diff --git a/src/main.cpp b/src/main.cpp
index faf54a4..dbf3909 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -85,40 +85,22 @@ int main( int argc, const char *argv[] )
     llvm::LLVMInitializeX86AsmParser();
     llvm::LLVMInitializeX86AsmPrinter();
 
+    TargetOptions opt;
+    llvm::SmallVector< char, 128 > buff;
+    llvm::raw_svector_ostream dest( buff );
+    legacy::PassManager pass;
+
     auto TargetTriple = sys::getDefaultTargetTriple();
     llvm_module.setTargetTriple( TargetTriple );
 
     std::string Error;
     auto Target = TargetRegistry::lookupTarget( TargetTriple, Error );
 
-    auto CPU = "generic";
-    auto Features = "";
-
-    TargetOptions opt;
-    auto RM = Optional< Reloc::Model >();
-    auto TheTargetMachine = Target->createTargetMachine( TargetTriple, CPU, Features, opt, RM );
-
-    llvm_module.setDataLayout( TheTargetMachine->createDataLayout() );
-
-    auto Filename = "output.o";
-    std::error_code EC;
-    raw_fd_ostream dest( Filename, EC, sys::fs::OF_None );
-
-    if ( EC )
-    {
-        errs() << "Could not open file: " << EC.message();
-        return 1;
-    }
-
-    legacy::PassManager pass;
-    auto FileType = CGFT_ObjectFile;
-
-    if ( TheTargetMachine->addPassesToEmitFile( pass, dest, nullptr, FileType ) )
-    {
-        errs() << "TheTargetMachine can't emit a file of this type";
-        return 1;
-    }
-
+    auto reloc_model = Optional< Reloc::Model >();
+    auto target_machine = Target->createTargetMachine( TargetTriple, "generic", "", opt, reloc_model );
+    llvm_module.setDataLayout( target_machine->createDataLayout() );
+    target_machine->addPassesToEmitFile( pass, dest, nullptr, CGFT_ObjectFile );
     pass.run( llvm_module );
-    dest.flush();
+
+    std::printf( "> obj size = %d\n", buff.size() );
 }
\ No newline at end of file
diff --git a/src/vmp_rtn.cpp b/src/vmp_rtn.cpp
index 874218d..92d6a50 100644
--- a/src/vmp_rtn.cpp
+++ b/src/vmp_rtn.cpp
@@ -54,34 +54,28 @@ namespace vm
     void vmp_rtn_t::push( std::uint8_t num_bytes, llvm::Value *val )
     {
         // sub rsp, num_bytes
-        auto rsp_addr = ir_builder->CreateLoad( stack );
-        auto rsp_i64 = ir_builder->CreatePtrToInt( rsp_addr, ir_builder->getInt64Ty() );
-        auto sub_rsp_val = ir_builder->CreateSub( rsp_i64, ir_builder->getInt64( num_bytes ) );
-        ir_builder->CreateStore(
-            ir_builder->CreateIntToPtr( sub_rsp_val, llvm::PointerType::get( ir_builder->getInt8Ty(), 0ull ) ), stack );
+        auto rsp_addr = ir_builder->CreateLoad( stack, "rsp_addr" );
+        auto sub_rsp_val = ir_builder->CreateGEP( ir_builder->getInt8Ty(), rsp_addr,
+                                                  ir_builder->getInt8( 0 - num_bytes ), "sub_rsp_val" );
+        ir_builder->CreateStore( sub_rsp_val, stack );
 
         // mov [rsp], val
-        rsp_addr = ir_builder->CreateLoad( stack );
-        auto rsp_cast_ptr = ir_builder->CreatePointerCast(
-            rsp_addr, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), false ) );
-        ir_builder->CreateStore( val, rsp_cast_ptr );
+        auto resized_new_rsp_addr = ir_builder->CreateBitCast(
+            sub_rsp_val, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), 0ull ) );
+        ir_builder->CreateStore( val, resized_new_rsp_addr );
     }
 
     llvm::Value *vmp_rtn_t::pop( std::uint8_t num_bytes )
     {
         // mov rax, [rsp]
-        auto rsp_addr = ir_builder->CreateLoad( stack );
-        auto rsp_cast_ptr = ir_builder->CreatePointerCast(
-            rsp_addr, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), false ) );
-        auto pop_val = ir_builder->CreateLoad( rsp_cast_ptr );
-
-        // add rsp, num_bytes
-        auto rsp_i64 = ir_builder->CreatePtrToInt( rsp_addr, ir_builder->getInt64Ty() );
-        auto sub_rsp_val = ir_builder->CreateAdd( rsp_i64, ir_builder->getInt64( num_bytes ) );
-        auto sub_rsp_val_ptr =
-            ir_builder->CreateIntToPtr( sub_rsp_val, llvm::PointerType::get( ir_builder->getInt8Ty(), 0ull ) );
-
-        ir_builder->CreateStore( sub_rsp_val_ptr, stack );
+        auto rsp_addr = ir_builder->CreateLoad( stack, "rsp_addr" );
+        auto new_rsp_addr = ir_builder->CreateGEP( ir_builder->getInt8Ty(), rsp_addr, ir_builder->getInt8( num_bytes ),
+                                                   "new_rsp_addr" );
+        auto resized_new_rsp_addr = ir_builder->CreateBitCast(
+            rsp_addr, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), 0ull ) );
+        auto pop_val = ir_builder->CreateLoad( resized_new_rsp_addr );
+        ir_builder->CreateStore( new_rsp_addr, stack );
+        ir_builder->CreateStore( llvm::UndefValue::get( ir_builder->getInt8Ty() ), rsp_addr );
         return pop_val;
     }