klimoza/isa-interpreter

Simple ISA

Implementation of a simple ISA in Rust. It supports SC, TS and PSO memory models as well as tracing mode for debugging.

Instructions

• r = 1 - Put constant into register.
• r1 = r2 # r3 - Binary operation on two registers.
• if r goto L - Conditional jump on label L.
• load m #r1 r2 - Load value from memory by address stored in r1 into register r2.
• store m #r1 r2 - Store value from register r2 into memory by address stored in r1.
• r1 := cas m #r2 r3 r4 - Compare-and-swap value in memory by address stored in r2, expected value is stored in r3, desired value is stored in r4, should return the actually read value in register r1.
• r1 := fai m #r2 r3 - Fetch-and-increment value in memory by address stored in r2, the value to increment by is stored in r3, should return the read value prior increment in register r1.
• fence m - Memory fence instruction.

Parameters and flags

The console app supports the following flags:

• --file - the path to the file with commands.
• --model - the name of the model you want to use.
• --trace - flag for activating trace mode.

Example

Different threads instructions should be separated in file by an empty line. For example:

✗ cat prog.txt
r1 = 1
r2 = 2
r3 = r1 + r2
store SEQ_CST #r1 r3

r1 = 1
load SEQ_CST #r1 r3

Now we can interpret this file:

✗ cargo run --bin main -- --file prog.txt --trace --model SC
1: r1 = 1
# REGISTERS
| Thread 0: {}
| Thread 1: {"r1": 1}
# MEMORY
| {}

1: load ACQ #r1 r3
# REGISTERS
| Thread 0: {}
| Thread 1: {"r1": 1, "r3": 0}
# MEMORY
| {}

0: r1 = 1
# REGISTERS
| Thread 0: {"r1": 1}
| Thread 1: {"r1": 1, "r3": 0}
# MEMORY
| {}

0: r2 = 2
# REGISTERS
| Thread 0: {"r1": 1, "r2": 2}
| Thread 1: {"r1": 1, "r3": 0}
# MEMORY
| {}

0: r3 = r1 + r2
# REGISTERS
| Thread 0: {"r1": 1, "r3": 3, "r2": 2}
| Thread 1: {"r1": 1, "r3": 0}
# MEMORY
| {}

0: store REL #r1 r3
# REGISTERS
| Thread 0: {"r1": 1, "r3": 3, "r2": 2}
| Thread 1: {"r1": 1, "r3": 0}
# MEMORY
| {1: 3}