tgsi_scan.c revision ba1ca28cc62fed71c77902b95ae4ed36c6bf25f8 
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 */
49void
50tgsi_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 */
182boolean
183tgsi_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}
248