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_build.h"
  39 #include "tgsi/tgsi_parse.h"
  40 #include "tgsi/tgsi_scan.h"
  41
  42
  43
  44
  45 /**
  46  * Scan the given TGSI shader to collect information such as number of
  47  * registers used, special instructions used, etc.
  48  * \return info  the result of the scan
  49  */
  50 void
  51 tgsi_scan_shader(const struct tgsi_token *tokens,
  52                  struct tgsi_shader_info *info)
  53 {
  54    uint procType, i;
  55    struct tgsi_parse_context parse;
  56
  57    memset(info, 0, sizeof(*info));
  58    for (i = 0; i < TGSI_FILE_COUNT; i++)
  59       info->file_max[i] = -1;
  60
  61    /**
  62     ** Setup to begin parsing input shader
  63     **/
  64    if (tgsi_parse_init( &parse, tokens ) != TGSI_PARSE_OK) {
  65       debug_printf("tgsi_parse_init() failed in tgsi_scan_shader()!\n");
  66       return;
  67    }
  68    procType = parse.FullHeader.Processor.Processor;
  69    assert(procType == TGSI_PROCESSOR_FRAGMENT ||
  70           procType == TGSI_PROCESSOR_VERTEX ||
  71           procType == TGSI_PROCESSOR_GEOMETRY);
  72
  73
  74    /**
  75     ** Loop over incoming program tokens/instructions
  76     */
  77    while( !tgsi_parse_end_of_tokens( &parse ) ) {
  78
  79       info->num_tokens++;
  80
  81       tgsi_parse_token( &parse );
  82
  83       switch( parse.FullToken.Token.Type ) {
  84       case TGSI_TOKEN_TYPE_INSTRUCTION:
  85          {
  86             const struct tgsi_full_instruction *fullinst
  87                = &parse.FullToken.FullInstruction;
  88
  89             assert(fullinst->Instruction.Opcode < TGSI_OPCODE_LAST);
  90             info->opcode_count[fullinst->Instruction.Opcode]++;
  91
  92             /* special case: scan fragment shaders for use of the fog
  93              * input/attribute.  The X component is fog, the Y component
  94              * is the front/back-face flag.
  95              */
  96             if (procType == TGSI_PROCESSOR_FRAGMENT) {
  97                uint i;
  98                for (i = 0; i < fullinst->Instruction.NumSrcRegs; i++) {
  99                   const struct tgsi_full_src_register *src =
 100                      &fullinst->FullSrcRegisters[i];
 101                   if (src->SrcRegister.File == TGSI_FILE_INPUT) {
 102                      const int ind = src->SrcRegister.Index;
 103                      if (info->input_semantic_name[ind] == TGSI_SEMANTIC_FOG) {
 104                         info->uses_fogcoord = TRUE;
 105                      }
 106                      else if (info->input_semantic_name[ind] == TGSI_SEMANTIC_FACE) {
 107                         info->uses_frontfacing = TRUE;
 108                      }
 109                   }
 110                }
 111             }
 112          }
 113          break;
 114
 115       case TGSI_TOKEN_TYPE_DECLARATION:
 116          {
 117             const struct tgsi_full_declaration *fulldecl
 118                = &parse.FullToken.FullDeclaration;
 119             const uint file = fulldecl->Declaration.File;
 120             uint reg;
 121             for (reg = fulldecl->DeclarationRange.First;
 122                  reg <= fulldecl->DeclarationRange.Last;
 123                  reg++) {
 124
 125                /* only first 32 regs will appear in this bitfield */
 126                info->file_mask[file] |= (1 << reg);
 127                info->file_count[file]++;
 128                info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 129
 130                if (file == TGSI_FILE_INPUT) {
 131                   info->input_semantic_name[reg] = (ubyte)fulldecl->Semantic.SemanticName;
 132                   info->input_semantic_index[reg] = (ubyte)fulldecl->Semantic.SemanticIndex;
 133                   info->input_interpolate[reg] = (ubyte)fulldecl->Declaration.Interpolate;
 134                   info->num_inputs++;
 135                }
 136                else if (file == TGSI_FILE_OUTPUT) {
 137                   info->output_semantic_name[reg] = (ubyte)fulldecl->Semantic.SemanticName;
 138                   info->output_semantic_index[reg] = (ubyte)fulldecl->Semantic.SemanticIndex;
 139                   info->num_outputs++;
 140                }
 141
 142                /* special case */
 143                if (procType == TGSI_PROCESSOR_FRAGMENT &&
 144                    file == TGSI_FILE_OUTPUT &&
 145                    fulldecl->Semantic.SemanticName == TGSI_SEMANTIC_POSITION) {
 146                   info->writes_z = TRUE;
 147                }
 148             }
 149          }
 150          break;
 151
 152       case TGSI_TOKEN_TYPE_IMMEDIATE:
 153          {
 154             uint reg = info->immediate_count++;
 155             uint file = TGSI_FILE_IMMEDIATE;
 156
 157             info->file_mask[file] |= (1 << reg);
 158             info->file_count[file]++;
 159             info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 160          }
 161          break;
 162
 163       default:
 164          assert( 0 );
 165       }
 166    }
 167
 168    info->uses_kill = (info->opcode_count[TGSI_OPCODE_KIL] ||
 169                       info->opcode_count[TGSI_OPCODE_KILP]);
 170
 171    tgsi_parse_free (&parse);
 172 }
 173
 174
 175
 176 /**
 177  * Check if the given shader is a "passthrough" shader consisting of only
 178  * MOV instructions of the form:  MOV OUT[n], IN[n]
 179  *
 180  */
 181 boolean
 182 tgsi_is_passthrough_shader(const struct tgsi_token *tokens)
 183 {
 184    struct tgsi_parse_context parse;
 185
 186    /**
 187     ** Setup to begin parsing input shader
 188     **/
 189    if (tgsi_parse_init(&parse, tokens) != TGSI_PARSE_OK) {
 190       debug_printf("tgsi_parse_init() failed in tgsi_is_passthrough_shader()!\n");
 191       return FALSE;
 192    }
 193
 194    /**
 195     ** Loop over incoming program tokens/instructions
 196     */
 197    while (!tgsi_parse_end_of_tokens(&parse)) {
 198
 199       tgsi_parse_token(&parse);
 200
 201       switch (parse.FullToken.Token.Type) {
 202       case TGSI_TOKEN_TYPE_INSTRUCTION:
 203          {
 204             struct tgsi_full_instruction *fullinst =
 205                &parse.FullToken.FullInstruction;
 206             const struct tgsi_full_src_register *src =
 207                &fullinst->FullSrcRegisters[0];
 208             const struct tgsi_full_dst_register *dst =
 209                &fullinst->FullDstRegisters[0];
 210
 211             /* Do a whole bunch of checks for a simple move */
 212             if (fullinst->Instruction.Opcode != TGSI_OPCODE_MOV ||
 213                 src->SrcRegister.File != TGSI_FILE_INPUT ||
 214                 dst->DstRegister.File != TGSI_FILE_OUTPUT ||
 215                 src->SrcRegister.Index != dst->DstRegister.Index ||
 216
 217                 src->SrcRegister.Negate ||
 218                 src->SrcRegisterExtMod.Negate ||
 219                 src->SrcRegisterExtMod.Absolute ||
 220                 src->SrcRegisterExtMod.Scale2X ||
 221                 src->SrcRegisterExtMod.Bias ||
 222                 src->SrcRegisterExtMod.Complement ||
 223
 224                 src->SrcRegister.SwizzleX != TGSI_SWIZZLE_X ||
 225                 src->SrcRegister.SwizzleY != TGSI_SWIZZLE_Y ||
 226                 src->SrcRegister.SwizzleZ != TGSI_SWIZZLE_Z ||
 227                 src->SrcRegister.SwizzleW != TGSI_SWIZZLE_W ||
 228
 229                 dst->DstRegister.WriteMask != TGSI_WRITEMASK_XYZW)
 230             {
 231                tgsi_parse_free(&parse);
 232                return FALSE;
 233             }
 234          }
 235          break;
 236
 237       case TGSI_TOKEN_TYPE_DECLARATION:
 238          /* fall-through */
 239       case TGSI_TOKEN_TYPE_IMMEDIATE:
 240          /* fall-through */
 241       default:
 242          ; /* no-op */
 243       }
 244    }
 245
 246    tgsi_parse_free(&parse);
 247
 248    /* if we get here, it's a pass-through shader */
 249    return TRUE;
 250 }