Caio Raphael

mov :
- General-purpose registers.
- Copies data from source to destination. Does not modify flags.
- Ex : mov eax, 5 (copies 5 into eax).
movss :
- Scalar single-precision float (SSE)
movzx :
- Move with zero extension (for unsigned values).
- Ex : movzx eax, bl (copies bl into eax, zeroing upper bits).
movsx :
- Move with sign extension (for signed values).
- Ex : movsx eax, bl (copies bl into eax, sign-extending).
xchg :
- Exchanges values between two operands.
- Ex : xchg eax, ebx (swaps eax and ebx).

lea :
- Load Effective Address (computes address without dereferencing).
- Usually used to obtain a pointer to a memory region.
- Ex : lea eax, [ebx+4] (stores ebx+4 in eax).

Perform mathematical operations.
add :
- Adds two operands.
- Ex : add eax, ebx (eax = eax + ebx).
sub :
- Subtracts the second operand from the first.
- Ex : sub eax, 5 (eax = eax - 5).
inc :
- Increments by 1.
- Ex : inc eax (eax++).
dec :
- Decrements by 1.
- Ex : dec eax (eax--).
mul :
- Unsigned multiply (stores result in eax/edx:eax).
- Ex : mul ebx (eax * ebx, result in edx:eax).
imul :
- Signed multiply.
- Ex : imul eax, ebx (eax = eax * ebx).
div :
- Unsigned division (divides edx:eax by operand).
- Ex : div ebx (edx:eax / ebx, quotient in eax).
idiv :
- Signed division.
- Ex : idiv ebx (same as div but signed).
neg :
- Negates a value (two's complement).
- Ex : neg eax (eax = -eax).
Creel - ADD, SUB, INC, DEC

shl :
- Shift left (logical shift).
- Ex : shl eax, 2 (eax << 2).
shr :
- Shift right (logical shift).
- Ex : shr eax, 2 (eax >> 2).
sal :
- Arithmetic shift left (same as shl).
- Ex : sal eax, 2 .
sar :
- Arithmetic shift right (preserves sign).
- Ex : sar eax, 2 .
rol :
- Shifts to the left, but as bits are shifted out from the left, they go back to the right.
ror :
- Shifts to the right, but as bits are shifted out from the right, they go back to the left.
rcl :
- Rotates to the left but includes the carry flag in the rotation.
rcr :
- Rotates to the right but includes the carry flag in the rotation.
Creel - Shift, Rotate, with animation

Change the execution flow (branches, loops, calls).
jmp :
- Unconditional jump.
- Ex : jmp label (jumps to label).
je / jz :
- Jump if equal/zero (ZF=1).
- Ex : je label (jumps if ZF=1).
jne / jnz :
- Jump if not equal/zero (ZF=0).
- Ex : jne label (jumps if ZF=0).
jg / jnle :
- Jump if greater (signed).
- Ex : jg label (jumps if SF=OF and ZF=0).
jl / jnge :
- Jump if less (signed).
- Ex : jl label (jumps if SF≠OF).
ja / jnbe :
- Jump if above (unsigned).
- Ex : ja label (jumps if CF=0 and ZF=0).
jb / jnae :
- Jump if below (unsigned).
- Ex : jb label (jumps if CF=1).
loop :
- Decrements ecx and jumps if not zero.
- Ex : loop label .

call :
- Calls a function (pushes return address).
- Ex : call func (calls func).
ret :
- Returns from a function (pops return address).
- Ex : ret .

Manipulate the stack.
push :
- Pushes a value onto the stack.
- Ex : push eax (decrements esp , stores eax ).
pop :
- Pops a value from the stack.
- Ex : pop eax (loads eax , increments esp ).
pusha / pushad :
- Pushes all general-purpose registers.
- Ex : pusha (x86).
popa / popad :
- Pops all general-purpose registers.
- Ex : popa (x86).

Modify or check CPU flags.
cmp :
- Compares two operands (subtracts without storing).
- Ex : cmp eax, ebx (sets flags based on eax - ebx).
test :
- Bitwise AND (without storing result).
- Checking if a value is zero or non-zero
- ZF (Zero Flag) → set if register is 0
- SF (Sign Flag) → sign of register
- CF / OF → cleared
- Ex :
  - test eax, eax
    - Sets ZF if eax = 0 .
  - test al, 1
    - Sets ZF if the least significant bit of al = 0 .
stc :
- Sets Carry Flag (CF=1).
- Ex : stc .
clc :
- Clears Carry Flag (CF=0).
- Ex : clc .

Work with strings (uses esi, edi).
movsb :
- Moves byte from [esi] to [edi] .
- Ex : rep movsb (copies a string).
cmpsb :
- Compares bytes at [esi] and [edi] .
- Ex : rep cmpsb .
stosb :
- Stores al into [edi] .
- Ex : rep stosb (fills memory).
lodsb :
- Loads byte from [esi] into al.
- Ex : lodsb .

Floating-point math (x87/SSE).
fadd :
- Floating-point add.
- Ex : fadd st0, st1 (st0 += st1).
fmul :
- Floating-point multiply.
- Ex : fmul st0, st1 .
fld :
- Loads float onto FPU stack.
- Ex : fld dword [x] .
fstp :
- Stores float and pops stack.
- Ex : fstp dword [y] .
mulss :
- Multiplies scalar single-precision floats
- Ex :
  - mulss xmm0, [half]
    - Only affects the lowest 32 bits of xmm0
subss
- Multiplies scalar single-precision floats
- Ex :
  - subss xmm0, dword [speed]
    - Only affects the lowest 32 bits of xmm0