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
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  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    boolean epilog_emitted = FALSE;
 114    int cond_stack = 0;
 115    int call_stack = 0;
 116
 117    /* input shader */
 118    struct tgsi_parse_context parse;
 119
 120    /* output shader */
 121    struct tgsi_processor *processor;
 122
 123
 124    /**
 125     ** callback context init
 126     **/
 127    ctx->emit_instruction = emit_instruction;
 128    ctx->emit_declaration = emit_declaration;
 129    ctx->emit_immediate = emit_immediate;
 130    ctx->emit_property = emit_property;
 131    ctx->tokens_out = tokens_out;
 132    ctx->max_tokens_out = max_tokens_out;
 133
 134
 135    /**
 136     ** Setup to begin parsing input shader
 137     **/
 138    if (tgsi_parse_init( &parse, tokens_in ) != TGSI_PARSE_OK) {
 139       debug_printf("tgsi_parse_init() failed in tgsi_transform_shader()!\n");
 140       return -1;
 141    }
 142    procType = parse.FullHeader.Processor.Processor;
 143
 144    /**
 145     **  Setup output shader
 146     **/
 147    ctx->header = (struct tgsi_header *)tokens_out;
 148    *ctx->header = tgsi_build_header();
 149
 150    processor = (struct tgsi_processor *) (tokens_out + 1);
 151    *processor = tgsi_build_processor( procType, ctx->header );
 152
 153    ctx->ti = 2;
 154
 155
 156    /**
 157     ** Loop over incoming program tokens/instructions
 158     */
 159    while( !tgsi_parse_end_of_tokens( &parse ) ) {
 160
 161       tgsi_parse_token( &parse );
 162
 163       switch( parse.FullToken.Token.Type ) {
 164       case TGSI_TOKEN_TYPE_INSTRUCTION:
 165          {
 166             struct tgsi_full_instruction *fullinst
 167                = &parse.FullToken.FullInstruction;
 168             enum tgsi_opcode opcode = fullinst->Instruction.Opcode;
 169
 170             if (first_instruction && ctx->prolog) {
 171                ctx->prolog(ctx);
 172             }
 173
 174             /*
 175              * XXX Note: we handle the case of ret in main.
 176              * However, the output redirections done by transform
 177              * have their limits with control flow and will generally
 178              * not work correctly. e.g.
 179              * if (cond) {
 180              *    oColor = x;
 181              *    ret;
 182              * }
 183              * oColor = y;
 184              * end;
 185              * If the color output is redirected to a temp and modified
 186              * by a transform, this will not work (the oColor assignment
 187              * in the conditional will never make it to the actual output).
 188              */
 189             if ((opcode == TGSI_OPCODE_END || opcode == TGSI_OPCODE_RET) &&
 190                  call_stack == 0 && ctx->epilog && !epilog_emitted) {
 191                if (opcode == TGSI_OPCODE_RET && cond_stack != 0) {
 192                   assert(!"transform ignoring RET in main");
 193                } else {
 194                   assert(cond_stack == 0);
 195                   /* Emit caller's epilog */
 196                   ctx->epilog(ctx);
 197                   epilog_emitted = TRUE;
 198                }
 199                /* Emit END (or RET) */
 200                ctx->emit_instruction(ctx, fullinst);
 201             }
 202             else {
 203                switch (opcode) {
 204                case TGSI_OPCODE_IF:
 205                case TGSI_OPCODE_UIF:
 206                case TGSI_OPCODE_SWITCH:
 207                case TGSI_OPCODE_BGNLOOP:
 208                   cond_stack++;
 209                   break;
 210                case TGSI_OPCODE_CAL:
 211                   call_stack++;
 212                   break;
 213                case TGSI_OPCODE_ENDIF:
 214                case TGSI_OPCODE_ENDSWITCH:
 215                case TGSI_OPCODE_ENDLOOP:
 216                   assert(cond_stack > 0);
 217                   cond_stack--;
 218                   break;
 219                case TGSI_OPCODE_ENDSUB:
 220                   assert(call_stack > 0);
 221                   call_stack--;
 222                   break;
 223                case TGSI_OPCODE_BGNSUB:
 224                case TGSI_OPCODE_RET:
 225                default:
 226                   break;
 227                }
 228                if (ctx->transform_instruction)
 229                   ctx->transform_instruction(ctx, fullinst);
 230                else
 231                   ctx->emit_instruction(ctx, fullinst);
 232             }
 233
 234             first_instruction = FALSE;
 235          }
 236          break;
 237
 238       case TGSI_TOKEN_TYPE_DECLARATION:
 239          {
 240             struct tgsi_full_declaration *fulldecl
 241                = &parse.FullToken.FullDeclaration;
 242
 243             if (ctx->transform_declaration)
 244                ctx->transform_declaration(ctx, fulldecl);
 245             else
 246                ctx->emit_declaration(ctx, fulldecl);
 247          }
 248          break;
 249
 250       case TGSI_TOKEN_TYPE_IMMEDIATE:
 251          {
 252             struct tgsi_full_immediate *fullimm
 253                = &parse.FullToken.FullImmediate;
 254
 255             if (ctx->transform_immediate)
 256                ctx->transform_immediate(ctx, fullimm);
 257             else
 258                ctx->emit_immediate(ctx, fullimm);
 259          }
 260          break;
 261       case TGSI_TOKEN_TYPE_PROPERTY:
 262          {
 263             struct tgsi_full_property *fullprop
 264                = &parse.FullToken.FullProperty;
 265
 266             if (ctx->transform_property)
 267                ctx->transform_property(ctx, fullprop);
 268             else
 269                ctx->emit_property(ctx, fullprop);
 270          }
 271          break;
 272
 273       default:
 274          assert( 0 );
 275       }
 276    }
 277    assert(call_stack == 0);
 278
 279    tgsi_parse_free (&parse);
 280
 281    return ctx->ti;
 282 }
 283
 284
 285 #include "tgsi_text.h"
 286
 287 extern int tgsi_transform_foo( struct tgsi_token *tokens_out,
 288                                uint max_tokens_out );
 289
 290 /* This function exists only so that tgsi_text_translate() doesn't get
 291  * magic-ed out of the libtgsi.a archive by the build system.  Don't
 292  * remove unless you know this has been fixed - check on mingw/scons
 293  * builds as well.
 294  */
 295 int
 296 tgsi_transform_foo( struct tgsi_token *tokens_out,
 297                     uint max_tokens_out )
 298 {
 299    const char *text =
 300       "FRAG\n"
 301       "DCL IN[0], COLOR, CONSTANT\n"
 302       "DCL OUT[0], COLOR\n"
 303       "  0: MOV OUT[0], IN[0]\n"
 304       "  1: END";
 305
 306    return tgsi_text_translate( text,
 307                                tokens_out,
 308                                max_tokens_out );
 309 }