Encoding:

Format:

HADD_U.df 

HADD_U.H wd,ws,wt

HADD_U.W wd,ws,wt

HADD_U.D wd,ws,wt

Purpose:

Vector Unsigned Horizontal Add

Vector zero extend and pairwise add the odd elements with the even elements to double width elements

Description:

(wd[2i+1], wd[2i]) = unsigned(ws[2i+1]) + unsigned(wt[2i])

The zero-extended odd elements in vector ws are added to the zero-extended even elements in vector wt producing a result twice the size of the input operands. The result is written to vector wd.

The operands are values in integer data format half the size of df. The results are values in integer data format df.

Restrictions:

No data-dependent exceptions are possible.

Operation:

HADD_U.H
   for i in 0 .. WRLEN/16-1
      WR[wd]16i+15..16i = hadd_u(WR[ws]16i+15..16i, WR[wt]16i+15..16i, 8)
   endfor
HADD_U.W
   for i in 0 .. WRLEN/32-1
      WR[wd]32i+31..32i = hadd_u(WR[ws]32i+31..32i, WR[wt]32i+31..32i, 16)
   endfor
HADD_U.D
   for i in 0 .. WRLEN/64-1
      WR[wd]64i+63..64i = hadd_u(WR[ws]64i+63..64i, WR[wt]64i+63..64i, 32)
   endfor
function hadd_u(ts, tt, n)
   t = (0n || ts2n-1..n) + (0n || ttn-1..0)
   return t
endfunction hadd_u

Exceptions:

Reserved Instruction Exception, MSA Disabled Exception.