3-501
INSTRUCTION SET REFERENCE
PEXTRW—Extract Word
Description
The PEXTRW instruction moves the word in MM (selected by the two least significant bits of
imm8) to the lower half of a 32-bit integer register.
Figure 3-63. Operation of the PEXTRW Instruction
Operation
SEL = imm8 AND 0X3;
MM_TEMP = (SRC >> (SEL * 16)) AND 0XFFFF;
r32[15-0] = MM_TEMP[15-0];
r32[31-16] = 0X0000;
Intel C/C++ Compiler Intrinsic Equivalent
Pre-4.0 Intel C/C++ Compiler intrinsic:
int_m_pextrw(__m64 a, int n)
Version 4.0 and later Intel C/C++ Compiler intrinsic:
int_mm_extract_pi16(__m64 a, int n)
Extracts one of the four words of a. The selector n must be an immediate.
OpcodeInstruction
Description
0F,C5, /r, ibPEXTRW r32, mm, imm8Extract the word pointed to by imm8 from MM and move it
to a 32-bit integer register.
PEXTRW r32,mm1,0x09
Mm1
R32
R32
=
=
