llvm/Analysis/InlineModelFeatureMaps.h

0001 //===- InlineModelFeatureMaps.h - common model runner defs ------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008 //
0009
0010 #ifndef LLVM_ANALYSIS_INLINEMODELFEATUREMAPS_H
0011 #define LLVM_ANALYSIS_INLINEMODELFEATUREMAPS_H
0012
0013 #include "llvm/Analysis/TensorSpec.h"
0014
0015 #include <array>
0016 #include <vector>
0017
0018 namespace llvm {
0019
0020 // List of cost features. A "cost" feature is a summand of the heuristic-based
0021 // inline cost, and we define them separately to preserve the original heuristic
0022 // behavior.
0023 #define INLINE_COST_FEATURE_ITERATOR(M)                                        \
0024   M(int64_t, {1}, sroa_savings,                                                \
0025     "Savings from SROA (scalar replacement of aggregates)")                    \
0026   M(int64_t, {1}, sroa_losses,                                                 \
0027     "Losses from SROA (scalar replacement of aggregates)")                     \
0028   M(int64_t, {1}, load_elimination, "Cost of load elimination in the call")    \
0029   M(int64_t, {1}, call_penalty,                                                \
0030     "Accumulation of penalty applied to call sites when inlining")             \
0031   M(int64_t, {1}, call_argument_setup,                                         \
0032     "Accumulation of call argument setup costs")                               \
0033   M(int64_t, {1}, load_relative_intrinsic,                                     \
0034     "Accumulation of costs of loading relative intrinsics")                    \
0035   M(int64_t, {1}, lowered_call_arg_setup,                                      \
0036     "Accumulation of cost of lowered call argument setups")                    \
0037   M(int64_t, {1}, indirect_call_penalty,                                       \
0038     "Accumulation of costs for indirect calls")                                \
0039   M(int64_t, {1}, jump_table_penalty, "Accumulation of costs for jump tables") \
0040   M(int64_t, {1}, case_cluster_penalty,                                        \
0041     "Accumulation of costs for case clusters")                                 \
0042   M(int64_t, {1}, switch_default_dest_penalty,                                 \
0043     "Accumulation of costs for switch default destination")                    \
0044   M(int64_t, {1}, switch_penalty,                                              \
0045     "Accumulation of costs for switch statements")                             \
0046   M(int64_t, {1}, unsimplified_common_instructions,                            \
0047     "Costs from unsimplified common instructions")                             \
0048   M(int64_t, {1}, num_loops, "Number of loops in the caller")                  \
0049   M(int64_t, {1}, dead_blocks, "Number of dead blocks in the caller")          \
0050   M(int64_t, {1}, simplified_instructions,                                     \
0051     "Number of simplified instructions")                                       \
0052   M(int64_t, {1}, constant_args,                                               \
0053     "Number of constant arguments in the call site")                           \
0054   M(int64_t, {1}, constant_offset_ptr_args,                                    \
0055     "Number of constant offset pointer args in the call site")                 \
0056   M(int64_t, {1}, callsite_cost, "Estimated cost of the call site")            \
0057   M(int64_t, {1}, cold_cc_penalty, "Penalty for a cold calling convention")    \
0058   M(int64_t, {1}, last_call_to_static_bonus,                                   \
0059     "Bonus for being the last call to static")                                 \
0060   M(int64_t, {1}, is_multiple_blocks,                                          \
0061     "Boolean; is the Callee multiple blocks")                                  \
0062   M(int64_t, {1}, nested_inlines,                                              \
0063     "Would the default inliner perfom nested inlining")                        \
0064   M(int64_t, {1}, nested_inline_cost_estimate,                                 \
0065     "Estimate of the accumulated cost of nested inlines")                      \
0066   M(int64_t, {1}, threshold, "Threshold for the heuristic inliner")
0067
0068 // clang-format off
0069 enum class InlineCostFeatureIndex : size_t {
0070 #define POPULATE_INDICES(DTYPE, SHAPE, NAME, DOC) NAME,
0071   INLINE_COST_FEATURE_ITERATOR(POPULATE_INDICES)
0072 #undef POPULATE_INDICES
0073
0074   NumberOfFeatures
0075 };
0076 // clang-format on
0077
0078 using InlineCostFeatures =
0079     std::array<int,
0080                static_cast<size_t>(InlineCostFeatureIndex::NumberOfFeatures)>;
0081
0082 constexpr bool isHeuristicInlineCostFeature(InlineCostFeatureIndex Feature) {
0083   return Feature != InlineCostFeatureIndex::sroa_savings &&
0084          Feature != InlineCostFeatureIndex::is_multiple_blocks &&
0085          Feature != InlineCostFeatureIndex::dead_blocks &&
0086          Feature != InlineCostFeatureIndex::simplified_instructions &&
0087          Feature != InlineCostFeatureIndex::constant_args &&
0088          Feature != InlineCostFeatureIndex::constant_offset_ptr_args &&
0089          Feature != InlineCostFeatureIndex::nested_inlines &&
0090          Feature != InlineCostFeatureIndex::nested_inline_cost_estimate &&
0091          Feature != InlineCostFeatureIndex::threshold;
0092 }
0093
0094 // List of features. Each feature is defined through a triple:
0095 // - the name of an enum member, which will be the feature index
0096 // - a textual name, used for ML model binding (so it needs to match the
0097 // names used by the ML model).
0098 // - a documentation description. Currently, that is not used anywhere
0099 // programmatically, and serves as workaround to inability of inserting comments
0100 // in macros.
0101 #define INLINE_FEATURE_ITERATOR(M)                                             \
0102   M(int64_t, {1}, callee_basic_block_count,                                    \
0103     "number of basic blocks of the callee")                                    \
0104   M(int64_t, {1}, callsite_height,                                             \
0105     "position of the call site in the original call graph - measured from "    \
0106     "the farthest SCC")                                                        \
0107   M(int64_t, {1}, node_count,                                                  \
0108     "total current number of defined functions in the module")                 \
0109   M(int64_t, {1}, nr_ctant_params,                                             \
0110     "number of parameters in the call site that are constants")                \
0111   M(int64_t, {1}, cost_estimate, "total cost estimate (threshold - free)")     \
0112   M(int64_t, {1}, edge_count, "total number of calls in the module")           \
0113   M(int64_t, {1}, caller_users,                                                \
0114     "number of module-internal users of the caller, +1 if the caller is "      \
0115     "exposed externally")                                                      \
0116   M(int64_t, {1}, caller_conditionally_executed_blocks,                        \
0117     "number of blocks reached from a conditional instruction, in the caller")  \
0118   M(int64_t, {1}, caller_basic_block_count,                                    \
0119     "number of basic blocks in the caller")                                    \
0120   M(int64_t, {1}, callee_conditionally_executed_blocks,                        \
0121     "number of blocks reached from a conditional instruction, in the callee")  \
0122   M(int64_t, {1}, callee_users,                                                \
0123     "number of module-internal users of the callee, +1 if the callee is "      \
0124     "exposed externally")                                                      \
0125   M(int64_t, {1}, is_callee_avail_external,                                    \
0126     "Is callee an available-externally linkage type (i.e. could be DCEd if "   \
0127     "not "                                                                     \
0128     "fully inlined by ElimAvailExtern)")                                       \
0129   M(int64_t, {1}, is_caller_avail_external,                                    \
0130     "Is caller an available-externally linkage type (i.e. could be DCEd if "   \
0131     "not "                                                                     \
0132     "fully inlined by ElimAvailExtern)")
0133
0134 // clang-format off
0135 enum class FeatureIndex : size_t {
0136 #define POPULATE_INDICES(DTYPE, SHAPE, NAME, COMMENT) NAME,
0137 // InlineCost features - these must come first
0138   INLINE_COST_FEATURE_ITERATOR(POPULATE_INDICES)
0139
0140 // Non-cost features
0141   INLINE_FEATURE_ITERATOR(POPULATE_INDICES)
0142 #undef POPULATE_INDICES
0143
0144   NumberOfFeatures
0145 };
0146 // clang-format on
0147
0148 constexpr FeatureIndex
0149 inlineCostFeatureToMlFeature(InlineCostFeatureIndex Feature) {
0150   return static_cast<FeatureIndex>(static_cast<size_t>(Feature));
0151 }
0152
0153 constexpr size_t NumberOfFeatures =
0154     static_cast<size_t>(FeatureIndex::NumberOfFeatures);
0155
0156 extern const std::vector<TensorSpec> FeatureMap;
0157
0158 extern const char *const DecisionName;
0159 extern const TensorSpec InlineDecisionSpec;
0160 extern const char *const DefaultDecisionName;
0161 extern const TensorSpec DefaultDecisionSpec;
0162 extern const char *const RewardName;
0163
0164 using InlineFeatures = std::vector<int64_t>;
0165
0166 } // namespace llvm
0167 #endif // LLVM_ANALYSIS_INLINEMODELFEATUREMAPS_H