In the x86 assembly programming language, MOVHPD is the name for a specific action performable by modern x86 processors with 2nd-generation Streaming SIMD Extensions (SSE2). This action involves either copying a number from memory to temporary space or copying a number from temporary space to memory.
Specifically, MOVHPD causes the value at an 8-byte memory region to be either copied to or assigned from the upper half of an XMM register.
Usage Opcode Assembly (Intel syntax) Assembly (AT&T syntax) intrinsic equivalent(s) built-in(s) 66 0F 16 /r MOVHPD xmm, m64 MOVHPD m64, xmm __m128d _mm_loadh_pd(__m128d a, double *dp) 66 0F 17 /r MOVHPD m64, xmm MOVHPD xmm, m64 void _mm_storeh_pd(double *pd, __m128d a)
The source operand can be either an XMM register (xmm) or a memory address (m64). When the source operand is an XMM register, the destination operand must be a memory address. When the source operand is a memory address, the destination operand must be an XMM register.
Note that the lower half of the XMM register is unaffected by this operation.
Potential exceptions
References page. Intel 64 and IA-32 Architectures Software Developer's Manual Volume 2A: Instruction Set Reference, A-M, November, 2006.
See also MOVAPS/MOVAPD MOVDDUP MOVHLPS MOVHPS/MOVHPD MOVLHPS MOVLPS/MOVLPD MOVMSKPS/MOVMSKPD MOVNTPS MOVSHDUP MOVSLDUP MOVSS/MOVSD MOVUPS/MOVUPD
x86 instruction listings