[ Previous | Next | Contents | Home | Search ]
AIX Version 4.3 Assembler Language Reference

stdu (Store Double Word with Update) Instruction


Store a double-word of data from a general purpose register into a specified memory location. Update the address base.


stdu RS, D (RA)


The stdu instruction stores a double-word in storage from the source general-purpose register (GPR) RS into the specified location in memory referenced by the effective address (EA).

If GPR RA is not 0, the EA is the sum of the contents of GPR RA and D, a 16-bit, signed two's complement integer, fullword-aligned, sign-extended to 64 bits. GRP RA is updated with the EA.

If GPR RA = 0, the instruction form is invalid.


RS Specifies the source general-purpose register containing data.
D Specifies a 16-bit, signed two's complement integer sign-extended to 32 bits for EA calculation.
RA Specifies source general-purpose register for EA calculation.


This instruction is defined only for 64-bit implementations. Using it on a 32-bit implementation will cause the system illegal instruction error handler to be invoked.

Related Information

Fixed-Point Processor.

Fixed-Point Load and Store with Update Instructions.

[ Previous | Next | Contents | Home | Search ]