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Add a library for writing the Propeller profile to disk
PiperOrigin-RevId: 700398427
1 parent 9827311 commit 8ad040c

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-1
lines changed

4 files changed

+353
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lines changed

‎propeller/BUILD

+22
Original file line numberDiff line numberDiff line change
@@ -1103,3 +1103,25 @@ cc_test(
11031103
"@com_google_googletest//:gtest_main",
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],
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)
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cc_library(
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name = "profile_writer",
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srcs = ["profile_writer.cc"],
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hdrs = ["profile_writer.h"],
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deps = [
1112+
":cfg",
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":cfg_edge",
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":cfg_id",
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":cfg_node",
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":function_chain_info",
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":profile",
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":propeller_options_cc_proto",
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"@abseil-cpp//absl/algorithm:container",
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"@abseil-cpp//absl/container:flat_hash_map",
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"@abseil-cpp//absl/log",
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"@abseil-cpp//absl/log:check",
1123+
"@abseil-cpp//absl/strings",
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"@abseil-cpp//absl/strings:str_format",
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"@llvm-project//llvm:Support",
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],
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)

‎propeller/CMakeLists.txt

+2-1
Original file line numberDiff line numberDiff line change
@@ -42,8 +42,9 @@ add_library(propeller_lib OBJECT
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node_chain_assembly.cc
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node_chain_builder.cc
4444
node_chain.cc
45-
perfdata_reader.cc
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perf_branch_frequencies_aggregator.cc
46+
perfdata_reader.cc
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profile_writer.cc
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program_cfg_builder.cc
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program_cfg.cc
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propeller_statistics.cc

‎propeller/profile_writer.cc

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@@ -0,0 +1,268 @@
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#include "propeller/profile_writer.h"
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#include <fstream>
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#include <memory>
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#include <optional>
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#include <ostream>
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#include <string>
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#include <utility>
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#include <vector>
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#include "absl/algorithm/container.h"
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#include "absl/container/flat_hash_map.h"
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#include "absl/log/check.h"
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#include "absl/strings/str_cat.h"
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#include "absl/strings/str_format.h"
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#include "absl/strings/str_join.h"
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#include "absl/strings/string_view.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/Path.h"
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#include "propeller/cfg.h"
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#include "propeller/cfg_edge.h"
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#include "propeller/cfg_id.h"
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#include "propeller/cfg_node.h"
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#include "propeller/function_chain_info.h"
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#include "propeller/profile.h"
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#include "propeller/propeller_options.pb.h"
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namespace propeller {
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namespace {
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void DumpCfgs(const PropellerProfile &profile,
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absl::string_view cfg_dump_dir_name) {
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// Create the cfg dump directory and the cfg index file.
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llvm::sys::fs::create_directory(cfg_dump_dir_name);
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llvm::SmallString<100> cfg_index_file_vec(cfg_dump_dir_name.begin(),
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cfg_dump_dir_name.end());
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llvm::sys::path::append(cfg_index_file_vec, "cfg-index.txt");
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std::string cfg_index_file(cfg_index_file_vec.str());
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std::ofstream cfg_index_os(cfg_index_file, std::ofstream::out);
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CHECK(cfg_index_os.good())
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<< "Failed to open " << cfg_index_file << " for writing.";
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cfg_index_os << absl::StrJoin({"Function.Name", "Function.Address", "N_Nodes",
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"N_Clusters", "Original.ExtTSP.Score",
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"Optimized.ExtTSP.Score"},
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" ")
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<< "\n";
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for (const auto &[section_name, section_function_chain_info] :
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profile.functions_chain_info_by_section_name) {
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for (const FunctionChainInfo &func_chain_info :
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section_function_chain_info) {
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const ControlFlowGraph *cfg =
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profile.program_cfg->GetCfgByIndex(func_chain_info.function_index);
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CHECK_NE(cfg, nullptr);
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// Dump hot cfgs into the given directory.
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auto func_addr_str =
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absl::StrCat("0x", absl::Hex(cfg->GetEntryNode()->addr()));
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cfg_index_os << cfg->GetPrimaryName().str() << " " << func_addr_str << " "
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<< cfg->nodes().size() << " "
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<< func_chain_info.bb_chains.size() << " "
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<< func_chain_info.original_score.intra_score << " "
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<< func_chain_info.optimized_score.intra_score << "\n";
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// Use the address of the function as the CFG filename for uniqueness.
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llvm::SmallString<100> cfg_dump_file_vec(cfg_dump_dir_name.begin(),
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cfg_dump_dir_name.end());
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llvm::sys::path::append(cfg_dump_file_vec,
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absl::StrCat(func_addr_str, ".dot"));
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std::string cfg_dump_file(cfg_dump_file_vec.str());
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std::ofstream cfg_dump_os(cfg_dump_file, std::ofstream::out);
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CHECK(cfg_dump_os.good())
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<< "Failed to open " << cfg_dump_file << " for writing.";
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absl::flat_hash_map<IntraCfgId, int> layout_index_map;
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for (auto &bb_chain : func_chain_info.bb_chains) {
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int bbs = 0;
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for (auto &bb_bundle : bb_chain.bb_bundles) {
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for (int bbi = 0; bbi < bb_bundle.full_bb_ids.size(); ++bbi) {
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layout_index_map.insert({bb_bundle.full_bb_ids[bbi].intra_cfg_id,
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bb_chain.layout_index + bbs + bbi});
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}
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bbs += bb_bundle.full_bb_ids.size();
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}
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}
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cfg->WriteDotFormat(cfg_dump_os, layout_index_map);
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}
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}
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}
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// Dumps the intra-function edge profile of `cfg` into `out`.
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// For each CFGNode, it prints out a line in the format of
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// "#<bb>:<bb_freq> <succ_bb_1>:<edge_freq_1> <succ_bb_2>:<edge_freq_2> ..."
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// which starts first with the bb id and frequency of that node, followed by the
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// successors and their edge frequencies. Please note that the edge weights
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// may not precisely add up to the node frequency.
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void DumpCfgProfile(const ControlFlowGraph &cfg, std::ofstream &out) {
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cfg.ForEachNodeRef([&](const CFGNode &node) {
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int node_frequency = node.CalculateFrequency();
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out << "#cfg-prof " << node.bb_id() << ":" << node_frequency;
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node.ForEachOutEdgeRef([&](const CFGEdge &edge) {
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if (!edge.IsBranchOrFallthrough()) return;
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out << " " << edge.sink()->bb_id() << ":" << edge.weight();
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});
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out << "\n";
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});
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}
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} // namespace
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void PropellerProfileWriter::Write(const PropellerProfile &profile) const {
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std::ofstream cc_profile_os(options_.cluster_out_name());
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std::ofstream ld_profile_os(options_.symbol_order_out_name());
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if (profile_encoding_.version != ClusterEncodingVersion::VERSION_0) {
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cc_profile_os << profile_encoding_.version_specifier << "\n";
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}
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// TODO(b/160339651): Remove this in favour of structured format in LLVM code.
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for (const auto &[section_name, section_function_chain_info] :
121+
profile.functions_chain_info_by_section_name) {
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if (options_.verbose_cluster_output())
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cc_profile_os << "#section " << section_name.str() << "\n";
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// Find total number of chains.
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unsigned total_chains = 0;
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for (const auto &func_chain_info : section_function_chain_info)
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total_chains += func_chain_info.bb_chains.size();
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// Allocate the symbol order vector
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std::vector<std::pair<llvm::SmallVector<llvm::StringRef, 3>,
131+
std::optional<unsigned>>>
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symbol_order(total_chains);
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// Allocate the cold symbol order vector equally sized as
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// function_chain_info, as there is (at most) one cold cluster per
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// function.
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std::vector<const FunctionChainInfo *> cold_symbol_order(
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section_function_chain_info.size());
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for (const FunctionChainInfo &func_layout_info :
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section_function_chain_info) {
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const ControlFlowGraph *cfg =
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profile.program_cfg->GetCfgByIndex(func_layout_info.function_index);
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CHECK_NE(cfg, nullptr);
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if (cfg->module_name().has_value() &&
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profile_encoding_.version == ClusterEncodingVersion::VERSION_1) {
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// For version 1, print the module name before the function name
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// specifier on a separate line.
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cc_profile_os << profile_encoding_.module_name_specifier
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<< cfg->module_name().value().str() << "\n";
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}
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// Print all alias names of the function.
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cc_profile_os << profile_encoding_.function_name_specifier
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<< llvm::join(cfg->names(),
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profile_encoding_.function_name_separator);
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if (cfg->module_name().has_value() &&
155+
profile_encoding_.version == ClusterEncodingVersion::VERSION_0) {
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// For version 0, print the module name after the function names and on
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// the same line.
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cc_profile_os << profile_encoding_.module_name_specifier
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<< cfg->module_name().value().str();
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}
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cc_profile_os << "\n";
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// Print cloning paths.
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if (!cfg->clone_paths().empty()) {
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CHECK_EQ(profile_encoding_.version, ClusterEncodingVersion::VERSION_1)
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<< "cloning is not supported for version: "
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<< profile_encoding_.version;
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}
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for (const std::vector<int> &clone_path : cfg->clone_paths()) {
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cc_profile_os << profile_encoding_.clone_path_specifier
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<< absl::StrJoin(
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clone_path, " ",
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[&](std::string *out, const int bb_index) {
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absl::StrAppend(out,
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cfg->nodes()[bb_index]->bb_id());
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})
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<< "\n";
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}
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if (options_.verbose_cluster_output()) {
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// Print the layout score for intra-function and inter-function edges
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// involving this function. This information allows us to study the
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// impact on layout score on each individual function.
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cc_profile_os << absl::StreamFormat(
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"#ext-tsp score: [intra: %f -> %f] [inter: %f -> %f]\n",
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func_layout_info.original_score.intra_score,
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func_layout_info.optimized_score.intra_score,
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func_layout_info.original_score.inter_out_score,
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func_layout_info.optimized_score.inter_out_score);
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// Print out the frequency of the function entry node.
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cc_profile_os << absl::StreamFormat(
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"#entry-freq %llu\n", cfg->GetEntryNode()->CalculateFrequency());
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}
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const std::vector<FunctionChainInfo::BbChain> &chains =
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func_layout_info.bb_chains;
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for (unsigned chain_id = 0; chain_id < chains.size(); ++chain_id) {
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auto &chain = chains[chain_id];
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std::vector<FullIntraCfgId> bb_ids_in_chain =
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chains[chain_id].GetAllBbs();
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// If a chain starts with zero BB index (function entry basic block),
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// the function name is sufficient for section ordering. Otherwise,
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// the chain number is required.
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symbol_order[chain.layout_index] =
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std::pair<llvm::SmallVector<llvm::StringRef, 3>,
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std::optional<unsigned>>(
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cfg->names(), bb_ids_in_chain.front().intra_cfg_id.bb_index == 0
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? std::optional<unsigned>()
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: chain_id);
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for (int bbi = 0; bbi < bb_ids_in_chain.size(); ++bbi) {
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const auto &full_bb_id = bb_ids_in_chain[bbi];
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cc_profile_os << (bbi != 0 ? " "
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: profile_encoding_.cluster_specifier)
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<< full_bb_id.bb_id;
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if (full_bb_id.intra_cfg_id.clone_number != 0)
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cc_profile_os << "." << full_bb_id.intra_cfg_id.clone_number;
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}
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cc_profile_os << "\n";
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}
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// Dump the edge profile for this CFG if requested.
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if (options_.verbose_cluster_output())
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DumpCfgProfile(*cfg, cc_profile_os);
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cold_symbol_order[func_layout_info.cold_chain_layout_index] =
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&func_layout_info;
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}
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for (const auto &[func_names, chain_id] : symbol_order) {
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// Print the symbol names corresponding to every function name alias. This
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// guarantees we get the right order regardless of which function name is
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// picked by the compiler.
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for (auto &func_name : func_names) {
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ld_profile_os << func_name.str();
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if (chain_id.has_value())
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ld_profile_os << ".__part." << chain_id.value();
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ld_profile_os << "\n";
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}
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}
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// Insert the .cold symbols for cold parts of hot functions.
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for (const FunctionChainInfo *chain_info : cold_symbol_order) {
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const ControlFlowGraph *cfg =
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profile.program_cfg->GetCfgByIndex(chain_info->function_index);
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CHECK_NE(cfg, nullptr);
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// The cold node should not be emitted if all basic blocks appear in the
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// chains.
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int num_bbs_in_chains = 0;
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for (const FunctionChainInfo::BbChain &chain : chain_info->bb_chains)
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num_bbs_in_chains += chain.GetNumBbs();
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if (num_bbs_in_chains == cfg->nodes().size()) continue;
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// Check if the function entry is in the chains. The entry node always
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// begins its chain. So this simply checks the first node in every
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// chain.
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bool entry_is_in_chains = absl::c_any_of(
253+
chain_info->bb_chains, [](const FunctionChainInfo::BbChain &chain) {
254+
return chain.GetFirstBb().intra_cfg_id.bb_index == 0;
255+
});
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for (auto &func_name : cfg->names()) {
257+
ld_profile_os << func_name.str();
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// If the entry node is not in chains, function name can serve as the
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// cold symbol name. So we don't need the ".cold" suffix.
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if (entry_is_in_chains) ld_profile_os << ".cold";
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ld_profile_os << "\n";
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}
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}
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}
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if (options_.has_cfg_dump_dir_name())
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DumpCfgs(profile, options_.cfg_dump_dir_name());
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}
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} // namespace propeller

‎propeller/profile_writer.h

+61
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@@ -0,0 +1,61 @@
1+
#ifndef PROPELLER_PROFILE_WRITER_H_
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#define PROPELLER_PROFILE_WRITER_H_
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#include <string>
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#include "absl/log/log.h"
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#include "propeller/profile.h"
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#include "propeller/propeller_options.pb.h"
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namespace propeller {
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// Writes the propeller profiles to output files.
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class PropellerProfileWriter {
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public:
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explicit PropellerProfileWriter(const PropellerOptions& options)
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: options_(options),
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profile_encoding_(GetProfileEncoding(options.cluster_out_version())) {}
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// Writes code layout result in `all_functions_cluster_info` into the output
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// file.
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void Write(const PropellerProfile& profile) const;
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private:
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struct ProfileEncoding {
24+
ClusterEncodingVersion version;
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std::string version_specifier;
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std::string function_name_specifier;
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std::string function_name_separator;
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std::string module_name_specifier;
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std::string cluster_specifier;
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std::string clone_path_specifier;
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};
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static ProfileEncoding GetProfileEncoding(
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const ClusterEncodingVersion& version) {
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switch (version) {
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case ClusterEncodingVersion::VERSION_0:
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return {.version = version,
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.version_specifier = "v0",
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.function_name_specifier = "!",
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.function_name_separator = "/",
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.module_name_specifier = " M=",
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.cluster_specifier = "!!",
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.clone_path_specifier = "#NOT_SUPPORTED"};
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case ClusterEncodingVersion::VERSION_1:
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return {.version = version,
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.version_specifier = "v1",
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.function_name_specifier = "f ",
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.function_name_separator = " ",
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.module_name_specifier = "m ",
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.cluster_specifier = "c",
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.clone_path_specifier = "p"};
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default:
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LOG(FATAL) << "Unknown value for ClusterEncodingVersion: "
54+
<< static_cast<int>(version);
55+
}
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}
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PropellerOptions options_;
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ProfileEncoding profile_encoding_;
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};
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} // namespace propeller
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#endif // PROPELLER_PROFILE_WRITER_H_

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