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