[Clang][RVV][SVE] Cache getScalableVectorType lookups (llvm#160108)

Currently, RVV/SVE intrinsics are cached, but the corresponding type construction is not. As a result, `ASTContext::getScalableVectorType` can become a performance hotspot, since every query must run through a long sequence of type checks and macro expansions.

Author: sunshaoce

clang/include/clang/AST/ASTContext.h

@@ -25,10 +25,12 @@
 #include "clang/AST/RawCommentList.h"
 #include "clang/AST/SYCLKernelInfo.h"
 #include "clang/AST/TemplateName.h"
+#include "clang/AST/TypeOrdering.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
@@ -51,6 +53,36 @@ class FixedPointSemantics;
 struct fltSemantics;
 template <typename T, unsigned N> class SmallPtrSet;
 
+struct ScalableVecTyKey {
+ clang::QualType EltTy;
+ unsigned NumElts;
+ unsigned NumFields;
+
+ bool operator==(const ScalableVecTyKey &RHS) const {
+ return EltTy == RHS.EltTy && NumElts == RHS.NumElts &&
+ NumFields == RHS.NumFields;
+ }
+};
+
+// Provide a DenseMapInfo specialization so that ScalableVecTyKey can be used
+// as a key in DenseMap.
+template <> struct DenseMapInfo<ScalableVecTyKey> {
+ static inline ScalableVecTyKey getEmptyKey() {
+ return {DenseMapInfo<clang::QualType>::getEmptyKey(), ~0U, ~0U};
+ }
+ static inline ScalableVecTyKey getTombstoneKey() {
+ return {DenseMapInfo<clang::QualType>::getTombstoneKey(), ~0U, ~0U};
+ }
+ static unsigned getHashValue(const ScalableVecTyKey &Val) {
+ return hash_combine(DenseMapInfo<clang::QualType>::getHashValue(Val.EltTy),
+ Val.NumElts, Val.NumFields);
+ }
+ static bool isEqual(const ScalableVecTyKey &LHS,
+ const ScalableVecTyKey &RHS) {
+ return LHS == RHS;
+ }
+};
+
 } // namespace llvm
 
 namespace clang {
@@ -505,6 +537,9 @@ class ASTContext : public RefCountedBase<ASTContext> {
  SmallVector<const ObjCInterfaceDecl *, 4>>
  ObjCSubClasses;
 
+ // A mapping from Scalable Vector Type keys to their corresponding QualType.
+ mutable llvm::DenseMap<llvm::ScalableVecTyKey, QualType> ScalableVecTyMap;
+
  ASTContext &this_() { return *this; }
 
 public:

clang/lib/AST/ASTContext.cpp

@@ -4567,6 +4567,10 @@ QualType ASTContext::getWebAssemblyExternrefType() const {
 /// type.
 QualType ASTContext::getScalableVectorType(QualType EltTy, unsigned NumElts,
  unsigned NumFields) const {
+ auto K = llvm::ScalableVecTyKey{EltTy, NumElts, NumFields};
+ if (auto It = ScalableVecTyMap.find(K); It != ScalableVecTyMap.end())
+ return It->second;
+
  if (Target->hasAArch64ACLETypes()) {
  uint64_t EltTySize = getTypeSize(EltTy);
 
@@ -4575,29 +4579,29 @@ QualType ASTContext::getScalableVectorType(QualType EltTy, unsigned NumElts,
  if (EltTy->hasIntegerRepresentation() && !EltTy->isBooleanType() && \
  EltTy->hasSignedIntegerRepresentation() == IsSigned && \
  EltTySize == ElBits && NumElts == (NumEls * NF) && NumFields == 1) { \
- return SingletonId;  \
+ return ScalableVecTyMap[K] = SingletonId; \
  }
 #define SVE_VECTOR_TYPE_FLOAT(Name, MangledName, Id, SingletonId, NumEls, \
  ElBits, NF) \
  if (EltTy->hasFloatingRepresentation() && !EltTy->isBFloat16Type() && \
  EltTySize == ElBits && NumElts == (NumEls * NF) && NumFields == 1) { \
- return SingletonId;  \
+ return ScalableVecTyMap[K] = SingletonId; \
  }
 #define SVE_VECTOR_TYPE_BFLOAT(Name, MangledName, Id, SingletonId, NumEls, \
  ElBits, NF) \
  if (EltTy->hasFloatingRepresentation() && EltTy->isBFloat16Type() && \
  EltTySize == ElBits && NumElts == (NumEls * NF) && NumFields == 1) { \
- return SingletonId;  \
+ return ScalableVecTyMap[K] = SingletonId; \
  }
 #define SVE_VECTOR_TYPE_MFLOAT(Name, MangledName, Id, SingletonId, NumEls, \
  ElBits, NF) \
  if (EltTy->isMFloat8Type() && EltTySize == ElBits && \
  NumElts == (NumEls * NF) && NumFields == 1) { \
- return SingletonId;  \
+ return ScalableVecTyMap[K] = SingletonId; \
  }
 #define SVE_PREDICATE_TYPE_ALL(Name, MangledName, Id, SingletonId, NumEls, NF) \
  if (EltTy->isBooleanType() && NumElts == (NumEls * NF) && NumFields == 1) \
- return SingletonId;
+ return ScalableVecTyMap[K] = SingletonId;
 #include "clang/Basic/AArch64ACLETypes.def"
  } else if (Target->hasRISCVVTypes()) {
  uint64_t EltTySize = getTypeSize(EltTy);
@@ -4611,10 +4615,10 @@ QualType ASTContext::getScalableVectorType(QualType EltTy, unsigned NumElts,
  (EltTy->hasFloatingRepresentation() && EltTy->isBFloat16Type() && \
  IsBF && !IsFP)) && \
  EltTySize == ElBits && NumElts == NumEls && NumFields == NF) \
- return SingletonId;
+ return ScalableVecTyMap[K] = SingletonId;
 #define RVV_PREDICATE_TYPE(Name, Id, SingletonId, NumEls) \
  if (EltTy->isBooleanType() && NumElts == NumEls) \
- return SingletonId;
+ return ScalableVecTyMap[K] = SingletonId;
 #include "clang/Basic/RISCVVTypes.def"
  }
  return QualType();