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Pseudo-instructions

Assembler-only helpers from asm/ext.asm. They rewrite into core opcodes and often use R7 plus the stack as scratch.

LDI (16-bit)

Syntax:

LDI rH rL imm16

Expands to:

LDI rH (imm16 >> 8)
LDI rL (imm16 & 0xFF)

Scratch: none
Flags: none
Description: Load a 16-bit immediate into two registers.

CALL (abs)

Syntax:

CALL addr16

Expands to:

LDI R6 (addr16 >> 8)
LDI R7 (addr16 & 0xFF)
CALL R6 R7

Scratch: uses R6, R7
Flags: none
Description: Absolute subroutine call to a 16-bit address.

JMP (abs)

Syntax:

JMP addr16

Expands to:

LDI R6 (addr16 >> 8)
LDI R7 (addr16 & 0xFF)
JMP R6 R7

Scratch: uses R6, R7
Flags: none
Description: Absolute jump to a 16-bit address.

JR (abs)

Syntax:

JR label

Expands to: relative JR with the computed offset.

Scratch: none
Flags: none
Description: Jump to a label using a computed relative offset (assembler checks the range).

JZR (abs)

Syntax:

JZR label

Expands to: relative JZR with the computed offset.

Scratch: none
Flags: reads Z
Description: Jump to a label when zero flag is set, using a computed offset.

JNZR (abs)

Syntax:

JNZR label

Expands to: relative JNZR with the computed offset.

Scratch: none
Flags: reads Z
Description: Jump to a label when zero flag is clear, using a computed offset.

ZERO

Syntax:

ZERO rD

Expands to:

LDI rD 0

Scratch: none
Flags: none
Description: Clear a register.

INC

Syntax:

INC rD

Expands to:

PUSH R7
LDI R7 1
ADD rD R7
POP R7

Scratch: uses R7, stack
Flags: from ADD (Z/N/C)
Description: Increment a register by one.

DEC

Syntax:

DEC rD

Expands to:

PUSH R7
LDI R7 1
SUB rD R7
POP R7

Scratch: uses R7, stack
Flags: from SUB (Z/N/C)
Description: Decrement a register by one.

INC16

Syntax:

INC16 rH rL

Expands to:

CMPI rL 0xFF
JZR inc_hi
INC rL
JR end
inc_hi:
LDI rL 0
INC rH
end:
NOP

Scratch: stack via INC
Flags: from CMPI, INC (Z/N/C)
Description: Increment a 16-bit register pair in-place.

NOT

Syntax:

NOT rD

Expands to:

PUSH R7
LDI R7 0xFF
XOR rD R7
POP R7

Scratch: uses R7, stack
Flags: from XOR (Z/N, clears C)
Description: Bitwise invert a register.

CMP

Syntax:

CMP rA rB

Expands to:

PUSH rA
SUB rA rB
POP rA

Scratch: stack
Flags: from SUB (Z/N/C)
Description: Compare two registers; flags reflect rA - rB, operands restored.

CMPI

Syntax:

CMPI rD imm

Expands to:

PUSH R7
LDI R7 imm
SUB R7 rD
POP R7

Scratch: uses R7, stack
Flags: from SUB (Z/N/C)
Description: Compare a register with an immediate; flags reflect imm - rD.

SHRI

Syntax:

SHRI rD imm

Expands to:

PUSH R7
LDI R7 imm
SHR rD R7
POP R7

Scratch: uses R7, stack
Flags: from SHR (Z/N/C)
Description: Shift right by an immediate count.

SHLI

Syntax:

SHLI rD imm

Expands to:

PUSH R7
LDI R7 imm
SHL rD R7
POP R7

Scratch: uses R7, stack
Flags: from SHL (Z/N/C)
Description: Shift left by an immediate count.

SWAP

Syntax:

SWAP rA rB

Expands to:

PUSH rA
MOV rA rB
POP rB

Scratch: stack
Flags: none
Description: Exchange the values of two registers.

MUL

Syntax:

MUL rD rA rB

Expands to:

ZERO rD
PUSH rB
iter:
    ADD rD rA
    DEC rB
    CMPI rB 0
    JNZR iter
POP rB

Scratch: uses rB, stack
Flags: from ADD, DEC, CMPI (Z/N/C)
Description: Unsigned multiply by repeated addition; destroys rB during the loop, restores it after.