Assembler Language Reference

fneg (Floating Negate) Instruction

Purpose

Negates the contents of a floating-point register and places the result into another floating-point register.

Syntax

Bits	Value
0-5	63
6-10	FRT
11-15	///
16-20	FRB
21-30	40
31	Rc

fneg	FRT, FRB
fneg.	FRT, FRB

Description

The fneg instruction places the negated contents of floating-point register FRB into the target FPR FRT.

The fneg instruction has two syntax forms. Each syntax form has a different effect on Condition Register Field 1.

Syntax Form	Floating-Point Status and Control Register	Record Bit (Rc)	Condition Register Field 1
fneg	None	0	None
fneg.	None	1	FX,FEX,VX,OX

The two syntax forms of the fneg instruction never affect the Floating-Point Status and Control Register. If the syntax form sets the Record (Rc) bit to 1, the instruction affects the Floating-Point Exception (FX), Floating-Point Enabled Exception (FEX), Floating-Point Invalid Operation Exception (VX), and Floating-Point Overflow Exception (OX) bits in Condition Register Field 1.

Parameters

FRT	Specifies target floating-point register for operation.
FRB	Specifies source floating-point register for operation.

Examples

The following code negates the contents of FPR 5 and places the result into FPR 6:

# Assume FPR 5 contains 0x400C 0000 0000 0000.
fneg 6,5
# FPR 6 now contains 0xC00C 0000 0000 0000.

The following code negates the contents of FPR 4, places the result into FPR 6, and sets Condition Register Field 1 to reflect the result of the operation:
```
# Assume FPR 4 contains 0xC053 4000 0000 0000.
fneg. 6,4
# FPR 6 now contains 0x4053 4000 0000 0000.
# CR now contains 0x0000 0000.
```

Related Information

Floating-Point Processor .

Floating-Point Move Instructions .

Interpreting the Contents of a Floating-Point Register .