Intel® Architecture Instruction Set Extensions Programming Reference

INSTRUCTION SET REFERENCE
PSADBW — Compute Sum of Absolute Differences
Opcode/
Instruction
Description
Instruction Operand Encoding
Computes the absolute value of the difference of packed groups of 8 unsigned byte integers from the second source
operand and from the first source operand. The first 8 differences are summed to produce an unsigned word
integer that is stored in the low word of the destination; the second 8 differences are summed to produce an
unsigned word in bits 79:64 of the destination. In case of VEX.256 encoded version, the third group of 8 differences
are summed to produce an unsigned word in bits[143:128] of the destination register and the fourth group of 8
differences are summed to produce an unsigned word in bits[207:192] of the destination register. The remaining
words of the destination are set to 0.
128-bit Legacy SSE version: The first source operand and destination register are XMM registers. The second
source operand is an XMM register or a 128-bit memory location. Bits (255:128) of the corresponding YMM destination
register remain unchanged.
VEX.128 encoded version: The first source operand and destination register are XMM registers. The second source
operand is an XMM register or a 128-bit memory location. Bits (255:128) of the corresponding YMM register are
zeroed.
VEX.256 encoded version: The first source operand and destination register are YMM registers. The second source
operand is an YMM register or a 256-bit memory location.
Operation
Op/
En
64/32
-bit
Mode
VPSADBW (VEX.256 encoded version)
TEMP0 ABS(SRC1[7:0] - SRC2[7:0])
(* Repeat operation for bytes 2 through 30*)
TEMP31 ABS(SRC1[255:248] - SRC2[255:248])
DEST[15:0] SUM(TEMP0:TEMP7)
DEST[63:16] 000000000000H
DEST[79:64] SUM(TEMP8:TEMP15)
DEST[127:80] 00000000000H
DEST[143:128] SUM(TEMP16:TEMP23)
CPUID
Feature
Flag
Description
66 0F F6 /r A V/V SSE2 Computes the absolute differences of the packed unsigned byte
PSADBW xmm1, xmm2/m128
integers from xmm2 /m128 and xmm1; the 8 low differences and 8
high differences are then summed separately to produce two
unsigned word integer results.
VEX.NDS.128.66.0F.WIG F6 /r B V/V AVX Computes the absolute differences of the packed unsigned byte
VPSADBW xmm1, xmm2,
xmm3/m128
integers from xmm3 /m128 and xmm2; the 8 low differences and 8
high differences are then summed separately to produce two
unsigned word integer results.
VEX.NDS.256.66.0F.WIG F6 /r B V/V AVX2 Computes the absolute differences of the packed unsigned byte
VPSADBW ymm1, ymm2,
ymm3/m256
integers from ymm3 /m256 and ymm2; then each consecutive 8 differences
are summed separately to produce four unsigned word
integer results.
Op/En Operand 1 Operand 2 Operand 3 Operand 4
A ModRM:reg (r, w) ModRM:r/m (r) NA NA
B ModRM:reg (w) VEX.vvvv ModRM:r/m (r) NA
5-118 Ref. # 319433-014