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->FullSrcRegisters[i];
 100                   if (src->SrcRegister.File == TGSI_FILE_INPUT) {
 101                      const int ind = src->SrcRegister.Index;
 102                      if (info->input_semantic_name[ind] == TGSI_SEMANTIC_FOG) {
 103                         if (src->SrcRegister.SwizzleX == TGSI_SWIZZLE_X) {
 104                            info->uses_fogcoord = TRUE;
 105                         }
 106                         else if (src->SrcRegister.SwizzleX == TGSI_SWIZZLE_Y) {
 107                            info->uses_frontfacing = TRUE;
 108                         }
 109                      }
 110                   }
 111                }
 112             }
 113          }
 114          break;
 115
 116       case TGSI_TOKEN_TYPE_DECLARATION:
 117          {
 118             const struct tgsi_full_declaration *fulldecl
 119                = &parse.FullToken.FullDeclaration;
 120             const uint file = fulldecl->Declaration.File;
 121             uint reg;
 122             for (reg = fulldecl->DeclarationRange.First;
 123                  reg <= fulldecl->DeclarationRange.Last;
 124                  reg++) {
 125
 126                /* only first 32 regs will appear in this bitfield */
 127                info->file_mask[file] |= (1 << reg);
 128                info->file_count[file]++;
 129                info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 130
 131                if (file == TGSI_FILE_INPUT) {
 132                   info->input_semantic_name[reg] = (ubyte)fulldecl->Semantic.SemanticName;
 133                   info->input_semantic_index[reg] = (ubyte)fulldecl->Semantic.SemanticIndex;
 134                   info->input_interpolate[reg] = (ubyte)fulldecl->Declaration.Interpolate;
 135                   info->num_inputs++;
 136                }
 137                else if (file == TGSI_FILE_OUTPUT) {
 138                   info->output_semantic_name[reg] = (ubyte)fulldecl->Semantic.SemanticName;
 139                   info->output_semantic_index[reg] = (ubyte)fulldecl->Semantic.SemanticIndex;
 140                   info->num_outputs++;
 141                }
 142
 143                /* special case */
 144                if (procType == TGSI_PROCESSOR_FRAGMENT &&
 145                    file == TGSI_FILE_OUTPUT &&
 146                    fulldecl->Semantic.SemanticName == TGSI_SEMANTIC_POSITION) {
 147                   info->writes_z = TRUE;
 148                }
 149             }
 150          }
 151          break;
 152
 153       case TGSI_TOKEN_TYPE_IMMEDIATE:
 154          {
 155             uint reg = info->immediate_count++;
 156             uint file = TGSI_FILE_IMMEDIATE;
 157
 158             info->file_mask[file] |= (1 << reg);
 159             info->file_count[file]++;
 160             info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 161          }
 162          break;
 163
 164       default:
 165          assert( 0 );
 166       }
 167    }
 168
 169    info->uses_kill = (info->opcode_count[TGSI_OPCODE_KIL] ||
 170                       info->opcode_count[TGSI_OPCODE_KILP]);
 171
 172    tgsi_parse_free (&parse);
 173 }
 174
 175
 176
 177 /**
 178  * Check if the given shader is a "passthrough" shader consisting of only
 179  * MOV instructions of the form:  MOV OUT[n], IN[n]
 180  *
 181  */
 182 boolean
 183 tgsi_is_passthrough_shader(const struct tgsi_token *tokens)
 184 {
 185    struct tgsi_parse_context parse;
 186
 187    /**
 188     ** Setup to begin parsing input shader
 189     **/
 190    if (tgsi_parse_init(&parse, tokens) != TGSI_PARSE_OK) {
 191       debug_printf("tgsi_parse_init() failed in tgsi_is_passthrough_shader()!\n");
 192       return FALSE;
 193    }
 194
 195    /**
 196     ** Loop over incoming program tokens/instructions
 197     */
 198    while (!tgsi_parse_end_of_tokens(&parse)) {
 199
 200       tgsi_parse_token(&parse);
 201
 202       switch (parse.FullToken.Token.Type) {
 203       case TGSI_TOKEN_TYPE_INSTRUCTION:
 204          {
 205             struct tgsi_full_instruction *fullinst =
 206                &parse.FullToken.FullInstruction;
 207             const struct tgsi_full_src_register *src =
 208                &fullinst->FullSrcRegisters[0];
 209             const struct tgsi_full_dst_register *dst =
 210                &fullinst->FullDstRegisters[0];
 211
 212             /* Do a whole bunch of checks for a simple move */
 213             if (fullinst->Instruction.Opcode != TGSI_OPCODE_MOV ||
 214                 src->SrcRegister.File != TGSI_FILE_INPUT ||
 215                 dst->DstRegister.File != TGSI_FILE_OUTPUT ||
 216                 src->SrcRegister.Index != dst->DstRegister.Index ||
 217
 218                 src->SrcRegister.Negate ||
 219                 src->SrcRegister.Absolute ||
 220
 221                 src->SrcRegister.SwizzleX != TGSI_SWIZZLE_X ||
 222                 src->SrcRegister.SwizzleY != TGSI_SWIZZLE_Y ||
 223                 src->SrcRegister.SwizzleZ != TGSI_SWIZZLE_Z ||
 224                 src->SrcRegister.SwizzleW != TGSI_SWIZZLE_W ||
 225
 226                 dst->DstRegister.WriteMask != TGSI_WRITEMASK_XYZW)
 227             {
 228                tgsi_parse_free(&parse);
 229                return FALSE;
 230             }
 231          }
 232          break;
 233
 234       case TGSI_TOKEN_TYPE_DECLARATION:
 235          /* fall-through */
 236       case TGSI_TOKEN_TYPE_IMMEDIATE:
 237          /* fall-through */
 238       default:
 239          ; /* no-op */
 240       }
 241    }
 242
 243    tgsi_parse_free(&parse);
 244
 245    /* if we get here, it's a pass-through shader */
 246    return TRUE;
 247 }