Contents | Prev | Next | Index

dup_x2

Operation
Duplicate top operand stack word and put three down

dup_x2

Forms
dup_x2 = 91 (0x5b)

Stack
..., word3, word2, word1 ..., word1, word3, word2, word1

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

The dup_x2 instruction must not be used unless each of word2 and word3 is a word that contains a 32-bit data type or together are the two words of a single 64-bit datum, and unless word1 contains a 32-bit data type.

Notes
Except for restrictions preserving the integrity of 64-bit data types, the dup_x2 instruction operates on untyped words, ignoring the types of the data they contain.


Contents | Prev | Next | Index

Java Virtual Machine Specification (HTML generated by dkramer on February 25, 1997)
Copyright © 1996 Sun Microsystems, Inc. All rights reserved
Please send any comments or corrections to doug.kramer@sun.com