xscvdphp

VSX Scalar Convert Double to Half-Precision

xscvdphp XT, XB

Converts a double-precision floating-point value to a half-precision floating-point value with rounding.

Encoding

Binary Layout

60

T

17

B

347

BX TX

 

Format XX2-form

Opcode 0xF011056C

Extension VSX

Operands

• XT
  Target
• XB
  Source

Example

xscvdphp vs1, vs3

Registers Altered

FPSCR, VSR[TX×32+T].hword[3]

Related

More in VSX

Reference

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

Description

Converts the double-precision floating-point value in XB to a half-precision floating-point value, placing the result in the lower half of XT. The conversion applies rounding according to the current floating-point rounding mode in FPSCR. Requires VSX support.

Operation

XT ← convert_to_half_precision(XB, round_mode=FPSCR[RN])

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, as is required by this version of the architecture.