RRR     (OP u 8) (X u 8) (Y u 8) (Z u 8)
J26     (OP u 8) (XYZ j 24)
U16R    (OP u 8) (XY u 16) (Z u 8)


0x01    RRR
#   Halt with exit code %X
:   halt    %X
    ulm_halt(ulm_regVal(X));

0x02    RRR
#   Read character into %X
:   getc    %X
    ulm_setReg(ulm_readChar() & 0xFF, X);

0x03    RRR
#   Print character from %X
:   putc    %X
    ulm_printChar(ulm_regVal(X) & 0xFF);

0x04    J26
#   Jump forward or backward
:   jmp XYZ
    ulm_unconditionalRelJump(XYZ);

0x05    RRR
#   Subtract immediate value X from register %Y. Store result in %Z
:   subq    X, %Y, %Z
    ulm_sub64(X, ulm_regVal(Y), Z);

0x06    J26
:   jnz XYZ
:   jne XYZ
    ulm_conditionalRelJump(ulm_statusReg[ULM_ZF] == 0, XYZ);

0x07    J26
:   jz  XYZ
:   je  XYZ
    ulm_conditionalRelJump(ulm_statusReg[ULM_ZF] == 1, XYZ);

0x08    U16R
:   ldzwq   XY, %Z
    ulm_setReg(XY, Z);

0x09    RRR
:   movzbq (%X), %Z
    ulm_fetch64(0, X, 0, 0, ULM_ZERO_EXT, 1, Z);

0x0A    RRR
#   Adds an immediate value X to register %Y. Stores result in register %Z.
:   addq    X, %Y, %Z
    ulm_add64(X, ulm_regVal(Y), Z);

0x0B    RRR
:   imulq   %X, %Y, %Z
    ulm_mul64(ulm_regVal(X), ulm_regVal(Y), Z);

0x0C    J26
:   ja      XYZ
    ulm_conditionalRelJump(ulm_statusReg[ULM_ZF] == 0
                        && ulm_statusReg[ULM_CF] == 0, XYZ);

0x0D    J26
:   jb      XYZ
    ulm_conditionalRelJump(ulm_statusReg[ULM_CF] == 1, XYZ);

0x0E    RRR
#   Adds register %X to register %Y. Stores result in register %Z.
:   addq    %X, %Y, %Z
    ulm_add64(ulm_regVal(X), ulm_regVal(Y), Z);

0x0F    RRR
:   imulq   X, %Y, %Z
    ulm_mul64(X, ulm_regVal(Y), Z);


# General meaning of the mnemonics

@addq
#   Integer addition.
@getc
#   Get character
@halt
#   Halt program
@imulq
#   64-bit unsigned and signed integer multiplication.
@ja
#   Jump if above (conditional jump).
@jb
#   Jump if below (conditional jump).
@je
#   Jump if equal (conditional jump).
@jmp
#   Jump (unconditional jump).
@jne
#   Jump if not equal (conditional jump).
@jnz
#   Jump if not zero (conditional jump).
@jz
#   Jump if zero (conditional jump).
@ldzwq
#   Load zero extended word to quad word register.
@putc
#   Put character
@subq
#   Integer subtraction.
@movzbq
#   Move zero extended byte to quad word register.