From: Hal Finkel Date: Thu, 24 Jul 2014 14:25:39 +0000 (+0000) Subject: Add scoped-noalias metadata X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9414665a3b0bd525f84d76e24048ca60ebe6c710;p=platform%2Fupstream%2Fllvm.git Add scoped-noalias metadata This commit adds scoped noalias metadata. The primary motivations for this feature are: 1. To preserve noalias function attribute information when inlining 2. To provide the ability to model block-scope C99 restrict pointers Neither of these two abilities are added here, only the necessary infrastructure. In fact, there should be no change to existing functionality, only the addition of new features. The logic that converts noalias function parameters into this metadata during inlining will come in a follow-up commit. What is added here is the ability to generally specify noalias memory-access sets. Regarding the metadata, alias-analysis scopes are defined similar to TBAA nodes: !scope0 = metadata !{ metadata !"scope of foo()" } !scope1 = metadata !{ metadata !"scope 1", metadata !scope0 } !scope2 = metadata !{ metadata !"scope 2", metadata !scope0 } !scope3 = metadata !{ metadata !"scope 2.1", metadata !scope2 } !scope4 = metadata !{ metadata !"scope 2.2", metadata !scope2 } Loads and stores can be tagged with an alias-analysis scope, and also, with a noalias tag for a specific scope: ... = load %ptr1, !alias.scope !{ !scope1 } ... = load %ptr2, !alias.scope !{ !scope1, !scope2 }, !noalias !{ !scope1 } When evaluating an aliasing query, if one of the instructions is associated with an alias.scope id that is identical to the noalias scope associated with the other instruction, or is a descendant (in the scope hierarchy) of the noalias scope associated with the other instruction, then the two memory accesses are assumed not to alias. Note that is the first element of the scope metadata is a string, then it can be combined accross functions and translation units. The string can be replaced by a self-reference to create globally unqiue scope identifiers. [Note: This overview is slightly stylized, since the metadata nodes really need to just be numbers (!0 instead of !scope0), and the scope lists are also global unnamed metadata.] Existing noalias metadata in a callee is "cloned" for use by the inlined code. This is necessary because the aliasing scopes are unique to each call site (because of possible control dependencies on the aliasing properties). For example, consider a function: foo(noalias a, noalias b) { *a = *b; } that gets inlined into bar() { ... if (...) foo(a1, b1); ... if (...) foo(a2, b2); } -- now just because we know that a1 does not alias with b1 at the first call site, and a2 does not alias with b2 at the second call site, we cannot let inlining these functons have the metadata imply that a1 does not alias with b2. llvm-svn: 213864 --- diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst index 885da86..ddbf400 100644 --- a/llvm/docs/LangRef.rst +++ b/llvm/docs/LangRef.rst @@ -2829,6 +2829,59 @@ Note that the fields need not be contiguous. In this example, there is a 4 byte gap between the two fields. This gap represents padding which does not carry useful data and need not be preserved. +'``noalias``' and '``alias.scope``' Metadata +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +``noalias`` and ``alias.scope`` metadata provide the ability to specify generic +noalias memory-access sets. This means that some collection of memory access +instructions (loads, stores, memory-accessing calls, etc.) that carry +``noalias`` metadata can specifically be specified not to alias with some other +collection of memory access instructions that carry ``alias.scope`` metadata. +Each type of metadata specifies a list of scopes, and when evaluating an +aliasing query, if one of the instructions has a scope in its ``alias.scope`` +list that is identical to a scope in the other instruction's ``noalias`` list, +or is a descendant (in the scope hierarchy) of a scope in the other +instruction's ``noalias`` list , then the two memory accesses are assumed not +to alias. + +The metadata identifying each scope is itself a list containing one or two +entries. The first entry is the name of the scope. Note that if the name is a +string then it can be combined accross functions and translation units. A +self-reference can be used to create globally unique scope names. +Optionally, a metadata reference to a parent scope can be provided as a second +entry in the list. + +For example, + +.. code-block:: llvm + + ; A root scope (which doubles as a list of itself): + !0 = metadata !{metadata !0} + + ; Two child scopes (which must be self-referential to avoid being "uniqued"): + !1 = metadata !{metadata !2} ; A list containing only scope !2 + !2 = metadata !{metadata !2, metadata !0} ; Scope !2 is a descendant of scope !0 + + !3 = metadata !{metadata !4} ; A list containing only scope !4 + !4 = metadata !{metadata !4, metadata !0} ; Scope !4 is a descendant of scope !0 + + ; These two instructions don't alias: + %0 = load float* %c, align 4, !alias.scope !0 + store float %0, float* %arrayidx.i, align 4, !noalias !0 + + ; These two instructions may alias (scope !2 and scope !4 are peers): + %2 = load float* %c, align 4, !alias.scope !1 + store float %2, float* %arrayidx.i2, align 4, !noalias !3 + + ; These two instructions don't alias (scope !2 is a descendant of scope !0 + ; and the store does not alias with anything in scope !0 or any of its descendants): + %2 = load float* %c, align 4, !alias.scope !1 + store float %0, float* %arrayidx.i, align 4, !noalias !0 + + ; These two instructions may alias: + %2 = load float* %c, align 4, !alias.scope !0 + store float %0, float* %arrayidx.i, align 4, !noalias !1 + '``fpmath``' Metadata ^^^^^^^^^^^^^^^^^^^^^ diff --git a/llvm/include/llvm-c/Transforms/Scalar.h b/llvm/include/llvm-c/Transforms/Scalar.h index 0ca72ce..c0d670e 100644 --- a/llvm/include/llvm-c/Transforms/Scalar.h +++ b/llvm/include/llvm-c/Transforms/Scalar.h @@ -132,6 +132,9 @@ void LLVMAddLowerExpectIntrinsicPass(LLVMPassManagerRef PM); /** See llvm::createTypeBasedAliasAnalysisPass function */ void LLVMAddTypeBasedAliasAnalysisPass(LLVMPassManagerRef PM); +/** See llvm::createScopedNoAliasAAPass function */ +void LLVMAddScopedNoAliasAAPass(LLVMPassManagerRef PM); + /** See llvm::createBasicAliasAnalysisPass function */ void LLVMAddBasicAliasAnalysisPass(LLVMPassManagerRef PM); diff --git a/llvm/include/llvm/Analysis/Passes.h b/llvm/include/llvm/Analysis/Passes.h index fd65ae5..683c179 100644 --- a/llvm/include/llvm/Analysis/Passes.h +++ b/llvm/include/llvm/Analysis/Passes.h @@ -88,6 +88,13 @@ namespace llvm { //===--------------------------------------------------------------------===// // + // createScopedNoAliasAAPass - This pass implements metadata-based + // scoped noalias analysis. + // + ImmutablePass *createScopedNoAliasAAPass(); + + //===--------------------------------------------------------------------===// + // // createObjCARCAliasAnalysisPass - This pass implements ObjC-ARC-based // alias analysis. // diff --git a/llvm/include/llvm/IR/IRBuilder.h b/llvm/include/llvm/IR/IRBuilder.h index aed2463..6134f86 100644 --- a/llvm/include/llvm/IR/IRBuilder.h +++ b/llvm/include/llvm/IR/IRBuilder.h @@ -364,43 +364,60 @@ public: /// \brief Create and insert a memset to the specified pointer and the /// specified value. /// - /// If the pointer isn't an i8*, it will be converted. If a TBAA tag is - /// specified, it will be added to the instruction. + /// If the pointer isn't an i8*, it will be converted. If a TBAA tag is + /// specified, it will be added to the instruction. Likewise with alias.scope + /// and noalias tags. CallInst *CreateMemSet(Value *Ptr, Value *Val, uint64_t Size, unsigned Align, - bool isVolatile = false, MDNode *TBAATag = nullptr) { - return CreateMemSet(Ptr, Val, getInt64(Size), Align, isVolatile, TBAATag); + bool isVolatile = false, MDNode *TBAATag = nullptr, + MDNode *ScopeTag = nullptr, + MDNode *NoAliasTag = nullptr) { + return CreateMemSet(Ptr, Val, getInt64(Size), Align, isVolatile, + TBAATag, ScopeTag, NoAliasTag); } CallInst *CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align, - bool isVolatile = false, MDNode *TBAATag = nullptr); + bool isVolatile = false, MDNode *TBAATag = nullptr, + MDNode *ScopeTag = nullptr, + MDNode *NoAliasTag = nullptr); /// \brief Create and insert a memcpy between the specified pointers. /// /// If the pointers aren't i8*, they will be converted. If a TBAA tag is - /// specified, it will be added to the instruction. + /// specified, it will be added to the instruction. Likewise with alias.scope + /// and noalias tags. CallInst *CreateMemCpy(Value *Dst, Value *Src, uint64_t Size, unsigned Align, bool isVolatile = false, MDNode *TBAATag = nullptr, - MDNode *TBAAStructTag = nullptr) { + MDNode *TBAAStructTag = nullptr, + MDNode *ScopeTag = nullptr, + MDNode *NoAliasTag = nullptr) { return CreateMemCpy(Dst, Src, getInt64(Size), Align, isVolatile, TBAATag, - TBAAStructTag); + TBAAStructTag, ScopeTag, NoAliasTag); } CallInst *CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align, bool isVolatile = false, MDNode *TBAATag = nullptr, - MDNode *TBAAStructTag = nullptr); + MDNode *TBAAStructTag = nullptr, + MDNode *ScopeTag = nullptr, + MDNode *NoAliasTag = nullptr); /// \brief Create and insert a memmove between the specified /// pointers. /// /// If the pointers aren't i8*, they will be converted. If a TBAA tag is - /// specified, it will be added to the instruction. + /// specified, it will be added to the instruction. Likewise with alias.scope + /// and noalias tags. CallInst *CreateMemMove(Value *Dst, Value *Src, uint64_t Size, unsigned Align, - bool isVolatile = false, MDNode *TBAATag = nullptr) { - return CreateMemMove(Dst, Src, getInt64(Size), Align, isVolatile, TBAATag); + bool isVolatile = false, MDNode *TBAATag = nullptr, + MDNode *ScopeTag = nullptr, + MDNode *NoAliasTag = nullptr) { + return CreateMemMove(Dst, Src, getInt64(Size), Align, isVolatile, + TBAATag, ScopeTag, NoAliasTag); } CallInst *CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align, - bool isVolatile = false, MDNode *TBAATag = nullptr); + bool isVolatile = false, MDNode *TBAATag = nullptr, + MDNode *ScopeTag = nullptr, + MDNode *NoAliasTag = nullptr); /// \brief Create a lifetime.start intrinsic. /// diff --git a/llvm/include/llvm/IR/LLVMContext.h b/llvm/include/llvm/IR/LLVMContext.h index 4d940d5..7025571 100644 --- a/llvm/include/llvm/IR/LLVMContext.h +++ b/llvm/include/llvm/IR/LLVMContext.h @@ -52,7 +52,9 @@ public: MD_fpmath = 3, // "fpmath" MD_range = 4, // "range" MD_tbaa_struct = 5, // "tbaa.struct" - MD_invariant_load = 6 // "invariant.load" + MD_invariant_load = 6, // "invariant.load" + MD_alias_scope = 7, // "alias.scope" + MD_noalias = 8 // "noalias" }; /// getMDKindID - Return a unique non-zero ID for the specified metadata kind. diff --git a/llvm/include/llvm/IR/MDBuilder.h b/llvm/include/llvm/IR/MDBuilder.h index 1da9d45..6672b14 100644 --- a/llvm/include/llvm/IR/MDBuilder.h +++ b/llvm/include/llvm/IR/MDBuilder.h @@ -63,24 +63,49 @@ public: MDNode *createRange(const APInt &Lo, const APInt &Hi); //===------------------------------------------------------------------===// - // TBAA metadata. + // AA metadata. //===------------------------------------------------------------------===// - /// \brief Return metadata appropriate for a TBAA root node. Each returned +protected: + /// \brief Return metadata appropriate for a AA root node (scope or TBAA). + /// Each returned node is distinct from all other metadata and will never + /// be identified (uniqued) with anything else. + MDNode *createAnonymousAARoot(StringRef Name = StringRef()); + +public: + /// \brief Return metadata appropriate for a TBAA root node. Each returned /// node is distinct from all other metadata and will never be identified /// (uniqued) with anything else. - MDNode *createAnonymousTBAARoot(); + MDNode *createAnonymousTBAARoot() { + return createAnonymousAARoot(); + } + + /// \brief Return metadata appropriate for an alias scope root node. + /// Each returned node is distinct from all other metadata and will never + /// be identified (uniqued) with anything else. + MDNode *createAnonymousAliasScopeRoot(StringRef Name = StringRef()) { + return createAnonymousAARoot(Name); + } /// \brief Return metadata appropriate for a TBAA root node with the given /// name. This may be identified (uniqued) with other roots with the same /// name. MDNode *createTBAARoot(StringRef Name); + /// \brief Return metadata appropriate for an alias scope root node with + /// the given name. This may be identified (uniqued) with other roots with + /// the same name. + MDNode *createAliasScopeRoot(StringRef Name); + /// \brief Return metadata for a non-root TBAA node with the given name, /// parent in the TBAA tree, and value for 'pointsToConstantMemory'. MDNode *createTBAANode(StringRef Name, MDNode *Parent, bool isConstant = false); + /// \brief Return metadata for a non-root alias scope node with the given + /// name and parent in the scope tree. + MDNode *createAliasScopeNode(StringRef Name, MDNode *Parent); + struct TBAAStructField { uint64_t Offset; uint64_t Size; diff --git a/llvm/include/llvm/IR/Metadata.h b/llvm/include/llvm/IR/Metadata.h index 17176ab..e7b379c 100644 --- a/llvm/include/llvm/IR/Metadata.h +++ b/llvm/include/llvm/IR/Metadata.h @@ -70,8 +70,8 @@ public: /// AAMDNodes - A collection of metadata nodes that might be associated with a /// memory access used by the alias-analysis infrastructure. struct AAMDNodes { - AAMDNodes(MDNode *T = nullptr) - : TBAA(T) {} + AAMDNodes(MDNode *T = nullptr, MDNode *S = nullptr, MDNode *N = nullptr) + : TBAA(T), Scope(S), NoAlias(N) {} bool operator == (const AAMDNodes &A) const { return equals(A); @@ -82,15 +82,21 @@ struct AAMDNodes { } operator bool() const { - return TBAA; + return TBAA || Scope || NoAlias; } /// TBAA - The tag for type-based alias analysis. MDNode *TBAA; + /// Scope - The tag for alias scope specification (used with noalias). + MDNode *Scope; + + /// NoAlias - The tag specifying the noalias scope. + MDNode *NoAlias; + protected: bool equals(const AAMDNodes &A) const { - return TBAA == A.TBAA; + return TBAA == A.TBAA && Scope == A.Scope && NoAlias == A.NoAlias; } }; @@ -98,13 +104,15 @@ protected: template<> struct DenseMapInfo { static inline AAMDNodes getEmptyKey() { - return AAMDNodes(DenseMapInfo::getEmptyKey()); + return AAMDNodes(DenseMapInfo::getEmptyKey(), 0, 0); } static inline AAMDNodes getTombstoneKey() { - return AAMDNodes(DenseMapInfo::getTombstoneKey()); + return AAMDNodes(DenseMapInfo::getTombstoneKey(), 0, 0); } static unsigned getHashValue(const AAMDNodes &Val) { - return DenseMapInfo::getHashValue(Val.TBAA); + return DenseMapInfo::getHashValue(Val.TBAA) ^ + DenseMapInfo::getHashValue(Val.Scope) ^ + DenseMapInfo::getHashValue(Val.NoAlias); } static bool isEqual(const AAMDNodes &LHS, const AAMDNodes &RHS) { return LHS == RHS; @@ -214,6 +222,8 @@ public: bool isTBAAVtableAccess() const; /// Methods for metadata merging. + static MDNode *concatenate(MDNode *A, MDNode *B); + static MDNode *intersect(MDNode *A, MDNode *B); static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B); static AAMDNodes getMostGenericAA(const AAMDNodes &A, const AAMDNodes &B); static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B); diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h index 02f4259..20074f0 100644 --- a/llvm/include/llvm/InitializePasses.h +++ b/llvm/include/llvm/InitializePasses.h @@ -263,6 +263,7 @@ void initializeNoTTIPass(PassRegistry&); void initializeTargetLibraryInfoPass(PassRegistry&); void initializeTwoAddressInstructionPassPass(PassRegistry&); void initializeTypeBasedAliasAnalysisPass(PassRegistry&); +void initializeScopedNoAliasAAPass(PassRegistry&); void initializeUnifyFunctionExitNodesPass(PassRegistry&); void initializeUnreachableBlockElimPass(PassRegistry&); void initializeUnreachableMachineBlockElimPass(PassRegistry&); diff --git a/llvm/include/llvm/LinkAllPasses.h b/llvm/include/llvm/LinkAllPasses.h index e06560c..b7f832dc 100644 --- a/llvm/include/llvm/LinkAllPasses.h +++ b/llvm/include/llvm/LinkAllPasses.h @@ -56,6 +56,7 @@ namespace { (void) llvm::createLibCallAliasAnalysisPass(nullptr); (void) llvm::createScalarEvolutionAliasAnalysisPass(); (void) llvm::createTypeBasedAliasAnalysisPass(); + (void) llvm::createScopedNoAliasAAPass(); (void) llvm::createBoundsCheckingPass(); (void) llvm::createBreakCriticalEdgesPass(); (void) llvm::createCallGraphPrinterPass(); diff --git a/llvm/lib/Analysis/Analysis.cpp b/llvm/lib/Analysis/Analysis.cpp index c58012f..010ad74 100644 --- a/llvm/lib/Analysis/Analysis.cpp +++ b/llvm/lib/Analysis/Analysis.cpp @@ -66,6 +66,7 @@ void llvm::initializeAnalysis(PassRegistry &Registry) { initializeScalarEvolutionAliasAnalysisPass(Registry); initializeTargetTransformInfoAnalysisGroup(Registry); initializeTypeBasedAliasAnalysisPass(Registry); + initializeScopedNoAliasAAPass(Registry); } void LLVMInitializeAnalysis(LLVMPassRegistryRef R) { diff --git a/llvm/lib/Analysis/CMakeLists.txt b/llvm/lib/Analysis/CMakeLists.txt index d1632fd..a673477 100644 --- a/llvm/lib/Analysis/CMakeLists.txt +++ b/llvm/lib/Analysis/CMakeLists.txt @@ -53,6 +53,7 @@ add_llvm_library(LLVMAnalysis TargetTransformInfo.cpp Trace.cpp TypeBasedAliasAnalysis.cpp + ScopedNoAliasAA.cpp ValueTracking.cpp ) diff --git a/llvm/lib/Analysis/ScopedNoAliasAA.cpp b/llvm/lib/Analysis/ScopedNoAliasAA.cpp new file mode 100644 index 0000000..f197f1c --- /dev/null +++ b/llvm/lib/Analysis/ScopedNoAliasAA.cpp @@ -0,0 +1,243 @@ +//===- ScopedNoAliasAA.cpp - Scoped No-Alias Alias Analysis ---------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines the ScopedNoAlias alias-analysis pass, which implements +// metadata-based scoped no-alias support. +// +// Alias-analysis scopes are defined similar to TBAA nodes: +// +// !scope0 = metadata !{ metadata !"scope of foo()" } +// !scope1 = metadata !{ metadata !"scope 1", metadata !scope0 } +// !scope2 = metadata !{ metadata !"scope 2", metadata !scope0 } +// !scope3 = metadata !{ metadata !"scope 2.1", metadata !scope2 } +// !scope4 = metadata !{ metadata !"scope 2.2", metadata !scope2 } +// +// Loads and stores can be tagged with an alias-analysis scope, and also, with +// a noalias tag for a specific scope: +// +// ... = load %ptr1, !alias.scope !{ !scope1 } +// ... = load %ptr2, !alias.scope !{ !scope1, !scope2 }, !noalias !{ !scope1 } +// +// When evaluating an aliasing query, if one of the instructions is associated +// with an alias.scope id that is identical to the noalias scope associated +// with the other instruction, or is a descendant (in the scope hierarchy) of +// the noalias scope associated with the other instruction, then the two memory +// accesses are assumed not to alias. +// +// Note that if the first element of the scope metadata is a string, then it +// can be combined accross functions and translation units. The string can be +// replaced by a self-reference to create globally unqiue scope identifiers. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Analysis/Passes.h" +#include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Metadata.h" +#include "llvm/IR/Module.h" +#include "llvm/Pass.h" +#include "llvm/Support/CommandLine.h" +using namespace llvm; + +// A handy option for disabling scoped no-alias functionality. The same effect +// can also be achieved by stripping the associated metadata tags from IR, but +// this option is sometimes more convenient. +static cl::opt +EnableScopedNoAlias("enable-scoped-noalias", cl::init(true)); + +namespace { +/// AliasScopeNode - This is a simple wrapper around an MDNode which provides +/// a higher-level interface by hiding the details of how alias analysis +/// information is encoded in its operands. +class AliasScopeNode { + const MDNode *Node; + +public: + AliasScopeNode() : Node(0) {} + explicit AliasScopeNode(const MDNode *N) : Node(N) {} + + /// getNode - Get the MDNode for this AliasScopeNode. + const MDNode *getNode() const { return Node; } + + /// getParent - Get this AliasScopeNode's Alias tree parent. + AliasScopeNode getParent() const { + if (Node->getNumOperands() < 2) + return AliasScopeNode(); + MDNode *P = dyn_cast_or_null(Node->getOperand(1)); + if (!P) + return AliasScopeNode(); + // Ok, this node has a valid parent. Return it. + return AliasScopeNode(P); + } +}; + +/// ScopedNoAliasAA - This is a simple alias analysis +/// implementation that uses scoped-noalias metadata to answer queries. +class ScopedNoAliasAA : public ImmutablePass, public AliasAnalysis { +public: + static char ID; // Class identification, replacement for typeinfo + ScopedNoAliasAA() : ImmutablePass(ID) { + initializeScopedNoAliasAAPass(*PassRegistry::getPassRegistry()); + } + + virtual void initializePass() { + InitializeAliasAnalysis(this); + } + + /// getAdjustedAnalysisPointer - This method is used when a pass implements + /// an analysis interface through multiple inheritance. If needed, it + /// should override this to adjust the this pointer as needed for the + /// specified pass info. + virtual void *getAdjustedAnalysisPointer(const void *PI) { + if (PI == &AliasAnalysis::ID) + return (AliasAnalysis*)this; + return this; + } + +protected: + bool mayAlias(const MDNode *A, const MDNode *B) const; + bool mayAliasInScopes(const MDNode *Scopes, const MDNode *NoAlias) const; + +private: + virtual void getAnalysisUsage(AnalysisUsage &AU) const; + virtual AliasResult alias(const Location &LocA, const Location &LocB); + virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal); + virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS); + virtual ModRefBehavior getModRefBehavior(const Function *F); + virtual ModRefResult getModRefInfo(ImmutableCallSite CS, + const Location &Loc); + virtual ModRefResult getModRefInfo(ImmutableCallSite CS1, + ImmutableCallSite CS2); +}; +} // End of anonymous namespace + +// Register this pass... +char ScopedNoAliasAA::ID = 0; +INITIALIZE_AG_PASS(ScopedNoAliasAA, AliasAnalysis, "scoped-noalias", + "Scoped NoAlias Alias Analysis", false, true, false) + +ImmutablePass *llvm::createScopedNoAliasAAPass() { + return new ScopedNoAliasAA(); +} + +void +ScopedNoAliasAA::getAnalysisUsage(AnalysisUsage &AU) const { + AU.setPreservesAll(); + AliasAnalysis::getAnalysisUsage(AU); +} + +/// mayAlias - Test whether the scope represented by A may alias the +/// scope represented by B. Specifically, A is the target scope, and B is the +/// noalias scope. +bool +ScopedNoAliasAA::mayAlias(const MDNode *A, + const MDNode *B) const { + // Climb the tree from A to see if we reach B. + for (AliasScopeNode T(A); ; ) { + if (T.getNode() == B) + // B is an ancestor of A. + return false; + + T = T.getParent(); + if (!T.getNode()) + break; + } + + return true; +} + +bool +ScopedNoAliasAA::mayAliasInScopes(const MDNode *Scopes, + const MDNode *NoAlias) const { + if (!Scopes || !NoAlias) + return true; + + for (unsigned i = 0, ie = Scopes->getNumOperands(); i != ie; ++i) + if (const MDNode *SMD = dyn_cast(Scopes->getOperand(i))) + for (unsigned j = 0, je = NoAlias->getNumOperands(); j != je; ++j) + if (const MDNode *NAMD = dyn_cast(NoAlias->getOperand(j))) + if (!mayAlias(SMD, NAMD)) + return false; + + return true; +} + +AliasAnalysis::AliasResult +ScopedNoAliasAA::alias(const Location &LocA, const Location &LocB) { + if (!EnableScopedNoAlias) + return AliasAnalysis::alias(LocA, LocB); + + // Get the attached MDNodes. + const MDNode *AScopes = LocA.AATags.Scope, + *BScopes = LocB.AATags.Scope; + + const MDNode *ANoAlias = LocA.AATags.NoAlias, + *BNoAlias = LocB.AATags.NoAlias; + + if (!mayAliasInScopes(AScopes, BNoAlias)) + return NoAlias; + + if (!mayAliasInScopes(BScopes, ANoAlias)) + return NoAlias; + + // If they may alias, chain to the next AliasAnalysis. + return AliasAnalysis::alias(LocA, LocB); +} + +bool ScopedNoAliasAA::pointsToConstantMemory(const Location &Loc, + bool OrLocal) { + return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal); +} + +AliasAnalysis::ModRefBehavior +ScopedNoAliasAA::getModRefBehavior(ImmutableCallSite CS) { + return AliasAnalysis::getModRefBehavior(CS); +} + +AliasAnalysis::ModRefBehavior +ScopedNoAliasAA::getModRefBehavior(const Function *F) { + return AliasAnalysis::getModRefBehavior(F); +} + +AliasAnalysis::ModRefResult +ScopedNoAliasAA::getModRefInfo(ImmutableCallSite CS, const Location &Loc) { + if (!EnableScopedNoAlias) + return AliasAnalysis::getModRefInfo(CS, Loc); + + if (!mayAliasInScopes(Loc.AATags.Scope, + CS.getInstruction()->getMetadata(LLVMContext::MD_noalias))) + return NoModRef; + + if (!mayAliasInScopes( + CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope), + Loc.AATags.NoAlias)) + return NoModRef; + + return AliasAnalysis::getModRefInfo(CS, Loc); +} + +AliasAnalysis::ModRefResult +ScopedNoAliasAA::getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) { + if (!EnableScopedNoAlias) + return AliasAnalysis::getModRefInfo(CS1, CS2); + + if (!mayAliasInScopes( + CS1.getInstruction()->getMetadata(LLVMContext::MD_alias_scope), + CS2.getInstruction()->getMetadata(LLVMContext::MD_noalias))) + return NoModRef; + + if (!mayAliasInScopes( + CS2.getInstruction()->getMetadata(LLVMContext::MD_alias_scope), + CS1.getInstruction()->getMetadata(LLVMContext::MD_noalias))) + return NoModRef; + + return AliasAnalysis::getModRefInfo(CS1, CS2); +} + diff --git a/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp b/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp index c68ba5a..27b469a 100644 --- a/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp +++ b/llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp @@ -618,5 +618,17 @@ void Instruction::getAAMetadata(AAMDNodes &N, bool Merge) const { getMetadata(LLVMContext::MD_tbaa)); else N.TBAA = getMetadata(LLVMContext::MD_tbaa); + + if (Merge) + N.Scope = MDNode::intersect(N.Scope, + getMetadata(LLVMContext::MD_alias_scope)); + else + N.Scope = getMetadata(LLVMContext::MD_alias_scope); + + if (Merge) + N.NoAlias = MDNode::intersect(N.NoAlias, + getMetadata(LLVMContext::MD_noalias)); + else + N.NoAlias = getMetadata(LLVMContext::MD_noalias); } diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp index 06cce92..c9fe234 100644 --- a/llvm/lib/CodeGen/MachineInstr.cpp +++ b/llvm/lib/CodeGen/MachineInstr.cpp @@ -523,6 +523,34 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineMemOperand &MMO) { OS << ")"; } + // Print AA scope info. + if (const MDNode *ScopeInfo = MMO.getAAInfo().Scope) { + OS << "(alias.scope="; + if (ScopeInfo->getNumOperands() > 0) + for (unsigned i = 0, ie = ScopeInfo->getNumOperands(); i != ie; ++i) { + ScopeInfo->getOperand(i)->printAsOperand(OS, /*PrintType=*/false); + if (i != ie-1) + OS << ","; + } + else + OS << ""; + OS << ")"; + } + + // Print AA noalias scope info. + if (const MDNode *NoAliasInfo = MMO.getAAInfo().NoAlias) { + OS << "(noalias="; + if (NoAliasInfo->getNumOperands() > 0) + for (unsigned i = 0, ie = NoAliasInfo->getNumOperands(); i != ie; ++i) { + NoAliasInfo->getOperand(i)->printAsOperand(OS, /*PrintType=*/false); + if (i != ie-1) + OS << ","; + } + else + OS << ""; + OS << ")"; + } + // Print nontemporal info. if (MMO.isNonTemporal()) OS << "(nontemporal)"; diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp index 6e86c8f..bac0433 100644 --- a/llvm/lib/CodeGen/Passes.cpp +++ b/llvm/lib/CodeGen/Passes.cpp @@ -377,6 +377,7 @@ void TargetPassConfig::addIRPasses() { // BasicAliasAnalysis wins if they disagree. This is intended to help // support "obvious" type-punning idioms. addPass(createTypeBasedAliasAnalysisPass()); + addPass(createScopedNoAliasAAPass()); addPass(createBasicAliasAnalysisPass()); // Before running any passes, run the verifier to determine if the input diff --git a/llvm/lib/IR/IRBuilder.cpp b/llvm/lib/IR/IRBuilder.cpp index 435e54f..7448e50 100644 --- a/llvm/lib/IR/IRBuilder.cpp +++ b/llvm/lib/IR/IRBuilder.cpp @@ -62,7 +62,8 @@ static CallInst *createCallHelper(Value *Callee, ArrayRef Ops, CallInst *IRBuilderBase:: CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align, - bool isVolatile, MDNode *TBAATag) { + bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag, + MDNode *NoAliasTag) { Ptr = getCastedInt8PtrValue(Ptr); Value *Ops[] = { Ptr, Val, Size, getInt32(Align), getInt1(isVolatile) }; Type *Tys[] = { Ptr->getType(), Size->getType() }; @@ -74,13 +75,20 @@ CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align, // Set the TBAA info if present. if (TBAATag) CI->setMetadata(LLVMContext::MD_tbaa, TBAATag); - + + if (ScopeTag) + CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag); + + if (NoAliasTag) + CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag); + return CI; } CallInst *IRBuilderBase:: CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align, - bool isVolatile, MDNode *TBAATag, MDNode *TBAAStructTag) { + bool isVolatile, MDNode *TBAATag, MDNode *TBAAStructTag, + MDNode *ScopeTag, MDNode *NoAliasTag) { Dst = getCastedInt8PtrValue(Dst); Src = getCastedInt8PtrValue(Src); @@ -98,13 +106,20 @@ CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align, // Set the TBAA Struct info if present. if (TBAAStructTag) CI->setMetadata(LLVMContext::MD_tbaa_struct, TBAAStructTag); - + + if (ScopeTag) + CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag); + + if (NoAliasTag) + CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag); + return CI; } CallInst *IRBuilderBase:: CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align, - bool isVolatile, MDNode *TBAATag) { + bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag, + MDNode *NoAliasTag) { Dst = getCastedInt8PtrValue(Dst); Src = getCastedInt8PtrValue(Src); @@ -118,7 +133,13 @@ CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align, // Set the TBAA info if present. if (TBAATag) CI->setMetadata(LLVMContext::MD_tbaa, TBAATag); - + + if (ScopeTag) + CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag); + + if (NoAliasTag) + CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag); + return CI; } diff --git a/llvm/lib/IR/LLVMContext.cpp b/llvm/lib/IR/LLVMContext.cpp index de825f0..d4ba83d 100644 --- a/llvm/lib/IR/LLVMContext.cpp +++ b/llvm/lib/IR/LLVMContext.cpp @@ -66,6 +66,16 @@ LLVMContext::LLVMContext() : pImpl(new LLVMContextImpl(*this)) { unsigned InvariantLdId = getMDKindID("invariant.load"); assert(InvariantLdId == MD_invariant_load && "invariant.load kind id drifted"); (void)InvariantLdId; + + // Create the 'alias.scope' metadata kind. + unsigned AliasScopeID = getMDKindID("alias.scope"); + assert(AliasScopeID == MD_alias_scope && "alias.scope kind id drifted"); + (void)AliasScopeID; + + // Create the 'noalias' metadata kind. + unsigned NoAliasID = getMDKindID("noalias"); + assert(NoAliasID == MD_noalias && "noalias kind id drifted"); + (void)NoAliasID; } LLVMContext::~LLVMContext() { delete pImpl; } diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp index 65cdf38..103915f 100644 --- a/llvm/lib/IR/MDBuilder.cpp +++ b/llvm/lib/IR/MDBuilder.cpp @@ -60,10 +60,15 @@ MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) { return MDNode::get(Context, Range); } -MDNode *MDBuilder::createAnonymousTBAARoot() { +MDNode *MDBuilder::createAnonymousAARoot(StringRef Name) { // To ensure uniqueness the root node is self-referential. - MDNode *Dummy = MDNode::getTemporary(Context, ArrayRef()); - MDNode *Root = MDNode::get(Context, Dummy); + MDNode *Dummy = MDNode::getTemporary(Context, ArrayRef()); + + SmallVector Args(1, Dummy); + if (!Name.empty()) + Args.push_back(createString(Name)); + MDNode *Root = MDNode::get(Context, Args); + // At this point we have // !0 = metadata !{} <- dummy // !1 = metadata !{metadata !0} <- root @@ -93,6 +98,15 @@ MDNode *MDBuilder::createTBAANode(StringRef Name, MDNode *Parent, } } +MDNode *MDBuilder::createAliasScopeRoot(StringRef Name) { + return MDNode::get(Context, createString(Name)); +} + +MDNode *MDBuilder::createAliasScopeNode(StringRef Name, MDNode *Parent) { + Value *Ops[2] = { createString(Name), Parent }; + return MDNode::get(Context, Ops); +} + /// \brief Return metadata for a tbaa.struct node with the given /// struct field descriptions. MDNode *MDBuilder::createTBAAStructNode(ArrayRef Fields) { diff --git a/llvm/lib/IR/Metadata.cpp b/llvm/lib/IR/Metadata.cpp index d7d6464..a017bd3 100644 --- a/llvm/lib/IR/Metadata.cpp +++ b/llvm/lib/IR/Metadata.cpp @@ -406,6 +406,41 @@ void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) { } } +MDNode *MDNode::concatenate(MDNode *A, MDNode *B) { + if (!A) + return B; + if (!B) + return A; + + SmallVector Vals(A->getNumOperands() + + B->getNumOperands()); + + unsigned j = 0; + for (unsigned i = 0, ie = A->getNumOperands(); i != ie; ++i) + Vals[j++] = A->getOperand(i); + for (unsigned i = 0, ie = B->getNumOperands(); i != ie; ++i) + Vals[j++] = B->getOperand(i); + + return MDNode::get(A->getContext(), Vals); +} + +MDNode *MDNode::intersect(MDNode *A, MDNode *B) { + if (!A || !B) + return nullptr; + + SmallVector Vals; + for (unsigned i = 0, ie = A->getNumOperands(); i != ie; ++i) { + Value *V = A->getOperand(i); + for (unsigned j = 0, je = B->getNumOperands(); j != je; ++j) + if (V == B->getOperand(j)) { + Vals.push_back(V); + break; + } + } + + return MDNode::get(A->getContext(), Vals); +} + MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) { if (!A || !B) return nullptr; @@ -689,6 +724,8 @@ void Instruction::setMetadata(unsigned KindID, MDNode *Node) { void Instruction::setAAMetadata(const AAMDNodes &N) { setMetadata(LLVMContext::MD_tbaa, N.TBAA); + setMetadata(LLVMContext::MD_alias_scope, N.Scope); + setMetadata(LLVMContext::MD_noalias, N.NoAlias); } MDNode *Instruction::getMetadataImpl(unsigned KindID) const { diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp index 701fb46..98477b5 100644 --- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp +++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp @@ -107,6 +107,7 @@ PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const { // BasicAliasAnalysis wins if they disagree. This is intended to help // support "obvious" type-punning idioms. PM.add(createTypeBasedAliasAnalysisPass()); + PM.add(createScopedNoAliasAAPass()); PM.add(createBasicAliasAnalysisPass()); } diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp index 43ccb99..7135874 100644 --- a/llvm/lib/Transforms/Scalar/GVN.cpp +++ b/llvm/lib/Transforms/Scalar/GVN.cpp @@ -1791,6 +1791,19 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) { case LLVMContext::MD_tbaa: ReplInst->setMetadata(Kind, MDNode::getMostGenericTBAA(IMD, ReplMD)); break; + case LLVMContext::MD_alias_scope: + case LLVMContext::MD_noalias: + // FIXME: If both the original and replacement value are part of the + // same control-flow region (meaning that the execution of one + // guarentees the executation of the other), then we can combine the + // noalias scopes here and do better than the general conservative + // answer. + + // In general, GVN unifies expressions over different control-flow + // regions, and so we need a conservative combination of the noalias + // scopes. + ReplInst->setMetadata(Kind, MDNode::intersect(IMD, ReplMD)); + break; case LLVMContext::MD_range: ReplInst->setMetadata(Kind, MDNode::getMostGenericRange(IMD, ReplMD)); break; diff --git a/llvm/lib/Transforms/Scalar/Scalar.cpp b/llvm/lib/Transforms/Scalar/Scalar.cpp index de724d4..12df676 100644 --- a/llvm/lib/Transforms/Scalar/Scalar.cpp +++ b/llvm/lib/Transforms/Scalar/Scalar.cpp @@ -203,6 +203,10 @@ void LLVMAddTypeBasedAliasAnalysisPass(LLVMPassManagerRef PM) { unwrap(PM)->add(createTypeBasedAliasAnalysisPass()); } +void LLVMAddScopedNoAliasAAPass(LLVMPassManagerRef PM) { + unwrap(PM)->add(createScopedNoAliasAAPass()); +} + void LLVMAddBasicAliasAnalysisPass(LLVMPassManagerRef PM) { unwrap(PM)->add(createBasicAliasAnalysisPass()); } diff --git a/llvm/lib/Transforms/Scalar/Scalarizer.cpp b/llvm/lib/Transforms/Scalar/Scalarizer.cpp index 7a73f11..813041a 100644 --- a/llvm/lib/Transforms/Scalar/Scalarizer.cpp +++ b/llvm/lib/Transforms/Scalar/Scalarizer.cpp @@ -312,6 +312,8 @@ bool Scalarizer::canTransferMetadata(unsigned Tag) { || Tag == LLVMContext::MD_fpmath || Tag == LLVMContext::MD_tbaa_struct || Tag == LLVMContext::MD_invariant_load + || Tag == LLVMContext::MD_alias_scope + || Tag == LLVMContext::MD_noalias || Tag == ParallelLoopAccessMDKind); } diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp index f0a9f2b..f4152dd 100644 --- a/llvm/lib/Transforms/Utils/InlineFunction.cpp +++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp @@ -13,10 +13,13 @@ //===----------------------------------------------------------------------===// #include "llvm/Transforms/Utils/Cloning.h" +#include "llvm/ADT/SmallSet.h" #include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/SetVector.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Analysis/CallGraph.h" #include "llvm/Analysis/InstructionSimplify.h" +#include "llvm/Analysis/ValueTracking.h" #include "llvm/IR/Attributes.h" #include "llvm/IR/CallSite.h" #include "llvm/IR/CFG.h" @@ -28,6 +31,7 @@ #include "llvm/IR/Instructions.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Intrinsics.h" +#include "llvm/IR/MDBuilder.h" #include "llvm/IR/Module.h" #include "llvm/Transforms/Utils/Local.h" using namespace llvm; @@ -260,6 +264,100 @@ static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock, InvokeDest->removePredecessor(II->getParent()); } +/// CloneAliasScopeMetadata - When inlining a function that contains noalias +/// scope metadata, this metadata needs to be cloned so that the inlined blocks +/// have different "unqiue scopes" at every call site. Were this not done, then +/// aliasing scopes from a function inlined into a caller multiple times could +/// not be differentiated (and this would lead to miscompiles because the +/// non-aliasing property communicated by the metadata could have +/// call-site-specific control dependencies). +static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) { + const Function *CalledFunc = CS.getCalledFunction(); + SetVector MD; + + // Note: We could only clone the metadata if it is already used in the + // caller. I'm omitting that check here because it might confuse + // inter-procedural alias analysis passes. We can revisit this if it becomes + // an efficiency or overhead problem. + + for (Function::const_iterator I = CalledFunc->begin(), IE = CalledFunc->end(); + I != IE; ++I) + for (BasicBlock::const_iterator J = I->begin(), JE = I->end(); J != JE; ++J) { + if (const MDNode *M = J->getMetadata(LLVMContext::MD_alias_scope)) + MD.insert(M); + if (const MDNode *M = J->getMetadata(LLVMContext::MD_noalias)) + MD.insert(M); + } + + if (MD.empty()) + return; + + // Walk the existing metadata, adding the complete (perhaps cyclic) chain to + // the set. + SmallVector Queue(MD.begin(), MD.end()); + while (!Queue.empty()) { + const MDNode *M = cast(Queue.pop_back_val()); + for (unsigned i = 0, ie = M->getNumOperands(); i != ie; ++i) + if (const MDNode *M1 = dyn_cast(M->getOperand(i))) + if (MD.insert(M1)) + Queue.push_back(M1); + } + + // Now we have a complete set of all metadata in the chains used to specify + // the noalias scopes and the lists of those scopes. + SmallVector DummyNodes; + DenseMap > MDMap; + for (SetVector::iterator I = MD.begin(), IE = MD.end(); + I != IE; ++I) { + MDNode *Dummy = MDNode::getTemporary(CalledFunc->getContext(), + ArrayRef()); + DummyNodes.push_back(Dummy); + MDMap[*I] = Dummy; + } + + // Create new metadata nodes to replace the dummy nodes, replacing old + // metadata references with either a dummy node or an already-created new + // node. + for (SetVector::iterator I = MD.begin(), IE = MD.end(); + I != IE; ++I) { + SmallVector NewOps; + for (unsigned i = 0, ie = (*I)->getNumOperands(); i != ie; ++i) { + const Value *V = (*I)->getOperand(i); + if (const MDNode *M = dyn_cast(V)) + NewOps.push_back(MDMap[M]); + else + NewOps.push_back(const_cast(V)); + } + + MDNode *NewM = MDNode::get(CalledFunc->getContext(), NewOps), + *TempM = MDMap[*I]; + + TempM->replaceAllUsesWith(NewM); + } + + // Now replace the metadata in the new inlined instructions with the + // repacements from the map. + for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end(); + VMI != VMIE; ++VMI) { + if (!VMI->second) + continue; + + Instruction *NI = dyn_cast(VMI->second); + if (!NI) + continue; + + if (MDNode *M = NI->getMetadata(LLVMContext::MD_alias_scope)) + NI->setMetadata(LLVMContext::MD_alias_scope, MDMap[M]); + + if (MDNode *M = NI->getMetadata(LLVMContext::MD_noalias)) + NI->setMetadata(LLVMContext::MD_noalias, MDMap[M]); + } + + // Now that everything has been replaced, delete the dummy nodes. + for (unsigned i = 0, ie = DummyNodes.size(); i != ie; ++i) + MDNode::deleteTemporary(DummyNodes[i]); +} + /// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee /// into the caller, update the specified callgraph to reflect the changes we /// made. Note that it's possible that not all code was copied over, so only @@ -648,6 +746,9 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI, // Update inlined instructions' line number information. fixupLineNumbers(Caller, FirstNewBlock, TheCall); + + // Clone existing noalias metadata if necessary. + CloneAliasScopeMetadata(CS, VMap); } // If there are any alloca instructions in the block that used to be the entry diff --git a/llvm/lib/Transforms/Vectorize/BBVectorize.cpp b/llvm/lib/Transforms/Vectorize/BBVectorize.cpp index 28ec83bf..9ee0ffb 100644 --- a/llvm/lib/Transforms/Vectorize/BBVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/BBVectorize.cpp @@ -2982,6 +2982,10 @@ namespace { case LLVMContext::MD_tbaa: K->setMetadata(Kind, MDNode::getMostGenericTBAA(JMD, KMD)); break; + case LLVMContext::MD_alias_scope: + case LLVMContext::MD_noalias: + K->setMetadata(Kind, MDNode::intersect(JMD, KMD)); + break; case LLVMContext::MD_fpmath: K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD)); break; diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp index b60ce61..a88eb49 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -535,6 +535,8 @@ static void propagateMetadata(Instruction *To, const Instruction *From) { // non-speculated memory access when the condition was false, this would be // caught by the runtime overlap checks). if (Kind != LLVMContext::MD_tbaa && + Kind != LLVMContext::MD_alias_scope && + Kind != LLVMContext::MD_noalias && Kind != LLVMContext::MD_fpmath) continue; diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp index 53a43d9..bbfdb4e 100644 --- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -230,6 +230,10 @@ static Instruction *propagateMetadata(Instruction *I, ArrayRef VL) { case LLVMContext::MD_tbaa: MD = MDNode::getMostGenericTBAA(MD, IMD); break; + case LLVMContext::MD_alias_scope: + case LLVMContext::MD_noalias: + MD = MDNode::intersect(MD, IMD); + break; case LLVMContext::MD_fpmath: MD = MDNode::getMostGenericFPMath(MD, IMD); break; diff --git a/llvm/test/Analysis/ScopedNoAliasAA/basic-hierarchy.ll b/llvm/test/Analysis/ScopedNoAliasAA/basic-hierarchy.ll new file mode 100644 index 0000000..12d358e --- /dev/null +++ b/llvm/test/Analysis/ScopedNoAliasAA/basic-hierarchy.ll @@ -0,0 +1,80 @@ +; RUN: opt < %s -basicaa -scoped-noalias -aa-eval -evaluate-aa-metadata -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @foo1(float* nocapture %a, float* nocapture readonly %c) #0 { +entry: +; CHECK-LABEL: Function: foo1 + %0 = load float* %c, align 4, !alias.scope !0 + %arrayidx.i = getelementptr inbounds float* %a, i64 5 + store float %0, float* %arrayidx.i, align 4, !noalias !0 + + %1 = load float* %c, align 4 + %arrayidx = getelementptr inbounds float* %a, i64 7 + store float %1, float* %arrayidx, align 4 + + %2 = load float* %c, align 4, !alias.scope !1 + %arrayidx.i2 = getelementptr inbounds float* %a, i64 15 + store float %2, float* %arrayidx.i2, align 4, !noalias !3 + + %3 = load float* %c, align 4, !alias.scope !3 + %arrayidx.i3 = getelementptr inbounds float* %a, i64 16 + store float %3, float* %arrayidx.i3, align 4, !noalias !0 + + %4 = load float* %c, align 4, !alias.scope !5 + %arrayidx.i4 = getelementptr inbounds float* %a, i64 17 + store float %4, float* %arrayidx.i4, align 4, !noalias !3 + ret void +} + +attributes #0 = { nounwind uwtable } + +; A root scope (which doubles as a list of itself): +!0 = metadata !{metadata !0} + +; Two child scopes (which must be self-referential to avoid being "uniqued"): +!1 = metadata !{metadata !2} +!2 = metadata !{metadata !2, metadata !0} + +!3 = metadata !{metadata !4} +!4 = metadata !{metadata !4, metadata !0} + +; A list of the two children: +!5 = metadata !{metadata !2, metadata !4} + +; CHECK: NoAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %1, float* %arrayidx, align 4 +; CHECK: MayAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: NoAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %3, float* %arrayidx.i3, align 4, !noalias !0 +; CHECK: MayAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %4, float* %arrayidx.i4, align 4, !noalias !3 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %1, float* %arrayidx, align 4 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %3, float* %arrayidx.i3, align 4, !noalias !0 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %4, float* %arrayidx.i4, align 4, !noalias !3 +; CHECK: NoAlias: %2 = load float* %c, align 4, !alias.scope !1 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %2 = load float* %c, align 4, !alias.scope !1 <-> store float %1, float* %arrayidx, align 4 +; CHECK: MayAlias: %2 = load float* %c, align 4, !alias.scope !1 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: NoAlias: %2 = load float* %c, align 4, !alias.scope !1 <-> store float %3, float* %arrayidx.i3, align 4, !noalias !0 +; CHECK: MayAlias: %2 = load float* %c, align 4, !alias.scope !1 <-> store float %4, float* %arrayidx.i4, align 4, !noalias !3 +; CHECK: NoAlias: %3 = load float* %c, align 4, !alias.scope !3 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %3 = load float* %c, align 4, !alias.scope !3 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: %3 = load float* %c, align 4, !alias.scope !3 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: NoAlias: %3 = load float* %c, align 4, !alias.scope !3 <-> store float %3, float* %arrayidx.i3, align 4, !noalias !0 +; CHECK: NoAlias: %3 = load float* %c, align 4, !alias.scope !3 <-> store float %4, float* %arrayidx.i4, align 4, !noalias !3 +; CHECK: NoAlias: %4 = load float* %c, align 4, !alias.scope !5 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %4 = load float* %c, align 4, !alias.scope !5 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: %4 = load float* %c, align 4, !alias.scope !5 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: NoAlias: %4 = load float* %c, align 4, !alias.scope !5 <-> store float %3, float* %arrayidx.i3, align 4, !noalias !0 +; CHECK: NoAlias: %4 = load float* %c, align 4, !alias.scope !5 <-> store float %4, float* %arrayidx.i4, align 4, !noalias !3 +; CHECK: NoAlias: store float %1, float* %arrayidx, align 4 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: NoAlias: store float %2, float* %arrayidx.i2, align 4, !noalias !3 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: NoAlias: store float %2, float* %arrayidx.i2, align 4, !noalias !3 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: store float %3, float* %arrayidx.i3, align 4, !noalias !0 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: NoAlias: store float %3, float* %arrayidx.i3, align 4, !noalias !0 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: store float %3, float* %arrayidx.i3, align 4, !noalias !0 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: NoAlias: store float %4, float* %arrayidx.i4, align 4, !noalias !3 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: NoAlias: store float %4, float* %arrayidx.i4, align 4, !noalias !3 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: store float %4, float* %arrayidx.i4, align 4, !noalias !3 <-> store float %2, float* %arrayidx.i2, align 4, !noalias !3 +; CHECK: NoAlias: store float %4, float* %arrayidx.i4, align 4, !noalias !3 <-> store float %3, float* %arrayidx.i3, align 4, !noalias !0 + diff --git a/llvm/test/Analysis/ScopedNoAliasAA/basic.ll b/llvm/test/Analysis/ScopedNoAliasAA/basic.ll new file mode 100644 index 0000000..bae977f --- /dev/null +++ b/llvm/test/Analysis/ScopedNoAliasAA/basic.ll @@ -0,0 +1,26 @@ +; RUN: opt < %s -basicaa -scoped-noalias -aa-eval -evaluate-aa-metadata -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @foo1(float* nocapture %a, float* nocapture readonly %c) #0 { +entry: +; CHECK-LABEL: Function: foo1 + %0 = load float* %c, align 4, !alias.scope !0 + %arrayidx.i = getelementptr inbounds float* %a, i64 5 + store float %0, float* %arrayidx.i, align 4, !noalias !0 + %1 = load float* %c, align 4 + %arrayidx = getelementptr inbounds float* %a, i64 7 + store float %1, float* %arrayidx, align 4 + ret void + +; CHECK: NoAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %1, float* %arrayidx, align 4 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: store float %1, float* %arrayidx, align 4 <-> store float %0, float* %arrayidx.i, align 4, !noalias !0 +} + +attributes #0 = { nounwind uwtable } + +!0 = metadata !{metadata !0} + diff --git a/llvm/test/Analysis/ScopedNoAliasAA/basic2.ll b/llvm/test/Analysis/ScopedNoAliasAA/basic2.ll new file mode 100644 index 0000000..44393bb --- /dev/null +++ b/llvm/test/Analysis/ScopedNoAliasAA/basic2.ll @@ -0,0 +1,34 @@ +; RUN: opt < %s -basicaa -scoped-noalias -aa-eval -evaluate-aa-metadata -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @foo2(float* nocapture %a, float* nocapture %b, float* nocapture readonly %c) #0 { +entry: +; CHECK-LABEL: Function: foo2 + %0 = load float* %c, align 4, !alias.scope !0 + %arrayidx.i = getelementptr inbounds float* %a, i64 5 + store float %0, float* %arrayidx.i, align 4, !alias.scope !2, !noalias !1 + %arrayidx1.i = getelementptr inbounds float* %b, i64 8 + store float %0, float* %arrayidx1.i, align 4, !alias.scope !1, !noalias !2 + %1 = load float* %c, align 4 + %arrayidx = getelementptr inbounds float* %a, i64 7 + store float %1, float* %arrayidx, align 4 + ret void + +; CHECK: NoAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %0, float* %arrayidx.i, align 4, !alias.scope !2, !noalias !1 +; CHECK: NoAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %0, float* %arrayidx1.i, align 4, !alias.scope !1, !noalias !2 +; CHECK: MayAlias: %0 = load float* %c, align 4, !alias.scope !0 <-> store float %1, float* %arrayidx, align 4 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %0, float* %arrayidx.i, align 4, !alias.scope !2, !noalias !1 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %0, float* %arrayidx1.i, align 4, !alias.scope !1, !noalias !2 +; CHECK: MayAlias: %1 = load float* %c, align 4 <-> store float %1, float* %arrayidx, align 4 +; CHECK: NoAlias: store float %0, float* %arrayidx1.i, align 4, !alias.scope !1, !noalias !2 <-> store float %0, float* %arrayidx.i, align 4, !alias.scope !2, !noalias !1 +; CHECK: NoAlias: store float %1, float* %arrayidx, align 4 <-> store float %0, float* %arrayidx.i, align 4, !alias.scope !2, !noalias !1 +; CHECK: MayAlias: store float %1, float* %arrayidx, align 4 <-> store float %0, float* %arrayidx1.i, align 4, !alias.scope !1, !noalias !2 +} + +attributes #0 = { nounwind uwtable } + +!0 = metadata !{metadata !1, metadata !2} +!1 = metadata !{metadata !1} +!2 = metadata !{metadata !2} + diff --git a/llvm/test/Transforms/GVN/noalias.ll b/llvm/test/Transforms/GVN/noalias.ll new file mode 100644 index 0000000..a774f38 --- /dev/null +++ b/llvm/test/Transforms/GVN/noalias.ll @@ -0,0 +1,43 @@ +; RUN: opt -scoped-noalias -basicaa -gvn -S < %s | FileCheck %s + +define i32 @test1(i32* %p, i32* %q) { +; CHECK-LABEL: @test1(i32* %p, i32* %q) +; CHECK: load i32* %p +; CHECK-NOT: noalias +; CHECK: %c = add i32 %a, %a + %a = load i32* %p, !noalias !0 + %b = load i32* %p + %c = add i32 %a, %b + ret i32 %c +} + +define i32 @test2(i32* %p, i32* %q) { +; CHECK-LABEL: @test2(i32* %p, i32* %q) +; CHECK: load i32* %p, !alias.scope !0 +; CHECK: %c = add i32 %a, %a + %a = load i32* %p, !alias.scope !0 + %b = load i32* %p, !alias.scope !0 + %c = add i32 %a, %b + ret i32 %c +} + +; FIXME: In this case we can do better than intersecting the scopes, and can +; concatenate them instead. Both loads are in the same basic block, the first +; makes the second safe to speculatively execute, and there are no calls that may +; throw in between. +define i32 @test3(i32* %p, i32* %q) { +; CHECK-LABEL: @test3(i32* %p, i32* %q) +; CHECK: load i32* %p, !alias.scope !1 +; CHECK: %c = add i32 %a, %a + %a = load i32* %p, !alias.scope !1 + %b = load i32* %p, !alias.scope !2 + %c = add i32 %a, %b + ret i32 %c +} + +declare i32 @foo(i32*) readonly + +!0 = metadata !{metadata !0} +!1 = metadata !{metadata !1} +!2 = metadata !{metadata !0, metadata !1} +