x86 Assembly Language Reference Manual

MMX Instructions

The MMX instructions enable x86 processors to perform single-instruction, multiple-data(SIMD) operations on packed byte, word, doubleword, or quadword integer operands contained in memory, in MMX registers, or in general-purpose registers.

Data Transfer Instructions (MMX)

The data transfer instructions move doubleword and quadword operands between MMX registers and between MMX registers and memory.

Table 3–20 Data Transfer Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description	Notes
`movd`	`MOVD`	move doubleword	`movdq` valid only under `-xarch=amd64`
`movq`	`MOVQ`	move quadword	valid only under `-xarch=amd64`

Conversion Instructions (MMX)

The conversion instructions pack and unpack bytes, words, and doublewords.

Table 3–21 Conversion Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description
`packssdw`	`PACKSSDW`	pack doublewords into words with signed saturation
`packsswb`	`PACKSSWB`	pack words into bytes with signed saturation
`packuswb`	`PACKUSWB`	pack words into bytes with unsigned saturation
`punpckhbw`	`PUNPCKHBW`	unpack high-order bytes
`punpckhdq`	`PUNPCKHDQ`	unpack high-order doublewords
`punpckhwd`	`PUNPCKHWD`	unpack high-order words
`punpcklbw`	`PUNPCKLBW`	unpack low-order bytes
`punpckldq`	`PUNPCKLDQ`	unpack low-order doublewords
`punpcklwd`	`PUNPCKLWD`	unpack low-order words

Packed Arithmetic Instructions (MMX)

The packed arithmetic instructions perform packed integer arithmetic on packed byte, word, and doubleword integers.

Table 3–22 Packed Arithmetic Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description
`paddb`	`PADDB`	add packed byte integers
`paddd`	`PADDD`	add packed doubleword integers
`paddsb`	`PADDSB`	add packed signed byte integers with signed saturation
`paddsw`	`PADDSW`	add packed signed word integers with signed saturation
`paddusb`	`PADDUSB`	add packed unsigned byte integers with unsigned saturation
`paddusw`	`PADDUSW`	add packed unsigned word integers with unsigned saturation
`paddw`	`PADDW`	add packed word integers
`pmaddwd`	`PMADDWD`	multiply and add packed word integers
`pmulhw`	`PMULHW`	multiply packed signed word integers and store high result
`pmullw`	`PMULLW`	multiply packed signed word integers and store low result
`psubb`	`PSUBB`	subtract packed byte integers
`psubd`	`PSUBD`	subtract packed doubleword integers
`psubsb`	`PSUBSB`	subtract packed signed byte integers with signed saturation
`psubsw`	`PSUBSW`	subtract packed signed word integers with signed saturation
`psubusb`	`PSUBUSB`	subtract packed unsigned byte integers with unsigned saturation
`psubusw`	`PSUBUSW`	subtract packed unsigned word integers with unsigned saturation
`psubw`	`PSUBW`	subtract packed word integers

Comparison Instructions (MMX)

The compare instructions compare packed bytes, words, or doublewords.

Table 3–23 Comparison Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description
`pcmpeqb`	`PCMPEQB`	compare packed bytes for equal
`pcmpeqd`	`PCMPEQD`	compare packed doublewords for equal
`pcmpeqw`	`PCMPEQW`	compare packed words for equal
`pcmpgtb`	`PCMPGTB`	compare packed signed byte integers for greater than
`pcmpgtd`	`PCMPGTD`	compare packed signed doubleword integers for greater than
`pcmpgtw`	`PCMPGTW`	compare packed signed word integers for greater than

Logical Instructions (MMX)

The logical instructions perform logical operations on quadword operands.

Table 3–24 Logical Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description
`pand`	`PAND`	bitwise logical AND
`pandn`	`PANDN`	bitwise logical AND NOT
`por`	`POR`	bitwise logical OR
`pxor`	`PXOR`	bitwise logical XOR

Shift and Rotate Instructions (MMX)

The shift and rotate instructions operate on packed bytes, words, doublewords, or quadwords in 64–bit operands.

Table 3–25 Shift and Rotate Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description
`pslld`	`PSLLD`	shift packed doublewords left logical
`psllq`	`PSLLQ`	shift packed quadword left logical
`psllw`	`PSLLW`	shift packed words left logical
`psrad`	`PSRAD`	shift packed doublewords right arithmetic
`psraw`	`PSRAW`	shift packed words right arithmetic
`psrld`	`PSRLD`	shift packed doublewords right logical
`psrlq`	`PSRLQ`	shift packed quadword right logical
`psrlw`	`PSRLW`	shift packed words right logical

State Management Instructions (MMX)

The emms (EMMS) instruction clears the MMX state from the MMX registers.

Table 3–26 State Management Instructions (MMX)


Solaris Mnemonic	Intel/AMD Mnemonic	Description	Notes
`emms`	`EMMS`	empty MMX state