frin.

Floating Round to Integer Nearest (Record)

frin. FRT,FRB

Rounds the floating-point operand in register FRB to an integral value using the rounding mode round to nearest.

Encoding

Binary Layout

18

0:5

FRT

6:29

FRB

30

Rc

31

 

Format X-form

Opcode 0xFC000310

Extension Floating-Point

Operands

• FRT
  Target Floating-Point Register
• FRB
  Source Floating-Point Register

Example

frin f1, f3

Registers Altered

FPSCR, (FPRF, FX, VXSNAN), FPSCR, (FR, FI), CR1, (if, Rc=1), CR0

Related

More in Floating-Point

Reference

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

Description

The floating-point operand in register FRB is rounded to an integral value as follows, with the result placed into register FRT. If the sign of the operand is positive, (FRB) + 0.5 is truncated to an integral value, otherwise (FRB) - 0.5 is truncated to an integral value.

Operation

if 'frin' then
    if (FRB) >= 0 then
        FRT <- truncate((FRB) + 0.5)
    else
        FRT <- truncate((FRB) - 0.5)

Programming Note

These instructions set FR and FI to 0b00 regardless of whether the result is inexact or rounded because there is a desire to preserve the value of XX.