src/gallium/auxiliary/tgsi/tgsi_scan.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  * Copyright 2008 VMware, Inc.  All rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  22  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  23  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28
  29 /**
  30  * TGSI program scan utility.
  31  * Used to determine which registers and instructions are used by a shader.
  32  *
  33  * Authors:  Brian Paul
  34  */
  35
  36
  37 #include "util/u_math.h"
  38 #include "tgsi/tgsi_parse.h"
  39 #include "tgsi/tgsi_scan.h"
  40
  41
  42
  43
  44 /**
  45  * Scan the given TGSI shader to collect information such as number of
  46  * registers used, special instructions used, etc.
  47  * \return info  the result of the scan
  48  */
  49 void
  50 tgsi_scan_shader(const struct tgsi_token *tokens,
  51                  struct tgsi_shader_info *info)
  52 {
  53    uint procType, i;
  54    struct tgsi_parse_context parse;
  55
  56    memset(info, 0, sizeof(*info));
  57    for (i = 0; i < TGSI_FILE_COUNT; i++)
  58       info->file_max[i] = -1;
  59
  60    /**
  61     ** Setup to begin parsing input shader
  62     **/
  63    if (tgsi_parse_init( &parse, tokens ) != TGSI_PARSE_OK) {
  64       debug_printf("tgsi_parse_init() failed in tgsi_scan_shader()!\n");
  65       return;
  66    }
  67    procType = parse.FullHeader.Processor.Processor;
  68    assert(procType == TGSI_PROCESSOR_FRAGMENT ||
  69           procType == TGSI_PROCESSOR_VERTEX ||
  70           procType == TGSI_PROCESSOR_GEOMETRY);
  71
  72
  73    /**
  74     ** Loop over incoming program tokens/instructions
  75     */
  76    while( !tgsi_parse_end_of_tokens( &parse ) ) {
  77
  78       info->num_tokens++;
  79
  80       tgsi_parse_token( &parse );
  81
  82       switch( parse.FullToken.Token.Type ) {
  83       case TGSI_TOKEN_TYPE_INSTRUCTION:
  84          {
  85             const struct tgsi_full_instruction *fullinst
  86                = &parse.FullToken.FullInstruction;
  87
  88             assert(fullinst->Instruction.Opcode < TGSI_OPCODE_LAST);
  89             info->opcode_count[fullinst->Instruction.Opcode]++;
  90
  91             /* special case: scan fragment shaders for use of the fog
  92              * input/attribute.  The X component is fog, the Y component
  93              * is the front/back-face flag.
  94              */
  95             if (procType == TGSI_PROCESSOR_FRAGMENT) {
  96                uint i;
  97                for (i = 0; i < fullinst->Instruction.NumSrcRegs; i++) {
  98                   const struct tgsi_full_src_register *src =
  99                      &fullinst->Src[i];
 100                   if (src->Register.File == TGSI_FILE_INPUT ||
 101                       src->Register.File == TGSI_FILE_SYSTEM_VALUE) {
 102                      const int ind = src->Register.Index;
 103                      if (info->input_semantic_name[ind] == TGSI_SEMANTIC_FOG) {
 104                         if (src->Register.SwizzleX == TGSI_SWIZZLE_X) {
 105                            info->uses_fogcoord = TRUE;
 106                         }
 107                         else if (src->Register.SwizzleX == TGSI_SWIZZLE_Y) {
 108                            info->uses_frontfacing = TRUE;
 109                         }
 110                      }
 111                   }
 112                }
 113             }
 114          }
 115          break;
 116
 117       case TGSI_TOKEN_TYPE_DECLARATION:
 118          {
 119             const struct tgsi_full_declaration *fulldecl
 120                = &parse.FullToken.FullDeclaration;
 121             const uint file = fulldecl->Declaration.File;
 122             uint reg;
 123             for (reg = fulldecl->Range.First;
 124                  reg <= fulldecl->Range.Last;
 125                  reg++) {
 126
 127                /* only first 32 regs will appear in this bitfield */
 128                info->file_mask[file] |= (1 << reg);
 129                info->file_count[file]++;
 130                info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 131
 132                if (file == TGSI_FILE_INPUT || file == TGSI_FILE_SYSTEM_VALUE) {
 133                   info->input_semantic_name[reg] = (ubyte)fulldecl->Semantic.Name;
 134                   info->input_semantic_index[reg] = (ubyte)fulldecl->Semantic.Index;
 135                   info->input_interpolate[reg] = (ubyte)fulldecl->Declaration.Interpolate;
 136                   info->num_inputs++;
 137                }
 138                else if (file == TGSI_FILE_OUTPUT) {
 139                   info->output_semantic_name[reg] = (ubyte)fulldecl->Semantic.Name;
 140                   info->output_semantic_index[reg] = (ubyte)fulldecl->Semantic.Index;
 141                   info->num_outputs++;
 142                }
 143
 144                /* special case */
 145                if (procType == TGSI_PROCESSOR_FRAGMENT &&
 146                    file == TGSI_FILE_OUTPUT &&
 147                    fulldecl->Semantic.Name == TGSI_SEMANTIC_POSITION) {
 148                   info->writes_z = TRUE;
 149                }
 150             }
 151          }
 152          break;
 153
 154       case TGSI_TOKEN_TYPE_IMMEDIATE:
 155          {
 156             uint reg = info->immediate_count++;
 157             uint file = TGSI_FILE_IMMEDIATE;
 158
 159             info->file_mask[file] |= (1 << reg);
 160             info->file_count[file]++;
 161             info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 162          }
 163          break;
 164       case TGSI_TOKEN_TYPE_PROPERTY:
 165       {
 166          const struct tgsi_full_property *fullprop
 167             = &parse.FullToken.FullProperty;
 168
 169          info->properties[info->num_properties].name =
 170             fullprop->Property.PropertyName;
 171          memcpy(info->properties[info->num_properties].data,
 172                 fullprop->u, 8 * sizeof(unsigned));;
 173
 174          ++info->num_properties;
 175       }
 176       break;
 177
 178       default:
 179          assert( 0 );
 180       }
 181    }
 182
 183    info->uses_kill = (info->opcode_count[TGSI_OPCODE_KIL] ||
 184                       info->opcode_count[TGSI_OPCODE_KILP]);
 185
 186    tgsi_parse_free (&parse);
 187 }
 188
 189
 190
 191 /**
 192  * Check if the given shader is a "passthrough" shader consisting of only
 193  * MOV instructions of the form:  MOV OUT[n], IN[n]
 194  *
 195  */
 196 boolean
 197 tgsi_is_passthrough_shader(const struct tgsi_token *tokens)
 198 {
 199    struct tgsi_parse_context parse;
 200
 201    /**
 202     ** Setup to begin parsing input shader
 203     **/
 204    if (tgsi_parse_init(&parse, tokens) != TGSI_PARSE_OK) {
 205       debug_printf("tgsi_parse_init() failed in tgsi_is_passthrough_shader()!\n");
 206       return FALSE;
 207    }
 208
 209    /**
 210     ** Loop over incoming program tokens/instructions
 211     */
 212    while (!tgsi_parse_end_of_tokens(&parse)) {
 213
 214       tgsi_parse_token(&parse);
 215
 216       switch (parse.FullToken.Token.Type) {
 217       case TGSI_TOKEN_TYPE_INSTRUCTION:
 218          {
 219             struct tgsi_full_instruction *fullinst =
 220                &parse.FullToken.FullInstruction;
 221             const struct tgsi_full_src_register *src =
 222                &fullinst->Src[0];
 223             const struct tgsi_full_dst_register *dst =
 224                &fullinst->Dst[0];
 225
 226             /* Do a whole bunch of checks for a simple move */
 227             if (fullinst->Instruction.Opcode != TGSI_OPCODE_MOV ||
 228                 src->Register.File != TGSI_FILE_INPUT ||
 229                 src->Register.File != TGSI_FILE_SYSTEM_VALUE ||
 230                 dst->Register.File != TGSI_FILE_OUTPUT ||
 231                 src->Register.Index != dst->Register.Index ||
 232
 233                 src->Register.Negate ||
 234                 src->Register.Absolute ||
 235
 236                 src->Register.SwizzleX != TGSI_SWIZZLE_X ||
 237                 src->Register.SwizzleY != TGSI_SWIZZLE_Y ||
 238                 src->Register.SwizzleZ != TGSI_SWIZZLE_Z ||
 239                 src->Register.SwizzleW != TGSI_SWIZZLE_W ||
 240
 241                 dst->Register.WriteMask != TGSI_WRITEMASK_XYZW)
 242             {
 243                tgsi_parse_free(&parse);
 244                return FALSE;
 245             }
 246          }
 247          break;
 248
 249       case TGSI_TOKEN_TYPE_DECLARATION:
 250          /* fall-through */
 251       case TGSI_TOKEN_TYPE_IMMEDIATE:
 252          /* fall-through */
 253       case TGSI_TOKEN_TYPE_PROPERTY:
 254          /* fall-through */
 255       default:
 256          ; /* no-op */
 257       }
 258    }
 259
 260    tgsi_parse_free(&parse);
 261
 262    /* if we get here, it's a pass-through shader */
 263    return TRUE;
 264 }