stvehx

Store Vector Element Halfword Indexed X-form

stvehx VRS,RA,RB

Stores a halfword element from a vector register to memory.

Details

Stores a halfword (16 bits) element from vector register VRS to memory at the indexed address (RA|0) + RB. The element is selected based on the least significant bits of the effective address to determine alignment. This is a VMX/AltiVec instruction that accesses memory with vector element granularity.

Pseudocode Operation

EA ← (RA|0) + RB
element_index ← EA[61:62]
[EA & ~0x1] ← VRS[element_index * 16 : element_index * 16 + 15]

Programming Note

Unless bits 60:62 of the address are known to match the halfword offset of the subject halfword element in VSR[VRS+32], software should use Vector Splat to splat the subject halfword element before performing the store.

Example

stvehx v1, r4, r5

Encoding

Binary Layout
011111
0
VRS
6
RA
11
RB
16
00101
21
00111
26
Rc
31
 
Format X-form
Opcode 0x7C00014E
Extension VMX (AltiVec)

Operands

  • VRS
    Vector Register
  • RA
    Source General Purpose Register
  • RB
    Source General Purpose Register