...

compiler/NubLang/Generation/QBE/QBEGenerator.cs

@@ -273,15 +273,6 @@ public class QBEGenerator
         _writer.Indented($"call $.memcpy(l {source}, l {destination}, l {length})");
     }
 
-    private string EmitArraySizeInBytes(ArrayTypeNode type, string array)
-    {
-        var size = TmpName();
-        _writer.Indented($"{size} =l call $.array_size(l {array})");
-        _writer.Indented($"{size} =l mul {size}, {SizeOf(type.ElementType)}");
-        _writer.Indented($"{size} =l add {size}, 8");
-        return size;
-    }
-
     private string EmitCStringSizeInBytes(string cstring)
     {
         var result = TmpName();
@@ -299,25 +290,31 @@ public class QBEGenerator
     }
 
     // todo(nub31): EmitRValue should take a destination parameter so we can skip copying rvalues
-    private void EmitCopyInto(ExpressionNode source, string destination)
+    private void EmitCopyInto(ExpressionNode source, string destinationAddress, bool tryMove = true)
     {
+        if (tryMove && source is RValueExpressionNode rValue)
+        {
+            EmitRValueInto(rValue, destinationAddress);
+            return;
+        }
+
         if (source.Type.IsScalar)
         {
-            EmitStore(source.Type, EmitExpression(source), destination);
+            EmitStore(source.Type, EmitExpression(source), destinationAddress);
             return;
         }
 
         if (source.Type.IsValueType)
         {
             var value = EmitExpression(source);
-            _writer.Indented($"blit {value}, {destination}, {SizeOf(source.Type)}");
+            _writer.Indented($"blit {value}, {destinationAddress}, {SizeOf(source.Type)}");
 
             if (source.Type is StructTypeNode structType)
             {
                 var copyFunc = structType.Functions.FirstOrDefault(x => x.Hook == "oncopy");
                 if (copyFunc != null)
                 {
-                    _writer.Indented($"call {StructFuncName(structType.Module, structType.Name, copyFunc.Name)}(l {destination})");
+                    _writer.Indented($"call {StructFuncName(structType.Module, structType.Name, copyFunc.Name)}(l {destinationAddress})");
                 }
             }
 
@@ -326,16 +323,6 @@ public class QBEGenerator
 
         switch (source.Type)
         {
-            case ArrayTypeNode arrayType:
-            {
-                var value = EmitExpression(source);
-                var size = EmitArraySizeInBytes(arrayType, value);
-                var buffer = TmpName();
-                _writer.Indented($"{buffer} =l alloc8 {size}");
-                EmitMemcpy(value, buffer, size);
-                EmitStore(arrayType, buffer, destination);
-                return;
-            }
             case CStringTypeNode:
             {
                 var value = EmitExpression(source);
@@ -343,7 +330,7 @@ public class QBEGenerator
                 var buffer = TmpName();
                 _writer.Indented($"{buffer} =l alloc8 {size}");
                 EmitMemcpy(value, buffer, size);
-                EmitStore(source.Type, buffer, destination);
+                EmitStore(source.Type, buffer, destinationAddress);
                 return;
             }
             case StringTypeNode:
@@ -353,7 +340,7 @@ public class QBEGenerator
                 var buffer = TmpName();
                 _writer.Indented($"{buffer} =l alloc8 {size}");
                 EmitMemcpy(value, buffer, size);
-                EmitStore(source.Type, buffer, destination);
+                EmitStore(source.Type, buffer, destinationAddress);
                 return;
             }
             case VoidTypeNode:
@@ -707,6 +694,43 @@ public class QBEGenerator
         };
     }
 
+    private void EmitRValueInto(RValueExpressionNode rValue, string destinationAddress)
+    {
+        if (rValue.Type.IsScalar)
+        {
+            EmitStore(rValue.Type, EmitRValue(rValue), destinationAddress);
+            return;
+        }
+
+        switch (rValue)
+        {
+            case StructInitializerNode expr:
+            {
+                EmitStructInitializer(expr, destinationAddress);
+                return;
+            }
+            case StringLiteralNode expr:
+            {
+                // String literals are read only, so safe to use without copy
+                EmitStore(expr.Type, EmitStringLiteral(expr), destinationAddress);
+                return;
+            }
+            case CStringLiteralNode expr:
+            {
+                // String literals are read only, so safe to use without copy
+                EmitStore(expr.Type, EmitCStringLiteral(expr), destinationAddress);
+                return;
+            }
+            default:
+            {
+                // If no special case is provided, fall back to copying
+                Console.WriteLine($"No fast initialization for {rValue.GetType().Name}. Using copy fallback");
+                EmitCopyInto(rValue, destinationAddress, false);
+                break;
+            }
+        }
+    }
+
     private string EmitLValue(LValueExpressionNode lValue)
     {
         var address = EmitAddressOf(lValue);
@@ -963,25 +987,29 @@ public class QBEGenerator
 
     private string EmitStructInitializer(StructInitializerNode structInitializer)
     {
-        var destination = TmpName();
+        var destinationAddress = TmpName();
         var size = SizeOf(structInitializer.StructType);
-        _writer.Indented($"{destination} =l alloc8 {size}");
+        _writer.Indented($"{destinationAddress} =l alloc8 {size}");
-        _writer.Indented($"call {StructCtorName(structInitializer.StructType.Module, structInitializer.StructType.Name)}(l {destination})");
+        EmitStructInitializer(structInitializer, destinationAddress);
+        return destinationAddress;
+    }
+
+    private void EmitStructInitializer(StructInitializerNode structInitializer, string destinationAddress)
+    {
+        _writer.Indented($"call {StructCtorName(structInitializer.StructType.Module, structInitializer.StructType.Name)}(l {destinationAddress})");
 
         var createFunc = structInitializer.StructType.Functions.FirstOrDefault(x => x.Hook == "oncreate");
         if (createFunc != null)
         {
-            _writer.Indented($"call {StructFuncName(structInitializer.StructType.Module, structInitializer.StructType.Name, createFunc.Name)}(l {destination})");
+            _writer.Indented($"call {StructFuncName(structInitializer.StructType.Module, structInitializer.StructType.Name, createFunc.Name)}(l {destinationAddress})");
         }
 
         foreach (var (field, value) in structInitializer.Initializers)
         {
             var offset = TmpName();
-            _writer.Indented($"{offset} =l add {destination}, {OffsetOf(structInitializer.StructType, field)}");
+            _writer.Indented($"{offset} =l add {destinationAddress}, {OffsetOf(structInitializer.StructType, field)}");
             EmitCopyInto(value, offset);
         }
-
-        return destination;
     }
 
     private string EmitUnaryExpression(UnaryExpressionNode unaryExpression)

compiler/NubLang/TypeChecking/Node/TypeNode.cs

@@ -126,6 +126,18 @@ public class StructTypeFunc(string name, string? hook, FuncTypeNode type)
     public FuncTypeNode Type { get; } = type;
 }
 
+public class ArrayTypeNode(TypeNode elementType) : TypeNode
+{
+    public override bool IsValueType => false;
+    public override bool IsScalar => true;
+
+    public TypeNode ElementType { get; } = elementType;
+
+    public override string ToString() => "[]" + ElementType;
+    public override bool Equals(TypeNode? other) => other is ArrayTypeNode array && ElementType.Equals(array.ElementType);
+    public override int GetHashCode() => HashCode.Combine(typeof(ArrayTypeNode), ElementType);
+}
+
 public class CStringTypeNode : TypeNode
 {
     public override bool IsValueType => false;
@@ -145,15 +157,3 @@ public class StringTypeNode : TypeNode
     public override bool Equals(TypeNode? other) => other is StringTypeNode;
     public override int GetHashCode() => HashCode.Combine(typeof(StringTypeNode));
 }
-
-public class ArrayTypeNode(TypeNode elementType) : TypeNode
-{
-    public override bool IsValueType => false;
-    public override bool IsScalar => false;
-
-    public TypeNode ElementType { get; } = elementType;
-
-    public override string ToString() => "[]" + ElementType;
-    public override bool Equals(TypeNode? other) => other is ArrayTypeNode array && ElementType.Equals(array.ElementType);
-    public override int GetHashCode() => HashCode.Combine(typeof(ArrayTypeNode), ElementType);
-}