From 0991847d4a38552eebe0f56744406d2c7f3854cb Mon Sep 17 00:00:00 2001
From: Andreas Kling <andreas@ladybird.org>
Date: Sun, 6 Apr 2025 22:50:55 +0200
Subject: [PATCH] LibJS: Remove unused `this` value from CallConstruct
 instruction

There's no `this` value prior in the caller context, and this was never
actually used by CallConstruct.
---
 Libraries/LibJS/Bytecode/ASTCodegen.cpp  | 1 -
 Libraries/LibJS/Bytecode/Interpreter.cpp | 7 +++----
 Libraries/LibJS/Bytecode/Op.h            | 6 +-----
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/Libraries/LibJS/Bytecode/ASTCodegen.cpp b/Libraries/LibJS/Bytecode/ASTCodegen.cpp
index 85d9f61f2e2..1f1ef6717fd 100644
--- a/Libraries/LibJS/Bytecode/ASTCodegen.cpp
+++ b/Libraries/LibJS/Bytecode/ASTCodegen.cpp
@@ -1806,7 +1806,6 @@ Bytecode::CodeGenerationErrorOr<Optional<ScopedOperand>> CallExpression::generat
                 argument_operands.size(),
                 dst,
                 callee,
-                this_value,
                 argument_operands,
                 expression_string_index);
         } else if (call_type == Op::CallType::DirectEval) {
diff --git a/Libraries/LibJS/Bytecode/Interpreter.cpp b/Libraries/LibJS/Bytecode/Interpreter.cpp
index 5c2b622106b..d4b48fb04f7 100644
--- a/Libraries/LibJS/Bytecode/Interpreter.cpp
+++ b/Libraries/LibJS/Bytecode/Interpreter.cpp
@@ -2630,7 +2630,7 @@ ThrowCompletionOr<void> CallConstruct::execute_impl(Bytecode::Interpreter& inter
     auto argument_values = interpreter.allocate_argument_values(m_argument_count);
     for (size_t i = 0; i < m_argument_count; ++i)
         argument_values[i] = interpreter.get(m_arguments[i]);
-    interpreter.set(dst(), TRY(perform_call(interpreter, interpreter.get(m_this_value), CallType::Construct, callee, argument_values)));
+    interpreter.set(dst(), TRY(perform_call(interpreter, Value(), CallType::Construct, callee, argument_values)));
     return {};
 }
 
@@ -3424,10 +3424,9 @@ ByteString Call::to_byte_string_impl(Bytecode::Executable const& executable) con
 ByteString CallConstruct::to_byte_string_impl(Bytecode::Executable const& executable) const
 {
     StringBuilder builder;
-    builder.appendff("CallConstruct {}, {}, {}, "sv,
+    builder.appendff("CallConstruct {}, {}, "sv,
         format_operand("dst"sv, m_dst, executable),
-        format_operand("callee"sv, m_callee, executable),
-        format_operand("this"sv, m_this_value, executable));
+        format_operand("callee"sv, m_callee, executable));
 
     builder.append(format_operand_list("args"sv, { m_arguments, m_argument_count }, executable));
 
diff --git a/Libraries/LibJS/Bytecode/Op.h b/Libraries/LibJS/Bytecode/Op.h
index 834a884be93..83bdeeecbf1 100644
--- a/Libraries/LibJS/Bytecode/Op.h
+++ b/Libraries/LibJS/Bytecode/Op.h
@@ -1900,11 +1900,10 @@ class CallConstruct final : public Instruction {
 public:
     static constexpr bool IsVariableLength = true;
 
-    CallConstruct(Operand dst, Operand callee, Operand this_value, ReadonlySpan<ScopedOperand> arguments, Optional<StringTableIndex> expression_string = {})
+    CallConstruct(Operand dst, Operand callee, ReadonlySpan<ScopedOperand> arguments, Optional<StringTableIndex> expression_string = {})
         : Instruction(Type::CallConstruct)
         , m_dst(dst)
         , m_callee(callee)
-        , m_this_value(this_value)
         , m_argument_count(arguments.size())
         , m_expression_string(expression_string)
     {
@@ -1919,7 +1918,6 @@ public:
 
     Operand dst() const { return m_dst; }
     Operand callee() const { return m_callee; }
-    Operand this_value() const { return m_this_value; }
     Optional<StringTableIndex> const& expression_string() const { return m_expression_string; }
 
     u32 argument_count() const { return m_argument_count; }
@@ -1930,7 +1928,6 @@ public:
     {
         visitor(m_dst);
         visitor(m_callee);
-        visitor(m_this_value);
         for (size_t i = 0; i < m_argument_count; i++)
             visitor(m_arguments[i]);
     }
@@ -1938,7 +1935,6 @@ public:
 private:
     Operand m_dst;
     Operand m_callee;
-    Operand m_this_value;
     u32 m_argument_count { 0 };
     Optional<StringTableIndex> m_expression_string;
     Operand m_arguments[];