Programming Language Interpreter Design MIPS
apply your understanding of MIPS assembly language to implement a program that simulates a simple esoteric language interpreter, specifically for a language called "Brainfry." This task will test your ability to work with memory manipulation, loops, and conditional branches in MIPS.
Description:
Brainfry is an esoteric programming language that operates on a virtual "tape" consisting of memory cells, where each cell can hold a single byte. The tape is manipulated by moving a "tape head" (a pointer to the current memory cell) left or right, and by incrementing or decrementing the value at the current memory cell.
You will implement a MIPS program that reads a series of Brainfry commands and executes them on a simulated tape of 5,000 memory cells. The following Brainfry commands must be supported in your MIPS implementation:
>: Move the tape head to the right.
<: Move the tape head to the left.
+: Increment the value of the current memory cell.
-: Decrement the value of the current memory cell.
.: Output the value of the current memory cell as an ASCII character.
,: Input a value from the user and store it in the current memory cell.
[: If the value of the current memory cell is 0, jump to the corresponding ] command.
]: If the value of the current memory cell is not 0, jump to the corresponding [ command.
All other characters should be ignored by your MIPS program. The end of the program is signified by a ~ character, after which the input to the Brainfry program follows.
Understanding Brainfry and MIPS
- Brainfry: A simple esoteric language operating on a tape of memory cells, using commands to move the tape head, modify cell values, and input/output.
- MIPS: A RISC architecture assembly language with a rich instruction set for memory manipulation, conditional branches, and arithmetic operations.
MIPS Implementation Outline
- Memory Initialization: Allocate a 5,000-byte array to simulate the Brainfry tape.
- Tape Head Pointer: Initialize a register to point to the current memory cell on the tape.
- Command Loop:
- Read a character from the input.
- Based on the character, execute the corresponding Brainfry command:
>: Increment the tape head pointer.<: Decrement the tape head pointer.+: Increment the value at the current memory cell.-: Decrement the value at the current memory cell..: Print the ASCII character corresponding to the current cell value.,: Read a character from the user and store its ASCII value in the current cell.[: If the current cell value is 0, jump to the matching].]: If the current cell value is not 0, jump to the matching[.
- Continue reading and executing commands until a
~is encountered.
MIPS Code Example
MIPS Assembler
# Initialize the tape and tape head pointer
.data
tape: .space 5000
tape_head: .word 0
.text
.globl main
main:
# Load the address of the tape into a register
la $t0, tape
# Initialize the tape head pointer
li $t1, 0
# Read commands and execute them
read_loop:
lb $t2, 0($a0)
beq $t2, '~', end_program
# Implement the Brainfry commands here
# For example:
beq $t2, '>', move_right
beq $t2, '<', move_left
# ...
# Continue reading commands
addi $a0, $a0, 1
j read_loop
end_program:
# End the program
li $v0, 10
syscallKey Considerations
- Memory Bounds Checking: Ensure that the tape head pointer doesn't go beyond the allocated memory.
- Nested Loops: Implement a stack-based approach to handle nested
[ ]loops. - Error Handling: Consider handling potential errors like invalid commands or memory access violations.
- Efficiency: Optimize your code for performance, especially for large inputs.
By following this outline and addressing these considerations, you can create a functional Brainfry interpreter in MIPS assembly.