1// Copyright (c) 2016 Google Inc.
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#ifndef SOURCE_OPT_PASS_H_
16#define SOURCE_OPT_PASS_H_
17
18#include <algorithm>
19#include <map>
20#include <unordered_map>
21#include <unordered_set>
22#include <utility>
23
24#include "source/opt/basic_block.h"
25#include "source/opt/def_use_manager.h"
26#include "source/opt/ir_context.h"
27#include "source/opt/module.h"
28#include "spirv-tools/libspirv.hpp"
29#include "types.h"
30
31namespace spvtools {
32namespace opt {
33
34// Abstract class of a pass. All passes should implement this abstract class
35// and all analysis and transformation is done via the Process() method.
36class Pass {
37 public:
38 // The status of processing a module using a pass.
39 //
40 // The numbers for the cases are assigned to make sure that Failure & anything
41 // is Failure, SuccessWithChange & any success is SuccessWithChange.
42 enum class Status {
43 Failure = 0x00,
44 SuccessWithChange = 0x10,
45 SuccessWithoutChange = 0x11,
46 };
47
48 using ProcessFunction = std::function<bool(Function*)>;
49
50 // Destructs the pass.
51 virtual ~Pass() = default;
52
53 // Returns a descriptive name for this pass.
54 //
55 // NOTE: When deriving a new pass class, make sure you make the name
56 // compatible with the corresponding spirv-opt command-line flag. For example,
57 // if you add the flag --my-pass to spirv-opt, make this function return
58 // "my-pass" (no leading hyphens).
59 virtual const char* name() const = 0;
60
61 // Sets the message consumer to the given |consumer|. |consumer| which will be
62 // invoked every time there is a message to be communicated to the outside.
63 void SetMessageConsumer(MessageConsumer c) { consumer_ = std::move(c); }
64
65 // Returns the reference to the message consumer for this pass.
66 const MessageConsumer& consumer() const { return consumer_; }
67
68 // Returns the def-use manager used for this pass. TODO(dnovillo): This should
69 // be handled by the pass manager.
70 analysis::DefUseManager* get_def_use_mgr() const {
71 return context()->get_def_use_mgr();
72 }
73
74 analysis::DecorationManager* get_decoration_mgr() const {
75 return context()->get_decoration_mgr();
76 }
77
78 FeatureManager* get_feature_mgr() const {
79 return context()->get_feature_mgr();
80 }
81
82 // Returns a pointer to the current module for this pass.
83 Module* get_module() const { return context_->module(); }
84
85 // Sets the pointer to the current context for this pass.
86 void SetContextForTesting(IRContext* ctx) { context_ = ctx; }
87
88 // Returns a pointer to the current context for this pass.
89 IRContext* context() const { return context_; }
90
91 // Returns a pointer to the CFG for current module.
92 CFG* cfg() const { return context()->cfg(); }
93
94 // Run the pass on the given |module|. Returns Status::Failure if errors occur
95 // when processing. Returns the corresponding Status::Success if processing is
96 // successful to indicate whether changes are made to the module. If there
97 // were any changes it will also invalidate the analyses in the IRContext
98 // that are not preserved.
99 //
100 // It is an error if |Run| is called twice with the same instance of the pass.
101 // If this happens the return value will be |Failure|.
102 Status Run(IRContext* ctx);
103
104 // Returns the set of analyses that the pass is guaranteed to preserve.
105 virtual IRContext::Analysis GetPreservedAnalyses() {
106 return IRContext::kAnalysisNone;
107 }
108
109 // Return type id for |ptrInst|'s pointee
110 uint32_t GetPointeeTypeId(const Instruction* ptrInst) const;
111
112 // Return base type of |ty_id| type
113 Instruction* GetBaseType(uint32_t ty_id);
114
115 // Return true if |inst| returns scalar, vector or matrix type with base
116 // float and |width|
117 bool IsFloat(uint32_t ty_id, uint32_t width);
118
119 // Return the id of OpConstantNull of type |type_id|. Create if necessary.
120 uint32_t GetNullId(uint32_t type_id);
121
122 protected:
123 // Constructs a new pass.
124 //
125 // The constructed instance will have an empty message consumer, which just
126 // ignores all messages from the library. Use SetMessageConsumer() to supply
127 // one if messages are of concern.
128 Pass();
129
130 // Processes the given |module|. Returns Status::Failure if errors occur when
131 // processing. Returns the corresponding Status::Success if processing is
132 // succesful to indicate whether changes are made to the module.
133 virtual Status Process() = 0;
134
135 // Return the next available SSA id and increment it.
136 // TODO(1841): Handle id overflow.
137 uint32_t TakeNextId() { return context_->TakeNextId(); }
138
139 // Returns the id whose value is the same as |object_to_copy| except its type
140 // is |new_type_id|. Any instructions needed to generate this value will be
141 // inserted before |insertion_position|.
142 uint32_t GenerateCopy(Instruction* object_to_copy, uint32_t new_type_id,
143 Instruction* insertion_position);
144
145 private:
146 MessageConsumer consumer_; // Message consumer.
147
148 // The context that this pass belongs to.
149 IRContext* context_;
150
151 // An instance of a pass can only be run once because it is too hard to
152 // enforce proper resetting of internal state for each instance. This member
153 // is used to check that we do not run the same instance twice.
154 bool already_run_;
155};
156
157inline Pass::Status CombineStatus(Pass::Status a, Pass::Status b) {
158 return std::min(a, b);
159}
160
161} // namespace opt
162} // namespace spvtools
163
164#endif // SOURCE_OPT_PASS_H_
165