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

4-140 Vol. 2B
INSTRUCTION SET REFERENCE, N-Z
POR—Bitwise Logical OR
Description
Performs a bitwise logical OR operation on the source operand (second operand) and
the destination operand (first operand) and stores the result in the destination
operand. The source operand can be an MMX technology register or a 64-bit memory
location or it can be an XMM register or a 128-bit memory location. The destination
operand can be an MMX technology register or an XMM register. Each bit of the result
is set to 1 if either or both of the corresponding bits of the first and second operands
are 1; otherwise, it is set to 0.
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 ← DEST OR SRC;
Intel C/C++ Compiler Intrinsic Equivalent
POR __m64 _mm_or_si64(__m64 m1, __m64 m2)
POR __m128i _mm_or_si128(__m128i m1, __m128i m2)
Flags Affected
None.
Numeric Exceptions
None.
Protected Mode Exceptions
#GP(0) If a memory operand effective address is outside the CS, DS,
ES, FS, or GS segment limit.
(128-bit operations only) If a memory operand is not aligned on
a 16-byte boundary, regardless of segment.
#SS(0) If a memory operand effective address is outside the SS
segment limit.
Opcode Instruction
64-Bit
Mode
Compat/
Leg Mode Description
0F EB /r POR mm, mm/m64 Valid Valid Bitwise OR of mm/m64 and mm.
66 0F EB /r POR xmm1,
xmm2/m128
Valid Valid Bitwise OR of xmm2/m128 and
xmm1.