xsmaxcqp

VSX Scalar Maximum Type-C Quad-Precision

xsmaxcqp vD, vA, vB

Compares two quad-precision floating-point values and selects the maximum.

Encoding

Binary Layout

63

0:5

FRT

6:10

FRA

11:15

FRB

16:20

674

21:30

Rc

31

 

Format X-form

Opcode 0xFC000548

Extension VSX

Operands

• vD
  Target
• vA
  Src A
• vB
  Src B
• VRT
  Target Vector-Scalar Register
• VRA
  Source Vector-Scalar Register
• VRB
  Source Vector-Scalar Register
• XT
  Target Vector Register

Example

xsmaxcqp vd, va, vb

Registers Altered

FPSCR (FX, VXSNAN)

Related

More in VSX

Reference

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

Description

Compares two quad-precision floating-point values in VSRs and returns the maximum, using Type-C comparison rules (NaN handling as per VSX specification). Results are written to the VSR specified by XT. No exception or condition register fields are altered unless Rc=1 for VSX comparisons.

Operation

fD ← max(fA, fB) using Type-C comparison
if fA is NaN or fB is NaN then
  fD ← QNaN
end if

Programming Note

xsmaxcqp can be used to implement the C/C++ conditional operation (x>y)?x:y for quad-precision arguments. VSR[VRT+32] ←result