The AVR instruction set is a bit more regular than z80's, which allows us for
simpler upcode spitting logic (simplicity which is lost when we need to take
into account all AVR models and instruction constraints on each models). This
file categorizes all available ops with their opcode signature. X means upcode
bit.

Categories are in descending order of "popularity"

Mnemonics with "*" are a bit special.

### 16-bit

## Plain

XXXX XXXX XXXX XXXX

BREAK, CLC, CLH, CLI, CLN, CLS, CLT, CLV, CLZ, EICALL, EIJMP, ELPM*, ICALL,
IJMP, NOP, RET, RETI, SEC, SEH, SEI, SEN, SES, SET, SEV, SEZ, SLEEP, SPM*, WDR

## Rd(5)

XXXX XXXd dddd XXXX

ASR, COM, DEC, ELPM*, INC, LAC, LAS, LAT, LD*, LPM*, LSL*, LSR, NEG, POP, PUSH,
ROR, ST*, SWAP, XCH

## Rd(5) + Rr(5)

XXXX XXrd dddd rrrr

ADC, ADD, AND, CLR, CP, CPC, CPSE, EOR, MOV, MUL, OR, ROL*, SBC, SUB,
TST*

## k(7)

XXXX XXkk kkkk kXXX

BRCC, BRCS, BREQ, BRGE, BRHC, BRHS, BRID, BRIE, BRLO, BRLT, BRMI, BRNE, BRPL,
BRSH, BRTC, BRTS, BRVC, BRVS 

## Rd(4) + K(8)

XXXX KKKK dddd KKKK

ANDI, CBR*, CPI, LDI, ORI, SBCI, SBR, SUBI

## Rd(5) + bit

XXXX XXXd dddd Xbbb

BLD, BST, SBRC, SBRS

## A(5) + bit

XXXX XXXX AAAA Abbb

CBI, SBI, SBIC, SBIS

## Rd(3) + Rr(3)

XXXX XXXX Xddd Xrrr

FMUL, FMULS, FMULSU, MULSU

## Rd(4) + Rr(4)

XXXX XXXX dddd rrrr

MOVW, MULS

## Rd(5) + A(6)

XXXX XAAd dddd AAAA

IN, OUT

## Rd(4) + k(7)

XXXX Xkkk dddd kkkk

LDS*, STS*

## Rd(2) + K

XXXX XXXX KKdd KKKK

ADIW, SBIW

## Rd(4)

XXXX XXXX dddd XXXX

SER

## K(4)

XXXX XXXX KKKK XXXX

DES

## k(12)

XXXX kkkk kkkk kkkk

RCALL, RJMP

## SREG

XXXX XXXX Xsss XXXX

BCLR, BSET

## SREG + k(7)

XXXX XXkk kkkk ksss

BRBC, BRBS

### 32-bit

## k(22)

XXXX XXXk kkkk XXXk
kkkk kkkk kkkk kkkk

CALL, JMP

## Rd(5) + k(16)

XXXX XXXd dddd XXXX
kkkk kkkk kkkk kkkk

LDS*, STS*