/*
 * Copyright (C) 2005-2007  Brian Paul   All Rights Reserved.
 * Copyright (C) 2008  VMware, Inc.   All Rights Reserved.
 * Copyright © 2010 Intel Corporation
 * Copyright © 2011 Bryan Cain
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "compiler/glsl/glsl_parser_extras.h"
#include "compiler/glsl/ir_optimization.h"
#include "compiler/glsl/program.h"

#include "st_nir.h"
#include "st_shader_cache.h"
#include "st_glsl_to_tgsi.h"

#include "tgsi/tgsi_from_mesa.h"

extern "C" {

/**
 * Link a shader.
 * Called via ctx->Driver.LinkShader()
 * This is a shared function that branches off to either GLSL IR -> TGSI or
 * GLSL IR -> NIR
 */
GLboolean
st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
{
   struct pipe_screen *pscreen = ctx->st->pipe->screen;

   enum pipe_shader_ir preferred_ir = (enum pipe_shader_ir)
      pscreen->get_shader_param(pscreen, PIPE_SHADER_VERTEX,
                                PIPE_SHADER_CAP_PREFERRED_IR);
   bool use_nir = preferred_ir == PIPE_SHADER_IR_NIR;

   /* Return early if we are loading the shader from on-disk cache */
   if (st_load_ir_from_disk_cache(ctx, prog, use_nir)) {
      return GL_TRUE;
   }

   assert(prog->data->LinkStatus);

   /* Skip the GLSL steps when using SPIR-V. */
   if (prog->data->spirv) {
      assert(use_nir);
      return st_link_nir(ctx, prog);
   }

   for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
      if (prog->_LinkedShaders[i] == NULL)
         continue;

      struct gl_linked_shader *shader = prog->_LinkedShaders[i];
      exec_list *ir = shader->ir;
      gl_shader_stage stage = shader->Stage;
      const struct gl_shader_compiler_options *options =
            &ctx->Const.ShaderCompilerOptions[stage];

      /* If there are forms of indirect addressing that the driver
       * cannot handle, perform the lowering pass.
       */
      if (options->EmitNoIndirectInput || options->EmitNoIndirectOutput ||
          options->EmitNoIndirectTemp || options->EmitNoIndirectUniform) {
         lower_variable_index_to_cond_assign(stage, ir,
                                             options->EmitNoIndirectInput,
                                             options->EmitNoIndirectOutput,
                                             options->EmitNoIndirectTemp,
                                             options->EmitNoIndirectUniform);
      }

      enum pipe_shader_type ptarget = pipe_shader_type_from_mesa(stage);
      bool have_dround = pscreen->get_shader_param(pscreen, ptarget,
                                                   PIPE_SHADER_CAP_TGSI_DROUND_SUPPORTED);
      bool have_dfrexp = pscreen->get_shader_param(pscreen, ptarget,
                                                   PIPE_SHADER_CAP_TGSI_DFRACEXP_DLDEXP_SUPPORTED);
      bool have_ldexp = pscreen->get_shader_param(pscreen, ptarget,
                                                  PIPE_SHADER_CAP_TGSI_LDEXP_SUPPORTED);

      if (!pscreen->get_param(pscreen, PIPE_CAP_INT64_DIVMOD))
         lower_64bit_integer_instructions(ir, DIV64 | MOD64);

      if (ctx->Extensions.ARB_shading_language_packing) {
         unsigned lower_inst = LOWER_PACK_SNORM_2x16 |
                               LOWER_UNPACK_SNORM_2x16 |
                               LOWER_PACK_UNORM_2x16 |
                               LOWER_UNPACK_UNORM_2x16 |
                               LOWER_PACK_SNORM_4x8 |
                               LOWER_UNPACK_SNORM_4x8 |
                               LOWER_UNPACK_UNORM_4x8 |
                               LOWER_PACK_UNORM_4x8;

         if (ctx->Extensions.ARB_gpu_shader5)
            lower_inst |= LOWER_PACK_USE_BFI |
                          LOWER_PACK_USE_BFE;
         if (!ctx->st->has_half_float_packing)
            lower_inst |= LOWER_PACK_HALF_2x16 |
                          LOWER_UNPACK_HALF_2x16;

         lower_packing_builtins(ir, lower_inst);
      }

      if (!pscreen->get_param(pscreen, PIPE_CAP_TEXTURE_GATHER_OFFSETS))
         lower_offset_arrays(ir);
      do_mat_op_to_vec(ir);

      if (stage == MESA_SHADER_FRAGMENT)
         lower_blend_equation_advanced(
            shader, ctx->Extensions.KHR_blend_equation_advanced_coherent);

      lower_instructions(ir,
                         (use_nir ? 0 : MOD_TO_FLOOR) |
                         FDIV_TO_MUL_RCP |
                         EXP_TO_EXP2 |
                         LOG_TO_LOG2 |
                         MUL64_TO_MUL_AND_MUL_HIGH |
                         (have_ldexp ? 0 : LDEXP_TO_ARITH) |
                         (have_dfrexp ? 0 : DFREXP_DLDEXP_TO_ARITH) |
                         CARRY_TO_ARITH |
                         BORROW_TO_ARITH |
                         (have_dround ? 0 : DOPS_TO_DFRAC) |
                         (options->EmitNoPow ? POW_TO_EXP2 : 0) |
                         (!ctx->Const.NativeIntegers ? INT_DIV_TO_MUL_RCP : 0) |
                         (options->EmitNoSat ? SAT_TO_CLAMP : 0) |
                         (ctx->Const.ForceGLSLAbsSqrt ? SQRT_TO_ABS_SQRT : 0) |
                         /* Assume that if ARB_gpu_shader5 is not supported
                          * then all of the extended integer functions need
                          * lowering.  It may be necessary to add some caps
                          * for individual instructions.
                          */
                         (!ctx->Extensions.ARB_gpu_shader5
                          ? BIT_COUNT_TO_MATH |
                            EXTRACT_TO_SHIFTS |
                            INSERT_TO_SHIFTS |
                            REVERSE_TO_SHIFTS |
                            FIND_LSB_TO_FLOAT_CAST |
                            FIND_MSB_TO_FLOAT_CAST |
                            IMUL_HIGH_TO_MUL
                          : 0));

      do_vec_index_to_cond_assign(ir);
      lower_vector_insert(ir, true);
      lower_quadop_vector(ir, false);
      lower_noise(ir);
      if (options->MaxIfDepth == 0) {
         lower_discard(ir);
      }

      validate_ir_tree(ir);
   }

   build_program_resource_list(ctx, prog);

   if (use_nir)
      return st_link_nir(ctx, prog);
   else
      return st_link_tgsi(ctx, prog);
}

} /* extern "C" */
