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AIX Version 4.3 Assembler Language Reference

## fnabs (Floating Negative Absolute Value) Instruction

### Purpose

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

### Syntax

 fnabs FRT,FRB fnabs. FRT,FRB

### Description

The fnabs instruction places the negative absolute of the contents of floating-point register (FPR) FRB with bit 0 set to 1 into the target FPR FRT.

The fnabs 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 fnabs None 0 None fnabs. None 1 FX,FEX,VX,OX

The two syntax forms of the fnabs 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

1. The following code negates the absolute contents of FPR 5 and places the result into FPR 6:
```# Assume FPR 5 contains 0x400C 0000 0000 0000.
fnabs 6,5
# FPR 6 now contains 0xC00C 0000 0000 0000.```
2. The following code negates the absolute 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.
# Assume CR = 0.
fnabs. 6,4
# FPR 6 now contains 0xC053 4000 0000 0000.
# CR now contains 0x0.```

### Related Information

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