dctdp

Decimal Convert To DFP Long

dctdp FRT, FRB

Converts DFP Short (32-bit compressed) to DFP Long (64-bit).

Encoding

Binary Layout

59

0:5

FRT

6:10

/

11:15

FRB

16:20

258

21:30

Rc

31

 

Format X-form

Opcode 0xEC000204

Extension Decimal Floating-Point

Operands

• FRT
  Target
• FRB
  Source

Example

dctdp f1, f3

Registers Altered

FPSCR (FPRF, FR, FI), CR (CR1)

Related

More in Decimal Floating-Point

Reference

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

Description

The DFP short operand in bits 32:63 of FRB is converted to DFP long format and the converted result is placed into FRT. The sign of the result is the same as the sign of the source operand. The ideal exponent is the exponent of the source operand.

Operation

FRT <- ConvertToDFPLong(FRB)

Programming Note

Note that DFP short format is a storage-only format. Therefore, conversion of a short SNaN to long format will not cause an exception and the SNaN is preserved. Subsequent operation on that SNaN in long format will cause an exception.