stxsdx

Store VSX Scalar Doubleword Indexed X-form

stxsdx XS,RA,RB

Stores a doubleword from a VSX scalar register to memory.

Encoding

Binary Layout

0

S

RA

RB

SX

 

Format X-form

Opcode 0x7C000598

Extension VSX

Operands

• XS
  VSX Scalar Register
• RA
  Source General Purpose Register (Base Address)
• RB
  Source General Purpose Register (Index)

Example

stxsdx vs1, r4, r5

Registers Altered

MSR

Related

More in VSX

Reference

View in PowerISA v3.1C Specification ↗ OPF Power ISA v3.1C

Description

The instruction stores the contents of the specified doubleword element of a VSX scalar register into memory at an address calculated from two general-purpose registers.

Operation

if MSR.VSX=0 then
    VSX_Unavailable()
EA ←((RA=0) ? 0 : GPR[RA]) + GPR[RB]
MEM(EA,8)    ←VSR[XS].dword[0]

Programming Note

The stxsdx instruction stores a doubleword from a VSX scalar register into memory. Ensure the VSX facility is enabled by checking and setting the MSR.VSX bit. The effective address (EA) is calculated by adding the contents of two general-purpose registers, RA and RB. This instruction requires 8-byte alignment for the memory address to avoid exceptions.