From 3cb4869ed5ac220651bd9ca85179fccfdca4b4de Mon Sep 17 00:00:00 2001
From: Konstantin Nazarov <mail@knazarov.com>
Date: Sat, 10 Aug 2024 21:47:07 +0100
Subject: [PATCH] First proper code generation for addition

---
 src/common.hpp   |  6 +++---
 src/compiler.cpp | 42 +++++++++++++++++++++++++++++-------------
 src/compiler.hpp | 15 ++++++++++++++-
 src/writer.cpp   |  4 +++-
 4 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/src/common.hpp b/src/common.hpp
index 092be5a..ed3500a 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -156,10 +156,10 @@ class Array : public Object {
     auto pod = TRY(arena_alloc<PodArray>(res_size * sizeof(PodObject*)));
     pod->size = res_size;
     for (uint64_t i = 0; i < size(); i++) {
-      pod->data[i] = _value->data[i];
+      pod->data[i] = _value->data[i].get();
     }
-    for (uint64_t i = size(); i < rhs.size(); i++) {
-      pod->data[i] = rhs._value->data[i];
+    for (uint64_t i = 0; i < rhs.size(); i++) {
+      pod->data[lhs_size + i] = rhs._value->data[i].get();
     }
 
     return Array(TRY(MkGcRoot(pod)));
diff --git a/src/compiler.cpp b/src/compiler.cpp
index 9abc77a..84f3259 100644
--- a/src/compiler.cpp
+++ b/src/compiler.cpp
@@ -1,5 +1,7 @@
 #include "compiler.hpp"
 
+#include "common.hpp"
+
 struct Context {
   Context() {}
   Context(Value&& env, Array&& constants, Dict&& constants_dict)
@@ -45,11 +47,11 @@ struct Context {
   uint64_t maxreg;
 };
 
-Result<Array> add_opcode(Array& opcodes, Oc opcode, OpArg arg1 = {0, 0},
-                         OpArg arg2 = {0, 0}, OpArg arg3 = {0, 0},
-                         OpArg arg4 = {0, 0}) {
+Result<void> Expression::add_opcode(Oc opcode, OpArg arg1, OpArg arg2,
+                                    OpArg arg3, OpArg arg4) {
   Value oc = Value(TRY(Opcode::create(opcode, arg1, arg2, arg3, arg4)));
-  return opcodes.append(oc);
+  code = TRY(code.append(oc));
+  return Result<void>();
 }
 
 Result<bool> is_primitive_op(Symbol& sym) {
@@ -61,7 +63,12 @@ Result<bool> is_primitive_op(Symbol& sym) {
 Result<Value> Compiler::compile(Value& expr) {
   auto context = TRY(Context::create());
 
-  TRY(compile_expr(context, expr));
+  auto ex = TRY(compile_expr(context, expr));
+
+  Value constants = TRY(context.constants.copy());
+  Value code = TRY(ex.code.copy());
+  TRY(debug_print(constants));
+  TRY(debug_print(code));
   return ERROR(NotImplemented);
 }
 
@@ -89,12 +96,12 @@ Result<Expression> Compiler::compile_expr(Context& context, Value& expr) {
 Result<Expression> Compiler::compile_primop(Context& context, Symbol& op,
                                             Pair& expr) {
   Value cur = TRY(expr.rest());
-  Array code = TRY(Array::create());
+  Expression ex = TRY(Expression::create());
 
   uint64_t reg = context.alloc_reg();
   int64_t zero = TRY(context.add_const(TRY(Value::create((int64_t)0))));
-  std::cout << "load-immediate r" << reg << ", " << 0 << "\n";
-  code = TRY(add_opcode(code, Oc::LoadImmediate, {0, (int64_t)reg}, {0, 0}));
+  std::cout << "mov r" << reg << ", c" << zero << "\n";
+  TRY(ex.add_opcode(Oc::Mov, {0, (int64_t)reg}, {1, zero}));
 
   while (!cur.is<Nil>()) {
     Pair& pair = *cur.to<Pair>();
@@ -102,15 +109,19 @@ Result<Expression> Compiler::compile_primop(Context& context, Symbol& op,
 
     auto comp = TRY(compile_expr(context, subexpr));
 
+    ex.add_code(comp.code);
+
     uint64_t res = context.alloc_reg();
     std::cout << "add r" << res << ", r" << reg << ", r" << comp.reg << "\n";
+    TRY(ex.add_opcode(Oc::Add, {0, (int64_t)res}, {0, (int64_t)reg},
+                      {0, (int64_t)comp.reg}));
 
     reg = res;
     cur = TRY(pair.rest());
   }
 
-  Expression ex = Expression(reg, TRY(Array::create()));
-  return ex;
+  ex.reg = reg;
+  return std::move(ex);
 }
 
 Result<Expression> Compiler::compile_list(Context& context, Pair& expr) {
@@ -126,9 +137,14 @@ Result<Expression> Compiler::compile_list(Context& context, Pair& expr) {
 }
 
 Result<Expression> Compiler::compile_int64(Context& context, Int64& value) {
+  Expression ex = TRY(Expression::create());
   uint64_t reg = context.alloc_reg();
-  std::cout << "loadc r" << reg << ", " << value.value() << "\n";
 
-  Expression expr = Expression(reg, TRY(Array::create()));
-  return expr;
+  int64_t c = TRY(context.add_const(TRY(value.copy())));
+
+  std::cout << "loadc r" << reg << ", " << value.value() << "\n";
+  TRY(ex.add_opcode(Oc::Mov, {0, (int64_t)reg}, {1, (int64_t)c}));
+
+  ex.reg = reg;
+  return std::move(ex);
 }
diff --git a/src/compiler.hpp b/src/compiler.hpp
index ef85def..4ba20f3 100644
--- a/src/compiler.hpp
+++ b/src/compiler.hpp
@@ -6,7 +6,20 @@ struct Context;
 
 struct Expression {
   Expression() {}
-  Expression(uint64_t reg, Array&& code) : reg(reg), code(std::move(code)) {}
+  Expression(Array&& code) : reg(0), code(std::move(code)) {}
+
+  static Result<Expression> create() {
+    Array c = TRY(Array::create());
+
+    return Expression(std::move(c));
+  }
+  Result<void> add_opcode(Oc opcode, OpArg arg1 = {0, 0}, OpArg arg2 = {0, 0},
+                          OpArg arg3 = {0, 0}, OpArg arg4 = {0, 0});
+
+  Result<void> add_code(Array& c) {
+    code = TRY(code.concat(c));
+    return Result<void>();
+  }
   uint64_t reg;
   Array code;
 };
diff --git a/src/writer.cpp b/src/writer.cpp
index 2521dcd..86238b9 100644
--- a/src/writer.cpp
+++ b/src/writer.cpp
@@ -215,7 +215,9 @@ Result<String> Writer::write_dict(Dict& val) {
 }
 
 Result<String> Writer::write_opcode(Opcode& val) {
-  return ERROR(NotImplemented);
+  String res = TRY(String::create("#<opcode>"));
+
+  return res;
 }
 
 Result<String> write_one(Value& value) {