Duplicate top operand stack word

Format

dup

Forms

dup = 61 (0x3d)

Stack

…, word → …, word, word

Description

The top word on the operand stack is duplicated and pushed onto the operand stack.

The dup instruction must not be used unless word contains a 16-bit data type.

Notes

Except for restrictions preserving the integrity of 32-bit data types, the dup instruction operates on an untyped word, ignoring the type of data it contains.