis<MachineModuleInfo>();
> + const TargetSubtargetInfo &STI = MMI.getMachineFunction(*M.begin())
> + .getSubtarget();
> + const TargetRegisterInfo *TRI = STI.getRegisterInfo();
> + const TargetInstrInfo *TII = STI.getInstrInfo();
> +
> + InstructionMapper Mapper;
> +
> + // Build instruction mappings for each function in the module.
> + for (Function &F : M) {
> + MachineFunction &MF = MMI.getMachineFunction(F);
> +
> + // Is the function empty? Safe to outline from?
> + if (F.empty() || !TII->isFunctionSafeToOutlineFrom(MF))
> + continue;
> +
> + // If it is, look at each MachineBasicBlock in the function.
> + for (MachineBasicBlock &MBB : MF) {
> +
> + // Is there anything in MBB?
> + if (MBB.empty())
> + continue;
> +
> + // If yes, map it.
> + Mapper.convertToUnsignedVec(MBB, *TRI, *TII);
> + }
> + }
> +
> + // Construct a suffix tree, use it to find candidates, and then outline them.
> + SuffixTree ST(Mapper.UnsignedVec);
> + std::vector<Candidate> CandidateList;
> + std::vector<OutlinedFunction> FunctionList;
> +
> + unsigned MaxCandidateLen =
> + buildCandidateList(CandidateList, FunctionList, ST, *TII);
> +
> + pruneOverlaps(CandidateList, FunctionList, MaxCandidateLen, *TII);
> + return outline(M, CandidateList, FunctionList, Mapper);
> +}
>
> Modified: llvm/trunk/lib/CodeGen/TargetPassConfig.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TargetPassConfig.cpp?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/TargetPassConfig.cpp (original)
> +++ llvm/trunk/lib/CodeGen/TargetPassConfig.cpp Mon Mar 6 15:31:18 2017
> @@ -92,6 +92,9 @@ static cl::opt<bool> VerifyMachineCode("
> cl::desc("Verify generated machine code"),
> cl::init(false),
> cl::ZeroOrMore);
> +static cl::opt<bool> EnableMachineOutliner("enable-machine-outliner",
> + cl::Hidden,
> + cl::desc("Enable machine outliner"));
>
> static cl::opt<std::string>
> PrintMachineInstrs("print-machineinstrs", cl::ValueOptional,
> @@ -674,6 +677,9 @@ void TargetPassConfig::addMachinePasses(
> addPass(&XRayInstrumentationID, false);
> addPass(&PatchableFunctionID, false);
>
> + if (EnableMachineOutliner)
> + PM->add(createMachineOutlinerPass());
> +
> AddingMachinePasses = false;
> }
>
>
> Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.cpp?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp Mon Mar 6 15:31:18 2017
> @@ -10383,3 +10383,83 @@ namespace {
> char LDTLSCleanup::ID = 0;
> FunctionPass*
> llvm::createCleanupLocalDynamicTLSPass() { return new LDTLSCleanup(); }
> +
> +unsigned X86InstrInfo::getOutliningBenefit(size_t SequenceSize,
> + size_t Occurrences) const {
> + unsigned NotOutlinedSize = SequenceSize * Occurrences;
> +
> + // Sequence appears once in outlined function (Sequence.size())
> + // One return instruction (+1)
> + // One call per occurrence (Occurrences)
> + unsigned OutlinedSize = (SequenceSize + 1) + Occurrences;
> +
> + // Return the number of instructions saved by outlining this sequence.
> + return NotOutlinedSize > OutlinedSize ? NotOutlinedSize - OutlinedSize : 0;
> +}
> +
> +bool X86InstrInfo::isFunctionSafeToOutlineFrom(MachineFunction &MF) const {
> + return MF.getFunction()->hasFnAttribute(Attribute::NoRedZone);
> +}
> +
> +X86GenInstrInfo::MachineOutlinerInstrType
> +X86InstrInfo::getOutliningType(MachineInstr &MI) const {
> +
> + // Don't outline returns or basic block terminators.
> + if (MI.isReturn() || MI.isTerminator())
> + return MachineOutlinerInstrType::Illegal;
> +
> + // Don't outline anything that modifies or reads from the stack pointer.
> + //
> + // FIXME: There are instructions which are being manually built without
> + // explicit uses/defs so we also have to check the MCInstrDesc. We should be
> + // able to remove the extra checks once those are fixed up. For example,
> + // sometimes we might get something like %RAX<def> = POP64r 1. This won't be
> + // caught by modifiesRegister or readsRegister even though the instruction
> + // really ought to be formed so that modifiesRegister/readsRegister would
> + // catch it.
> + if (MI.modifiesRegister(X86::RSP, &RI) || MI.readsRegister(X86::RSP, &RI) ||
> + MI.getDesc().hasImplicitUseOfPhysReg(X86::RSP) ||
> + MI.getDesc().hasImplicitDefOfPhysReg(X86::RSP))
> + return MachineOutlinerInstrType::Illegal;
> +
> + if (MI.readsRegister(X86::RIP, &RI) ||
> + MI.getDesc().hasImplicitUseOfPhysReg(X86::RIP) ||
> + MI.getDesc().hasImplicitDefOfPhysReg(X86::RIP))
> + return MachineOutlinerInstrType::Illegal;
> +
> + if (MI.isPosition())
> + return MachineOutlinerInstrType::Illegal;
> +
> + for (const MachineOperand &MOP : MI.operands())
> + if (MOP.isCPI() || MOP.isJTI() || MOP.isCFIIndex() || MOP.isFI() ||
> + MOP.isTargetIndex())
> + return MachineOutlinerInstrType::Illegal;
> +
> + // Don't allow debug values to impact outlining type.
> + if (MI.isDebugValue() || MI.isIndirectDebugValue())
> + return MachineOutlinerInstrType::Invisible;
> +
> + return MachineOutlinerInstrType::Legal;
> +}
> +
> +void X86InstrInfo::insertOutlinerEpilogue(MachineBasicBlock &MBB,
> + MachineFunction &MF) const {
> +
> + MachineInstr *retq = BuildMI(MF, DebugLoc(), get(X86::RETQ));
> + MBB.insert(MBB.end(), retq);
> +}
> +
> +void X86InstrInfo::insertOutlinerPrologue(MachineBasicBlock &MBB,
> + MachineFunction &MF) const {
> + return;
> +}
> +
> +MachineBasicBlock::iterator
> +X86InstrInfo::insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
> + MachineBasicBlock::iterator &It,
> + MachineFunction &MF) const {
> + It = MBB.insert(It,
> + BuildMI(MF, DebugLoc(), get(X86::CALL64pcrel32))
> + .addGlobalAddress(M.getNamedValue(MF.getName())));
> + return It;
> +}
>
> Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.h?rev=297081&r1=297080&r2=297081&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86InstrInfo.h (original)
> +++ llvm/trunk/lib/Target/X86/X86InstrInfo.h Mon Mar 6 15:31:18 2017
> @@ -545,6 +545,25 @@ public:
>
> bool isTailCall(const MachineInstr &Inst) const override;
>
> + unsigned getOutliningBenefit(size_t SequenceSize,
> + size_t Occurrences) const override;
> +
> + bool isFunctionSafeToOutlineFrom(MachineFunction &MF) const override;
> +
> + llvm::X86GenInstrInfo::MachineOutlinerInstrType
> + getOutliningType(MachineInstr &MI) const override;
> +
> + void insertOutlinerEpilogue(MachineBasicBlock &MBB,
> + MachineFunction &MF) const override;
> +
> + void insertOutlinerPrologue(MachineBasicBlock &MBB,
> + MachineFunction &MF) const override;
> +
> + MachineBasicBlock::iterator
> + insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
> + MachineBasicBlock::iterator &It,
> + MachineFunction &MF) const override;
> +
> protected:
> /// Commutes the operands in the given instruction by changing the operands
> /// order and/or changing the instruction's opcode and/or the immediate value
>
> Added: llvm/trunk/test/CodeGen/X86/machine-outliner-debuginfo.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/machine-outliner-debuginfo.ll?rev=297081&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/machine-outliner-debuginfo.ll (added)
> +++ llvm/trunk/test/CodeGen/X86/machine-outliner-debuginfo.ll Mon Mar 6 15:31:18 2017
> @@ -0,0 +1,75 @@
> +; RUN: llc -enable-machine-outliner -mtriple=x86_64-apple-darwin < %s | FileCheck %s
> +
> + at x = global i32 0, align 4, !dbg !0
> +
> +define i32 @main() #0 !dbg !11 {
> + ; CHECK-LABEL: _main:
> + %1 = alloca i32, align 4
> + %2 = alloca i32, align 4
> + %3 = alloca i32, align 4
> + %4 = alloca i32, align 4
> + %5 = alloca i32, align 4
> + ; There is a debug value in the middle of this section, make sure debug values are ignored.
> + ; CHECK: callq l_OUTLINED_FUNCTION_0
> + store i32 1, i32* %2, align 4
> + store i32 2, i32* %3, align 4
> + store i32 3, i32* %4, align 4
> + call void @llvm.dbg.value(metadata i32 10, i64 0, metadata !15, metadata !16), !dbg !17
> + store i32 4, i32* %5, align 4
> + store i32 0, i32* @x, align 4, !dbg !24
> + ; This is the same sequence of instructions without a debug value. It should be outlined
> + ; in the same way.
> + ; CHECK: callq l_OUTLINED_FUNCTION_0
> + store i32 1, i32* %2, align 4
> + store i32 2, i32* %3, align 4
> + store i32 3, i32* %4, align 4
> + store i32 4, i32* %5, align 4
> + store i32 1, i32* @x, align 4, !dbg !14
> + ret i32 0, !dbg !25
> +}
> +
> +; CHECK-LABEL: l_OUTLINED_FUNCTION_0:
> +; CHECK-NOT: .loc {{[0-9]+}} {{[0-9]+}} {{[0-9]+}} {{^(is_stmt)}}
> +; CHECK-NOT: ##DEBUG_VALUE: main:{{[a-z]}} <- {{[0-9]+}}
> +; CHECK: movl $1, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $2, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $3, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $4, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: retq
> +
> +declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
> +
> +declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
> +
> +attributes #0 = { noredzone nounwind ssp uwtable "no-frame-pointer-elim"="true" }
> +
> +!llvm.dbg.cu = !{!2}
> +!llvm.module.flags = !{!7, !8, !9}
> +!llvm.ident = !{!10}
> +
> +!0 = !DIGlobalVariableExpression(var: !1)
> +!1 = distinct !DIGlobalVariable(name: "x", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
> +!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 5.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
> +!3 = !DIFile(filename: "debug-test.c", directory: "dir")
> +!4 = !{}
> +!5 = !{!0}
> +!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
> +!7 = !{i32 2, !"Dwarf Version", i32 4}
> +!8 = !{i32 2, !"Debug Info Version", i32 3}
> +!9 = !{i32 1, !"PIC Level", i32 2}
> +!10 = !{!"clang version 5.0.0"}
> +!11 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 4, type: !12, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, unit: !2, variables: !4)
> +!12 = !DISubroutineType(types: !13)
> +!13 = !{!6}
> +!14 = !DILocation(line: 7, column: 4, scope: !11)
> +!15 = !DILocalVariable(name: "a", scope: !11, file: !3, line: 5, type: !6)
> +!16 = !DIExpression()
> +!17 = !DILocation(line: 5, column: 6, scope: !11)
> +!18 = !DILocalVariable(name: "b", scope: !11, file: !3, line: 5, type: !6)
> +!19 = !DILocation(line: 5, column: 9, scope: !11)
> +!20 = !DILocalVariable(name: "c", scope: !11, file: !3, line: 5, type: !6)
> +!21 = !DILocation(line: 5, column: 12, scope: !11)
> +!22 = !DILocalVariable(name: "d", scope: !11, file: !3, line: 5, type: !6)
> +!23 = !DILocation(line: 5, column: 15, scope: !11)
> +!24 = !DILocation(line: 14, column: 4, scope: !11)
> +!25 = !DILocation(line: 21, column: 2, scope: !11)
>
> Added: llvm/trunk/test/CodeGen/X86/machine-outliner.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/machine-outliner.ll?rev=297081&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/machine-outliner.ll (added)
> +++ llvm/trunk/test/CodeGen/X86/machine-outliner.ll Mon Mar 6 15:31:18 2017
> @@ -0,0 +1,110 @@
> +; RUN: llc -enable-machine-outliner -mtriple=x86_64-apple-darwin < %s | FileCheck %s
> +
> + at x = global i32 0, align 4
> +
> +define i32 @check_boundaries() #0 {
> + ; CHECK-LABEL: _check_boundaries:
> + %1 = alloca i32, align 4
> + %2 = alloca i32, align 4
> + %3 = alloca i32, align 4
> + %4 = alloca i32, align 4
> + %5 = alloca i32, align 4
> + store i32 0, i32* %1, align 4
> + store i32 0, i32* %2, align 4
> + %6 = load i32, i32* %2, align 4
> + %7 = icmp ne i32 %6, 0
> + br i1 %7, label %9, label %8
> +
> + ; CHECK: callq l_OUTLINED_FUNCTION_1
> + ; CHECK: cmpl $0, -{{[0-9]+}}(%rbp)
> + store i32 1, i32* %2, align 4
> + store i32 2, i32* %3, align 4
> + store i32 3, i32* %4, align 4
> + store i32 4, i32* %5, align 4
> + br label %10
> +
> + store i32 1, i32* %4, align 4
> + br label %10
> +
> + %11 = load i32, i32* %2, align 4
> + %12 = icmp ne i32 %11, 0
> + br i1 %12, label %14, label %13
> +
> + ; CHECK: callq l_OUTLINED_FUNCTION_1
> + store i32 1, i32* %2, align 4
> + store i32 2, i32* %3, align 4
> + store i32 3, i32* %4, align 4
> + store i32 4, i32* %5, align 4
> + br label %15
> +
> + store i32 1, i32* %4, align 4
> + br label %15
> +
> + ret i32 0
> +}
> +
> +define i32 @empty_1() #0 {
> + ; CHECK-LABEL: _empty_1:
> + ; CHECK-NOT: callq l_OUTLINED_FUNCTION_{{[0-9]+}}
> + ret i32 1
> +}
> +
> +define i32 @empty_2() #0 {
> + ; CHECK-LABEL: _empty_2
> + ; CHECK-NOT: callq l_OUTLINED_FUNCTION_{{[0-9]+}}
> + ret i32 1
> +}
> +
> +define i32 @no_empty_outlining() #0 {
> + ; CHECK-LABEL: _no_empty_outlining:
> + %1 = alloca i32, align 4
> + store i32 0, i32* %1, align 4
> + ; CHECK-NOT: callq l_OUTLINED_FUNCTION_{{[0-9]+}}
> + %2 = call i32 @empty_1() #1
> + %3 = call i32 @empty_2() #1
> + %4 = call i32 @empty_1() #1
> + %5 = call i32 @empty_2() #1
> + %6 = call i32 @empty_1() #1
> + %7 = call i32 @empty_2() #1
> + ret i32 0
> +}
> +
> +define i32 @main() #0 {
> + ; CHECK-LABEL: _main:
> + %1 = alloca i32, align 4
> + %2 = alloca i32, align 4
> + %3 = alloca i32, align 4
> + %4 = alloca i32, align 4
> + %5 = alloca i32, align 4
> +
> + store i32 0, i32* %1, align 4
> + store i32 0, i32* @x, align 4
> + ; CHECK: callq l_OUTLINED_FUNCTION_0
> + store i32 1, i32* %2, align 4
> + store i32 2, i32* %3, align 4
> + store i32 3, i32* %4, align 4
> + store i32 4, i32* %5, align 4
> + store i32 1, i32* @x, align 4
> + ; CHECK: callq l_OUTLINED_FUNCTION_0
> + store i32 1, i32* %2, align 4
> + store i32 2, i32* %3, align 4
> + store i32 3, i32* %4, align 4
> + store i32 4, i32* %5, align 4
> + ret i32 0
> +}
> +
> +attributes #0 = { noredzone nounwind ssp uwtable "no-frame-pointer-elim"="true" }
> +
> +; CHECK-LABEL: l_OUTLINED_FUNCTION_0:
> +; CHECK: movl $1, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $2, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $3, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $4, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: retq
> +
> +; CHECK-LABEL: l_OUTLINED_FUNCTION_1:
> +; CHECK: movl $1, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $2, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $3, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: movl $4, -{{[0-9]+}}(%rbp)
> +; CHECK-NEXT: retq
>
>
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