1 // Copyright (c) 2018 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "source/opt/replace_invalid_opc.h"
16
17 #include <bitset>
18 #include <vector>
19
20 namespace spvtools {
21 namespace opt {
22
Process()23 Pass::Status ReplaceInvalidOpcodePass::Process() {
24 bool modified = false;
25
26 if (context()->get_feature_mgr()->HasCapability(SpvCapabilityLinkage)) {
27 return Status::SuccessWithoutChange;
28 }
29
30 SpvExecutionModel execution_model = GetExecutionModel();
31 if (execution_model == SpvExecutionModelKernel) {
32 // We do not handle kernels.
33 return Status::SuccessWithoutChange;
34 }
35 if (execution_model == SpvExecutionModelMax) {
36 // Mixed execution models for the entry points. This case is not currently
37 // handled.
38 return Status::SuccessWithoutChange;
39 }
40
41 for (Function& func : *get_module()) {
42 modified |= RewriteFunction(&func, execution_model);
43 }
44 return (modified ? Status::SuccessWithChange : Status::SuccessWithoutChange);
45 }
46
GetExecutionModel()47 SpvExecutionModel ReplaceInvalidOpcodePass::GetExecutionModel() {
48 SpvExecutionModel result = SpvExecutionModelMax;
49 bool first = true;
50 for (Instruction& entry_point : get_module()->entry_points()) {
51 if (first) {
52 result =
53 static_cast<SpvExecutionModel>(entry_point.GetSingleWordInOperand(0));
54 first = false;
55 } else {
56 SpvExecutionModel current_model =
57 static_cast<SpvExecutionModel>(entry_point.GetSingleWordInOperand(0));
58 if (current_model != result) {
59 result = SpvExecutionModelMax;
60 break;
61 }
62 }
63 }
64 return result;
65 }
66
RewriteFunction(Function * function,SpvExecutionModel model)67 bool ReplaceInvalidOpcodePass::RewriteFunction(Function* function,
68 SpvExecutionModel model) {
69 bool modified = false;
70 Instruction* last_line_dbg_inst = nullptr;
71 function->ForEachInst(
72 [model, &modified, &last_line_dbg_inst, this](Instruction* inst) {
73 // Track the debug information so we can have a meaningful message.
74 if (inst->opcode() == SpvOpLabel || inst->IsNoLine()) {
75 last_line_dbg_inst = nullptr;
76 return;
77 } else if (inst->IsLine()) {
78 last_line_dbg_inst = inst;
79 return;
80 }
81
82 bool replace = false;
83 if (model != SpvExecutionModelFragment &&
84 IsFragmentShaderOnlyInstruction(inst)) {
85 replace = true;
86 }
87
88 if (model != SpvExecutionModelTessellationControl &&
89 model != SpvExecutionModelGLCompute) {
90 if (inst->opcode() == SpvOpControlBarrier) {
91 assert(model != SpvExecutionModelKernel &&
92 "Expecting to be working on a shader module.");
93 replace = true;
94 }
95 }
96
97 if (replace) {
98 modified = true;
99 if (last_line_dbg_inst == nullptr) {
100 ReplaceInstruction(inst, nullptr, 0, 0);
101 } else {
102 // Get the name of the source file.
103 uint32_t file_name_id = 0;
104 if (last_line_dbg_inst->opcode() == SpvOpLine) {
105 file_name_id = last_line_dbg_inst->GetSingleWordInOperand(0);
106 } else { // Shader100::DebugLine
107 uint32_t debug_source_id =
108 last_line_dbg_inst->GetSingleWordInOperand(2);
109 Instruction* debug_source_inst =
110 context()->get_def_use_mgr()->GetDef(debug_source_id);
111 file_name_id = debug_source_inst->GetSingleWordInOperand(2);
112 }
113 Instruction* file_name =
114 context()->get_def_use_mgr()->GetDef(file_name_id);
115 const char* source = reinterpret_cast<const char*>(
116 &file_name->GetInOperand(0).words[0]);
117
118 // Get the line number and column number.
119 uint32_t line_number =
120 last_line_dbg_inst->GetSingleWordInOperand(1);
121 uint32_t col_number = last_line_dbg_inst->GetSingleWordInOperand(2);
122
123 // Replace the instruction.
124 ReplaceInstruction(inst, source, line_number, col_number);
125 }
126 }
127 },
128 /* run_on_debug_line_insts = */ true);
129 return modified;
130 }
131
IsFragmentShaderOnlyInstruction(Instruction * inst)132 bool ReplaceInvalidOpcodePass::IsFragmentShaderOnlyInstruction(
133 Instruction* inst) {
134 switch (inst->opcode()) {
135 case SpvOpDPdx:
136 case SpvOpDPdy:
137 case SpvOpFwidth:
138 case SpvOpDPdxFine:
139 case SpvOpDPdyFine:
140 case SpvOpFwidthFine:
141 case SpvOpDPdxCoarse:
142 case SpvOpDPdyCoarse:
143 case SpvOpFwidthCoarse:
144 case SpvOpImageSampleImplicitLod:
145 case SpvOpImageSampleDrefImplicitLod:
146 case SpvOpImageSampleProjImplicitLod:
147 case SpvOpImageSampleProjDrefImplicitLod:
148 case SpvOpImageSparseSampleImplicitLod:
149 case SpvOpImageSparseSampleDrefImplicitLod:
150 case SpvOpImageQueryLod:
151 // TODO: Teach |ReplaceInstruction| to handle block terminators. Then
152 // uncomment the OpKill case.
153 // case SpvOpKill:
154 // case SpvOpTerminateInstruction:
155 return true;
156 default:
157 return false;
158 }
159 }
160
ReplaceInstruction(Instruction * inst,const char * source,uint32_t line_number,uint32_t column_number)161 void ReplaceInvalidOpcodePass::ReplaceInstruction(Instruction* inst,
162 const char* source,
163 uint32_t line_number,
164 uint32_t column_number) {
165 if (inst->result_id() != 0) {
166 uint32_t const_id = GetSpecialConstant(inst->type_id());
167 context()->KillNamesAndDecorates(inst);
168 context()->ReplaceAllUsesWith(inst->result_id(), const_id);
169 }
170 assert(!inst->IsBlockTerminator() &&
171 "We cannot simply delete a block terminator. It must be replaced "
172 "with something.");
173 if (consumer()) {
174 std::string message = BuildWarningMessage(inst->opcode());
175 consumer()(SPV_MSG_WARNING, source, {line_number, column_number, 0},
176 message.c_str());
177 }
178 context()->KillInst(inst);
179 }
180
GetSpecialConstant(uint32_t type_id)181 uint32_t ReplaceInvalidOpcodePass::GetSpecialConstant(uint32_t type_id) {
182 const analysis::Constant* special_const = nullptr;
183 analysis::ConstantManager* const_mgr = context()->get_constant_mgr();
184 analysis::TypeManager* type_mgr = context()->get_type_mgr();
185
186 Instruction* type = context()->get_def_use_mgr()->GetDef(type_id);
187 if (type->opcode() == SpvOpTypeVector) {
188 uint32_t component_const =
189 GetSpecialConstant(type->GetSingleWordInOperand(0));
190 std::vector<uint32_t> ids;
191 for (uint32_t i = 0; i < type->GetSingleWordInOperand(1); ++i) {
192 ids.push_back(component_const);
193 }
194 special_const = const_mgr->GetConstant(type_mgr->GetType(type_id), ids);
195 } else {
196 assert(type->opcode() == SpvOpTypeInt || type->opcode() == SpvOpTypeFloat);
197 std::vector<uint32_t> literal_words;
198 for (uint32_t i = 0; i < type->GetSingleWordInOperand(0); i += 32) {
199 literal_words.push_back(0xDEADBEEF);
200 }
201 special_const =
202 const_mgr->GetConstant(type_mgr->GetType(type_id), literal_words);
203 }
204 assert(special_const != nullptr);
205 return const_mgr->GetDefiningInstruction(special_const)->result_id();
206 }
207
BuildWarningMessage(SpvOp opcode)208 std::string ReplaceInvalidOpcodePass::BuildWarningMessage(SpvOp opcode) {
209 spv_opcode_desc opcode_info;
210 context()->grammar().lookupOpcode(opcode, &opcode_info);
211 std::string message = "Removing ";
212 message += opcode_info->name;
213 message += " instruction because of incompatible execution model.";
214 return message;
215 }
216
217 } // namespace opt
218 } // namespace spvtools
219