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  */
  47 void
  48 tgsi_scan_shader(const struct tgsi_token *tokens,
  49                  struct tgsi_shader_info *info)
  50 {
  51    uint procType, i;
  52    struct tgsi_parse_context parse;
  53
  54    memset(info, 0, sizeof(*info));
  55    for (i = 0; i < TGSI_FILE_COUNT; i++)
  56       info->file_max[i] = -1;
  57
  58    /**
  59     ** Setup to begin parsing input shader
  60     **/
  61    if (tgsi_parse_init( &parse, tokens ) != TGSI_PARSE_OK) {
  62       debug_printf("tgsi_parse_init() failed in tgsi_scan_shader()!\n");
  63       return;
  64    }
  65    procType = parse.FullHeader.Processor.Processor;
  66    assert(procType == TGSI_PROCESSOR_FRAGMENT ||
  67           procType == TGSI_PROCESSOR_VERTEX ||
  68           procType == TGSI_PROCESSOR_GEOMETRY);
  69
  70
  71    /**
  72     ** Loop over incoming program tokens/instructions
  73     */
  74    while( !tgsi_parse_end_of_tokens( &parse ) ) {
  75
  76       info->num_tokens++;
  77
  78       tgsi_parse_token( &parse );
  79
  80       switch( parse.FullToken.Token.Type ) {
  81       case TGSI_TOKEN_TYPE_INSTRUCTION:
  82          {
  83             const struct tgsi_full_instruction *fullinst
  84                = &parse.FullToken.FullInstruction;
  85
  86             assert(fullinst->Instruction.Opcode < TGSI_OPCODE_LAST);
  87             info->opcode_count[fullinst->Instruction.Opcode]++;
  88
  89             /* special case: scan fragment shaders for use of the fog
  90              * input/attribute.  The X component is fog, the Y component
  91              * is the front/back-face flag.
  92              */
  93             if (procType == TGSI_PROCESSOR_FRAGMENT) {
  94                uint i;
  95                for (i = 0; i < fullinst->Instruction.NumSrcRegs; i++) {
  96                   const struct tgsi_full_src_register *src =
  97                      &fullinst->FullSrcRegisters[i];
  98                   if (src->SrcRegister.File == TGSI_FILE_INPUT) {
  99                      const int ind = src->SrcRegister.Index;
 100                      if (info->input_semantic_name[ind] == TGSI_SEMANTIC_FOG) {
 101                         if (src->SrcRegister.SwizzleX == TGSI_SWIZZLE_X) {
 102                            info->uses_fogcoord = TRUE;
 103                         }
 104                         else if (src->SrcRegister.SwizzleX == TGSI_SWIZZLE_Y) {
 105                            info->uses_frontfacing = TRUE;
 106                         }
 107                      }
 108                   }
 109                }
 110             }
 111          }
 112          break;
 113
 114       case TGSI_TOKEN_TYPE_DECLARATION:
 115          {
 116             const struct tgsi_full_declaration *fulldecl
 117                = &parse.FullToken.FullDeclaration;
 118             uint file = fulldecl->Declaration.File;
 119             uint reg;
 120             for (reg = fulldecl->DeclarationRange.First;
 121                  reg <= fulldecl->DeclarationRange.Last;
 122                  reg++) {
 123
 124                /* only first 32 regs will appear in this bitfield */
 125                info->file_mask[file] |= (1 << reg);
 126                info->file_count[file]++;
 127                info->file_max[file] = MAX2(info->file_max[file], (int)reg);
 128
 129                if (file == TGSI_FILE_INPUT) {
 130                   info->input_semantic_name[reg] = (ubyte)fulldecl->Semantic.SemanticName;
 131                   info->input_semantic_index[reg] = (ubyte)fulldecl->Semantic.SemanticIndex;
 132                   info->num_inputs++;
 133                }
 134
 135                if (file == TGSI_FILE_OUTPUT) {
 136                   info->output_semantic_name[reg] = (ubyte)fulldecl->Semantic.SemanticName;
 137                   info->output_semantic_index[reg] = (ubyte)fulldecl->Semantic.SemanticIndex;
 138                   info->num_outputs++;
 139                }
 140
 141                /* special case */
 142                if (procType == TGSI_PROCESSOR_FRAGMENT &&
 143                    file == TGSI_FILE_OUTPUT &&
 144                    fulldecl->Semantic.SemanticName == TGSI_SEMANTIC_POSITION) {
 145                   info->writes_z = TRUE;
 146                }
 147             }
 148          }
 149          break;
 150
 151       case TGSI_TOKEN_TYPE_IMMEDIATE:
 152          info->immediate_count++;
 153          break;
 154
 155       default:
 156          assert( 0 );
 157       }
 158    }
 159
 160    info->uses_kill = (info->opcode_count[TGSI_OPCODE_KIL] ||
 161                       info->opcode_count[TGSI_OPCODE_KILP]);
 162
 163    tgsi_parse_free (&parse);
 164 }
 165
 166
 167
 168 /**
 169  * Check if the given shader is a "passthrough" shader consisting of only
 170  * MOV instructions of the form:  MOV OUT[n], IN[n]
 171  *
 172  */
 173 boolean
 174 tgsi_is_passthrough_shader(const struct tgsi_token *tokens)
 175 {
 176    struct tgsi_parse_context parse;
 177
 178    /**
 179     ** Setup to begin parsing input shader
 180     **/
 181    if (tgsi_parse_init(&parse, tokens) != TGSI_PARSE_OK) {
 182       debug_printf("tgsi_parse_init() failed in tgsi_is_passthrough_shader()!\n");
 183       return FALSE;
 184    }
 185
 186    /**
 187     ** Loop over incoming program tokens/instructions
 188     */
 189    while (!tgsi_parse_end_of_tokens(&parse)) {
 190
 191       tgsi_parse_token(&parse);
 192
 193       switch (parse.FullToken.Token.Type) {
 194       case TGSI_TOKEN_TYPE_INSTRUCTION:
 195          {
 196             struct tgsi_full_instruction *fullinst =
 197                &parse.FullToken.FullInstruction;
 198             const struct tgsi_full_src_register *src =
 199                &fullinst->FullSrcRegisters[0];
 200             const struct tgsi_full_dst_register *dst =
 201                &fullinst->FullDstRegisters[0];
 202
 203             /* Do a whole bunch of checks for a simple move */
 204             if (fullinst->Instruction.Opcode != TGSI_OPCODE_MOV ||
 205                 src->SrcRegister.File != TGSI_FILE_INPUT ||
 206                 dst->DstRegister.File != TGSI_FILE_OUTPUT ||
 207                 src->SrcRegister.Index != dst->DstRegister.Index ||
 208
 209                 src->SrcRegister.Negate ||
 210                 src->SrcRegisterExtMod.Negate ||
 211                 src->SrcRegisterExtMod.Absolute ||
 212                 src->SrcRegisterExtMod.Scale2X ||
 213                 src->SrcRegisterExtMod.Bias ||
 214                 src->SrcRegisterExtMod.Complement ||
 215
 216                 src->SrcRegister.SwizzleX != TGSI_SWIZZLE_X ||
 217                 src->SrcRegister.SwizzleY != TGSI_SWIZZLE_Y ||
 218                 src->SrcRegister.SwizzleZ != TGSI_SWIZZLE_Z ||
 219                 src->SrcRegister.SwizzleW != TGSI_SWIZZLE_W ||
 220
 221                 src->SrcRegisterExtSwz.ExtSwizzleX != TGSI_EXTSWIZZLE_X ||
 222                 src->SrcRegisterExtSwz.ExtSwizzleY != TGSI_EXTSWIZZLE_Y ||
 223                 src->SrcRegisterExtSwz.ExtSwizzleZ != TGSI_EXTSWIZZLE_Z ||
 224                 src->SrcRegisterExtSwz.ExtSwizzleW != TGSI_EXTSWIZZLE_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 }