tgsi_scan.c revision f595e72337f4cdc2ec6b0378f747e31666e70d5c 
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 */
50void
51tgsi_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 */
181boolean
182tgsi_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}
251