示例#1
0
static nir_src
get_deref_reg_src(nir_deref_instr *deref, struct locals_to_regs_state *state)
{
   nir_builder *b = &state->builder;

   nir_src src;

   src.is_ssa = false;
   src.reg.reg = get_reg_for_deref(deref, state);
   src.reg.base_offset = 0;
   src.reg.indirect = NULL;

   /* It is possible for a user to create a shader that has an array with a
    * single element and then proceed to access it indirectly.  Indirectly
    * accessing a non-array register is not allowed in NIR.  In order to
    * handle this case we just convert it to a direct reference.
    */
   if (src.reg.reg->num_array_elems == 0)
      return src;

   unsigned inner_array_size = 1;
   for (const nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) {
      if (d->deref_type != nir_deref_type_array)
         continue;

      if (nir_src_is_const(d->arr.index) && !src.reg.indirect) {
         src.reg.base_offset += nir_src_as_uint(d->arr.index) *
                                inner_array_size;
      } else {
         if (src.reg.indirect) {
            assert(src.reg.base_offset == 0);
         } else {
            src.reg.indirect = ralloc(b->shader, nir_src);
            *src.reg.indirect =
               nir_src_for_ssa(nir_imm_int(b, src.reg.base_offset));
            src.reg.base_offset = 0;
         }

         assert(src.reg.indirect->is_ssa);
         nir_ssa_def *index = nir_i2i(b, nir_ssa_for_src(b, d->arr.index, 1), 32);
         src.reg.indirect->ssa =
            nir_iadd(b, src.reg.indirect->ssa,
                        nir_imul(b, index, nir_imm_int(b, inner_array_size)));
      }

      inner_array_size *= glsl_get_length(nir_deref_instr_parent(d)->type);
   }

   return src;
}
示例#2
0
static nir_src
get_deref_reg_src(nir_deref_var *deref, nir_instr *instr,
                  struct locals_to_regs_state *state)
{
   nir_src src;

   src.is_ssa = false;
   src.reg.reg = get_reg_for_deref(deref, state);
   src.reg.base_offset = 0;
   src.reg.indirect = NULL;

   /* It is possible for a user to create a shader that has an array with a
    * single element and then proceed to access it indirectly.  Indirectly
    * accessing a non-array register is not allowed in NIR.  In order to
    * handle this case we just convert it to a direct reference.
    */
   if (src.reg.reg->num_array_elems == 0)
      return src;

   nir_deref *tail = &deref->deref;
   while (tail->child != NULL) {
      const struct glsl_type *parent_type = tail->type;
      tail = tail->child;

      if (tail->deref_type != nir_deref_type_array)
         continue;

      nir_deref_array *deref_array = nir_deref_as_array(tail);

      src.reg.base_offset *= glsl_get_length(parent_type);
      src.reg.base_offset += deref_array->base_offset;

      if (src.reg.indirect) {
         nir_load_const_instr *load_const =
            nir_load_const_instr_create(state->shader, 1, 32);
         load_const->value.u32[0] = glsl_get_length(parent_type);
         nir_instr_insert_before(instr, &load_const->instr);

         nir_alu_instr *mul = nir_alu_instr_create(state->shader, nir_op_imul);
         mul->src[0].src = *src.reg.indirect;
         mul->src[1].src.is_ssa = true;
         mul->src[1].src.ssa = &load_const->def;
         mul->dest.write_mask = 1;
         nir_ssa_dest_init(&mul->instr, &mul->dest.dest, 1, 32, NULL);
         nir_instr_insert_before(instr, &mul->instr);

         src.reg.indirect->is_ssa = true;
         src.reg.indirect->ssa = &mul->dest.dest.ssa;
      }

      if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
         if (src.reg.indirect == NULL) {
            src.reg.indirect = ralloc(state->shader, nir_src);
            nir_src_copy(src.reg.indirect, &deref_array->indirect,
                         state->shader);
         } else {
            nir_alu_instr *add = nir_alu_instr_create(state->shader,
                                                      nir_op_iadd);
            add->src[0].src = *src.reg.indirect;
            nir_src_copy(&add->src[1].src, &deref_array->indirect, add);
            add->dest.write_mask = 1;
            nir_ssa_dest_init(&add->instr, &add->dest.dest, 1, 32, NULL);
            nir_instr_insert_before(instr, &add->instr);

            src.reg.indirect->is_ssa = true;
            src.reg.indirect->ssa = &add->dest.dest.ssa;
         }
      }
   }

   return src;
}