tyalie / stm8-instruction-analysis

Small scripts for analysing the STM8 instruction set.

Analysis script for STM8 opcodes

This is a small and simple script that I used to analyze the STM8 opcodes as described in stm8-binutils-gdb (see struct stm8_opcodes in opcodes/stm8-opc.c). It was mainly used to allow us to discuss possible opcode classifications for the STM8 ISA that could then be used to reduce the overhead when implementing all instructions for our STM8 LLVM backend.

Note

The issues are open for discussions. So if you have suggestions, please write me ^^

Output

The script has the following output when using the commit 07d863397.

================
Distribution of how many different opcodes a single asm mnemonic has

1:
    nop, break, callr, ccf, divw, exgw, halt, int, iret, 
    jra, jrc, jreq, jrf, jrh, jrih, jril, jrm, jrmi, 
    jrnc, jrne, jrnh, jrnm, jrnv, jrpl, jrsge, jrsgt, jrsle, 
    jrslt, jrt, jruge, jrugt, jrule, jrult, jrv, rcf, ret, 
    retf, rim, rvf, scf, sim, trap, wfe, wfi, 
2:
    callf, clrw, cplw, decw, div, incw, jpf, mul, negw, 
    popw, pushw, rlcw, rlwa, rrcw, rrwa, sllw, slaw, sraw, 
    srlw, swapw, tnzw, 
3:
    exg, mov, pop, 
4:
    push, 
6:
    subw, 
7:
    addw, 
8:
    bccm, bcpl, bres, bset, btjf, btjt, 
12:
    call, jp, ldf, 
15:
    adc, add, and, bcp, clr, cp, cpl, dec, inc, 
    neg, or, rlc, rrc, sbc, sll, sla, sra, srl, 
    swap, tnz, xor, 
16:
    sub, 
19:
    cpw, 
37:
    ld, 
44:
    ldw, 

================
There are 26 different opcode argument tuples
   - 
   - BYTE
   - SHORTMEM
   - LONGMEM
   - SHORTOFF_X
   - LONGOFF_X
   - SHORTOFF_Y
   - LONGOFF_Y
   - SHORTOFF_SP
   - SHORTPTRW
   - LONGPTRW
   - SHORTPTRW_X
   - LONGPTRW_X
   - SHORTPTRW_Y
   - WORD
   - LONGMEM, PCREL
   - EXTMEM
   - LONGPTRE
   - PCREL
   - EXTOFF_X
   - EXTOFF_Y
   - LONGPTRE_X
   - LONGPTRE_Y
   - LONGMEM, BYTE
   - SHORTMEM, SHORTMEM
   - LONGMEM, LONGMEM

================
The following mnemonic groups exist. The criterias have been:
  - same amount of opcodes / argument types per mnemonic
  - for each opcode & argument from a mnemonic there is a matching pair
    in the other mnemonic where the opcode just has a constant offset

Group 1:
    callr, jra, jrc, jreq, jrf, jrh, jrih, jril, jrm, 
    jrmi, jrnc, jrne, jrnh, jrnm, jrnv, jrpl, jrsge, jrsgt, 
    jrsle, jrslt, jrt, jruge, jrugt, jrule, jrult, jrv, 
Group 2:
    adc, add, and, bcp, cp, or, sbc, xor, 
Group 3:
    clrw, cplw, decw, incw, negw, popw, pushw, rlcw, rrcw, 
    sllw, slaw, sraw, srlw, swapw, tnzw, 
Group 4:
    nop, break, ccf, halt, iret, rcf, ret, retf, rim, 
    rvf, scf, sim, trap, wfe, wfi, 
Group 5:
    div, mul, rlwa, rrwa, 
Group 6:
    clr, cpl, dec, inc, neg, rlc, rrc, sll, sla, 
    sra, srl, swap, tnz, 
Group 7:
    btjf, btjt, 
Group 8:
    divw, exgw, 
Group 9:
    call, jp, 
Group 10:
    callf, jpf, 
Group 11:
    bccm, bcpl, bres, bset, 

unique:
    sub, ldf, int, pop, subw, push, ldw, addw, ld, 
    mov, cpw, exg, 

Requirements

The script currently uses tree sitter to build the opcode database from the above-mentioned struct.