/*
 * Copyright © 2016 Red Hat.
 * Copyright © 2016 Bas Nieuwenhuizen
 * Copyright © 2023 Valve Corporation
 *
 * SPDX-License-Identifier: MIT
 */

#include "nir.h"
#include "nir_builder.h"
#include "radv_nir.h"

static bool
pass(nir_builder *b, nir_intrinsic_instr *intr, void *_)
{
   if (intr->intrinsic != nir_intrinsic_load_deref)
      return false;

   nir_variable *var = nir_intrinsic_get_var(intr, 0);
   if (var->data.mode != nir_var_shader_in || var->data.location != VARYING_SLOT_VIEWPORT)
      return false;

   b->cursor = nir_before_instr(&intr->instr);
   nir_def_replace(&intr->def, nir_imm_zero(b, 1, 32));
   return true;
}

bool
radv_nir_lower_viewport_to_zero(nir_shader *nir)
{
   return nir_shader_intrinsics_pass(nir, pass, nir_metadata_control_flow, NULL);
}