From 6dd904346e58a8a97fe670aae499c1e8ef9fd31b Mon Sep 17 00:00:00 2001
From: Krzosa Karol <krzosa.karol@gmail.com>
Date: Fri, 24 Jun 2022 21:56:21 +0200
Subject: [PATCH] Trying to do some ir stuff

---
 bytecode_codegen.cpp | 194 +++++++++++++++++++++++++++++++++++++++++++
 main.cpp             |   3 +-
 2 files changed, 196 insertions(+), 1 deletion(-)
 create mode 100644 bytecode_codegen.cpp

diff --git a/bytecode_codegen.cpp b/bytecode_codegen.cpp
new file mode 100644
index 0000000..c490c2b
--- /dev/null
+++ b/bytecode_codegen.cpp
@@ -0,0 +1,194 @@
+typedef S32 Register_Index;
+union Register{
+  F64   f64;
+  S64   s64;
+
+  S64  *pointer_s64;
+  F64  *pointer_f64;
+  U8   *pointer;
+  U64  *pointer64;
+
+  U64  *pointer_u64;
+  U32  *pointer_u32;
+  U16  *pointer_u16;
+  U8   *pointer_u8;
+
+  U64   u64;
+  U32   u32;
+  U16   u16;
+  U8    u8;
+
+};
+static_assert(sizeof(Register) == 8, "not 8 bytes");
+
+enum Ir_Storage_Kind{
+  STORAGE_NULL,
+  STORAGE_GLOBAL,
+  STORAGE_CONSTANT,
+  STORAGE_REGISTER,
+  STORAGE_STACK,
+};
+
+struct Ir_Storage{
+  Ast_Type *type;
+  Ir_Storage *next;
+  Ir_Storage_Kind kind;
+  union{ S64 register_index; S64 offset; Register constant; };
+};
+
+enum Ir_Instruction_Kind{
+  IR_NOOP,
+
+  IR_STORE,
+  IR_LOAD,
+
+  IR_ADD,
+  IR_SUB,
+  IR_MUL,
+  IR_DIV,
+};
+
+struct Ir_Instruction{
+  Ir_Instruction_Kind kind;
+  Ir_Storage *a;
+  Ir_Storage *b;
+  Ir_Storage *c;
+};
+
+struct Ir_Block{
+  Simple_Bucket_Array<Ir_Instruction, 64> instructions;
+};
+
+struct Ir_Call;
+struct Ir_Var{
+  Ast_Decl *decl;
+  Ir_Storage storage;
+  Ir_Call *call;
+  Simple_Bucket_Array<Ir_Block, 16> blocks;
+};
+
+struct Ir_Call{
+  Ast_Decl *decl;
+
+  Array<Register_Index> used_registers;
+  Array<Register_Index> free_registers;
+  Register_Index register_ids;
+
+  Ir_Storage return_value;
+  Simple_Bucket_Array<Ir_Var,   4> args;
+  Simple_Bucket_Array<Ir_Block, 8> blocks;
+};
+
+struct Ir_Builder{
+  #define IR_NEW(T) exp_alloc_type(ir->arena, T, AF_ZeroMemory)
+  Arena _arena;
+  Arena *arena;
+
+  Simple_Bucket_Array<Ir_Var,  32> global_variables;
+  Simple_Bucket_Array<Ir_Call, 64> calls;
+};
+
+function Register_Index
+allocate_register(Ir_Call *call){
+  Register_Index result = -1;
+  if(call->free_registers.len > 0){
+    result = call->free_registers.pop();
+  }
+  else{
+    result = call->register_ids++;
+  }
+
+  assert(result != -1);
+  call->used_registers.add(result);
+  return result;
+}
+
+function void
+release_register(Ir_Call *call, Register_Index index){
+  if(index == -1) return;
+
+  B32 found = false;
+  For(call->used_registers){
+    if(index == it){
+      call->used_registers.unordered_remove(&it);
+      found = true;
+      break;
+    }
+  }
+
+  assert_msg(found, "Internal compiler error: releasing register that is not marked as used");
+  call->free_registers.add(index);
+}
+
+function void
+build_bytecode(){
+  Ir_Builder ir_builder = {};
+  arena_init(&ir_builder._arena, "Ir builder arena"_s);
+  ir_builder.arena = &ir_builder._arena;
+
+  Ir_Builder *ir = &ir_builder;
+  For_Named(pctx->ordered_decls, ast){
+    switch(ast->kind){
+      CASE(LAMBDA, Decl){
+        Ir_Call *call = ir->calls.allocate(ir->arena);
+        call->decl = node;
+        // @todo multiple return values
+        call->return_value.type = node->lambda->ret[0]->resolved_type;
+        call->free_registers = array_make<Register_Index>(ir->arena, 32);
+        call->used_registers = array_make<Register_Index>(ir->arena, 32);
+
+        For_It(node->lambda->args){
+          Ir_Var *arg = call->args.allocate(ir->arena);
+          arg->decl = *it.it;
+          arg->call = call;
+          arg->storage.kind = STORAGE_REGISTER;
+          arg->storage.register_index = allocate_register(call);
+        }
+
+        // @todo: Allocate all variables in function
+        //
+        //
+
+        For(node->lambda->scope->stmts){
+          CASE(VAR, Decl){
+
+
+
+            BREAK();
+          }
+        }
+
+        BREAK();
+      }
+
+      CASE(VAR, Decl){
+        if(is_flag_set(node->flags, AST_FOREIGN)){
+          break; // @todo
+        }
+        if(!is_flag_set(node->flags, AST_VAR_IS_CONST)){
+          compiler_error(node->pos, "Global variable has value assigned that is not constant and requires computation");
+        }
+
+        Ir_Var *v = ir->global_variables.allocate(ir->arena);
+        v->decl    = node;
+        v->storage.kind = STORAGE_GLOBAL;
+        v->storage.type = node->type;
+        if(node->type->size <= 8){
+          switch(node->type->kind){
+            CASE_UINT: v->storage.constant.u64 = bigint_as_unsigned(&node->big_int_val); break;
+            CASE_SINT: v->storage.constant.s64 = bigint_as_signed(&node->big_int_val); break;
+            CASE_FLOAT: v->storage.constant.f64 = node->f64_val; break;
+            invalid_default_case;
+          }
+        }
+        else {
+          // Doesn't fit in register
+          invalid_codepath;
+        }
+
+        BREAK();
+      }
+      default: {};
+    }
+  }
+}
\ No newline at end of file
diff --git a/main.cpp b/main.cpp
index 19d2a64..ab3eba1 100644
--- a/main.cpp
+++ b/main.cpp
@@ -171,7 +171,7 @@ want to export all the symbols, we can namespace them optionally.
 #include "c_language_codegen.cpp"
 #include "intermediate_representation.cpp"
 // #include "bytecode_interpreter.cpp"
-// #include "bytecode_codegen.cpp"
+#include "bytecode_codegen.cpp"
 
 
 int main(int argument_count, char **arguments){
@@ -236,6 +236,7 @@ int main(int argument_count, char **arguments){
 
 
   arena_clear(&pctx->stage_arena);
+  build_bytecode();
   // compile_to_bc();
   // __debugbreak();
   String result = get_compilation_result();