1 //===- InlineModelFeatureMaps.h - common model runner defs ------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 
10 #ifndef LLVM_ANALYSIS_INLINEMODELFEATUREMAPS_H
11 #define LLVM_ANALYSIS_INLINEMODELFEATUREMAPS_H
12 
13 #include "llvm/Analysis/TensorSpec.h"
14 
15 #include <array>
16 #include <vector>
17 
18 namespace llvm {
19 
20 // List of cost features. A "cost" feature is a summand of the heuristic-based
21 // inline cost, and we define them separately to preserve the original heuristic
22 // behavior.
23 #define INLINE_COST_FEATURE_ITERATOR(M)                                        \
24   M(int64_t, {1}, sroa_savings,                                                \
25     "Savings from SROA (scalar replacement of aggregates)")                    \
26   M(int64_t, {1}, sroa_losses,                                                 \
27     "Losses from SROA (scalar replacement of aggregates)")                     \
28   M(int64_t, {1}, load_elimination, "Cost of load elimination in the call")    \
29   M(int64_t, {1}, call_penalty,                                                \
30     "Accumulation of penalty applied to call sites when inlining")             \
31   M(int64_t, {1}, call_argument_setup,                                         \
32     "Accumulation of call argument setup costs")                               \
33   M(int64_t, {1}, load_relative_intrinsic,                                     \
34     "Accumulation of costs of loading relative intrinsics")                    \
35   M(int64_t, {1}, lowered_call_arg_setup,                                      \
36     "Accumulation of cost of lowered call argument setups")                    \
37   M(int64_t, {1}, indirect_call_penalty,                                       \
38     "Accumulation of costs for indirect calls")                                \
39   M(int64_t, {1}, jump_table_penalty, "Accumulation of costs for jump tables") \
40   M(int64_t, {1}, case_cluster_penalty,                                        \
41     "Accumulation of costs for case clusters")                                 \
42   M(int64_t, {1}, switch_penalty,                                              \
43     "Accumulation of costs for switch statements")                             \
44   M(int64_t, {1}, unsimplified_common_instructions,                            \
45     "Costs from unsimplified common instructions")                             \
46   M(int64_t, {1}, num_loops, "Number of loops in the caller")                  \
47   M(int64_t, {1}, dead_blocks, "Number of dead blocks in the caller")          \
48   M(int64_t, {1}, simplified_instructions,                                     \
49     "Number of simplified instructions")                                       \
50   M(int64_t, {1}, constant_args,                                               \
51     "Number of constant arguments in the call site")                           \
52   M(int64_t, {1}, constant_offset_ptr_args,                                    \
53     "Number of constant offset pointer args in the call site")                 \
54   M(int64_t, {1}, callsite_cost, "Estimated cost of the call site")            \
55   M(int64_t, {1}, cold_cc_penalty, "Penalty for a cold calling convention")    \
56   M(int64_t, {1}, last_call_to_static_bonus,                                   \
57     "Bonus for being the last call to static")                                 \
58   M(int64_t, {1}, is_multiple_blocks,                                          \
59     "Boolean; is the Callee multiple blocks")                                  \
60   M(int64_t, {1}, nested_inlines,                                              \
61     "Would the default inliner perfom nested inlining")                        \
62   M(int64_t, {1}, nested_inline_cost_estimate,                                 \
63     "Estimate of the accumulated cost of nested inlines")                      \
64   M(int64_t, {1}, threshold, "Threshold for the heuristic inliner")
65 
66 // clang-format off
67 enum class InlineCostFeatureIndex : size_t {
68 #define POPULATE_INDICES(DTYPE, SHAPE, NAME, DOC) NAME,
69   INLINE_COST_FEATURE_ITERATOR(POPULATE_INDICES)
70 #undef POPULATE_INDICES
71 
72   NumberOfFeatures
73 };
74 // clang-format on
75 
76 using InlineCostFeatures =
77     std::array<int,
78                static_cast<size_t>(InlineCostFeatureIndex::NumberOfFeatures)>;
79 
80 constexpr bool isHeuristicInlineCostFeature(InlineCostFeatureIndex Feature) {
81   return Feature != InlineCostFeatureIndex::sroa_savings &&
82          Feature != InlineCostFeatureIndex::is_multiple_blocks &&
83          Feature != InlineCostFeatureIndex::dead_blocks &&
84          Feature != InlineCostFeatureIndex::simplified_instructions &&
85          Feature != InlineCostFeatureIndex::constant_args &&
86          Feature != InlineCostFeatureIndex::constant_offset_ptr_args &&
87          Feature != InlineCostFeatureIndex::nested_inlines &&
88          Feature != InlineCostFeatureIndex::nested_inline_cost_estimate &&
89          Feature != InlineCostFeatureIndex::threshold;
90 }
91 
92 // List of features. Each feature is defined through a triple:
93 // - the name of an enum member, which will be the feature index
94 // - a textual name, used for ML model binding (so it needs to match the
95 // names used by the ML model).
96 // - a documentation description. Currently, that is not used anywhere
97 // programmatically, and serves as workaround to inability of inserting comments
98 // in macros.
99 #define INLINE_FEATURE_ITERATOR(M)                                             \
100   M(int64_t, {1}, callee_basic_block_count,                                    \
101     "number of basic blocks of the callee")                                    \
102   M(int64_t, {1}, callsite_height,                                             \
103     "position of the call site in the original call graph - measured from "    \
104     "the farthest SCC")                                                        \
105   M(int64_t, {1}, node_count,                                                  \
106     "total current number of defined functions in the module")                 \
107   M(int64_t, {1}, nr_ctant_params,                                             \
108     "number of parameters in the call site that are constants")                \
109   M(int64_t, {1}, cost_estimate, "total cost estimate (threshold - free)")     \
110   M(int64_t, {1}, edge_count, "total number of calls in the module")           \
111   M(int64_t, {1}, caller_users,                                                \
112     "number of module-internal users of the caller, +1 if the caller is "      \
113     "exposed externally")                                                      \
114   M(int64_t, {1}, caller_conditionally_executed_blocks,                        \
115     "number of blocks reached from a conditional instruction, in the caller")  \
116   M(int64_t, {1}, caller_basic_block_count,                                    \
117     "number of basic blocks in the caller")                                    \
118   M(int64_t, {1}, callee_conditionally_executed_blocks,                        \
119     "number of blocks reached from a conditional instruction, in the callee")  \
120   M(int64_t, {1}, callee_users,                                                \
121     "number of module-internal users of the callee, +1 if the callee is "      \
122     "exposed externally")
123 
124 // clang-format off
125 enum class FeatureIndex : size_t {
126 #define POPULATE_INDICES(DTYPE, SHAPE, NAME, COMMENT) NAME,
127 // InlineCost features - these must come first
128   INLINE_COST_FEATURE_ITERATOR(POPULATE_INDICES)
129 
130 // Non-cost features
131   INLINE_FEATURE_ITERATOR(POPULATE_INDICES)
132 #undef POPULATE_INDICES
133 
134   NumberOfFeatures
135 };
136 // clang-format on
137 
138 constexpr FeatureIndex
139 inlineCostFeatureToMlFeature(InlineCostFeatureIndex Feature) {
140   return static_cast<FeatureIndex>(static_cast<size_t>(Feature));
141 }
142 
143 constexpr size_t NumberOfFeatures =
144     static_cast<size_t>(FeatureIndex::NumberOfFeatures);
145 
146 extern const std::vector<TensorSpec> FeatureMap;
147 
148 extern const char *const DecisionName;
149 extern const TensorSpec InlineDecisionSpec;
150 extern const char *const DefaultDecisionName;
151 extern const TensorSpec DefaultDecisionSpec;
152 extern const char *const RewardName;
153 
154 using InlineFeatures = std::vector<int64_t>;
155 
156 } // namespace llvm
157 #endif // LLVM_ANALYSIS_INLINEMODELFEATUREMAPS_H
158