[clang][bytecode] Avoid classifying in visitArrayElemInit() (#139674)

We usually call this more than once, but the type of the initializer
never changes. Let's classify only once and pass that to
visitArrayElemInit().

Author: tbaederr

clang/lib/AST/ByteCode/Compiler.cpp

@@ -570,11 +570,11 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *CE) {
         return false;
     }
 
+    PrimType T = classifyPrim(SubExpr->getType());
     // Init the complex value to {SubExpr, 0}.
-    if (!this->visitArrayElemInit(0, SubExpr))
+    if (!this->visitArrayElemInit(0, SubExpr, T))
       return false;
     // Zero-init the second element.
-    PrimType T = classifyPrim(SubExpr->getType());
     if (!this->visitZeroInitializer(T, SubExpr->getType(), SubExpr))
       return false;
     return this->emitInitElem(T, 1, SubExpr);
@@ -772,7 +772,7 @@ bool Compiler<Emitter>::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
     return false;
   if (!this->emitInitElem(SubExprT, 0, SubExpr))
     return false;
-  return this->visitArrayElemInit(1, SubExpr);
+  return this->visitArrayElemInit(1, SubExpr, SubExprT);
 }
 
 template <class Emitter>
@@ -1886,6 +1886,7 @@ bool Compiler<Emitter>::visitInitList(ArrayRef<const Expr *> Inits,
     if (!this->emitCheckArraySize(NumElems, E))
       return false;
 
+    std::optional<PrimType> InitT = classify(CAT->getElementType());
     unsigned ElementIndex = 0;
     for (const Expr *Init : Inits) {
       if (const auto *EmbedS =
@@ -1905,7 +1906,7 @@ bool Compiler<Emitter>::visitInitList(ArrayRef<const Expr *> Inits,
         if (!EmbedS->doForEachDataElement(Eval, ElementIndex))
           return false;
       } else {
-        if (!this->visitArrayElemInit(ElementIndex, Init))
+        if (!this->visitArrayElemInit(ElementIndex, Init, InitT))
           return false;
         ++ElementIndex;
       }
@@ -1915,7 +1916,7 @@ bool Compiler<Emitter>::visitInitList(ArrayRef<const Expr *> Inits,
     // FIXME: This should go away.
     if (ArrayFiller) {
       for (; ElementIndex != NumElems; ++ElementIndex) {
-        if (!this->visitArrayElemInit(ElementIndex, ArrayFiller))
+        if (!this->visitArrayElemInit(ElementIndex, ArrayFiller, InitT))
           return false;
       }
     }
@@ -1998,13 +1999,13 @@ bool Compiler<Emitter>::visitInitList(ArrayRef<const Expr *> Inits,
 /// Pointer to the array(not the element!) must be on the stack when calling
 /// this.
 template <class Emitter>
-bool Compiler<Emitter>::visitArrayElemInit(unsigned ElemIndex,
-                                           const Expr *Init) {
-  if (std::optional<PrimType> T = classify(Init->getType())) {
+bool Compiler<Emitter>::visitArrayElemInit(unsigned ElemIndex, const Expr *Init,
+                                           std::optional<PrimType> InitT) {
+  if (InitT) {
     // Visit the primitive element like normal.
     if (!this->visit(Init))
       return false;
-    return this->emitInitElem(*T, ElemIndex, Init);
+    return this->emitInitElem(*InitT, ElemIndex, Init);
   }
 
   InitLinkScope<Emitter> ILS(this, InitLink::Elem(ElemIndex));
@@ -2298,6 +2299,7 @@ bool Compiler<Emitter>::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
   //   Investigate compiling this to a loop.
   const Expr *SubExpr = E->getSubExpr();
   size_t Size = E->getArraySize().getZExtValue();
+  std::optional<PrimType> SubExprT = classify(SubExpr);
 
   // So, every iteration, we execute an assignment here
   // where the LHS is on the stack (the target array)
@@ -2306,7 +2308,7 @@ bool Compiler<Emitter>::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
     ArrayIndexScope<Emitter> IndexScope(this, I);
     BlockScope<Emitter> BS(this);
 
-    if (!this->visitArrayElemInit(I, SubExpr))
+    if (!this->visitArrayElemInit(I, SubExpr, SubExprT))
       return false;
     if (!BS.destroyLocals())
       return false;

clang/lib/AST/ByteCode/Compiler.h

@@ -302,7 +302,8 @@ class Compiler : public ConstStmtVisitor<Compiler<Emitter>, bool>,
 
   bool visitInitList(ArrayRef<const Expr *> Inits, const Expr *ArrayFiller,
                      const Expr *E);
-  bool visitArrayElemInit(unsigned ElemIndex, const Expr *Init);
+  bool visitArrayElemInit(unsigned ElemIndex, const Expr *Init,
+                          std::optional<PrimType> InitT);
 
   /// Creates a local primitive value.
   unsigned allocateLocalPrimitive(DeclTy &&Decl, PrimType Ty, bool IsConst,