src/gallium/auxiliary/tgsi/tgsi_transform.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
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  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * TGSI program transformation utility.
  30  *
  31  * Authors:  Brian Paul
  32  */
  33
  34 #include "util/u_debug.h"
  35
  36 #include "tgsi_transform.h"
  37
  38
  39
  40 static void
  41 emit_instruction(struct tgsi_transform_context *ctx,
  42                  const struct tgsi_full_instruction *inst)
  43 {
  44    uint ti = ctx->ti;
  45
  46    ti += tgsi_build_full_instruction(inst,
  47                                      ctx->tokens_out + ti,
  48                                      ctx->header,
  49                                      ctx->max_tokens_out - ti);
  50    ctx->ti = ti;
  51 }
  52
  53
  54 static void
  55 emit_declaration(struct tgsi_transform_context *ctx,
  56                  const struct tgsi_full_declaration *decl)
  57 {
  58    uint ti = ctx->ti;
  59
  60    ti += tgsi_build_full_declaration(decl,
  61                                      ctx->tokens_out + ti,
  62                                      ctx->header,
  63                                      ctx->max_tokens_out - ti);
  64    ctx->ti = ti;
  65 }
  66
  67
  68 static void
  69 emit_immediate(struct tgsi_transform_context *ctx,
  70                const struct tgsi_full_immediate *imm)
  71 {
  72    uint ti = ctx->ti;
  73
  74    ti += tgsi_build_full_immediate(imm,
  75                                    ctx->tokens_out + ti,
  76                                    ctx->header,
  77                                    ctx->max_tokens_out - ti);
  78    ctx->ti = ti;
  79 }
  80
  81
  82 static void
  83 emit_property(struct tgsi_transform_context *ctx,
  84               const struct tgsi_full_property *prop)
  85 {
  86    uint ti = ctx->ti;
  87
  88    ti += tgsi_build_full_property(prop,
  89                                   ctx->tokens_out + ti,
  90                                   ctx->header,
  91                                   ctx->max_tokens_out - ti);
  92    ctx->ti = ti;
  93 }
  94
  95
  96 /**
  97  * Apply user-defined transformations to the input shader to produce
  98  * the output shader.
  99  * For example, a register search-and-replace operation could be applied
 100  * by defining a transform_instruction() callback that examined and changed
 101  * the instruction src/dest regs.
 102  *
 103  * \return number of tokens emitted
 104  */
 105 int
 106 tgsi_transform_shader(const struct tgsi_token *tokens_in,
 107                       struct tgsi_token *tokens_out,
 108                       uint max_tokens_out,
 109                       struct tgsi_transform_context *ctx)
 110 {
 111    uint procType;
 112    boolean first_instruction = TRUE;
 113
 114    /* input shader */
 115    struct tgsi_parse_context parse;
 116
 117    /* output shader */
 118    struct tgsi_processor *processor;
 119
 120
 121    /**
 122     ** callback context init
 123     **/
 124    ctx->emit_instruction = emit_instruction;
 125    ctx->emit_declaration = emit_declaration;
 126    ctx->emit_immediate = emit_immediate;
 127    ctx->emit_property = emit_property;
 128    ctx->tokens_out = tokens_out;
 129    ctx->max_tokens_out = max_tokens_out;
 130
 131
 132    /**
 133     ** Setup to begin parsing input shader
 134     **/
 135    if (tgsi_parse_init( &parse, tokens_in ) != TGSI_PARSE_OK) {
 136       debug_printf("tgsi_parse_init() failed in tgsi_transform_shader()!\n");
 137       return -1;
 138    }
 139    procType = parse.FullHeader.Processor.Processor;
 140    assert(procType == PIPE_SHADER_FRAGMENT ||
 141           procType == PIPE_SHADER_VERTEX ||
 142           procType == PIPE_SHADER_GEOMETRY);
 143
 144
 145    /**
 146     **  Setup output shader
 147     **/
 148    ctx->header = (struct tgsi_header *)tokens_out;
 149    *ctx->header = tgsi_build_header();
 150
 151    processor = (struct tgsi_processor *) (tokens_out + 1);
 152    *processor = tgsi_build_processor( procType, ctx->header );
 153
 154    ctx->ti = 2;
 155
 156
 157    /**
 158     ** Loop over incoming program tokens/instructions
 159     */
 160    while( !tgsi_parse_end_of_tokens( &parse ) ) {
 161
 162       tgsi_parse_token( &parse );
 163
 164       switch( parse.FullToken.Token.Type ) {
 165       case TGSI_TOKEN_TYPE_INSTRUCTION:
 166          {
 167             struct tgsi_full_instruction *fullinst
 168                = &parse.FullToken.FullInstruction;
 169
 170             if (first_instruction && ctx->prolog) {
 171                ctx->prolog(ctx);
 172             }
 173
 174             /* XXX Note: we may also want to look for a main/top-level
 175              * TGSI_OPCODE_RET instruction in the future.
 176              */
 177             if (fullinst->Instruction.Opcode == TGSI_OPCODE_END
 178                 && ctx->epilog) {
 179                /* Emit caller's epilog */
 180                ctx->epilog(ctx);
 181                /* Emit END */
 182                ctx->emit_instruction(ctx, fullinst);
 183             }
 184             else {
 185                if (ctx->transform_instruction)
 186                   ctx->transform_instruction(ctx, fullinst);
 187                else
 188                   ctx->emit_instruction(ctx, fullinst);
 189             }
 190
 191             first_instruction = FALSE;
 192          }
 193          break;
 194
 195       case TGSI_TOKEN_TYPE_DECLARATION:
 196          {
 197             struct tgsi_full_declaration *fulldecl
 198                = &parse.FullToken.FullDeclaration;
 199
 200             if (ctx->transform_declaration)
 201                ctx->transform_declaration(ctx, fulldecl);
 202             else
 203                ctx->emit_declaration(ctx, fulldecl);
 204          }
 205          break;
 206
 207       case TGSI_TOKEN_TYPE_IMMEDIATE:
 208          {
 209             struct tgsi_full_immediate *fullimm
 210                = &parse.FullToken.FullImmediate;
 211
 212             if (ctx->transform_immediate)
 213                ctx->transform_immediate(ctx, fullimm);
 214             else
 215                ctx->emit_immediate(ctx, fullimm);
 216          }
 217          break;
 218       case TGSI_TOKEN_TYPE_PROPERTY:
 219          {
 220             struct tgsi_full_property *fullprop
 221                = &parse.FullToken.FullProperty;
 222
 223             if (ctx->transform_property)
 224                ctx->transform_property(ctx, fullprop);
 225             else
 226                ctx->emit_property(ctx, fullprop);
 227          }
 228          break;
 229
 230       default:
 231          assert( 0 );
 232       }
 233    }
 234
 235    tgsi_parse_free (&parse);
 236
 237    return ctx->ti;
 238 }
 239
 240
 241 #include "tgsi_text.h"
 242
 243 extern int tgsi_transform_foo( struct tgsi_token *tokens_out,
 244                                uint max_tokens_out );
 245
 246 /* This function exists only so that tgsi_text_translate() doesn't get
 247  * magic-ed out of the libtgsi.a archive by the build system.  Don't
 248  * remove unless you know this has been fixed - check on mingw/scons
 249  * builds as well.
 250  */
 251 int
 252 tgsi_transform_foo( struct tgsi_token *tokens_out,
 253                     uint max_tokens_out )
 254 {
 255    const char *text =
 256       "FRAG\n"
 257       "DCL IN[0], COLOR, CONSTANT\n"
 258       "DCL OUT[0], COLOR\n"
 259       "  0: MOV OUT[0], IN[0]\n"
 260       "  1: END";
 261
 262    return tgsi_text_translate( text,
 263                                tokens_out,
 264                                max_tokens_out );
 265 }