fabs (Floating Absolute Value) instruction
Purpose
Stores the absolute value of the contents of a floating-point register in another floating-point register.
Syntax
Bits | Value |
---|---|
0-5 | 63 |
6-10 | FRT |
11-15 | /// |
16-20 | FRB |
21-30 | 264 |
31 | Rc |
Description
The fabs instruction sets bit 0 of floating-point register (FPR) FRB to 0 and places the result into FPR FRT.
The fabs instruction has two syntax forms. Each syntax form has a different effect on Condition Register Field 1.
Item | Description | ||
---|---|---|---|
Syntax Form | Floating-Point Status and Control Register | Record Bit (Rc) | Condition Register Field 1 |
fabs | None | 0 | None |
fabs. | None | 1 | FX,FEX,VX,OX |
The two syntax forms of the fabs 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 Summary (FX), Floating-Point Enabled Exception Summary (FEX), Floating-Point Invalid Operation Exception Summary (VX), and Floating-Point Overflow Exception (OX) bits in Condition Register Field 1.
Parameters
Item | Description |
---|---|
FRT | Specifies target floating-point register for operation. |
FRB | Specifies source floating-point register for operation. |
Examples
- The following code sets bit 0 of FPR 4 to zero and
place sthe result in FPR 6:
# Assume FPR 4 holds 0xC053 4000 0000 0000. fabs 6,4 # GPR 6 now holds 0x4053 4000 0000 0000.
- The following code sets bit 0 of FPR 25 to zero,
places the result in FPR 6, and sets Condition Register Field 1 to
reflect the result of the operation:
# Assume FPR 25 holds 0xFFFF FFFF FFFF FFFF. fabs. 6,25 # GPR 6 now holds 0x7FFF FFFF FFFF FFFF.