drintn

Decimal Floating-Point Round To FP Integer Without Inexact

drintn R,FRT,FRB,RMC

Rounds a decimal floating-point number to an integer without recognizing an inexact exception.

Encoding

Binary Layout

0

0:5

FRT

6:10

R

11:14

FRB

15

RMC

16:20

Rc

21:31

 

Format Z23-form

Opcode 0xEC0001C6

Extension Decimal Floating-Point

Operands

• R
  Rounding mode control
• FRT
  Target Floating-Point Register
• FRB
  Source Floating-Point Register
• RMC
  Rounding Mode Control

Example

drintn 0, f1, f3, 0

Registers Altered

FPSCR, (FPRF, FX, VXSNAN), FPSCR, (FR, FI), CR1, CR0

Related

More in Decimal Floating-Point

Reference

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

Description

This operation rounds the value in FRB to an integer using the specified rounding mode (RMC) and places the result in FRT. It does not recognize an inexact exception.

Operation

if 'drintn' then
    FRT <- Round(FRB, RMC)
    FI <- 0
    FR <- 0
    VXSNAN <- 0
    if Rc=1 then
        CR1 <- ClassAndSign(FRT)
else if 'drintn.' then
    FRT <- Round(FRB, RMC)
    FI <- 0
    FR <- 0
    VXSNAN <- 0
    CR1 <- ClassAndSign(FRT)

Programming Note

The DFP Round To FP Integer Without Inexact and DFP Round To FP Integer Without Inexact Quad instructions can be used to implement decimal equivalents of several C99 rounding functions by specifying the appropriate R and RMC field values.