3-617
INSTRUCTION SET REFERENCE
RSQRTPS—Packed Single-FP Square Root Reciprocal
Description
RSQRTPS returns an approximation of the reciprocal of the square root of the SP FP numbers
from xmm2/m128. The maximum error for this approximation is:
|Error| <= 1.5x2
-12
Figure 3-88. Operation of the RSQRTPS Instruction
Operation
DEST[31-0] = APPROX (1.0/SQRT(SRC/m128[31-0]));
DEST[63-32] = APPROX (1.0/SQRT(SRC/m128[63-32]));
DEST[95-64] = APPROX (1.0/SQRT(SRC/m128[95-64]));
DEST[127-96] = APPROX (1.0/SQRT(SRC/m128[127-96]));
Intel C/C++ Compiler Intrinsic Equivalent
__m128 _mm_rsqrt_ps(__m128 a)
Computes the approximations of the reciprocals of the square roots of the four SP FP values of a.
OpcodeInstruction
Description
0F,52,/rRSQRTPS xmm1,
xmm2/m128
Return a packed approximation of the square root of the
reciprocal of XMM2/Mem.
Xmm1
Xmm1
RSQRTPS xmm1,xmm2/m128
Xmm2/
m1280.0007716
0.0086553
36.0
=
=
=
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