frsqrte

Floating Reciprocal Square Root Estimate

frsqrte FRT,FRB
frsqrte. FRT,FRB

Estimates the reciprocal of the square root of a floating-point operand.

Details

A estimate of the reciprocal of the square root of the floating-point operand in register FRB is placed into register FRT. The estimate placed into register FRT is correct to a precision of one part in 32 of the reciprocal of the square root of (FRB).

Pseudocode Operation

FRT ← estimate(1 / √FRB)

Programming Note

The frsqrte instruction provides a fast, approximate reciprocal square root calculation. It is useful for performance-critical applications where precision can be traded for speed. Ensure the input in FRB is positive to avoid undefined behavior. The result may need refinement for higher precision applications.

Example

frsqrte f1, f3

Encoding

Binary Layout
63
0
FRT
6
0
11
0
26
FRB
26
/
 
Format A-form
Opcode 0xFC000034
Extension Floating-Point
Registers Altered FPSCR, CR1

Operands

  • FRT
    Target
  • FRB
    Source