1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
// Copyright (c) 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SOURCE_REDUCE_REMOVE_STRUCT_MEMBER_REDUCTION_OPPORTUNITY_H_
#define SOURCE_REDUCE_REMOVE_STRUCT_MEMBER_REDUCTION_OPPORTUNITY_H_
#include "source/reduce/reduction_opportunity.h"
#include "source/opt/instruction.h"
namespace spvtools {
namespace reduce {
// An opportunity for removing a member from a struct type, adjusting all uses
// of the struct accordingly.
class RemoveStructMemberReductionOpportunity : public ReductionOpportunity {
public:
// Constructs a reduction opportunity from the struct type |struct_type|, for
// removal of member |member_index|.
RemoveStructMemberReductionOpportunity(opt::Instruction* struct_type,
uint32_t member_index)
: struct_type_(struct_type),
member_index_(member_index),
original_number_of_members_(struct_type->NumInOperands()) {}
// Opportunities to remove fields from a common struct type mutually
// invalidate each other. We guard against this by requiring that the struct
// still has the number of members it had when the opportunity was created.
bool PreconditionHolds() override;
protected:
void Apply() override;
private:
// |composite_access_instruction| is an instruction that accesses a composite
// id using either a series of literal indices (e.g. in the case of
// OpCompositeInsert) or a series of index ids (e.g. in the case of
// OpAccessChain).
//
// This function adjusts the indices that are used by
// |composite_access_instruction| to that whenever an index is accessing a
// member of |struct_type_|, it is decremented if the member is beyond
// |member_index_|, to account for the removal of the |member_index_|-th
// member.
//
// |composite_type_id| is the id of the composite type that the series of
// indices is to be applied to.
//
// |first_index_input_operand| specifies the first input operand that is an
// index.
//
// |literal_indices| specifies whether indices are given as literals (true),
// or as ids (false).
//
// If id-based indexing is used, this function will add a constant for
// |member_index_| - 1 to the module if needed.
void AdjustAccessedIndices(
uint32_t composite_type_id, uint32_t first_index_input_operand,
bool literal_indices, opt::IRContext* context,
opt::Instruction* composite_access_instruction) const;
// The struct type from which a member is to be removed.
opt::Instruction* struct_type_;
uint32_t member_index_;
uint32_t original_number_of_members_;
};
} // namespace reduce
} // namespace spvtools
#endif // SOURCE_REDUCE_REMOVE_STRUCT_MEMBER_REDUCTION_OPPORTUNITY_H_
|
