Difference Between Assembler and Compiler

The difference between assembler and compiler is that the compiler takes the source code and translates it into assembly code, while the assembler takes the assembly code generated by the compiler and translates it into machine code.

Assembler vs Compiler

Two terms that play the most important role in program execution are compiler and assembler. The compiler’s job is to take the preprocessed source code and translate it into assembly code. Then an assembler’s job is to take the compiler’s assembly code and translate it into machine code. If we talk about the main difference, then the main difference between assembler and compiler is that the compiler takes the source code and translates it into assembly code while the assembler takes the assembly code generated by the compiler and translates it into machine code. The compiler reads the program that is written in a source language. The compiler is a computer program that translates the source code into assembly language, and this assembly language code is sent to the assembler. There are types of compilers like single-pass compiler, multi-pass compiler, load-and-run compiler, and debug-and-optimize compiler. The assembler takes the assembly code generated by the compiler and translates it into machine code. The assembler’s main job is to take data as input and form relocatable machine code. There is a compiler available that performs the task of the assembler and generates the machine code directly, but that does not mean that we cannot study the functions of the assembler. There is a big difference between the assembly code and the machine code. All of these different types of compilers perform different functions and are different depending on the job. Assembly code is the mnemonic version of machine code. while machine code uses binary codes to represent operations of a memory address. Two passes are preformed in assembler which are the first pass that identifies the assembly code and stores that code in the symbol table and then the second pass that scans the code again and performs the operations on the code. There are two passes where compilation is done, one step is the parsing part where the source code is split into chunks and intermediate rendering is done. In the synthesis part, the target code forms the intermediate representation. There are compiler phases which are a lexical analyzer, syntax analyzer, semantic analyzer, intermediate code generation, code optimizer, code generator, symbol table and error handler.

Comparison chart

What is a compiler?

The compiler reads the program that is written in a source language. The compiler is a computer program that translates the source code into assembly language, and this assembly language code is sent to the assembler. There are types of compilers like single-pass compiler, multi-pass compiler, load-and-run compiler, and debug-and-optimize compiler. All of these different types of compilers perform different functions and are different depending on the job. There are two steps in which the compilation is done, one step is the parsing part where the source code is decomposed into chunks and intermediate rendering is done. In the synthesis part, the target code forms the intermediate representation. There are compiler phases which are a lexical analyzer, syntax analyzer,

The assembler and the compiler are not the same processes, but they do the same job, that is, they generate the object code of a source program and deliver it to the linker. The main process of the linker is to take the object code and generate the executable code for the program after this linker work is done, and assign the code to the loader. There are some built-in libraries and header files in a high-level language. There are some library functions that are defined in built-in libraries. These functions are linked to a library function by the linker. The compiler is informed in the event that the library function for the particular function is not found. When there is a large program, it is divided into smaller programs known as modules. Object modules are generated when these modules are compiled or assembled. Linker has to combine the entire program. There are two types of linkers, one is the link editor that generates a relocated executable module, and another is a dynamic linker that links external modules until the load module is generated. The program to be executed is present in main memory. Loader, loads the executable file into the operating system. Loader allocates memory space to the executable module in main memory. There are three types of loader which are: absolute loader, relocatable loader and dynamic runtime loader. These three loaders have different loading approaches which are absolute loading approach, relocatable loading approach and dynamic runtime loading approach. The absolute loader loads the program’s executable file to the same location in main memory. In absolute loader, the programmer must know the allocation. The relocation loader compiles or assembles the actual main memory address. Dynamic runtime loader, absolute memory program is spawned when an instruction is executed.

What is Assembler?

The assembler takes the assembly code generated by the compiler and translates it into machine code. The assembler’s main job is to take data as input and form relocatable machine code. There is a compiler available that performs the task of the assembler and directly generates the machine code, but that doesn’t mean that we can’t study the functions of the assembler. There is a big difference between assembly code and machine code. Assembly code is the mnemonic version of machine code, while machine code uses binary codes for the representation of memory address operations.

Key differences

1. Assembler is a computer program that takes the assembly code generated by the compiler and translates it into machine code, while Compiler is a computer program that takes the source code and translates it into assembly code.
2. The assembler enters the assembly language code while the compiler enters the source code.
3. The phases of the assembler are the first and a second phase . The compiler phases are a lexical analyzer, syntax analyzer, semantic analyzer, generated intermediate code, code optimizer, code generator, symbol table, and error handler.
4. The assembler output is binary code, while the compiler output is a mnemonic version of the code.