fix dup instruction result to no longer reference the original memory in WASM (#5784)

 fix dup instruction result to no longer reference the original memory
 added additional dup test cases

2 files changed, 20 insertions, 18 deletions

diff --git a/src/ILCompiler.WebAssembly/src/CodeGen/EvaluationStack.cs b/src/ILCompiler.WebAssembly/src/CodeGen/EvaluationStack.cs
index 92c191976..fb510889a 100644
--- a/src/ILCompiler.WebAssembly/src/CodeGen/EvaluationStack.cs
+++ b/src/ILCompiler.WebAssembly/src/CodeGen/EvaluationStack.cs
@@ -239,7 +239,7 @@ namespace Internal.IL
         /// Create a new copy of current entry.
         /// </summary>
         /// <returns>A new instance of the same type as the current entry.</returns>
-        public abstract StackEntry Duplicate();
+        public abstract StackEntry Duplicate(LLVMBuilderRef builder);
     }
 
     /// <summary>
@@ -298,7 +298,7 @@ namespace Internal.IL
             }
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new Int32ConstantEntry(Value, Type);
         }
@@ -333,7 +333,7 @@ namespace Internal.IL
         {
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new Int64ConstantEntry(Value, Type);
         }
@@ -397,7 +397,7 @@ namespace Internal.IL
             return LLVM.ConstReal(type, Value);
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new FloatConstantEntry(Value, Type);
         }
@@ -425,7 +425,7 @@ namespace Internal.IL
             RawLLVMValue = llvmValue;
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new ExpressionEntry(Kind, Name, RawLLVMValue, Type);
         }
@@ -449,9 +449,9 @@ namespace Internal.IL
         {
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
-            return new LoadExpressionEntry(Kind, Name, RawLLVMValue, Type);
+            return new ExpressionEntry(Kind, "duplicate_" + Name, ILImporter.LoadValue(builder, RawLLVMValue, Type, ILImporter.GetLLVMTypeForTypeDesc(Type), false, "load_duplicate_" + Name), Type);
         }
 
         protected override LLVMValueRef ValueAsTypeInternal(LLVMTypeRef type, LLVMBuilderRef builder, bool signExtend)
@@ -472,9 +472,9 @@ namespace Internal.IL
         {
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
-            return new LoadExpressionEntry(Kind, Name, RawLLVMValue, Type);
+            return new AddressExpressionEntry(Kind, Name, RawLLVMValue, Type);
         }
 
         protected override LLVMValueRef ValueAsTypeInternal(LLVMTypeRef type, LLVMBuilderRef builder, bool signExtend)
@@ -501,7 +501,7 @@ namespace Internal.IL
             IsVirtual = isVirtual;
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new FunctionPointerEntry(Name, Method, RawLLVMValue, Type, IsVirtual);
         }
@@ -519,7 +519,7 @@ namespace Internal.IL
             LdToken = token;
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new LdTokenEntry<T>(Kind, Name, LdToken, RawLLVMValue, Type);
         }
@@ -544,7 +544,7 @@ namespace Internal.IL
         {
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return this;
         }
@@ -576,7 +576,7 @@ namespace Internal.IL
             return ILImporter.CastIfNecessary(builder, value, type);
         }
 
-        public override StackEntry Duplicate()
+        public override StackEntry Duplicate(LLVMBuilderRef builder)
         {
             return new SpilledExpressionEntry(Kind, Name, Type, LocalIndex, _importer);
         }
diff --git a/src/ILCompiler.WebAssembly/src/CodeGen/ILToWebAssemblyImporter.cs b/src/ILCompiler.WebAssembly/src/CodeGen/ILToWebAssemblyImporter.cs
index d96ff3123..53d9d9e75 100644
--- a/src/ILCompiler.WebAssembly/src/CodeGen/ILToWebAssemblyImporter.cs
+++ b/src/ILCompiler.WebAssembly/src/CodeGen/ILToWebAssemblyImporter.cs
@@ -295,7 +295,7 @@ namespace Internal.IL
                 int n = entryStack.Length;
                 for (int i = 0; i < n; i++)
                 {
-                    _stack.Push(entryStack[i].Duplicate());
+                    _stack.Push(entryStack[i].Duplicate(_builder));
                 }
             }
 
@@ -365,19 +365,19 @@ namespace Internal.IL
             LLVM.BuildStore(_builder, CastToTypeDesc(value, type), CastToPointerToTypeDesc(address, type));
         }
 
-        internal static LLVMValueRef LoadValue(LLVMBuilderRef builder, LLVMValueRef address, TypeDesc sourceType, LLVMTypeRef targetType, bool signExtend)
+        internal static LLVMValueRef LoadValue(LLVMBuilderRef builder, LLVMValueRef address, TypeDesc sourceType, LLVMTypeRef targetType, bool signExtend, string loadName = null)
         {
             var underlyingSourceType = sourceType.UnderlyingType;
             if (targetType.TypeKind == LLVMTypeKind.LLVMIntegerTypeKind && underlyingSourceType.IsPrimitive && !underlyingSourceType.IsPointer)
             {
                 var sourceLLVMType = ILImporter.GetLLVMTypeForTypeDesc(underlyingSourceType);
                 var typedAddress = CastIfNecessary(builder, address, LLVM.PointerType(sourceLLVMType, 0));
-                return CastIntValue(builder, LLVM.BuildLoad(builder, typedAddress, "ldvalue"), targetType, signExtend);
+                return CastIntValue(builder, LLVM.BuildLoad(builder, typedAddress, loadName ?? "ldvalue"), targetType, signExtend);
             }
             else
             {
                 var typedAddress = CastIfNecessary(builder, address, LLVM.PointerType(targetType, 0));
-                return LLVM.BuildLoad(builder, typedAddress, "ldvalue");
+                return LLVM.BuildLoad(builder, typedAddress, loadName ?? "ldvalue");
             }
         }
 
@@ -836,7 +836,9 @@ namespace Internal.IL
 
         private void ImportDup()
         {
-            _stack.Push(_stack.Peek().Duplicate());
+            var entry = _stack.Pop();
+            _stack.Push(entry.Duplicate(_builder));
+            _stack.Push(entry.Duplicate(_builder));
         }
 
         private void ImportPop()