riscv/insns/vsmul_vx.h


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// vsmul.vx vd, vs2, rs1
VRM xrm = P.VU.get_vround_mode();
int64_t int_max = INT64_MAX >> (64 - P.VU.vsew);
int64_t int_min = INT64_MIN >> (64 - P.VU.vsew);

VI_VX_LOOP
({
  bool overflow = rs1 == vs2 && rs1 == int_min;
  int128_t result = (int128_t)rs1 * (int128_t)vs2;

  // rounding
  INT_ROUNDING(result, xrm, sew - 1);

  // remove guard bits
  result = result >> (sew - 1);

  // max saturation
  if (overflow) {
    result = int_max;
    P_SET_OV(1);
  }

  vd = result;
})