Ejemplos de nir_ssa_for_alu_src en C++ (Cpp)

Ejemplo n.º 1

Archivo: nir_lower_wpos_ytransform.c Proyecto: Echelon9/mesa

/* turns 'fddy(p)' into 'fddy(fmul(p, transform.x))' */
static void
lower_fddy(lower_wpos_ytransform_state *state, nir_alu_instr *fddy)
{
    nir_builder *b = &state->b;
    nir_ssa_def *p, *pt, *trans;

    b->cursor = nir_before_instr(&fddy->instr);

    p = nir_ssa_for_alu_src(b, fddy, 0);
    trans = get_transform(state);
    pt = nir_fmul(b, p, nir_channel(b, trans, 0));

    nir_instr_rewrite_src(&fddy->instr,
                          &fddy->src[0].src,
                          nir_src_for_ssa(pt));

    for (unsigned i = 0; i < 4; i++)
        fddy->src[0].swizzle[i] = MIN2(i, pt->num_components - 1);
}

Ejemplo n.º 2

Archivo: nir_lower_idiv.c Proyecto: Distrotech/Mesa

static void
convert_instr(nir_builder *bld, nir_alu_instr *alu)
{
   nir_ssa_def *numer, *denom, *af, *bf, *a, *b, *q, *r;
   nir_op op = alu->op;
   bool is_signed;

   if ((op != nir_op_idiv) &&
       (op != nir_op_udiv) &&
       (op != nir_op_umod))
      return;

   is_signed = (op == nir_op_idiv);

   bld->cursor = nir_before_instr(&alu->instr);

   numer = nir_ssa_for_alu_src(bld, alu, 0);
   denom = nir_ssa_for_alu_src(bld, alu, 1);

   if (is_signed) {
      af = nir_i2f(bld, numer);
      bf = nir_i2f(bld, denom);
      af = nir_fabs(bld, af);
      bf = nir_fabs(bld, bf);
      a  = nir_iabs(bld, numer);
      b  = nir_iabs(bld, denom);
   } else {
      af = nir_u2f(bld, numer);
      bf = nir_u2f(bld, denom);
      a  = numer;
      b  = denom;
   }

   /* get first result: */
   bf = nir_frcp(bld, bf);
   bf = nir_isub(bld, bf, nir_imm_int(bld, 2));  /* yes, really */
   q  = nir_fmul(bld, af, bf);

   if (is_signed) {
      q = nir_f2i(bld, q);
   } else {
      q = nir_f2u(bld, q);
   }

   /* get error of first result: */
   r = nir_imul(bld, q, b);
   r = nir_isub(bld, a, r);
   r = nir_u2f(bld, r);
   r = nir_fmul(bld, r, bf);
   r = nir_f2u(bld, r);

   /* add quotients: */
   q = nir_iadd(bld, q, r);

   /* correction: if modulus >= divisor, add 1 */
   r = nir_imul(bld, q, b);
   r = nir_isub(bld, a, r);

   r = nir_uge(bld, r, b);
   r = nir_b2i(bld, r);

   q = nir_iadd(bld, q, r);
   if (is_signed)  {
      /* fix the sign: */
      r = nir_ixor(bld, numer, denom);
      r = nir_ushr(bld, r, nir_imm_int(bld, 31));
      r = nir_i2b(bld, r);
      b = nir_ineg(bld, q);
      q = nir_bcsel(bld, r, b, q);
   }

   if (op == nir_op_umod) {
      /* division result in q */
      r = nir_imul(bld, q, b);
      q = nir_isub(bld, a, r);
   }

   assert(alu->dest.dest.is_ssa);
   nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa, nir_src_for_ssa(q));
}