Performs an SIMD computation of the approximate reciprocals of the square roots of the four packed single-precision floating-point values in the source operand (second operand) and stores the packed single-precision floating-point results in the destination operand. The source operand can be an XMM register or a 128-bit memory location. The destination operand is an XMM register. See Figure 10-5 in the IA-32 Intel Architecture Software Developer's Manual, Volume 1 for an illustration of an SIMD single-precision floating-point operation.

The relative error for this approximation is:

|Relative Error| <= 1.5 * 2-12 The RSQRTPS instruction is not affected by the rounding control bits in the MXCSR register.

When a source value is a 0.0, an infinite of the sign of the source value is returned. A denormal source value is treated as a 0.0 (of the same sign). When a source value is a negative value (other than -0.0), a floating-point indefinite is returned. When a source value is an SNaN or QNaN, the SNaN is converted to a QNaN or the source QNaN is returned.

Destination[0..31] = Approximate(1.0 / SquareRoot(Source[0..31]));
Destination[32..63] = Approximate(1.0 / SquareRoot(Source[32..63]));
Destination[64..95] = Approximate(1.0 / SquareRoot(Source[64..95]));
Destination[96..127] = Approximate(1.0 / SquareRoot(Source[96..127]));