dctqpq

Decimal Convert To Quad-Precision DFP

dctqpq vD, FRB

Converts DFP Long (64-bit) to DFP Quad (128-bit).

Encoding

Binary Layout

63

0:5

vD

6:10

/

11:15

FRB

16:20

258

21:30

/

31

 

Format X-form

Opcode 0xFC000204

Extension Decimal Floating-Point

Operands

• vD
  Target Quad
• FRB
  Source Long

Example

dctqpq vd, f3

Registers Altered

FPSCR

Related

More in Decimal Floating-Point

Reference

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

Description

Convert a DFP long (64-bit) value from FPR FRB into a DFP quad (128-bit) value and store it in VSR vD. This is a Decimal Floating-Point (DFP) instruction. FPSCR status fields may be updated to indicate conversion results.

Operation

quad_value ← convert_dfp_long_to_quad(FRB)
vD ← quad_value
FPSCR[...] ← updated as per conversion

Programming Note

The dctqpq instruction is used to convert a DFP number from long format to extended format. Ensure that the source register (FRAp) contains a valid DFP value in long format, and the target register (FRTp) is properly aligned for storing an extended format DFP number. This operation does not alter the FPSCR register.