VMIPS functional and performance simulator

The functional/performance simulator provides both correct results and performance info under all parameter configurations.

How to run:

python3 main.py --iodir <iodir>

Dependencies

No third party libraries needed, although pytest could be used to select test cases with regular expression.

Developed and tested with Python 3.11

Test

Tests are written with the built-in unittest module, and the scripts are stored in the tests directory. The tests/NoOp directory stores example input and output files, along with a Code.asm containing all instructions which will be used to provide test coverage information. All commands provided should be executed from project root.

Instruction set

These test cases are in tests/test_isa.py.

The TestIntegratedSmallProgram class holds tests that test instructions with small programs, which you can find in the isa_test directory. They include ADD, BLE, BLT, HALT, LS, LV, SS, SUB, SUBVV, and SV, covering 10 (21%) instructions.

The TestSingleInstruction class holds tests that focus on testing one instruction and one instruction only. They generate code and manipulate internal state directly during runtime to isolate itself from bugs in other instructions. They include ADDVS, ADDVV, AND, BEQ, BGE, BGT, BLE, BLT, BNE, CVM, DIVVS, DIVVV, HALT, LVI, LVWS, MFCL, MTCL, MULVS, MULVV, OR, POP, SEQVS, SEQVV, SGEVS, SGEVV, SGTVS, SGTVV, SLEVS, SLEVV, SLL, SLTVS, SLTVV, SNEVS, SNEVV, SRA, SRL, SUBVS, SUBVV, SVI, SVWS, and XOR, covering 41 (87%) instructions. (yes they overlap a little)

An report of a previous run can be found at instruction_test_results.txt. Run python3 -Wignore -m unittest discover tests test_isa.py -v to test it yourself.

Use environmental variable DEBUG to change the verbosity of runtime logs. Defaults to level 0 and will not bother you with too much detail. Try level 1 and you'll get instruction parsing info. Level 2 gives you transaction logs, including all scalar/vector register-file/memory read/writes, with reads colored in red and writes colored in blue. We use DEBUG=2 python3 -Wignore -m unittest discover tests test_isa.py -v a lot when we're debugging our assembly, hope you like it too.

Dot product

You can test this either with standard python3 main.py --iodir dot_product_test command and check the outputs,

or run python3 -Wignore -m unittest discover tests test_dot_product.py -v and let the program test assertions for you.

Code

Syntax sugar has been added to let users check internal state more easily.

Access vcore.scalar_register_file[6] with vcore.SR7, and the same goes for vector_register_file. Access vcore.vector_data_mem[0] with vcore.SR0, and the same goes for scalar_data_mem.

e.g.

scalar register file
- vcore.SR1
- vcore.SR2
- vcore.SR3
vector register file
- vcore.VR5
- vcore.VR6
- vcore.VR7
scalar memory
- vcore.SM0
- vcore.SM2
- vcore.SM4
vector memory
- vcore.VM0
- vcore.VM3
- vcore.VM6

Instruction execution is delegated to the ALU class, in which I grouped instructions with operation type:

handler name	operation type
`vector_op`	vector operations
`vec_mask_reg`	vector mask register operations
`vec_len_reg`	vector length register (flag register) operations
`mem_op`	memory operations
`scalar_op`	scalar operations
`control`	flow control
`stop`	halt

And most instruction handlers are structured with these following stages:

Set common aliases
Map operation name to standard operators
Get operands
Do operation and store the result

Step 2 and 3 are optional, but they looks really clean on arithmetics and branching, where I directly map add/sub/mul/div and eq/ne/lt/le/gt/ge to native operators.