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Simple Code Generator

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  • Difficulty Level : Hard
  • Last Updated : 18 Nov, 2022
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Compiler Design is an important component of compiler construction. It involves many different tasks, such as analyzing the source code and producing an intermediate representation (IR) from it, performing optimizations on the IR to produce a target machine code, and generating external representations (ORs) for programs used in debugging or testing. In this paper, we describe our efforts to improve the design of simple language generators. We introduce a new reusable component called “Simple Code Generator” (SCG), which implements several functions that make it easy to create simple code generators for any programming language. The SCG component consists of two parts: firstly it contains a parser that transforms textual inputs into an abstract syntax tree; secondly, its generated AST has expressions in a symbolic form wherever possible instead of merely representing them as strings like most other compilers do today.

A code generator is a compiler that translates the intermediate representation of the source program into the target program. In other words, a code generator translates an abstract syntax tree into machine-dependent executable code. The process of generating machine-dependent output from an abstract syntax tree involves two steps: one for constructing the abstract syntax tree and another for generating its corresponding machine code.

The first step involves constructing an Abstract Syntax Tree (AST) by traversing all possible paths through your input file(s). This tree will contain information about every bit of data in your program as they are encountered during parsing or execution time; it’s important to note that this can take place both at compile time (as part of compiling) or runtime (in some cases).

Register Descriptor

Register descriptors are data structures that store information about the registers used in the program. This includes the registration number and its name, along with its type. The compiler uses this information when generating machine code for your program, so it’s important to keep it up-to-date while writing code!

The compiler uses the register file to determine what values will be available for use in your program. This is done by walking through each of the registers and determining if they contain valid data or not. If there’s nothing in a register, then it can be used for other purposes!

Address Descriptor

An address descriptor is used to represent the memory locations used by a program. Address descriptors are created by the getReg function, which returns a structure containing information about how to access memory. Address descriptors can be created for any instruction in your program’s code and stored in registers or on the stack; however, only one instance of an address descriptor will exist at any given time (unless another thread is executing).

When the user wants to retrieve data from an arbitrary location within the program’s source code using getReg, call this method with two arguments: The first argument specifies which register contains your desired value (e.g., ‘M’), while the second argument specifies where exactly within this register should it be placed back onto its original storage location on disk/memory before returning it back up into main memory again after successfully accessing its contents via indirect calls like LoadFromBuffer() or StoreToBuffer().

Code Generation Algorithm

The code generation algorithm is the core of the compiler. It sets up register and address descriptors, then generates machine instructions that give you CPU-level control over your program.

The algorithm is split into four parts: register descriptor set-up, basic block generation, instruction generation for operations on registers (e.g., addition), and ending the basic block with a jump statement or return command.

Register Descriptor Set Up: This part sets up an individual register’s value in memory space by taking its index into an array of all possible values for that type of register (i32). It also stores information about what kind of operation was performed on it so that subsequent steps can identify which operation happened if they’re called multiple times during execution.

Basic Block Generation: This step involves creating individual blocks within each basic block as well as lines between them so we can keep track of where things are happening at any given moment during execution.

Instruction Generation For Operations On Registers: This step converts source code statements into machine instructions using information from both our ELF file format files (the ones generated by GCC) as well as other sources such as Bazel’s build system which knows how to generate particular kind of machine code for particular CPUs. This is where we start to see the magic of how compilers work in practice, as they’re able to generate code that’s optimized in various ways based on the type of operation being performed (e.g., addition) and the registers involved (i32). This step can also be thought of as “register allocation” because it’s where we determine which registers will be used for each operation, and how many there are in total. This step uses the information generated in the previous steps as well as other information such as rules about how many registers are needed for certain operations. For example, we might know that 32-bit addition requires two registers: one to hold the value being added, and one for the result of this operation.

Instruction Scheduling: This step reorders instructions so that they’re executed efficiently on a particular CPU architecture. This step uses information about the execution resources available on each CPU architecture to determine the best order for executing operations. It also considers things like whether or not we have enough registers to store values (if some are in use), or if there’s a bottleneck somewhere else in the pipeline.

Design of the Function getReg

The getReg function is the main function that returns the value of a register passed in. It uses two parameters: A register number, and an action to perform on it. When you call getReg with no parameter, it will return all registers’ values (i.e., all registers).

If you want to return a specific register’s value, then you can call getReg with that register number and nothing else; if there are other parameters after this one (ie: 2nd parameter), then they’ll be searched for related to that first parameter’s type instead of being added as yet another argument after everything else has been evaluated already — this way we don’t waste any time processing data when nothing happens at all! If there isn’t anything after those two types but just an empty string (” “); then nothing happens either!

The output of this phase is a sequence of machine instructions that can be executed, with the help of a runtime system. This code generator generates assembly language for the target computer and object code for the target computer. The code generator is responsible for generating the assembly language for the target computer. It takes as input an intermediate format (sometimes called a compiler IR), which has been processed by the parser and typed checker but not yet lowered into machine code.

The code generator is also responsible for generating object code that can be executed on the target computer. This object code is usually in a format specific to the target architecture, such as Intel 8086 or Motorola 68000.

The compiler front end parses source code and performs some initial analysis on it. It then passes this data through several phases of compilation which turns it into machine instructions that can run on a computer processor.


Creating code generators can be a very complex task. The output of such a code generator should be as readable and concise as possible, with no extraneous noise or clutter. 

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