vrem.vv

No synopsis available.

This instruction is defined by:

V, version >= 0

This instruction is included in the following profiles:

RVA22S64 (Optional)
RVA22U64 (Optional)

Encoding

Assembly format

vrem.vv vm, vs2, vs1, vd

Synopsis

No description available.

Access

M	HS	U	VS	VU
Always	Always	Always	Always	Always

Always

Decode Variables

Bits<1> vm = $encoding[25];
Bits<5> vs2 = $encoding[24:20];
Bits<5> vs1 = $encoding[19:15];
Bits<5> vd = $encoding[11:7];

Execution

IDL
Sail

{
  let SEW      = get_sew();
  let LMUL_pow = get_lmul_pow();
  let num_elem = get_num_elem(LMUL_pow, SEW);

  if illegal_normal(vd, vm) then { handle_illegal(); return RETIRE_FAIL };

  let 'n = num_elem;
  let 'm = SEW;

  let vm_val  : vector('n, dec, bool)     = read_vmask(num_elem, vm, 0b00000);
  let vs1_val : vector('n, dec, bits('m)) = read_vreg(num_elem, SEW, LMUL_pow, vs1);
  let vs2_val : vector('n, dec, bits('m)) = read_vreg(num_elem, SEW, LMUL_pow, vs2);
  let vd_val  : vector('n, dec, bits('m)) = read_vreg(num_elem, SEW, LMUL_pow, vd);
  result      : vector('n, dec, bits('m)) = undefined;
  mask        : vector('n, dec, bool)     = undefined;

  (result, mask) = init_masked_result(num_elem, SEW, LMUL_pow, vd_val, vm_val);

  foreach (i from 0 to (num_elem - 1)) {
    if mask[i] then {
      result[i] = match funct6 {
        MVV_VAADDU   => {
                          let result_add = zero_extend('m + 1, vs2_val[i]) + zero_extend('m + 1, vs1_val[i]);
                          let rounding_incr = get_fixed_rounding_incr(result_add, 1);
                          slice(result_add >> 1, 0, 'm) + zero_extend('m, rounding_incr)
                        },
        MVV_VAADD    => {
                          let result_add = sign_extend('m + 1, vs2_val[i]) + sign_extend('m + 1, vs1_val[i]);
                          let rounding_incr = get_fixed_rounding_incr(result_add, 1);
                          slice(result_add >> 1, 0, 'm) + zero_extend('m, rounding_incr)
                        },
        MVV_VASUBU   => {
                          let result_sub = zero_extend('m + 1, vs2_val[i]) - zero_extend('m + 1, vs1_val[i]);
                          let rounding_incr = get_fixed_rounding_incr(result_sub, 1);
                          slice(result_sub >> 1, 0, 'm) + zero_extend('m, rounding_incr)
                        },
        MVV_VASUB    => {
                          let result_sub = sign_extend('m + 1, vs2_val[i]) - sign_extend('m + 1, vs1_val[i]);
                          let rounding_incr = get_fixed_rounding_incr(result_sub, 1);
                          slice(result_sub >> 1, 0, 'm) + zero_extend('m, rounding_incr)
                        },
        MVV_VMUL     => get_slice_int(SEW, signed(vs2_val[i]) * signed(vs1_val[i]), 0),
        MVV_VMULH    => get_slice_int(SEW, signed(vs2_val[i]) * signed(vs1_val[i]), SEW),
        MVV_VMULHU   => get_slice_int(SEW, unsigned(vs2_val[i]) * unsigned(vs1_val[i]), SEW),
        MVV_VMULHSU  => get_slice_int(SEW, signed(vs2_val[i]) * unsigned(vs1_val[i]), SEW),
        MVV_VDIVU    => {
                          let q : int = if unsigned(vs1_val[i]) == 0 then -1 else quot_round_zero(unsigned(vs2_val[i]), unsigned(vs1_val[i]));
                          to_bits(SEW, q)
                        },
        MVV_VDIV     => {
                          let elem_max : int = 2 ^ (SEW - 1) - 1;
                          let elem_min : int = 0 - 2 ^ (SEW - 1);
                          let q : int = if signed(vs1_val[i]) == 0 then -1 else quot_round_zero(signed(vs2_val[i]), signed(vs1_val[i]));
                          /* check for signed overflow */
                          let q' : int = if q > elem_max then elem_min else q;
                          to_bits(SEW, q')
                        },
        MVV_VREMU    => {
                          let r : int = if unsigned(vs1_val[i]) == 0 then unsigned(vs2_val[i]) else rem_round_zero(unsigned(vs2_val[i]), unsigned(vs1_val[i]));
                          /* signed overflow case returns zero naturally as required due to -1 divisor */
                          to_bits(SEW, r)
                        },
        MVV_VREM     => {
                          let r : int = if signed(vs1_val[i]) == 0 then signed(vs2_val[i]) else rem_round_zero(signed(vs2_val[i]), signed(vs1_val[i]));
                          /* signed overflow case returns zero naturally as required due to -1 divisor */
                          to_bits(SEW, r)
                        }
      }
    }
  };

  write_vreg(num_elem, SEW, LMUL_pow, vd, result);
  vstart = zeros();
  RETIRE_SUCCESS
}