A.5.199 PADDSB, PADDSW: Add Packed Signed Integers With Saturation
PADDSB mm1,mm2/m64 ; 0F EC /r [PENT,MMX]
PADDSW mm1,mm2/m64 ; 0F ED /r [PENT,MMX]
PADDSB xmm1,xmm2/m128 ; 66 0F EC /r [WILLAMETTE,SSE2]
PADDSW xmm1,xmm2/m128 ; 66 0F ED /r [WILLAMETTE,SSE2]
PADDSx performs packed addition of the two operands, storing the result
in the destination (first) operand. PADDSB treats the operands as packed
bytes, and adds each byte individually; and PADDSW treats the operands
as packed words.
When an individual result is too large to fit in its destination, a
saturated value is stored. The resulting value is the value with the
largest magnitude of the same sign as the result which will fit in the
available space.