auxiliary/tgsi/tgsi_scan.c

/**************************************************************************
 *
 * Copyright 2008 VMware, Inc.
 * All Rights Reserved.
 * Copyright 2008 VMware, Inc.  All rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
 *
 **************************************************************************/

/**
 * TGSI program scan utility.
 * Used to determine which registers and instructions are used by a shader.
 *
 * Authors:  Brian Paul
 */


#include "util/u_debug.h"
#include "util/u_math.h"
#include "util/u_memory.h"
#include "tgsi/tgsi_info.h"
#include "tgsi/tgsi_parse.h"
#include "tgsi/tgsi_util.h"
#include "tgsi/tgsi_scan.h"


static bool
is_memory_file(enum tgsi_file_type file)
{
   return file == TGSI_FILE_SAMPLER ||
          file == TGSI_FILE_SAMPLER_VIEW ||
          file == TGSI_FILE_IMAGE ||
          file == TGSI_FILE_BUFFER ||
          file == TGSI_FILE_HW_ATOMIC;
}


static bool
is_mem_query_inst(enum tgsi_opcode opcode)
{
   return opcode == TGSI_OPCODE_RESQ ||
          opcode == TGSI_OPCODE_TXQ ||
          opcode == TGSI_OPCODE_TXQS ||
          opcode == TGSI_OPCODE_LODQ;
}

/**
 * Is the opcode a "true" texture instruction which samples from a
 * texture map?
 */
static bool
is_texture_inst(enum tgsi_opcode opcode)
{
   return (!is_mem_query_inst(opcode) &&
           tgsi_get_opcode_info(opcode)->is_tex);
}


static void
scan_src_operand(struct tgsi_shader_info *info,
                 const struct tgsi_full_instruction *fullinst,
                 const struct tgsi_full_src_register *src,
                 unsigned src_index,
                 unsigned usage_mask_after_swizzle,
                 bool *is_mem_inst)
{
   int ind = src->Register.Index;

   if (info->processor == PIPE_SHADER_COMPUTE &&
       src->Register.File == TGSI_FILE_SYSTEM_VALUE) {
      unsigned name;

      name = info->system_value_semantic_name[src->Register.Index];

      switch (name) {
      case TGSI_SEMANTIC_GRID_SIZE:
         info->uses_grid_size = true;
         break;
      }
   }

   /* Mark which inputs are effectively used */
   if (src->Register.File == TGSI_FILE_INPUT) {
      if (src->Register.Indirect) {
         for (ind = 0; ind < info->num_inputs; ++ind) {
            info->input_usage_mask[ind] |= usage_mask_after_swizzle;
         }
      } else {
         assert(ind >= 0);
         assert(ind < PIPE_MAX_SHADER_INPUTS);
         info->input_usage_mask[ind] |= usage_mask_after_swizzle;
      }

      if (info->processor == PIPE_SHADER_FRAGMENT) {
         unsigned name, input;

         if (src->Register.Indirect && src->Indirect.ArrayID)
            input = info->input_array_first[src->Indirect.ArrayID];
         else
            input = src->Register.Index;

         name = info->input_semantic_name[input];

         if (name == TGSI_SEMANTIC_POSITION &&
             usage_mask_after_swizzle & TGSI_WRITEMASK_Z)
            info->reads_z = true;
      }
   }

   if (info->processor == PIPE_SHADER_TESS_CTRL &&
       src->Register.File == TGSI_FILE_OUTPUT) {
      unsigned input;

      if (src->Register.Indirect && src->Indirect.ArrayID)
         input = info->output_array_first[src->Indirect.ArrayID];
      else
         input = src->Register.Index;

      switch (info->output_semantic_name[input]) {
      case TGSI_SEMANTIC_PATCH:
         info->reads_perpatch_outputs = true;
         break;
      case TGSI_SEMANTIC_TESSINNER:
      case TGSI_SEMANTIC_TESSOUTER:
         info->reads_tessfactor_outputs = true;
         break;
      default:
         info->reads_pervertex_outputs = true;
      }
   }

   /* check for indirect register reads */
   if (src->Register.Indirect)
      info->indirect_files |= (1 << src->Register.File);

   if (src->Register.Dimension && src->Dimension.Indirect)
      info->dim_indirect_files |= 1u << src->Register.File;

   /* Texture samplers */
   if (src->Register.File == TGSI_FILE_SAMPLER) {
      const unsigned index = src->Register.Index;

      assert(fullinst->Instruction.Texture);
      assert(index < PIPE_MAX_SAMPLERS);

      if (is_texture_inst(fullinst->Instruction.Opcode)) {
         const unsigned target = fullinst->Texture.Texture;
         assert(target < TGSI_TEXTURE_UNKNOWN);
         /* for texture instructions, check that the texture instruction
          * target matches the previous sampler view declaration (if there
          * was one.)
          */
         if (info->sampler_targets[index] == TGSI_TEXTURE_UNKNOWN) {
            /* probably no sampler view declaration */
            info->sampler_targets[index] = target;
         } else {
            /* Make sure the texture instruction's sampler/target info
             * agrees with the sampler view declaration.
             */
            assert(info->sampler_targets[index] == target);
         }
      }
   }

   if (is_memory_file(src->Register.File) &&
       !is_mem_query_inst(fullinst->Instruction.Opcode)) {
      *is_mem_inst = true;

      if (src->Register.File == TGSI_FILE_IMAGE &&
          (fullinst->Memory.Texture == TGSI_TEXTURE_2D_MSAA ||
           fullinst->Memory.Texture == TGSI_TEXTURE_2D_ARRAY_MSAA)) {
         if (src->Register.Indirect)
            info->msaa_images_declared = info->images_declared;
         else
            info->msaa_images_declared |= 1 << src->Register.Index;
      }

      if (tgsi_get_opcode_info(fullinst->Instruction.Opcode)->is_store) {
         info->writes_memory = true;

         if (src->Register.File == TGSI_FILE_BUFFER) {
            if (src->Register.Indirect)
               info->shader_buffers_atomic = info->shader_buffers_declared;
            else
               info->shader_buffers_atomic |= 1 << src->Register.Index;
         }
      } else {
         if (src->Register.File == TGSI_FILE_BUFFER) {
            if (src->Register.Indirect)
               info->shader_buffers_load = info->shader_buffers_declared;
            else
               info->shader_buffers_load |= 1 << src->Register.Index;
         }
      }
   }
}


static void
scan_instruction(struct tgsi_shader_info *info,
                 const struct tgsi_full_instruction *fullinst,
                 unsigned *current_depth)
{
   unsigned i;
   bool is_mem_inst = false;

   assert(fullinst->Instruction.Opcode < TGSI_OPCODE_LAST);
   info->opcode_count[fullinst->Instruction.Opcode]++;

   switch (fullinst->Instruction.Opcode) {
   case TGSI_OPCODE_IF:
   case TGSI_OPCODE_UIF:
   case TGSI_OPCODE_BGNLOOP:
      (*current_depth)++;
      break;
   case TGSI_OPCODE_ENDIF:
   case TGSI_OPCODE_ENDLOOP:
      (*current_depth)--;
      break;
   case TGSI_OPCODE_FBFETCH:
      info->uses_fbfetch = true;
      break;
   default:
      break;
   }

   for (i = 0; i < fullinst->Instruction.NumSrcRegs; i++) {
      scan_src_operand(info, fullinst, &fullinst->Src[i], i,
                       tgsi_util_get_inst_usage_mask(fullinst, i),
                       &is_mem_inst);

      if (fullinst->Src[i].Register.Indirect) {
         struct tgsi_full_src_register src = {{0}};

         src.Register.File = fullinst->Src[i].Indirect.File;
         src.Register.Index = fullinst->Src[i].Indirect.Index;

         scan_src_operand(info, fullinst, &src, -1,
                          1 << fullinst->Src[i].Indirect.Swizzle,
                          NULL);
      }

      if (fullinst->Src[i].Register.Dimension &&
          fullinst->Src[i].Dimension.Indirect) {
         struct tgsi_full_src_register src = {{0}};

         src.Register.File = fullinst->Src[i].DimIndirect.File;
         src.Register.Index = fullinst->Src[i].DimIndirect.Index;

         scan_src_operand(info, fullinst, &src, -1,
                          1 << fullinst->Src[i].DimIndirect.Swizzle,
                          NULL);
      }
   }

   if (fullinst->Instruction.Texture) {
      for (i = 0; i < fullinst->Texture.NumOffsets; i++) {
         struct tgsi_full_src_register src = {{0}};

         src.Register.File = fullinst->TexOffsets[i].File;
         src.Register.Index = fullinst->TexOffsets[i].Index;

         /* The usage mask is suboptimal but should be safe. */
         scan_src_operand(info, fullinst, &src, -1,
                          (1 << fullinst->TexOffsets[i].SwizzleX) |
                          (1 << fullinst->TexOffsets[i].SwizzleY) |
                          (1 << fullinst->TexOffsets[i].SwizzleZ),
                          &is_mem_inst);
      }
   }

   /* check for indirect register writes */
   for (i = 0; i < fullinst->Instruction.NumDstRegs; i++) {
      const struct tgsi_full_dst_register *dst = &fullinst->Dst[i];

      if (dst->Register.Indirect) {
         struct tgsi_full_src_register src = {{0}};

         src.Register.File = dst->Indirect.File;
         src.Register.Index = dst->Indirect.Index;

         scan_src_operand(info, fullinst, &src, -1,
                          1 << dst->Indirect.Swizzle, NULL);

         info->indirect_files |= (1 << dst->Register.File);
      }

      if (dst->Register.Dimension && dst->Dimension.Indirect) {
         struct tgsi_full_src_register src = {{0}};

         src.Register.File = dst->DimIndirect.File;
         src.Register.Index = dst->DimIndirect.Index;

         scan_src_operand(info, fullinst, &src, -1,
                          1 << dst->DimIndirect.Swizzle, NULL);

         info->dim_indirect_files |= 1u << dst->Register.File;
      }

      if (is_memory_file(dst->Register.File)) {
         assert(fullinst->Instruction.Opcode == TGSI_OPCODE_STORE);

         is_mem_inst = true;
         info->writes_memory = true;

         if (dst->Register.File == TGSI_FILE_IMAGE) {
            if (fullinst->Memory.Texture == TGSI_TEXTURE_2D_MSAA ||
                fullinst->Memory.Texture == TGSI_TEXTURE_2D_ARRAY_MSAA) {
               if (dst->Register.Indirect)
                  info->msaa_images_declared = info->images_declared;
               else
                  info->msaa_images_declared |= 1 << dst->Register.Index;
            }
         } else if (dst->Register.File == TGSI_FILE_BUFFER) {
            if (dst->Register.Indirect)
               info->shader_buffers_store = info->shader_buffers_declared;
            else
               info->shader_buffers_store |= 1 << dst->Register.Index;
         }
      }
   }

   info->num_instructions++;
}


static void
scan_declaration(struct tgsi_shader_info *info,
                 const struct tgsi_full_declaration *fulldecl)
{
   enum tgsi_file_type file = fulldecl->Declaration.File;
   const unsigned procType = info->processor;
   unsigned reg;

   if (fulldecl->Declaration.Array) {
      unsigned array_id = fulldecl->Array.ArrayID;

      switch (file) {
      case TGSI_FILE_INPUT:
         assert(array_id < ARRAY_SIZE(info->input_array_first));
         info->input_array_first[array_id] = fulldecl->Range.First;
         break;
      case TGSI_FILE_OUTPUT:
         assert(array_id < ARRAY_SIZE(info->output_array_first));
         info->output_array_first[array_id] = fulldecl->Range.First;
         break;

      case TGSI_FILE_NULL:
         unreachable("unexpected file");

      default:
         break;
      }
   }

   for (reg = fulldecl->Range.First; reg <= fulldecl->Range.Last; reg++) {
      unsigned semName = fulldecl->Semantic.Name;
      unsigned semIndex = fulldecl->Semantic.Index +
         (reg - fulldecl->Range.First);
      int buffer;
      unsigned index, target, type;

      /*
       * only first 32 regs will appear in this bitfield, if larger
       * bits will wrap around.
       */
      info->file_mask[file] |= (1u << (reg & 31));
      info->file_count[file]++;
      info->file_max[file] = MAX2(info->file_max[file], (int)reg);

      switch (file) {
      case TGSI_FILE_CONSTANT:
         buffer = 0;

         if (fulldecl->Declaration.Dimension)
            buffer = fulldecl->Dim.Index2D;

         info->const_file_max[buffer] =
            MAX2(info->const_file_max[buffer], (int)reg);
         info->const_buffers_declared |= 1u << buffer;
         break;

      case TGSI_FILE_IMAGE:
         info->images_declared |= 1u << reg;
         if (fulldecl->Image.Resource == TGSI_TEXTURE_BUFFER)
            info->images_buffers |= 1 << reg;
         break;

      case TGSI_FILE_BUFFER:
         info->shader_buffers_declared |= 1u << reg;
         break;

      case TGSI_FILE_HW_ATOMIC:
         info->hw_atomic_declared |= 1u << reg;
         break;

      case TGSI_FILE_INPUT:
         info->input_semantic_name[reg] = (uint8_t) semName;
         info->input_semantic_index[reg] = (uint8_t) semIndex;
         info->input_interpolate[reg] = (uint8_t)fulldecl->Interp.Interpolate;
         info->input_interpolate_loc[reg] = (uint8_t)fulldecl->Interp.Location;

         /* Vertex shaders can have inputs with holes between them. */
         info->num_inputs = MAX2(info->num_inputs, reg + 1);

         switch (semName) {
         case TGSI_SEMANTIC_PRIMID:
            info->uses_primid = true;
            break;
         case TGSI_SEMANTIC_FACE:
            info->uses_frontface = true;
            break;
         }
         break;

      case TGSI_FILE_SYSTEM_VALUE:
         index = fulldecl->Range.First;

         info->system_value_semantic_name[index] = semName;
         info->num_system_values = MAX2(info->num_system_values, index + 1);

         switch (semName) {
         case TGSI_SEMANTIC_INSTANCEID:
            info->uses_instanceid = true;
            break;
         case TGSI_SEMANTIC_VERTEXID:
            info->uses_vertexid = true;
            break;
         case TGSI_SEMANTIC_VERTEXID_NOBASE:
            info->uses_vertexid_nobase = true;
            break;
         case TGSI_SEMANTIC_BASEVERTEX:
            info->uses_basevertex = true;
            break;
         case TGSI_SEMANTIC_PRIMID:
            info->uses_primid = true;
            break;
         case TGSI_SEMANTIC_INVOCATIONID:
            info->uses_invocationid = true;
            break;
         case TGSI_SEMANTIC_FACE:
            info->uses_frontface = true;
            break;
         }
         break;

      case TGSI_FILE_OUTPUT:
         info->output_semantic_name[reg] = (uint8_t) semName;
         info->output_semantic_index[reg] = (uint8_t) semIndex;
         info->output_usagemask[reg] |= fulldecl->Declaration.UsageMask;
         info->num_outputs = MAX2(info->num_outputs, reg + 1);

         if (fulldecl->Declaration.UsageMask & TGSI_WRITEMASK_X) {
            info->output_streams[reg] |= (uint8_t)fulldecl->Semantic.StreamX;
            info->num_stream_output_components[fulldecl->Semantic.StreamX]++;
         }
         if (fulldecl->Declaration.UsageMask & TGSI_WRITEMASK_Y) {
            info->output_streams[reg] |= (uint8_t)fulldecl->Semantic.StreamY << 2;
            info->num_stream_output_components[fulldecl->Semantic.StreamY]++;
         }
         if (fulldecl->Declaration.UsageMask & TGSI_WRITEMASK_Z) {
            info->output_streams[reg] |= (uint8_t)fulldecl->Semantic.StreamZ << 4;
            info->num_stream_output_components[fulldecl->Semantic.StreamZ]++;
         }
         if (fulldecl->Declaration.UsageMask & TGSI_WRITEMASK_W) {
            info->output_streams[reg] |= (uint8_t)fulldecl->Semantic.StreamW << 6;
            info->num_stream_output_components[fulldecl->Semantic.StreamW]++;
         }

         switch (semName) {
         case TGSI_SEMANTIC_VIEWPORT_INDEX:
            info->writes_viewport_index = true;
            break;
         case TGSI_SEMANTIC_LAYER:
            info->writes_layer = true;
            break;
         case TGSI_SEMANTIC_PSIZE:
            info->writes_psize = true;
            break;
         case TGSI_SEMANTIC_CLIPVERTEX:
            info->writes_clipvertex = true;
            break;
         case TGSI_SEMANTIC_STENCIL:
            info->writes_stencil = true;
            break;
         case TGSI_SEMANTIC_SAMPLEMASK:
            info->writes_samplemask = true;
            break;
         case TGSI_SEMANTIC_EDGEFLAG:
            info->writes_edgeflag = true;
            break;
         case TGSI_SEMANTIC_POSITION:
            if (procType == PIPE_SHADER_FRAGMENT)
               info->writes_z = true;
            else
               info->writes_position = true;
            break;
         }
         break;

      case TGSI_FILE_SAMPLER:
         STATIC_ASSERT(sizeof(info->samplers_declared) * 8 >= PIPE_MAX_SAMPLERS);
         info->samplers_declared |= 1u << reg;
         break;

      case TGSI_FILE_SAMPLER_VIEW:
         target = fulldecl->SamplerView.Resource;
         type = fulldecl->SamplerView.ReturnTypeX;

         assert(target < TGSI_TEXTURE_UNKNOWN);
         if (info->sampler_targets[reg] == TGSI_TEXTURE_UNKNOWN) {
            /* Save sampler target for this sampler index */
            info->sampler_targets[reg] = target;
            info->sampler_type[reg] = type;
         } else {
            /* if previously declared, make sure targets agree */
            assert(info->sampler_targets[reg] == target);
            assert(info->sampler_type[reg] == type);
         }
         break;

      case TGSI_FILE_NULL:
         unreachable("unexpected file");

      default:
         break;
      }
   }
}


static void
scan_immediate(struct tgsi_shader_info *info)
{
   unsigned reg = info->immediate_count++;
   enum tgsi_file_type file = TGSI_FILE_IMMEDIATE;

   info->file_mask[file] |= (1 << reg);
   info->file_count[file]++;
   info->file_max[file] = MAX2(info->file_max[file], (int)reg);
}


static void
scan_property(struct tgsi_shader_info *info,
              const struct tgsi_full_property *fullprop)
{
   unsigned name = fullprop->Property.PropertyName;
   unsigned value = fullprop->u[0].Data;

   assert(name < ARRAY_SIZE(info->properties));
   info->properties[name] = value;

   switch (name) {
   case TGSI_PROPERTY_NUM_CLIPDIST_ENABLED:
      info->num_written_clipdistance = value;
      break;
   case TGSI_PROPERTY_NUM_CULLDIST_ENABLED:
      info->num_written_culldistance = value;
      break;
   }
}


/**
 * Scan the given TGSI shader to collect information such as number of
 * registers used, special instructions used, etc.
 * \return info  the result of the scan
 */
void
tgsi_scan_shader(const struct tgsi_token *tokens,
                 struct tgsi_shader_info *info)
{
   unsigned procType, i;
   struct tgsi_parse_context parse;
   unsigned current_depth = 0;

   memset(info, 0, sizeof(*info));
   for (i = 0; i < TGSI_FILE_COUNT; i++)
      info->file_max[i] = -1;
   for (i = 0; i < ARRAY_SIZE(info->const_file_max); i++)
      info->const_file_max[i] = -1;
   for (i = 0; i < ARRAY_SIZE(info->sampler_targets); i++)
      info->sampler_targets[i] = TGSI_TEXTURE_UNKNOWN;

   /**
    ** Setup to begin parsing input shader
    **/
   if (tgsi_parse_init( &parse, tokens ) != TGSI_PARSE_OK) {
      debug_printf("tgsi_parse_init() failed in tgsi_scan_shader()!\n");
      return;
   }
   procType = parse.FullHeader.Processor.Processor;
   assert(procType == PIPE_SHADER_FRAGMENT ||
          procType == PIPE_SHADER_VERTEX ||
          procType == PIPE_SHADER_GEOMETRY ||
          procType == PIPE_SHADER_TESS_CTRL ||
          procType == PIPE_SHADER_TESS_EVAL ||
          procType == PIPE_SHADER_COMPUTE);
   info->processor = procType;

   if (procType == PIPE_SHADER_GEOMETRY)
      info->properties[TGSI_PROPERTY_GS_INVOCATIONS] = 1;

   /**
    ** Loop over incoming program tokens/instructions
    */
   while (!tgsi_parse_end_of_tokens(&parse)) {
      tgsi_parse_token( &parse );

      switch( parse.FullToken.Token.Type ) {
      case TGSI_TOKEN_TYPE_INSTRUCTION:
         scan_instruction(info, &parse.FullToken.FullInstruction,
                          &current_depth);
         break;
      case TGSI_TOKEN_TYPE_DECLARATION:
         scan_declaration(info, &parse.FullToken.FullDeclaration);
         break;
      case TGSI_TOKEN_TYPE_IMMEDIATE:
         scan_immediate(info);
         break;
      case TGSI_TOKEN_TYPE_PROPERTY:
         scan_property(info, &parse.FullToken.FullProperty);
         break;
      default:
         assert(!"Unexpected TGSI token type");
      }
   }

   info->uses_kill = (info->opcode_count[TGSI_OPCODE_KILL_IF] ||
                      info->opcode_count[TGSI_OPCODE_KILL]);

   /* The dimensions of the IN decleration in geometry shader have
    * to be deduced from the type of the input primitive.
    */
   if (procType == PIPE_SHADER_GEOMETRY) {
      unsigned input_primitive =
            info->properties[TGSI_PROPERTY_GS_INPUT_PRIM];
      int num_verts = mesa_vertices_per_prim(input_primitive);
      int j;
      info->file_count[TGSI_FILE_INPUT] = num_verts;
      info->file_max[TGSI_FILE_INPUT] =
            MAX2(info->file_max[TGSI_FILE_INPUT], num_verts - 1);
      for (j = 0; j < num_verts; ++j) {
         info->file_mask[TGSI_FILE_INPUT] |= (1 << j);
      }
   }

   tgsi_parse_free(&parse);
}