[llvm] dbbf076 - [ctx_prof] CtxProfAnalysis (#102084)

via llvm-commits llvm-commits at lists.llvm.org
Wed Aug 7 11:39:51 PDT 2024


Author: Mircea Trofin
Date: 2024-08-07T14:39:48-04:00
New Revision: dbbf0762b6ee9611d80ba94fdbe3968b228b527a

URL: https://github.com/llvm/llvm-project/commit/dbbf0762b6ee9611d80ba94fdbe3968b228b527a
DIFF: https://github.com/llvm/llvm-project/commit/dbbf0762b6ee9611d80ba94fdbe3968b228b527a.diff

LOG: [ctx_prof] CtxProfAnalysis (#102084)

This is an immutable analysis that loads and makes the contextual profile available to other passes. This patch introduces the analysis and an analysis printer pass. Subsequent patches will introduce the APIs that IPO passes will call to modify the profile as result of their changes.

Added: 
    llvm/include/llvm/Analysis/CtxProfAnalysis.h
    llvm/lib/Analysis/CtxProfAnalysis.cpp
    llvm/test/Analysis/CtxProfAnalysis/load.ll

Modified: 
    llvm/lib/Analysis/CMakeLists.txt
    llvm/lib/Passes/PassBuilder.cpp
    llvm/lib/Passes/PassBuilderPipelines.cpp
    llvm/lib/Passes/PassRegistry.def

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/CtxProfAnalysis.h b/llvm/include/llvm/Analysis/CtxProfAnalysis.h
new file mode 100644
index 0000000000000..d77c81d03582e
--- /dev/null
+++ b/llvm/include/llvm/Analysis/CtxProfAnalysis.h
@@ -0,0 +1,70 @@
+//===- CtxProfAnalysis.h - maintain contextual profile info   -*- C++ ---*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+#ifndef LLVM_ANALYSIS_CTXPROFANALYSIS_H
+#define LLVM_ANALYSIS_CTXPROFANALYSIS_H
+
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/ProfileData/PGOCtxProfReader.h"
+#include <map>
+
+namespace llvm {
+
+class CtxProfAnalysis;
+
+/// The instrumented contextual profile, produced by the CtxProfAnalysis.
+class PGOContextualProfile {
+  std::optional<PGOCtxProfContext::CallTargetMapTy> Profiles;
+
+public:
+  explicit PGOContextualProfile(PGOCtxProfContext::CallTargetMapTy &&Profiles)
+      : Profiles(std::move(Profiles)) {}
+  PGOContextualProfile() = default;
+  PGOContextualProfile(const PGOContextualProfile &) = delete;
+  PGOContextualProfile(PGOContextualProfile &&) = default;
+
+  operator bool() const { return Profiles.has_value(); }
+
+  const PGOCtxProfContext::CallTargetMapTy &profiles() const {
+    return *Profiles;
+  }
+
+  bool invalidate(Module &, const PreservedAnalyses &PA,
+                  ModuleAnalysisManager::Invalidator &) {
+    // Check whether the analysis has been explicitly invalidated. Otherwise,
+    // it's stateless and remains preserved.
+    auto PAC = PA.getChecker<CtxProfAnalysis>();
+    return !PAC.preservedWhenStateless();
+  }
+};
+
+class CtxProfAnalysis : public AnalysisInfoMixin<CtxProfAnalysis> {
+  StringRef Profile;
+
+public:
+  static AnalysisKey Key;
+  explicit CtxProfAnalysis(StringRef Profile) : Profile(Profile) {};
+
+  using Result = PGOContextualProfile;
+
+  PGOContextualProfile run(Module &M, ModuleAnalysisManager &MAM);
+};
+
+class CtxProfAnalysisPrinterPass
+    : public PassInfoMixin<CtxProfAnalysisPrinterPass> {
+  raw_ostream &OS;
+
+public:
+  explicit CtxProfAnalysisPrinterPass(raw_ostream &OS) : OS(OS) {}
+
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM);
+  static bool isRequired() { return true; }
+};
+} // namespace llvm
+#endif // LLVM_ANALYSIS_CTXPROFANALYSIS_H

diff  --git a/llvm/lib/Analysis/CMakeLists.txt b/llvm/lib/Analysis/CMakeLists.txt
index 997bb7a0bb178..2cb3547ec4047 100644
--- a/llvm/lib/Analysis/CMakeLists.txt
+++ b/llvm/lib/Analysis/CMakeLists.txt
@@ -46,6 +46,7 @@ add_llvm_component_library(LLVMAnalysis
   CostModel.cpp
   CodeMetrics.cpp
   ConstantFolding.cpp
+  CtxProfAnalysis.cpp
   CycleAnalysis.cpp
   DDG.cpp
   DDGPrinter.cpp

diff  --git a/llvm/lib/Analysis/CtxProfAnalysis.cpp b/llvm/lib/Analysis/CtxProfAnalysis.cpp
new file mode 100644
index 0000000000000..f56f910bd7784
--- /dev/null
+++ b/llvm/lib/Analysis/CtxProfAnalysis.cpp
@@ -0,0 +1,95 @@
+//===- CtxProfAnalysis.cpp - contextual profile analysis ------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of the contextual profile analysis, which maintains contextual
+// profiling info through IPO passes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CtxProfAnalysis.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/Analysis.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/ProfileData/PGOCtxProfReader.h"
+#include "llvm/Support/JSON.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+#define DEBUG_TYPE "ctx_prof"
+
+namespace llvm {
+namespace json {
+Value toJSON(const PGOCtxProfContext &P) {
+  Object Ret;
+  Ret["Guid"] = P.guid();
+  Ret["Counters"] = Array(P.counters());
+  if (P.callsites().empty())
+    return Ret;
+  auto AllCS =
+      ::llvm::map_range(P.callsites(), [](const auto &P) { return P.first; });
+  auto MaxIt = ::llvm::max_element(AllCS);
+  assert(MaxIt != AllCS.end() && "We should have a max value because the "
+                                 "callsites collection is not empty.");
+  Array CSites;
+  // Iterate to, and including, the maximum index.
+  for (auto I = 0U, Max = *MaxIt; I <= Max; ++I) {
+    CSites.push_back(Array());
+    Array &Targets = *CSites.back().getAsArray();
+    if (P.hasCallsite(I))
+      for (const auto &[_, Ctx] : P.callsite(I))
+        Targets.push_back(toJSON(Ctx));
+  }
+  Ret["Callsites"] = std::move(CSites);
+
+  return Ret;
+}
+
+Value toJSON(const PGOCtxProfContext::CallTargetMapTy &P) {
+  Array Ret;
+  for (const auto &[_, Ctx] : P)
+    Ret.push_back(toJSON(Ctx));
+  return Ret;
+}
+} // namespace json
+} // namespace llvm
+
+using namespace llvm;
+
+AnalysisKey CtxProfAnalysis::Key;
+
+CtxProfAnalysis::Result CtxProfAnalysis::run(Module &M,
+                                             ModuleAnalysisManager &MAM) {
+  ErrorOr<std::unique_ptr<MemoryBuffer>> MB = MemoryBuffer::getFile(Profile);
+  if (auto EC = MB.getError()) {
+    M.getContext().emitError("could not open contextual profile file: " +
+                             EC.message());
+    return {};
+  }
+  PGOCtxProfileReader Reader(MB.get()->getBuffer());
+  auto MaybeCtx = Reader.loadContexts();
+  if (!MaybeCtx) {
+    M.getContext().emitError("contextual profile file is invalid: " +
+                             toString(MaybeCtx.takeError()));
+    return {};
+  }
+  return Result(std::move(*MaybeCtx));
+}
+
+PreservedAnalyses CtxProfAnalysisPrinterPass::run(Module &M,
+                                                  ModuleAnalysisManager &MAM) {
+  CtxProfAnalysis::Result &C = MAM.getResult<CtxProfAnalysis>(M);
+  if (!C) {
+    M.getContext().emitError("Invalid CtxProfAnalysis");
+    return PreservedAnalyses::all();
+  }
+  const auto JSONed = ::llvm::json::toJSON(C.profiles());
+
+  OS << formatv("{0:2}", JSONed);
+  OS << "\n";
+  return PreservedAnalyses::all();
+}

diff  --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 5dbb1e2f49871..bcc69d5ac3db6 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -28,6 +28,7 @@
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/CallPrinter.h"
 #include "llvm/Analysis/CostModel.h"
+#include "llvm/Analysis/CtxProfAnalysis.h"
 #include "llvm/Analysis/CycleAnalysis.h"
 #include "llvm/Analysis/DDG.h"
 #include "llvm/Analysis/DDGPrinter.h"
@@ -330,6 +331,8 @@ cl::opt<bool> PrintPipelinePasses(
              "(best-effort only)."));
 } // namespace llvm
 
+extern cl::opt<std::string> UseCtxProfile;
+
 AnalysisKey NoOpModuleAnalysis::Key;
 AnalysisKey NoOpCGSCCAnalysis::Key;
 AnalysisKey NoOpFunctionAnalysis::Key;

diff  --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index adebbb5eeba32..c175ee8980984 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -304,7 +304,7 @@ static cl::opt<bool> UseLoopVersioningLICM(
     "enable-loop-versioning-licm", cl::init(false), cl::Hidden,
     cl::desc("Enable the experimental Loop Versioning LICM pass"));
 
-static cl::opt<std::string>
+cl::opt<std::string>
     UseCtxProfile("use-ctx-profile", cl::init(""), cl::Hidden,
                   cl::desc("Use the specified contextual profile file"));
 

diff  --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 03c7d0c3c469a..61a5bab92927f 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -20,6 +20,7 @@
 #endif
 MODULE_ANALYSIS("callgraph", CallGraphAnalysis())
 MODULE_ANALYSIS("collector-metadata", CollectorMetadataAnalysis())
+MODULE_ANALYSIS("ctx-prof-analysis", CtxProfAnalysis(UseCtxProfile))
 MODULE_ANALYSIS("inline-advisor", InlineAdvisorAnalysis())
 MODULE_ANALYSIS("ir-similarity", IRSimilarityAnalysis())
 MODULE_ANALYSIS("lcg", LazyCallGraphAnalysis())
@@ -79,6 +80,7 @@ MODULE_PASS("insert-gcov-profiling", GCOVProfilerPass())
 MODULE_PASS("instrorderfile", InstrOrderFilePass())
 MODULE_PASS("instrprof", InstrProfilingLoweringPass())
 MODULE_PASS("ctx-instr-lower", PGOCtxProfLoweringPass())
+MODULE_PASS("print<ctx-prof-analysis>", CtxProfAnalysisPrinterPass(dbgs()))
 MODULE_PASS("invalidate<all>", InvalidateAllAnalysesPass())
 MODULE_PASS("iroutliner", IROutlinerPass())
 MODULE_PASS("jmc-instrumenter", JMCInstrumenterPass())

diff  --git a/llvm/test/Analysis/CtxProfAnalysis/load.ll b/llvm/test/Analysis/CtxProfAnalysis/load.ll
new file mode 100644
index 0000000000000..fdf40d1b7f136
--- /dev/null
+++ b/llvm/test/Analysis/CtxProfAnalysis/load.ll
@@ -0,0 +1,56 @@
+; RUN: split-file %s %t
+; RUN: llvm-ctxprof-util fromJSON --input=%t/profile.json --output=%t/profile.ctxprofdata
+; RUN: not opt -passes='require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
+; RUN:   %t/empty.ll -S 2>&1 | FileCheck %s --check-prefix=NO-FILE
+
+; RUN: not opt -passes='require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
+; RUN:   -use-ctx-profile=does_not_exist.ctxprofdata %t/empty.ll -S 2>&1 | FileCheck %s --check-prefix=NO-FILE
+
+; RUN: opt -passes='require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
+; RUN:   -use-ctx-profile=%t/profile.ctxprofdata %t/empty.ll -S 2> %t/output.json
+; RUN: 
diff  %t/profile.json %t/output.json
+
+; NO-FILE: error: could not open contextual profile file
+;
+; This is the reference profile, laid out in the format the json formatter will
+; output it from opt.
+;--- profile.json
+[
+  {
+    "Callsites": [
+      [],
+      [
+        {
+          "Counters": [
+            4,
+            5
+          ],
+          "Guid": 2000
+        },
+        {
+          "Counters": [
+            6,
+            7,
+            8
+          ],
+          "Guid": 18446744073709551613
+        }
+      ]
+    ],
+    "Counters": [
+      1,
+      2,
+      3
+    ],
+    "Guid": 1000
+  },
+  {
+    "Counters": [
+      5,
+      9,
+      10
+    ],
+    "Guid": 18446744073709551612
+  }
+]
+;--- empty.ll


        


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