# PADDUSB/PADDUSW

# Add Packed Unsigned Integers with Unsigned Saturation

Opcode	Mnemonic	Description
0F DC /r PADDUSB mm, mm/m64	Add packed unsigned byte integers from mm/m64 and mm and saturate the results.
66 0F DC /r PADDUSB xmm1, xmm2/m128	Add packed unsigned byte integers from xmm2/m128 and xmm1 saturate the results.
0F DD /r PADDUSW mm, mm/m64	Add packed unsigned word integers from mm/m64 and mm and saturate the results.
66 0F DD /r PADDUSW xmm1, xmm2/m128	Add packed unsigned word integers from xmm2/m128 to xmm1 and saturate the results.

# Description

Performs an SIMD add of the packed unsigned integers from the source operand (second operand) and the destination operand (first operand), and stores the packed integer results in the destination operand. See Figure 9-4 in the IA-32 Intel Architecture Software Developer's Manual, Volume 1 for an illustration of an SIMD operation. Overflow is handled with unsigned saturation, as described in the following paragraphs.

These instructions can operate on either 64-bit or 128-bit operands. When operating on 64-bit operands, the destination operand must be an MMX technology register and the source operand can be either an MMX technology register or a 64-bit memory location. When operating on 128- bit operands, the destination operand must be an XMM register and the source operand can be either an XMM register or a 128-bit memory location.

The PADDUSB instruction adds packed unsigned byte integers. When an individual byte result is beyond the range of an unsigned byte integer (that is, greater than FFH), the saturated value of FFH is written to the destination operand.

The PADDUSW instruction adds packed unsigned word integers. When an individual word result is beyond the range of an unsigned word integer (that is, greater than FFFFH), the saturated value of FFFFH is written to the destination operand.

# Operation

switch(Instruction) {
	case PADDUSB:
		if(OperandSize == 64) {
			//PADDUSB instruction with 64-bit operands:
			Destination[0..7] = SaturateToUnsignedByte(Destination[0..7] + Source[0..7]);
			Destination[8..15] = SaturateToUnsignedByte(Destination[8..15] + Source[8..15]);
			Destination[16..23] = SaturateToUnsignedByte(Destination[16..23] + Source[16..23]);
			Destination[24..31] = SaturateToUnsignedByte(Destination[24..31] + Source[24..31]);
			Destination[32..39] = SaturateToUnsignedByte(Destination[32..39] + Source[32..39]);
			Destination[40..47] = SaturateToUnsignedByte(Destination[40..47] + Source[40..47]);
			Destination[48..55] = SaturateToUnsignedByte(Destination[48..55] + Source[48..55]);
			Destination[56..63] = SaturateToUnsignedByte(Destination[56..63] + Source[56..63]);
		}
		else {
			//PADDUSB instruction with 128-bit operands:
			Destination[0..7] = SaturateToUnsignedByte(Destination[0..7] + Source[0..7]);
			Destination[8..15] = SaturateToUnsignedByte(Destination[8..15] + Source[8..15]);
			Destination[16..23] = SaturateToUnsignedByte(Destination[16..23] + Source[16..23]);
			Destination[24..31] = SaturateToUnsignedByte(Destination[24..31] + Source[24..31]);
			Destination[32..39] = SaturateToUnsignedByte(Destination[32..39] + Source[32..39]);
			Destination[40..47] = SaturateToUnsignedByte(Destination[40..47] + Source[40..47]);
			Destination[48..55] = SaturateToUnsignedByte(Destination[48..55] + Source[48..55]);
			Destination[56..63] = SaturateToUnsignedByte(Destination[56..63] + Source[56..63]);
			Destination[64..71] = SaturateToUnsignedByte(Destination[64..71] + Source[64..71]);
			Destination[72..79] = SaturateToUnsignedByte(Destination[72..79] + Source[]72..79);
			Destination[80..87] = SaturateToUnsignedByte(Destination[80..87] + Source[80..87]);
			Destination[88..95] = SaturateToUnsignedByte(Destination[88..95] + Source[88..95]);
			Destination[96..103] = SaturateToUnsignedByte(Destination[96..103] + Source[96..103]);
			Destination[104..111] = SaturateToUnsignedByte(Destination[104..111] + Source[104..111]);
			Destination[112..119] = SaturateToUnsignedByte(Destination[112..119] + Source[112..119]);
			Destination[120..127] = SaturateToUnsignedByte(Destination[120..111] + Source[120..127]);
		}
		break;
	case PADDUSW:
		if(OperandSize == 64) {
			//PADDUSW instruction with 64-bit operands:
			Destination[0..15] = SaturateToUnsignedWord(Destination[0..15] + Source[0..15]);
			Destination[16..31] = SaturateToUnsignedWordDestination[16..31] + Source[16..31]);
			Destination[32..47] = SaturateToUnsignedWordDestination[32..47] + Source[32..47]);
			Destination[48..63] = SaturateToUnsignedWordDestination[48..63] + Source[48..63]);
		}
		else {
			//PADDUSW instruction with 128-bit operands:
			Destination[0..15] = SaturateToUnsignedWordDestination[0..15] + Source[0..15]);
			Destination[16..31] = SaturateToUnsignedWordDestination[16..31] + Source[16..31]);
			Destination[32..47] = SaturateToUnsignedWordDestination[32..47] + Source[32..47]);
			Destination[48..63] = SaturateToUnsignedWordDestination[48..63] + Source[48..63]);
			Destination[64..79] = SaturateToUnsignedWordDestination[64..79] + Source[64..79]);
			Destination[80..95] = SaturateToUnsignedWordDestination[80..95] + Source[80..95]);
			Destination[96..111] = SaturateToUnsignedWordDestination[96..111] + Source[96..111]);
			Destination[112..127] = SaturateToSignedWordDestination[112..127] + Source[112..127];
		}
		break;
}

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# Flags affected

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.
#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.
#UD	If EM in CR0 is set. 128-bit operations will generate #UD only if OSFXSR in CR4 is 0. Execution of 128-bit instructions on a non-SSE2 capable processor (one that is MMX technology capable) will result in the instruction operating on the mm registers, not #UD.
#NM	If TS in CR0 is set.
#MF	(64-bit operations only) If there is a pending x87 FPU exception.
#PF(fault-code)	If a page fault occurs.

# Real-Address Mode Exceptions


#GP(0)	(128-bit operations only) If a memory operand is not aligned on a 16-byte boundary, regardless of segment. If any part of the operand lies outside of the effective address space from 0 to FFFFH.
#GP(0)	(128-bit operations only) If a memory operand is not aligned on a 16-byte boundary, regardless of segment. If any part of the operand lies outside of the effective address space from 0 to FFFFH.
#UD	If EM in CR0 is set. 128-bit operations will generate #UD only if OSFXSR in CR4 is 0. Execution of 128-bit instructions on a non-SSE2 capable processor (one that is MMX technology capable) will result in the instruction operating on the mm registers, not #UD.
#NM	If TS in CR0 is set.

# Virtual-8086 Mode Exceptions

Same exceptions as in Real Address Mode


#PF(fault-code)	For a page fault.
#PF(fault-code)	For a page fault.

# Numeric Exceptions

None.

Instruction	Latency	Throughput	Execution Unit
CPUID	0F3n/0F2n/069n	0F3n/0F2n/069n	0F2n
PADDUSB/PADDUSW mm, mm	2/2/-	1/1/-	MMX_ALU
PADDUSB/PADDUSW xmm, xmm	2/2/1	2/2/1	MMX_ALU

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