dup_x1

Operation
Duplicate top operand stack word and put two down

dup_x1

Forms
dup_x1 = 90 (0x5a)

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

Description
The top word on the operand stack is duplicated and the copy inserted two words down in the operand stack.

The dup_x1 instruction must not be used unless each of word1 and word2 is a word that contains a 32-bit data type.

Notes
Except for restrictions preserving the integrity of 64-bit data types, the dup_x1 instruction operates on untyped words, ignoring the types of the data they contain.