diff --git a/llvm/include/llvm/Analysis/StaticDataProfileInfo.h b/llvm/include/llvm/Analysis/StaticDataProfileInfo.h index bb7f3be2e8d90..ac03137c93610 100644 --- a/llvm/include/llvm/Analysis/StaticDataProfileInfo.h +++ b/llvm/include/llvm/Analysis/StaticDataProfileInfo.h @@ -60,11 +60,18 @@ class StaticDataProfileInfo { LLVM_ABI StaticDataHotness getConstantHotnessUsingProfileCount( const Constant *C, const ProfileSummaryInfo *PSI, uint64_t Count) const; + /// Return the hotness based on section prefix \p SectionPrefix. + LLVM_ABI StaticDataHotness getSectionHotnessUsingDataAccessProfile( + std::optional SectionPrefix) const; + /// Return the string representation of the hotness enum \p Hotness. LLVM_ABI StringRef hotnessToStr(StaticDataHotness Hotness) const; + bool EnableDataAccessProf = false; + public: - StaticDataProfileInfo() = default; + StaticDataProfileInfo(bool EnableDataAccessProf) + : EnableDataAccessProf(EnableDataAccessProf) {} /// If \p Count is not nullopt, add it to the profile count of the constant \p /// C in a saturating way, and clamp the count to \p getInstrMaxCountValue if @@ -73,14 +80,10 @@ class StaticDataProfileInfo { LLVM_ABI void addConstantProfileCount(const Constant *C, std::optional Count); - /// Return a section prefix for the constant \p C based on its profile count. - /// - If a constant doesn't have a counter, return an empty string. - /// - Otherwise, - /// - If it has a hot count, return "hot". - /// - If it is seen by unprofiled function, return an empty string. - /// - If it has a cold count, return "unlikely". - /// - Otherwise (e.g. it's used by lukewarm functions), return an empty - /// string. + /// Given a constant \p C, returns a section prefix. + /// If \p C is a global variable, the section prefix is the bigger one + /// between its existing section prefix and its use profile count. Otherwise, + /// the section prefix is based on its use profile count. LLVM_ABI StringRef getConstantSectionPrefix( const Constant *C, const ProfileSummaryInfo *PSI) const; }; diff --git a/llvm/lib/Analysis/StaticDataProfileInfo.cpp b/llvm/lib/Analysis/StaticDataProfileInfo.cpp index e7f0b2c15d604..61d49350c7702 100644 --- a/llvm/lib/Analysis/StaticDataProfileInfo.cpp +++ b/llvm/lib/Analysis/StaticDataProfileInfo.cpp @@ -1,10 +1,14 @@ #include "llvm/Analysis/StaticDataProfileInfo.h" #include "llvm/Analysis/ProfileSummaryInfo.h" #include "llvm/IR/Constant.h" +#include "llvm/IR/Constants.h" #include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/Module.h" #include "llvm/InitializePasses.h" #include "llvm/ProfileData/InstrProf.h" +#define DEBUG_TYPE "static-data-profile-info" + using namespace llvm; namespace llvm { @@ -79,6 +83,17 @@ StaticDataProfileInfo::getConstantHotnessUsingProfileCount( return StaticDataHotness::LukewarmOrUnknown; } +StaticDataProfileInfo::StaticDataHotness +StaticDataProfileInfo::getSectionHotnessUsingDataAccessProfile( + std::optional MaybeSectionPrefix) const { + if (!MaybeSectionPrefix) + return StaticDataHotness::LukewarmOrUnknown; + StringRef Prefix = *MaybeSectionPrefix; + assert((Prefix == "hot" || Prefix == "unlikely") && + "Expect section_prefix to be one of hot or unlikely"); + return Prefix == "hot" ? StaticDataHotness::Hot : StaticDataHotness::Cold; +} + StringRef StaticDataProfileInfo::hotnessToStr(StaticDataHotness Hotness) const { switch (Hotness) { case StaticDataHotness::Cold: @@ -101,13 +116,66 @@ StaticDataProfileInfo::getConstantProfileCount(const Constant *C) const { StringRef StaticDataProfileInfo::getConstantSectionPrefix( const Constant *C, const ProfileSummaryInfo *PSI) const { std::optional Count = getConstantProfileCount(C); + +#ifndef NDEBUG + auto DbgPrintPrefix = [](StringRef Prefix) { + return Prefix.empty() ? "" : Prefix; + }; +#endif + + if (EnableDataAccessProf) { + // Module flag `HasDataAccessProf` is 1 -> empty section prefix means + // unknown hotness except for string literals. + if (const GlobalVariable *GV = dyn_cast(C); + GV && llvm::memprof::IsAnnotationOK(*GV) && + !GV->getName().starts_with(".str")) { + auto HotnessFromDataAccessProf = + getSectionHotnessUsingDataAccessProfile(GV->getSectionPrefix()); + + if (!Count) { + StringRef Prefix = hotnessToStr(HotnessFromDataAccessProf); + LLVM_DEBUG(dbgs() << GV->getName() << " has section prefix " + << DbgPrintPrefix(Prefix) + << ", solely from data access profiles\n"); + return Prefix; + } + + // Both data access profiles and PGO counters are available. Use the + // hotter one. + auto HotnessFromPGO = getConstantHotnessUsingProfileCount(C, PSI, *Count); + StaticDataHotness GlobalVarHotness = StaticDataHotness::LukewarmOrUnknown; + if (HotnessFromDataAccessProf == StaticDataHotness::Hot || + HotnessFromPGO == StaticDataHotness::Hot) { + GlobalVarHotness = StaticDataHotness::Hot; + } else if (HotnessFromDataAccessProf == + StaticDataHotness::LukewarmOrUnknown || + HotnessFromPGO == StaticDataHotness::LukewarmOrUnknown) { + GlobalVarHotness = StaticDataHotness::LukewarmOrUnknown; + } else { + GlobalVarHotness = StaticDataHotness::Cold; + } + StringRef Prefix = hotnessToStr(GlobalVarHotness); + LLVM_DEBUG( + dbgs() << GV->getName() << " has section prefix " + << DbgPrintPrefix(Prefix) + << ", the max from data access profiles as " + << DbgPrintPrefix(hotnessToStr(HotnessFromDataAccessProf)) + << " and PGO counters as " + << DbgPrintPrefix(hotnessToStr(HotnessFromPGO)) << "\n"); + return Prefix; + } + } if (!Count) return ""; return hotnessToStr(getConstantHotnessUsingProfileCount(C, PSI, *Count)); } bool StaticDataProfileInfoWrapperPass::doInitialization(Module &M) { - Info.reset(new StaticDataProfileInfo()); + bool EnableDataAccessProf = false; + if (auto *MD = mdconst::extract_or_null( + M.getModuleFlag("EnableDataAccessProf"))) + EnableDataAccessProf = MD->getZExtValue(); + Info.reset(new StaticDataProfileInfo(EnableDataAccessProf)); return false; } diff --git a/llvm/test/CodeGen/X86/global-variable-partition-with-dap.ll b/llvm/test/CodeGen/X86/global-variable-partition-with-dap.ll index f3950b75a969f..b2b0a6dab843f 100644 --- a/llvm/test/CodeGen/X86/global-variable-partition-with-dap.ll +++ b/llvm/test/CodeGen/X86/global-variable-partition-with-dap.ll @@ -1,17 +1,101 @@ target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" -;; A minimal test case. Subsequent PRs will expand on this test case -;; (e.g., with more functions, variables and profiles) and test the hotness -;; reconcillation implementation. +;; Requires asserts for -debug-only. +; REQUIRES: asserts + +; RUN: rm -rf %t && split-file %s %t && cd %t + +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -relocation-model=pic \ +; RUN: -partition-static-data-sections=true \ +; RUN: -debug-only=static-data-profile-info \ +; RUN: -data-sections=true -unique-section-names=false \ +; RUN: input-with-data-access-prof-on.ll -o - 2>&1 | FileCheck %s --check-prefixes=LOG,IR + ; RUN: llc -mtriple=x86_64-unknown-linux-gnu -relocation-model=pic \ ; RUN: -partition-static-data-sections=true \ +; RUN: -debug-only=static-data-profile-info \ ; RUN: -data-sections=true -unique-section-names=false \ -; RUN: %s -o - 2>&1 | FileCheck %s --check-prefix=IR +; RUN: input-with-data-access-prof-off.ll -o - 2>&1 | FileCheck %s --check-prefixes=OFF + +; LOG: hot_bss has section prefix hot, the max from data access profiles as hot and PGO counters as hot +; LOG: data_unknown_hotness has section prefix , the max from data access profiles as and PGO counters as unlikely +; LOG: external_relro_array has section prefix unlikely, solely from data access profiles + +; IR: .type hot_bss,@object +; IR-NEXT: .section .bss.hot.,"aw" +; IR: .type data_unknown_hotness,@object +; IR-NEXT: .section .data,"aw" +; IR: .type external_relro_array,@object +; IR-NEXT: .section .data.rel.ro.unlikely.,"aw" + + +; OFF: .type hot_bss,@object +; OFF-NEXT: .section .bss.hot.,"aw" +; OFF: .type data_unknown_hotness,@object +; OFF-NEXT: .section .data.unlikely.,"aw" +;; Global variable section prefix metadata is not used when +;; module flag `EnableDataAccessProf` is 0, and @external_relro_array has +;; external linkage, so analysis based on PGO counters doesn't apply. +; OFF: .type external_relro_array,@object # @external_relro_array +; OFF-NEXT: .section .data.rel.ro,"aw" + +;--- input-with-data-access-prof-on.ll +; Internal vars +@hot_bss = internal global i32 0, !section_prefix !17 +@data_unknown_hotness = internal global i32 1 +; External vars +@external_relro_array = constant [2 x ptr] [ptr @hot_bss, ptr @data_unknown_hotness], !section_prefix !18 + +define void @cold_func() !prof !15 { + %9 = load i32, ptr @data_unknown_hotness + %11 = call i32 (...) @func_taking_arbitrary_param(i32 %9) + ret void +} + +define void @hot_func() !prof !14 { + %9 = load i32, ptr @hot_bss + %11 = call i32 (...) @func_taking_arbitrary_param(i32 %9) + ret void +} + +declare i32 @func_taking_arbitrary_param(...) -; IR: .section .bss.hot.,"aw" +!llvm.module.flags = !{!0, !1} +!0 = !{i32 2, !"EnableDataAccessProf", i32 1} +!1 = !{i32 1, !"ProfileSummary", !2} +!2 = !{!3, !4, !5, !6, !7, !8, !9, !10} +!3 = !{!"ProfileFormat", !"InstrProf"} +!4 = !{!"TotalCount", i64 1460183} +!5 = !{!"MaxCount", i64 849024} +!6 = !{!"MaxInternalCount", i64 32769} +!7 = !{!"MaxFunctionCount", i64 849024} +!8 = !{!"NumCounts", i64 23627} +!9 = !{!"NumFunctions", i64 3271} +!10 = !{!"DetailedSummary", !11} +!11 = !{!12, !13} +!12 = !{i32 990000, i64 166, i32 73} +!13 = !{i32 999999, i64 3, i32 1443} +!14 = !{!"function_entry_count", i64 100000} +!15 = !{!"function_entry_count", i64 1} +!16 = !{!"branch_weights", i32 1, i32 99999} +!17 = !{!"section_prefix", !"hot"} +!18 = !{!"section_prefix", !"unlikely"} + +;--- input-with-data-access-prof-off.ll +; Same as file above except that module flag `EnableDataAccessProf` has value 0. +; Internal vars @hot_bss = internal global i32 0, !section_prefix !17 +@data_unknown_hotness = internal global i32 1 +; External vars +@external_relro_array = constant [2 x ptr] [ptr @hot_bss, ptr @data_unknown_hotness], !section_prefix !18 + +define void @cold_func() !prof !15 { + %9 = load i32, ptr @data_unknown_hotness + %11 = call i32 (...) @func_taking_arbitrary_param(i32 %9) + ret void +} define void @hot_func() !prof !14 { %9 = load i32, ptr @hot_bss @@ -21,8 +105,9 @@ define void @hot_func() !prof !14 { declare i32 @func_taking_arbitrary_param(...) -!llvm.module.flags = !{!1} +!llvm.module.flags = !{!0, !1} +!0 = !{i32 2, !"EnableDataAccessProf", i32 0} !1 = !{i32 1, !"ProfileSummary", !2} !2 = !{!3, !4, !5, !6, !7, !8, !9, !10} !3 = !{!"ProfileFormat", !"InstrProf"} @@ -40,3 +125,4 @@ declare i32 @func_taking_arbitrary_param(...) !15 = !{!"function_entry_count", i64 1} !16 = !{!"branch_weights", i32 1, i32 99999} !17 = !{!"section_prefix", !"hot"} +!18 = !{!"section_prefix", !"unlikely"}