dup2

Operation
Duplicate top two operand stack word

dup2
s

Forms
dup2 = 92 (0x5c)

Stack
..., word2, word1 ..., word2, word1, word2, word1

Description
The top two words on the operand stack are duplicated and pushed onto the operand stack, in the original order.

The dup2 instruction must not be used unless each of word1 and word2 is a word that contains a 32-bit data type or both together are the two words of a single 64-bit datum.

Notes
Except for restrictions preserving the integrity of 64-bit data types, the dup2 instruction operates on untyped words, ignoring the types of the data they contain.