Intel 64 and IA-32 Architectures Software Developers Manual Volume 2B, Instruction Set Reference, N-Z

4-324 Vol. 2B
INSTRUCTION SET REFERENCE, N-Z
SQRTSD—Compute Square Root of Scalar Double-Precision Floating-
Point Value
Description
Computes the square root of the low double-precision floating-point value in the
source operand (second operand) and stores the double-precision floating-point
result in the destination operand. The source operand can be an XMM register or a
64-bit memory location. The destination operand is an XMM register. The high quad-
word of the destination operand remains unchanged. See Figure 11-4 in the Intel
®
64 and IA-32 Architectures Software Developer’s Manual, Volume 1, for an illustra-
tion of a scalar double-precision floating-point operation.
In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to
access additional registers (XMM8-XMM15).
Operation
DEST[63:0] ← SQRT(SRC[63:0]);
(* DEST[127:64] unchanged *)
Intel C/C++ Compiler Intrinsic Equivalent
SQRTSD __m128d _mm_sqrt_sd (m128d a)
SIMD Floating-Point Exceptions
Invalid, Precision, Denormal.
Protected Mode Exceptions
#GP(0) For an illegal memory operand effective address in the CS, DS,
ES, FS or GS segments.
#SS(0) For an illegal address in the SS segment.
#PF(fault-code) For a page fault.
#NM If CR0.TS[bit 3] = 1.
#XM If an unmasked SIMD floating-point exception and CR4.OSXM-
MEXCPT[bit 10] = 1.
Opcode Instruction
64-Bit
Mode
Compat/
Leg Mode Description
F2 0F 51
/r
SQRTSD xmm1,
xmm2/m64
Valid Valid Computes square root of the
low double-precision floating-
point value in xmm2/m64 and
stores the results in xmm1.