[Driver]Add cland and lld driver option, as well as llc CLI option

Author: mingmingl-llvm

clang/include/clang/Basic/CodeGenOptions.def

@@ -101,6 +101,8 @@ CODEGENOPT(ForbidGuardVariables , 1, 0) ///< Issue errors if C++ guard variables
                                         ///< are required.
 CODEGENOPT(FunctionSections  , 1, 0) ///< Set when -ffunction-sections is enabled.
 CODEGENOPT(BBAddrMap  , 1, 0) ///< Set when -fbasic-block-address-map is enabled.
+CODEGENOPT(SplitDataSections, 1,
+           0) ///< Set when -fsplit-data-sections is enabled.
 CODEGENOPT(InstrumentFunctions , 1, 0) ///< Set when -finstrument-functions is
                                        ///< enabled.
 CODEGENOPT(InstrumentFunctionsAfterInlining , 1, 0) ///< Set when

clang/include/clang/Driver/Options.td

@@ -4352,6 +4352,12 @@ defm split_machine_functions: BoolFOption<"split-machine-functions",
   NegFlag<SetFalse, [], [ClangOption], "Disable">,
   BothFlags<[], [ClangOption], " late function splitting using profile information (x86 ELF)">>;
 
+defm split_data_sections: BoolFOption<"split-data-sections",
+  CodeGenOpts<"SplitDataSections">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option], "Enable">,
+  NegFlag<SetFalse, [], [ClangOption], "Disable">,
+  BothFlags<[], [ClangOption], "Split static data sections using profile information (x86 ELF)">>;
+
 defm strict_return : BoolFOption<"strict-return",
   CodeGenOpts<"StrictReturn">, DefaultTrue,
   NegFlag<SetFalse, [], [ClangOption, CC1Option],

clang/lib/CodeGen/BackendUtil.cpp

@@ -441,6 +441,7 @@ static bool initTargetOptions(DiagnosticsEngine &Diags,
   }
 
   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
+  Options.EnableDataSectionSplitting = CodeGenOpts.SplitDataSections;
   Options.FunctionSections = CodeGenOpts.FunctionSections;
   Options.DataSections = CodeGenOpts.DataSections;
   Options.IgnoreXCOFFVisibility = LangOpts.IgnoreXCOFFVisibility;

clang/lib/Driver/ToolChains/Clang.cpp

@@ -6355,6 +6355,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
+  if (Arg *A = Args.getLastArg(options::OPT_fsplit_data_sections,
+                               options::OPT_fno_split_data_sections)) {
+    if (!A->getOption().matches(options::OPT_fno_split_data_sections)) {
+      if (Triple.isX86() && Triple.isOSBinFormatELF())
+        A->render(Args, CmdArgs);
+      else
+        D.Diag(diag::err_drv_unsupported_opt_for_target)
+            << A->getAsString(Args) << TripleStr;
+    }
+  }
+
   Args.AddLastArg(CmdArgs, options::OPT_finstrument_functions,
                   options::OPT_finstrument_functions_after_inlining,
                   options::OPT_finstrument_function_entry_bare);

clang/test/Driver/fsplit-data-sections.c

@@ -0,0 +1,6 @@
+// RUN: %clang -### --target=x86_64 -fprofile-use=default.profdata -fsplit-data-sections %s 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: not %clang -### --target=aarch64 -fprofile-use=default.profdata -fsplit-data-sections %s 2>&1 | FileCheck %s --check-prefixes=ERR
+
+// CHECK: "-cc1" {{.*}} "-fsplit-data-sections"
+
+// ERR: error: unsupported option '-fsplit-data-sections' for target 'aarch64'

lld/ELF/Config.h

@@ -491,6 +491,10 @@ struct Config {
   // If an input file matches a wildcard pattern, remap it to the value.
   llvm::SmallVector<std::pair<llvm::GlobPattern, llvm::StringRef>, 0>
       remapInputsWildcards;
+
+  // Propagated to TargetOptions in lto::Config.
+  // If true, emit suffix for a static data section to indicate its hotness.
+  bool ltoEmitStaticDataSectionSuffix = false;
 };
 
 // Some index properties of a symbol are stored separately in this auxiliary

lld/ELF/Options.td

@@ -670,6 +670,9 @@ defm lto_basic_block_address_map: BB<"lto-basic-block-address-map",
 defm lto_unique_basic_block_section_names: BB<"lto-unique-basic-block-section-names",
     "Give unique names to every basic block section for LTO",
     "Do not give unique names to every basic block section for LTO (default)">;
+defm lto_split_data_sections: BB<"lto-split-data-sections",
+    "Split a static data section into a hot section and a non-hot one",
+    "Do not split static data sections (default)">;
 defm shuffle_sections: EEq<"shuffle-sections",
   "Shuffle matched sections using the given seed before mapping them to the output sections. "
   "If -1, reverse the section order. If 0, use a random seed">,

llvm/include/llvm/CodeGen/CommandFlags.h

@@ -136,6 +136,8 @@ bool getEmitCallSiteInfo();
 
 bool getEnableMachineFunctionSplitter();
 
+bool getEnableDataSectionSplitting();
+
 bool getEnableDebugEntryValues();
 
 bool getValueTrackingVariableLocations();

llvm/include/llvm/Target/TargetOptions.h

@@ -146,7 +146,7 @@ namespace llvm {
           EmulatedTLS(false), EnableTLSDESC(false), EnableIPRA(false),
           EmitStackSizeSection(false), EnableMachineOutliner(false),
           EnableMachineFunctionSplitter(false), SupportsDefaultOutlining(false),
-          EmitAddrsig(false), BBAddrMap(false), EmitCallSiteInfo(false),
+          EmitAddrsig(false), BBAddrMap(false), EnableDataSectionSplitting(false), EmitCallSiteInfo(false),
           SupportsDebugEntryValues(false), EnableDebugEntryValues(false),
           ValueTrackingVariableLocations(false), ForceDwarfFrameSection(false),
           XRayFunctionIndex(true), DebugStrictDwarf(false), Hotpatch(false),
@@ -322,6 +322,9 @@ namespace llvm {
     // which can be used to map virtual addresses to machine basic blocks.
     unsigned BBAddrMap : 1;
 
+    // For a static data section, emit a section suffix to indicate its hotness.
+    unsigned EnableDataSectionSplitting : 1;
+
     /// Emit basic blocks into separate sections.
     BasicBlockSection BBSections = BasicBlockSection::None;
 

llvm/lib/CodeGen/CommandFlags.cpp

@@ -103,6 +103,7 @@ CGOPT(bool, EnableStackSizeSection)
 CGOPT(bool, EnableAddrsig)
 CGOPT(bool, EmitCallSiteInfo)
 CGOPT(bool, EnableMachineFunctionSplitter)
+CGOPT(bool, EnableDataSectionSplitting)
 CGOPT(bool, EnableDebugEntryValues)
 CGOPT(bool, ForceDwarfFrameSection)
 CGOPT(bool, XRayFunctionIndex)
@@ -480,6 +481,13 @@ codegen::RegisterCodeGenFlags::RegisterCodeGenFlags() {
       cl::init(false));
   CGBINDOPT(EnableMachineFunctionSplitter);
 
+  static cl::opt<bool> EnableDataSectionSplitting(
+      "split-data-sections",
+      cl::desc("Partition static data sections into hot and cold sections "
+               "using profile information"),
+      cl::init(false));
+  CGBINDOPT(EnableDataSectionSplitting);
+
   static cl::opt<bool> ForceDwarfFrameSection(
       "force-dwarf-frame-section",
       cl::desc("Always emit a debug frame section."), cl::init(false));
@@ -586,6 +594,7 @@ codegen::InitTargetOptionsFromCodeGenFlags(const Triple &TheTriple) {
   Options.ExceptionModel = getExceptionModel();
   Options.EmitStackSizeSection = getEnableStackSizeSection();
   Options.EnableMachineFunctionSplitter = getEnableMachineFunctionSplitter();
+  Options.EnableDataSectionSplitting = getEnableDataSectionSplitting();
   Options.EmitAddrsig = getEnableAddrsig();
   Options.EmitCallSiteInfo = getEmitCallSiteInfo();
   Options.EnableDebugEntryValues = getEnableDebugEntryValues();