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 #ifndef SOURCE_REDUCE_REDUCTION_PASS_H_
16 #define SOURCE_REDUCE_REDUCTION_PASS_H_
17 
18 #include "spirv-tools/libspirv.hpp"
19 
20 #include "reduction_opportunity.h"
21 #include "source/opt/ir_context.h"
22 
23 namespace spvtools {
24 namespace reduce {
25 
26 // Abstract class representing a reduction pass, which can be repeatedly
27 // invoked to find and apply particular reduction opportunities to a SPIR-V
28 // binary.  In the spirit of delta debugging, a pass initially tries to apply
29 // large chunks of reduction opportunities, iterating through available
30 // opportunities at a given granularity.  When an iteration over available
31 // opportunities completes, the granularity is reduced and iteration starts
32 // again, until the minimum granularity is reached.
33 class ReductionPass {
34  public:
35   // Constructs a reduction pass with a given target environment, |target_env|.
36   // Initially the pass is uninitialized.
ReductionPass(const spv_target_env target_env)37   explicit ReductionPass(const spv_target_env target_env)
38       : target_env_(target_env), is_initialized_(false) {}
39 
40   virtual ~ReductionPass() = default;
41 
42   // Apply the reduction pass to the given binary.
43   std::vector<uint32_t> TryApplyReduction(const std::vector<uint32_t>& binary);
44 
45   // Set a consumer to which relevant messages will be directed.
46   void SetMessageConsumer(MessageConsumer consumer);
47 
48   // Determines whether the granularity with which reduction opportunities are
49   // applied has reached a minimum.
50   bool ReachedMinimumGranularity() const;
51 
52   // Returns the name of the reduction pass (useful for monitoring reduction
53   // progress).
54   virtual std::string GetName() const = 0;
55 
56  protected:
57   // Finds the reduction opportunities relevant to this pass that could be
58   // applied to a given SPIR-V module.
59   virtual std::vector<std::unique_ptr<ReductionOpportunity>>
60   GetAvailableOpportunities(opt::IRContext* context) const = 0;
61 
62  private:
63   const spv_target_env target_env_;
64   MessageConsumer consumer_;
65   bool is_initialized_;
66   uint32_t index_;
67   uint32_t granularity_;
68 };
69 
70 }  // namespace reduce
71 }  // namespace spvtools
72 
73 #endif  // SOURCE_REDUCE_REDUCTION_PASS_H_
74