Simple Calculator (2022 IP2 Project1)

This is a compiler-based calculator that translates mathematical expressions into Assembly Code for a custom 32-bit CPU.

1. Execution Flow

Generate & Validate Assembly

1. Run the Compiler: Execute package/calculator_recursion_mergedcalculator_merged.c and pipe a testcase into it to generate input.txt.

   cd package/calculator_recursion_merged
   
   gcc calculator_merged.c -o calculator_merged.exe
   
   Get-Content "../../assembly_parser/testcase/1.txt" | ./calculator_merged.exe

2. Verify Results: Use the assembly simulator to read the generated input.txt. It will output the final register states and Total Clock Cycles (CPU Time).

   gcc ../../assembly_parser/main.c -o ../../assembly_parser/main.exe
   
   & "../../assembly_parser/main.exe" input.txt

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2. File Descriptions (Codebase)

Compiler Components (package/calculator_loop/ & package/calculator_recursion/) (Experiment Only)

• main.c: The entry point. Manages the overall compilation flow.
• lex.c / .h: Lexical Analyzer. Converts raw input strings into structured tokens (Integers, IDs, Operators).
• parser.c / .h: Syntax Analyzer. Implements recursive descent parsing to build the syntax tree based on operator precedence.
• codeGen.c / .h: Prefix-order Code Emitter. Performs prefix traversal on the syntax tree to calculate register indices and immediately emit assembly instructions based on node types.

Integrated Environment (package/calculator_recursion_merged/)

• calculator_merged.c (Unified Source): A simulated merge that coordinates the Lexer, Parser, and CodeGen logic as a single entry point to simplify compilation.
• correct.c (Reference Implementation)

Reference & Simulation (assembly_parser/)

• main.c (Assembly Simulator):
  • Role: Acts as the "Hardware" to execute the input.txt generated by my compiler.
  • Evaluation: It calculates the Total Clock Cycles (CPU Time) and register states to determine the final grade.

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3. Project Specifications

Supported Operators & Priority

• Level 1: ( ), ++ (Prefix), -- (Prefix)
• Level 2: *, /
• Level 3: +, -
• Level 4: &, ^, | (& > ^ > |) (Bitwise logic)
• Level 5: = (Assignment)

CPU Cycle Calculation (Performance Grading)

The total score depends on the efficiency of your generated code.

Instruction Type	Example	Cycle Cost
Move (Register/Immediate)	MOV r0 10, MOV r0 r1	10
Memory Access (Load/Store)	MOV [0] r0, MOV r0 [4]	200
Basic Arithmetic	ADD, SUB	10
Bitwise Logic	AND, OR, XOR	10
Multiplication	MUL	30
Division	DIV	50
System Termination	EXIT	20

Note: Variable Initialization

By default, the variables x, y, and z are initialized to 0 by the simulator. However, The compiler allows for custom initialization if needed in future hardware specifications.