Revert "[InstrPGO] Support cold function coverage instrumentation (llvm#109837)"

This reverts commit e517cfc.

Author: Dmitry Chernenkov

clang/include/clang/Driver/Options.td

@@ -1786,12 +1786,6 @@ defm debug_info_for_profiling : BoolFOption<"debug-info-for-profiling",
   PosFlag<SetTrue, [], [ClangOption, CC1Option],
           "Emit extra debug info to make sample profile more accurate">,
   NegFlag<SetFalse>>;
-def fprofile_generate_cold_function_coverage : Flag<["-"], "fprofile-generate-cold-function-coverage">, 
-    Group<f_Group>, Visibility<[ClangOption, CLOption]>,
-    HelpText<"Generate instrumented code to collect coverage info for cold functions into default.profraw file (overridden by '=' form of option or LLVM_PROFILE_FILE env var)">;
-def fprofile_generate_cold_function_coverage_EQ : Joined<["-"], "fprofile-generate-cold-function-coverage=">, 
-    Group<f_Group>, Visibility<[ClangOption, CLOption]>, MetaVarName<"<directory>">,
-    HelpText<"Generate instrumented code to collect coverage info for cold functions into <directory>/default.profraw (overridden by LLVM_PROFILE_FILE env var)">; 
 def fprofile_instr_generate : Flag<["-"], "fprofile-instr-generate">,
     Group<f_Group>, Visibility<[ClangOption, CLOption]>,
     HelpText<"Generate instrumented code to collect execution counts into default.profraw file (overridden by '=' form of option or LLVM_PROFILE_FILE env var)">;

clang/lib/Driver/ToolChain.cpp

@@ -899,9 +899,7 @@ bool ToolChain::needsProfileRT(const ArgList &Args) {
          Args.hasArg(options::OPT_fprofile_instr_generate) ||
          Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
          Args.hasArg(options::OPT_fcreate_profile) ||
-         Args.hasArg(options::OPT_forder_file_instrumentation) ||
-         Args.hasArg(options::OPT_fprofile_generate_cold_function_coverage) ||
-         Args.hasArg(options::OPT_fprofile_generate_cold_function_coverage_EQ);
+         Args.hasArg(options::OPT_forder_file_instrumentation);
 }
 
 bool ToolChain::needsGCovInstrumentation(const llvm::opt::ArgList &Args) {

clang/lib/Driver/ToolChains/Clang.cpp

@@ -632,26 +632,6 @@ static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
     }
   }
 
-  if (auto *ColdFuncCoverageArg = Args.getLastArg(
-          options::OPT_fprofile_generate_cold_function_coverage,
-          options::OPT_fprofile_generate_cold_function_coverage_EQ)) {
-    SmallString<128> Path(
-        ColdFuncCoverageArg->getOption().matches(
-            options::OPT_fprofile_generate_cold_function_coverage_EQ)
-            ? ColdFuncCoverageArg->getValue()
-            : "");
-    llvm::sys::path::append(Path, "default_%m.profraw");
-    // FIXME: Idealy the file path should be passed through
-    // `-fprofile-instrument-path=`(InstrProfileOutput), however, this field is
-    // shared with other profile use path(see PGOOptions), we need to refactor
-    // PGOOptions to make it work.
-    CmdArgs.push_back("-mllvm");
-    CmdArgs.push_back(Args.MakeArgString(
-        Twine("--instrument-cold-function-only-path=") + Path));
-    CmdArgs.push_back("-mllvm");
-    CmdArgs.push_back("--pgo-function-entry-coverage");
-  }
-
   Arg *PGOGenArg = nullptr;
   if (PGOGenerateArg) {
     assert(!CSPGOGenerateArg);

clang/test/CodeGen/pgo-cold-function-coverage.c

@@ -296,12 +296,7 @@ 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> InstrumentColdFuncOnlyPath(
-    "instrument-cold-function-only-path", cl::init(""),
-    cl::desc("File path for cold function only instrumentation"), cl::Hidden);
-
 extern cl::opt<std::string> UseCtxProfile;
-extern cl::opt<bool> PGOInstrumentColdFunctionOnly;
 
 namespace llvm {
 extern cl::opt<bool> EnableMemProfContextDisambiguation;
@@ -1188,13 +1183,8 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   const bool IsCtxProfUse =
       !UseCtxProfile.empty() && Phase == ThinOrFullLTOPhase::ThinLTOPreLink;
 
-  // Enable cold function coverage instrumentation if
-  // InstrumentColdFuncOnlyPath is provided.
-  const bool IsColdFuncOnlyInstrGen = PGOInstrumentColdFunctionOnly =
-      IsPGOPreLink && !InstrumentColdFuncOnlyPath.empty();
-
   if (IsPGOInstrGen || IsPGOInstrUse || IsMemprofUse || IsCtxProfGen ||
-      IsCtxProfUse || IsColdFuncOnlyInstrGen)
+      IsCtxProfUse)
     addPreInlinerPasses(MPM, Level, Phase);
 
   // Add all the requested passes for instrumentation PGO, if requested.
@@ -1216,11 +1206,6 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
       return MPM;
     addPostPGOLoopRotation(MPM, Level);
     MPM.addPass(PGOCtxProfLoweringPass());
-  } else if (IsColdFuncOnlyInstrGen) {
-    addPGOInstrPasses(
-        MPM, Level, /* RunProfileGen */ true, /* IsCS */ false,
-        /* AtomicCounterUpdate */ false, InstrumentColdFuncOnlyPath,
-        /* ProfileRemappingFile */ "", IntrusiveRefCntPtr<vfs::FileSystem>());
   }
 
   if (IsPGOInstrGen || IsPGOInstrUse || IsCtxProfGen)

clang/test/Driver/fprofile-generate-cold-function-coverage.c

@@ -319,20 +319,6 @@ static cl::opt<unsigned> PGOFunctionCriticalEdgeThreshold(
     cl::desc("Do not instrument functions with the number of critical edges "
              " greater than this threshold."));
 
-static cl::opt<uint64_t> PGOColdInstrumentEntryThreshold(
-    "pgo-cold-instrument-entry-threshold", cl::init(0), cl::Hidden,
-    cl::desc("For cold function instrumentation, skip instrumenting functions "
-             "whose entry count is above the given value."));
-
-static cl::opt<bool> PGOTreatUnknownAsCold(
-    "pgo-treat-unknown-as-cold", cl::init(false), cl::Hidden,
-    cl::desc("For cold function instrumentation, treat count unknown(e.g. "
-             "unprofiled) functions as cold."));
-
-cl::opt<bool> PGOInstrumentColdFunctionOnly(
-    "pgo-instrument-cold-function-only", cl::init(false), cl::Hidden,
-    cl::desc("Enable cold function only instrumentation."));
-
 extern cl::opt<unsigned> MaxNumVTableAnnotations;
 
 namespace llvm {
@@ -1911,11 +1897,6 @@ static bool skipPGOGen(const Function &F) {
     return true;
   if (F.getInstructionCount() < PGOFunctionSizeThreshold)
     return true;
-  if (PGOInstrumentColdFunctionOnly) {
-    if (auto EntryCount = F.getEntryCount())
-      return EntryCount->getCount() > PGOColdInstrumentEntryThreshold;
-    return !PGOTreatUnknownAsCold;
-  }
   return false;
 }