[AST] NFC: Tail allocate TupleShuffleExpr data

Author: davezarzycki

include/swift/AST/Expr.h

@@ -287,8 +287,17 @@ class alignas(8) Expr {
 
   SWIFT_INLINE_BITFIELD_EMPTY(ImplicitConversionExpr, Expr);
 
-  SWIFT_INLINE_BITFIELD(TupleShuffleExpr, ImplicitConversionExpr, 2,
-    TypeImpact : 2
+  SWIFT_INLINE_BITFIELD_FULL(TupleShuffleExpr, ImplicitConversionExpr, 2+16+16+16,
+    TypeImpact : 2,
+    : NumPadBits,
+    NumCallerDefaultArgs : 16,
+    /// This contains an entry for each element in the Expr type.  Each element
+    /// specifies which index from the SubExpr that the destination element gets.
+    /// If the element value is DefaultInitialize, then the destination value
+    /// gets the default initializer for that tuple element value.
+    NumElementMappings : 16,
+    /// The arguments that are packed into the variadic element.
+    NumVariadicArgs : 16
   );
 
   SWIFT_INLINE_BITFIELD(InOutToPointerExpr, ImplicitConversionExpr, 1,
@@ -2842,7 +2851,20 @@ class UnevaluatedInstanceExpr : public ImplicitConversionExpr {
 /// If hasScalarSource() is true, the subexpression should be treated
 /// as if it were implicitly injected into a single-element tuple
 /// type.  Otherwise, the subexpression is known to have a tuple type.
-class TupleShuffleExpr : public ImplicitConversionExpr {
+class TupleShuffleExpr final : public ImplicitConversionExpr,
+    private llvm::TrailingObjects<TupleShuffleExpr, Expr *, int, unsigned> {
+  friend TrailingObjects;
+
+  size_t numTrailingObjects(OverloadToken<Expr *>) const {
+    return Bits.TupleShuffleExpr.NumCallerDefaultArgs;
+  }
+  size_t numTrailingObjects(OverloadToken<int>) const {
+    return Bits.TupleShuffleExpr.NumElementMappings;
+  }
+  size_t numTrailingObjects(OverloadToken<unsigned>) const {
+    return Bits.TupleShuffleExpr.NumVariadicArgs;
+  }
+
 public:
   enum : int {
     /// The element mapping value indicating that a field of the destination
@@ -2877,41 +2899,48 @@ class TupleShuffleExpr : public ImplicitConversionExpr {
   };
 
 private:
-  /// This contains an entry for each element in the Expr type.  Each element
-  /// specifies which index from the SubExpr that the destination element gets.
-  /// If the element value is DefaultInitialize, then the destination value
-  /// gets the default initializer for that tuple element value.
-  ArrayRef<int> ElementMapping;
-
   /// If we're doing a varargs shuffle, this is the array type to build.
   Type VarargsArrayTy;
 
   /// If there are any default arguments, the owning function
   /// declaration.
   ConcreteDeclRef DefaultArgsOwner;
 
-  /// The arguments that are packed into the variadic element.
-  ArrayRef<unsigned> VariadicArgs;
-
-  MutableArrayRef<Expr *> CallerDefaultArgs;
-
-public:
-  TupleShuffleExpr(Expr *subExpr, ArrayRef<int> elementMapping, 
+  TupleShuffleExpr(Expr *subExpr, ArrayRef<int> elementMapping,
                    TypeImpact typeImpact,
                    ConcreteDeclRef defaultArgsOwner,
                    ArrayRef<unsigned> VariadicArgs,
                    Type VarargsArrayTy,
-                   MutableArrayRef<Expr *> CallerDefaultArgs,
+                   ArrayRef<Expr *> CallerDefaultArgs,
                    Type ty)
     : ImplicitConversionExpr(ExprKind::TupleShuffle, subExpr, ty),
-      ElementMapping(elementMapping), VarargsArrayTy(VarargsArrayTy),
-      DefaultArgsOwner(defaultArgsOwner), VariadicArgs(VariadicArgs),
-      CallerDefaultArgs(CallerDefaultArgs)
-  {
+      VarargsArrayTy(VarargsArrayTy), DefaultArgsOwner(defaultArgsOwner) {
     Bits.TupleShuffleExpr.TypeImpact = typeImpact;
+    Bits.TupleShuffleExpr.NumCallerDefaultArgs = CallerDefaultArgs.size();
+    Bits.TupleShuffleExpr.NumElementMappings = elementMapping.size();
+    Bits.TupleShuffleExpr.NumVariadicArgs = VariadicArgs.size();
+    std::uninitialized_copy(CallerDefaultArgs.begin(), CallerDefaultArgs.end(),
+                            getTrailingObjects<Expr*>());
+    std::uninitialized_copy(elementMapping.begin(), elementMapping.end(),
+                            getTrailingObjects<int>());
+    std::uninitialized_copy(VariadicArgs.begin(), VariadicArgs.end(),
+                            getTrailingObjects<unsigned>());
   }
 
-  ArrayRef<int> getElementMapping() const { return ElementMapping; }
+public:
+  static TupleShuffleExpr *create(ASTContext &ctx, Expr *subExpr,
+                                  ArrayRef<int> elementMapping,
+                                  TypeImpact typeImpact,
+                                  ConcreteDeclRef defaultArgsOwner,
+                                  ArrayRef<unsigned> VariadicArgs,
+                                  Type VarargsArrayTy,
+                                  ArrayRef<Expr *> CallerDefaultArgs,
+                                  Type ty);
+
+  ArrayRef<int> getElementMapping() const {
+    return {getTrailingObjects<int>(),
+            Bits.TupleShuffleExpr.NumElementMappings};
+  }
 
   /// What is the type impact of this shuffle?
   TypeImpact getTypeImpact() const {
@@ -2935,16 +2964,25 @@ class TupleShuffleExpr : public ImplicitConversionExpr {
   }
 
   /// Retrieve the argument indices for the variadic arguments.
-  ArrayRef<unsigned> getVariadicArgs() const { return VariadicArgs; }
+  ArrayRef<unsigned> getVariadicArgs() const {
+    return {getTrailingObjects<unsigned>(),
+            Bits.TupleShuffleExpr.NumVariadicArgs};
+  }
 
   /// Retrieve the owner of the default arguments.
   ConcreteDeclRef getDefaultArgsOwner() const { return DefaultArgsOwner; }
 
   /// Retrieve the caller-defaulted arguments.
-  ArrayRef<Expr *> getCallerDefaultArgs() const { return CallerDefaultArgs; }
+  ArrayRef<Expr *> getCallerDefaultArgs() const {
+    return {getTrailingObjects<Expr*>(),
+            Bits.TupleShuffleExpr.NumCallerDefaultArgs};
+  }
 
   /// Retrieve the caller-defaulted arguments.
-  MutableArrayRef<Expr *> getCallerDefaultArgs() { return CallerDefaultArgs; }
+  MutableArrayRef<Expr *> getCallerDefaultArgs() {
+    return {getTrailingObjects<Expr*>(),
+            Bits.TupleShuffleExpr.NumCallerDefaultArgs};
+  }
 
   static bool classof(const Expr *E) {
     return E->getKind() == ExprKind::TupleShuffle;

lib/AST/Expr.cpp

@@ -1395,6 +1395,24 @@ CaptureListExpr *CaptureListExpr::create(ASTContext &ctx,
   return ::new(mem) CaptureListExpr(captureList, closureBody);
 }
 
+TupleShuffleExpr *TupleShuffleExpr::create(ASTContext &ctx,
+                                           Expr *subExpr,
+                                           ArrayRef<int> elementMapping,
+                                           TypeImpact typeImpact,
+                                           ConcreteDeclRef defaultArgsOwner,
+                                           ArrayRef<unsigned> VariadicArgs,
+                                           Type VarargsArrayTy,
+                                           ArrayRef<Expr *> CallerDefaultArgs,
+                                           Type ty) {
+  auto size = totalSizeToAlloc<Expr*, int, unsigned>(CallerDefaultArgs.size(),
+                                                     elementMapping.size(),
+                                                     VariadicArgs.size());
+  auto mem = ctx.Allocate(size, alignof(TupleShuffleExpr));
+  return ::new(mem) TupleShuffleExpr(subExpr, elementMapping, typeImpact,
+                                     defaultArgsOwner, VariadicArgs,
+                                     VarargsArrayTy, CallerDefaultArgs, ty);
+}
+
 SourceRange TupleExpr::getSourceRange() const {
   SourceLoc start = SourceLoc();
   SourceLoc end = SourceLoc();

lib/Sema/CSApply.cpp

@@ -4975,16 +4975,14 @@ Expr *ExprRewriter::coerceTupleToTuple(Expr *expr, TupleType *fromTuple,
   }
 
   // Create the tuple shuffle.
-  ArrayRef<int> mapping = tc.Context.AllocateCopy(sources);
-  auto callerDefaultArgsCopy = tc.Context.AllocateCopy(callerDefaultArgs);
   return
-    cs.cacheType(new (tc.Context) TupleShuffleExpr(
-                     expr, mapping,
+    cs.cacheType(TupleShuffleExpr::create(tc.Context,
+                     expr, sources,
                      TupleShuffleExpr::TupleToTuple,
                      callee,
-                     tc.Context.AllocateCopy(variadicArgs),
+                     variadicArgs,
                      arrayType,
-                     callerDefaultArgsCopy,
+                     callerDefaultArgs,
                      toSugarType));
 }
 
@@ -5073,13 +5071,13 @@ Expr *ExprRewriter::coerceScalarToTuple(Expr *expr, TupleType *toTuple,
   Type destSugarTy = hasInit? toTuple
                             : TupleType::get(sugarFields, tc.Context);
 
-  return cs.cacheType(new (tc.Context) TupleShuffleExpr(expr,
-                                        tc.Context.AllocateCopy(elements),
+  return cs.cacheType(TupleShuffleExpr::create(tc.Context, expr,
+                                        elements,
                                         TupleShuffleExpr::ScalarToTuple,
                                         callee,
-                                        tc.Context.AllocateCopy(variadicArgs),
+                                        variadicArgs,
                                         arrayType,
-                                     tc.Context.AllocateCopy(callerDefaultArgs),
+                                        callerDefaultArgs,
                                         destSugarTy));
 }
 
@@ -5704,17 +5702,10 @@ Expr *ExprRewriter::coerceCallArguments(
   }
 
   // Create the tuple shuffle.
-  ArrayRef<int> mapping = tc.Context.AllocateCopy(sources);
-  auto callerDefaultArgsCopy = tc.Context.AllocateCopy(callerDefaultArgs);
-  return
-    cs.cacheType(new (tc.Context) TupleShuffleExpr(
-                     arg, mapping,
-                     typeImpact,
-                     callee,
-                     tc.Context.AllocateCopy(variadicArgs),
-                     sliceType,
-                     callerDefaultArgsCopy,
-                     paramType));
+  return cs.cacheType(TupleShuffleExpr::create(tc.Context, arg, sources,
+                                               typeImpact, callee, variadicArgs,
+                                               sliceType, callerDefaultArgs,
+                                               paramType));
 }
 
 static ClosureExpr *getClosureLiteralExpr(Expr *expr) {