Author: Ellis Hoag Date: 2022-07-14T11:41:30-07:00 New Revision: af58684f272046f293a9f469f03d23bd2b138349
URL: https://github.com/llvm/llvm-project/commit/af58684f272046f293a9f469f03d23bd2b138349 DIFF: https://github.com/llvm/llvm-project/commit/af58684f272046f293a9f469f03d23bd2b138349.diff LOG: [InstrProf] Add options to profile function groups Add two options, `-fprofile-function-groups=N` and `-fprofile-selected-function-group=i` used to partition functions into `N` groups and only instrument the functions in group `i`. Similar options were added to xray in https://reviews.llvm.org/D87953 and the goal is the same; to reduce instrumented size overhead by spreading the overhead across multiple builds. Raw profiles from different groups can be added like normal using the `llvm-profdata merge` command. Reviewed By: ianlevesque Differential Revision: https://reviews.llvm.org/D129594 Added: clang/test/CodeGen/profile-function-groups.c compiler-rt/test/profile/instrprof-groups.c Modified: clang/docs/ClangCommandLineReference.rst clang/docs/UsersManual.rst clang/include/clang/Basic/CodeGenOptions.def clang/include/clang/Driver/Options.td clang/lib/CodeGen/CodeGenFunction.cpp clang/lib/CodeGen/CodeGenModule.cpp clang/lib/CodeGen/CodeGenModule.h clang/lib/Driver/ToolChains/Clang.cpp Removed: ################################################################################ diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst index 776b84da96572..216872b60cdc8 100644 --- a/clang/docs/ClangCommandLineReference.rst +++ b/clang/docs/ClangCommandLineReference.rst @@ -2329,6 +2329,10 @@ Use instrumentation data for profile-guided optimization Filename defining the list of functions/files to instrument +.. option:: -fprofile-function-groups=<N>, -fprofile-selected-function-group=<i> + +Partition functions into <N> groups and select only functions in group <i> to be instrumented + .. option:: -fprofile-remapping-file=<file> Use the remappings described in <file> to match the profile data against names in the program diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst index e12dc72407b13..c2767d65adbf0 100644 --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -2513,6 +2513,32 @@ When the file contains only excludes, all files and functions except for the excluded ones will be instrumented. Otherwise, only the files and functions specified will be instrumented. +Instrument function groups +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Sometimes it is desirable to minimize the size overhead of instrumented +binaries. One way to do this is to partition functions into groups and only +instrument functions in a specified group. This can be done using the +`-fprofile-function-groups` and `-fprofile-selected-function-group` options. + +.. option:: -fprofile-function-groups=<N>, -fprofile-selected-function-group=<i> + + The following uses 3 groups + + .. code-block:: console + + $ clang++ -Oz -fprofile-generate=group_0/ -fprofile-function-groups=3 -fprofile-selected-function-group=0 code.cc -o code.0 + $ clang++ -Oz -fprofile-generate=group_1/ -fprofile-function-groups=3 -fprofile-selected-function-group=1 code.cc -o code.1 + $ clang++ -Oz -fprofile-generate=group_2/ -fprofile-function-groups=3 -fprofile-selected-function-group=2 code.cc -o code.2 + + After collecting raw profiles from the three binaries, they can be merged into + a single profile like normal. + + .. code-block:: console + + $ llvm-profdata merge -output=code.profdata group_*/*.profraw + + Profile remapping ^^^^^^^^^^^^^^^^^ diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def index b1d394edd04ab..ef7957979dccd 100644 --- a/clang/include/clang/Basic/CodeGenOptions.def +++ b/clang/include/clang/Basic/CodeGenOptions.def @@ -213,6 +213,10 @@ CODEGENOPT(AtomicProfileUpdate , 1, 0) ///< Set -fprofile-update=atomic ENUM_CODEGENOPT(ProfileInstr, ProfileInstrKind, 2, ProfileNone) /// Choose profile kind for PGO use compilation. ENUM_CODEGENOPT(ProfileUse, ProfileInstrKind, 2, ProfileNone) +/// Partition functions into N groups and select only functions in group i to be +/// instrumented. Selected group numbers can be 0 to N-1 inclusive. +VALUE_CODEGENOPT(ProfileTotalFunctionGroups, 32, 1) +VALUE_CODEGENOPT(ProfileSelectedFunctionGroup, 32, 0) CODEGENOPT(CoverageMapping , 1, 0) ///< Generate coverage mapping regions to ///< enable code coverage analysis. CODEGENOPT(DumpCoverageMapping , 1, 0) ///< Dump the generated coverage mapping diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 532d7780c529b..404effb4e1de4 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -1333,6 +1333,15 @@ def fprofile_list_EQ : Joined<["-"], "fprofile-list=">, Group<f_Group>, Flags<[CC1Option, CoreOption]>, HelpText<"Filename defining the list of functions/files to instrument">, MarshallingInfoStringVector<LangOpts<"ProfileListFiles">>; +def fprofile_function_groups : Joined<["-"], "fprofile-function-groups=">, + Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<N>">, + HelpText<"Partition functions into N groups and select only functions in group i to be instrumented using -fprofile-selected-function-group">, + MarshallingInfoInt<CodeGenOpts<"ProfileTotalFunctionGroups">, "1">; +def fprofile_selected_function_group : + Joined<["-"], "fprofile-selected-function-group=">, Group<f_Group>, + Flags<[CC1Option]>, MetaVarName<"<i>">, + HelpText<"Partition functions into N groups using -fprofile-function-groups and select only functions in group i to be instrumented. The valid range is 0 to N-1 inclusive">, + MarshallingInfoInt<CodeGenOpts<"ProfileSelectedFunctionGroup">>; def fswift_async_fp_EQ : Joined<["-"], "fswift-async-fp=">, Group<f_Group>, Flags<[CC1Option, CC1AsOption, CoreOption]>, MetaVarName<"<option>">, HelpText<"Control emission of Swift async extended frame info">, diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp index 17c1c91c7e8f4..5012bd822bd36 100644 --- a/clang/lib/CodeGen/CodeGenFunction.cpp +++ b/clang/lib/CodeGen/CodeGenFunction.cpp @@ -852,7 +852,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy, } if (CGM.getCodeGenOpts().getProfileInstr() != CodeGenOptions::ProfileNone) - if (CGM.isProfileInstrExcluded(Fn, Loc)) + if (CGM.isFunctionBlockedFromProfileInstr(Fn, Loc)) Fn->addFnAttr(llvm::Attribute::NoProfile); unsigned Count, Offset; diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index bdee31b504aec..1e90b09145385 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -58,6 +58,7 @@ #include "llvm/IR/Module.h" #include "llvm/IR/ProfileSummary.h" #include "llvm/ProfileData/InstrProfReader.h" +#include "llvm/Support/CRC.h" #include "llvm/Support/CodeGen.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/ConvertUTF.h" @@ -2843,8 +2844,8 @@ bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc, return true; } -bool CodeGenModule::isProfileInstrExcluded(llvm::Function *Fn, - SourceLocation Loc) const { +bool CodeGenModule::isFunctionBlockedByProfileList(llvm::Function *Fn, + SourceLocation Loc) const { const auto &ProfileList = getContext().getProfileList(); // If the profile list is empty, then instrument everything. if (ProfileList.isEmpty()) @@ -2871,6 +2872,20 @@ bool CodeGenModule::isProfileInstrExcluded(llvm::Function *Fn, return ProfileList.getDefault(); } +bool CodeGenModule::isFunctionBlockedFromProfileInstr( + llvm::Function *Fn, SourceLocation Loc) const { + if (isFunctionBlockedByProfileList(Fn, Loc)) + return true; + + auto NumGroups = getCodeGenOpts().ProfileTotalFunctionGroups; + if (NumGroups > 1) { + auto Group = llvm::crc32(arrayRefFromStringRef(Fn->getName())) % NumGroups; + if (Group != getCodeGenOpts().ProfileSelectedFunctionGroup) + return true; + } + return false; +} + bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) { // Never defer when EmitAllDecls is specified. if (LangOpts.EmitAllDecls) diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h index 10b49da27dab7..1123a7cfce15d 100644 --- a/clang/lib/CodeGen/CodeGenModule.h +++ b/clang/lib/CodeGen/CodeGenModule.h @@ -1340,9 +1340,15 @@ class CodeGenModule : public CodeGenTypeCache { bool imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc, StringRef Category = StringRef()) const; - /// Returns true if function at the given location should be excluded from - /// profile instrumentation. - bool isProfileInstrExcluded(llvm::Function *Fn, SourceLocation Loc) const; + /// \returns true if \p Fn at \p Loc should be excluded from profile + /// instrumentation by the SCL passed by \p -fprofile-list. + bool isFunctionBlockedByProfileList(llvm::Function *Fn, + SourceLocation Loc) const; + + /// \returns true if \p Fn at \p Loc should be excluded from profile + /// instrumentation. + bool isFunctionBlockedFromProfileInstr(llvm::Function *Fn, + SourceLocation Loc) const; SanitizerMetadata *getSanitizerMetadata() { return SanitizerMD.get(); diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 97435f1a73de2..3e36d4def2f33 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -956,6 +956,27 @@ static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C, CmdArgs.push_back("-fprofile-update=atomic"); } + int FunctionGroups = 1; + int SelectedFunctionGroup = 0; + if (const auto *A = Args.getLastArg(options::OPT_fprofile_function_groups)) { + StringRef Val = A->getValue(); + if (Val.getAsInteger(0, FunctionGroups) || FunctionGroups < 1) + D.Diag(diag::err_drv_invalid_int_value) << A->getAsString(Args) << Val; + } + if (const auto *A = + Args.getLastArg(options::OPT_fprofile_selected_function_group)) { + StringRef Val = A->getValue(); + if (Val.getAsInteger(0, SelectedFunctionGroup) || + SelectedFunctionGroup < 0 || SelectedFunctionGroup >= FunctionGroups) + D.Diag(diag::err_drv_invalid_int_value) << A->getAsString(Args) << Val; + } + if (FunctionGroups != 1) + CmdArgs.push_back(Args.MakeArgString("-fprofile-function-groups=" + + Twine(FunctionGroups))); + if (SelectedFunctionGroup != 0) + CmdArgs.push_back(Args.MakeArgString("-fprofile-selected-function-group=" + + Twine(SelectedFunctionGroup))); + // Leave -fprofile-dir= an unused argument unless .gcda emission is // enabled. To be polite, with '-fprofile-arcs -fno-profile-arcs' consider // the flag used. There is no -fno-profile-dir, so the user has no diff --git a/clang/test/CodeGen/profile-function-groups.c b/clang/test/CodeGen/profile-function-groups.c new file mode 100644 index 0000000000000..9e04c9060df48 --- /dev/null +++ b/clang/test/CodeGen/profile-function-groups.c @@ -0,0 +1,24 @@ +// RUN: %clang -fprofile-generate -fprofile-function-groups=3 -fprofile-selected-function-group=0 -emit-llvm -S %s -o - | FileCheck %s --check-prefixes=CHECK,SELECT0 +// RUN: %clang -fprofile-generate -fprofile-function-groups=3 -fprofile-selected-function-group=1 -emit-llvm -S %s -o - | FileCheck %s --check-prefixes=CHECK,SELECT1 +// RUN: %clang -fprofile-generate -fprofile-function-groups=3 -fprofile-selected-function-group=2 -emit-llvm -S %s -o - | FileCheck %s --check-prefixes=CHECK,SELECT2 + +// Group 0 +// SELECT0-NOT: noprofile +// SELECT1: noprofile +// SELECT2: noprofile +// CHECK: define {{.*}} @hoo() +void hoo() {} + +// Group 1 +// SELECT0: noprofile +// SELECT1-NOT: noprofile +// SELECT2: noprofile +// CHECK: define {{.*}} @goo() +void goo() {} + +// Group 2 +// SELECT0: noprofile +// SELECT1: noprofile +// SELECT2-NOT: noprofile +// CHECK: define {{.*}} @boo() +void boo() {} diff --git a/compiler-rt/test/profile/instrprof-groups.c b/compiler-rt/test/profile/instrprof-groups.c new file mode 100644 index 0000000000000..1a56453da9141 --- /dev/null +++ b/compiler-rt/test/profile/instrprof-groups.c @@ -0,0 +1,28 @@ +// RUN: %clang_pgogen -fprofile-function-groups=3 -fprofile-selected-function-group=0 %s -o %t.0.out +// RUN: %clang_pgogen -fprofile-function-groups=3 -fprofile-selected-function-group=1 %s -o %t.1.out +// RUN: %clang_pgogen -fprofile-function-groups=3 -fprofile-selected-function-group=2 %s -o %t.2.out +// RUN: env LLVM_PROFILE_FILE=%t.0.profraw %run %t.0.out +// RUN: env LLVM_PROFILE_FILE=%t.1.profraw %run %t.1.out +// RUN: env LLVM_PROFILE_FILE=%t.2.profraw %run %t.2.out +// RUN: llvm-profdata merge -o %t.profdata %t.*.profraw +// RUN: llvm-profdata show %t.profdata --all-functions | FileCheck %s + +int foo(int i) { return 4 * i + 1; } +int bar(int i) { return 4 * i + 2; } +int goo(int i) { return 4 * i + 3; } + +int main(int argc, char *argv[]) { + foo(5); + bar(6); + goo(7); + return 0; +} + +// Even though we ran this code three times, we expect all counts to be one if +// functions were partitioned into groups correctly. + +// CHECK: Counters: 1 +// CHECK: Counters: 1 +// CHECK: Counters: 1 +// CHECK: Counters: 1 +// CHECK: Total functions: 4 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
