Encoding:

Format:

SAT_U.df 

SAT_U.B wd,ws,m

SAT_U.H wd,ws,m

SAT_U.W wd,ws,m

SAT_U.D wd,ws,m

Purpose:

Immediate Unsigned Saturate

Immediate selected bit width saturation of unsigned values.

Description:

wd[i] = saturate_unsigned(ws[i], m+1)

Unsigned elements in vector ws are saturated to unsigned values of m+1 bits without changing the data width. The result is written to vector wd.

The operands and results are values in integer data format df.

Restrictions:

No data-dependent exceptions are possible.

Operation:

SAT_U.B
   for i in 0 .. WRLEN/8-1
      WR[wd]8i+7..8i = sat_u(WR[ws]8i+7..8i, 8, m+1)
   endfor
SAT_U.H
   for i in 0 .. WRLEN/16-1
      WR[wd]16i+15..16i = sat_u(WR[ws]16i+15..16i, 16, m+1)
   endfor
SAT_U.W
   for i in 0 .. WRLEN/32-1
      WR[wd]32i+31..32i = sat_u(WR[ws]32i+31..32i, 32, m+1)
   endfor
SAT_U.D
   for i in 0 .. WRLEN/64-1
      WR[wd]64i+63..64i = sat_u(WR[ws]64i+63..64i, 64, m+1)
   endfor
function sat_u(tt, n, b)
   if ttn-1..b != 0n-b then
      return 0n-b || 1b
   else
      return tt
   endif
endfunction sat_u

Exceptions:

Reserved Instruction Exception, MSA Disabled Exception.