xsnabsdp

VSX Scalar Negative Absolute Double-Precision

xsnabsdp XT,XB

Computes the negative absolute value of a double-precision floating-point number.

Encoding

Binary Layout

T

6:10

B

11:15

BX

16:20

TX

21:31

 

Format XX2-form

Opcode 0xF00005A4

Extension VSX

Operands

• XT
  Target Vector-Specific Register
• XB
  Source Vector-Specific Register

Example

xsnabsdp vs1, vs3

Related

More in VSX

Reference

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

Description

The instruction computes the negative absolute value of the double-precision floating-point number in VSR[XB] and stores it in VSR[XT]. The result is zeroed out for the second doubleword.

Operation

if MSR.VSX=0 then
    VSX_Unavailable()
src ←VSR[32×BX+B].dword[0]
VSR[32×TX+T].dword[0] ←bfp64_NEGATIVE_ABSOLUTE(src)
VSR[32×TX+T].dword[1] ←0x0000_0000_0000_0000

Programming Note

This instruction can be used to operate on a single-precision source operand. Previous versions of the architecture allowed the contents of doubleword 1 of the result register to be undefined. However, all processors that support this instruction write 0s into doubleword 1 of the result register.