[Analysis] Add DebugInfoCache analysis

llvm/include/llvm/Analysis/DebugInfoCache.h

@@ -0,0 +1,46 @@
+//===- llvm/Analysis/DebugInfoCache.h - debug info cache --------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an analysis that builds a cache of debug info for each
+// DICompileUnit in a module.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_DEBUGINFOCACHE_H
+#define LLVM_ANALYSIS_DEBUGINFOCACHE_H
+
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// Processes and caches debug info for each DICompileUnit in a module.
+///
+/// The result of the analysis is a set of DebugInfoFinders primed on their
+/// respective DICompileUnit. Such DebugInfoFinders can be used to speed up
+/// function cloning which otherwise requires an expensive traversal of
+/// DICompileUnit-level debug info. See an example usage in CoroSplit.
+class DebugInfoCache {
+public:
+  SmallDenseMap<const DICompileUnit *, DebugInfoFinder> Result;
+
+  DebugInfoCache(const Module &M);
+};
+
+class DebugInfoCacheAnalysis
+    : public AnalysisInfoMixin<DebugInfoCacheAnalysis> {
+  friend AnalysisInfoMixin<DebugInfoCacheAnalysis>;
+  static AnalysisKey Key;
+
+public:
+  using Result = DebugInfoCache;
+  Result run(Module &M, ModuleAnalysisManager &);
+};
+} // namespace llvm
+
+#endif

llvm/include/llvm/IR/DebugInfo.h

@@ -120,11 +120,13 @@ class DebugInfoFinder {
   /// Process subprogram.
   void processSubprogram(DISubprogram *SP);
 
+  /// Process a compile unit.
+  void processCompileUnit(DICompileUnit *CU);
+
   /// Clear all lists.
   void reset();
 
 private:
-  void processCompileUnit(DICompileUnit *CU);
   void processScope(DIScope *Scope);
   void processType(DIType *DT);
   bool addCompileUnit(DICompileUnit *CU);

llvm/lib/Analysis/CMakeLists.txt

@@ -52,6 +52,7 @@ add_llvm_component_library(LLVMAnalysis
   DDGPrinter.cpp
   ConstraintSystem.cpp
   Delinearization.cpp
+  DebugInfoCache.cpp
   DemandedBits.cpp
   DependenceAnalysis.cpp
   DependenceGraphBuilder.cpp

llvm/lib/Analysis/DebugInfoCache.cpp

@@ -0,0 +1,39 @@
+//===- llvm/Analysis/DebugInfoCache.cpp - debug info cache ----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an analysis that builds a cache of debug info for each
+// DICompileUnit in a module.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/DebugInfoCache.h"
+#include "llvm/IR/Module.h"
+
+using namespace llvm;
+
+namespace {
+DebugInfoFinder processCompileUnit(DICompileUnit *CU) {
+  DebugInfoFinder DIFinder;
+  DIFinder.processCompileUnit(CU);
+
+  return DIFinder;
+}
+} // namespace
+
+DebugInfoCache::DebugInfoCache(const Module &M) {
+  for (auto *CU : M.debug_compile_units()) {
+    auto DIFinder = processCompileUnit(CU);
+    Result.insert_or_assign(CU, std::move(DIFinder));
+  }
+}
+
+AnalysisKey DebugInfoCacheAnalysis::Key;
+
+DebugInfoCache DebugInfoCacheAnalysis::run(Module &M, ModuleAnalysisManager &) {
+  return DebugInfoCache(M);
+}

llvm/lib/Passes/PassBuilder.cpp

@@ -34,6 +34,7 @@
 #include "llvm/Analysis/DDGPrinter.h"
 #include "llvm/Analysis/DXILMetadataAnalysis.h"
 #include "llvm/Analysis/DXILResource.h"
+#include "llvm/Analysis/DebugInfoCache.h"
 #include "llvm/Analysis/Delinearization.h"
 #include "llvm/Analysis/DemandedBits.h"
 #include "llvm/Analysis/DependenceAnalysis.h"

llvm/lib/Passes/PassRegistry.def

@@ -21,6 +21,7 @@
 MODULE_ANALYSIS("callgraph", CallGraphAnalysis())
 MODULE_ANALYSIS("collector-metadata", CollectorMetadataAnalysis())
 MODULE_ANALYSIS("ctx-prof-analysis", CtxProfAnalysis())
+MODULE_ANALYSIS("debug-info-cache", DebugInfoCacheAnalysis())
 MODULE_ANALYSIS("dxil-metadata", DXILMetadataAnalysis())
 MODULE_ANALYSIS("dxil-resource-binding", DXILResourceBindingAnalysis())
 MODULE_ANALYSIS("dxil-resource-type", DXILResourceTypeAnalysis())

llvm/unittests/Analysis/CMakeLists.txt

@@ -25,6 +25,7 @@ set(ANALYSIS_TEST_SOURCES
   ConstraintSystemTest.cpp
   CtxProfAnalysisTest.cpp
   DDGTest.cpp
+  DebugInfoCacheTest.cpp
   DomTreeUpdaterTest.cpp
   DXILResourceTest.cpp
   GraphWriterTest.cpp

llvm/unittests/Analysis/DebugInfoCacheTest.cpp

@@ -0,0 +1,214 @@
+//===- DebugInfoCacheTest.cpp - DebugInfoCache unit tests -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/DebugInfoCache.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/raw_ostream.h"
+#include "gtest/gtest.h"
+
+namespace llvm {
+namespace {
+
+// Forward declare the IR string
+extern StringRef MultiCUModule;
+
+DICompileUnit *findCU(const Module &M, StringRef FileName) {
+  auto CUs = M.debug_compile_units();
+  auto Matching = llvm::find_if(
+      CUs, [&](auto *CU) { return CU->getFilename() == FileName; });
+  return Matching != CUs.end() ? *Matching : nullptr;
+}
+
+void checkEqualDI(const DebugInfoFinder &DIFinder1,
+                  const DebugInfoFinder &DIFinder2) {
+  EXPECT_TRUE(
+      llvm::equal(DIFinder1.compile_units(), DIFinder2.compile_units()));
+  EXPECT_TRUE(llvm::equal(DIFinder1.types(), DIFinder2.types()));
+  EXPECT_TRUE(llvm::equal(DIFinder1.subprograms(), DIFinder2.subprograms()));
+  EXPECT_TRUE(llvm::equal(DIFinder1.scopes(), DIFinder2.scopes()));
+}
+
+void checkCachedDISameAsFromScratch(llvm::Module &M, const DebugInfoCache &DIC,
+                                    StringRef CUName) {
+  auto *CU = findCU(M, CUName);
+  EXPECT_NE(CU, nullptr);
+
+  auto CachedDIFinder = DIC.Result.find(CU);
+  EXPECT_NE(CachedDIFinder, DIC.Result.end());
+
+  DebugInfoFinder ExpectedDIFinder;
+  ExpectedDIFinder.processCompileUnit(CU);
+
+  checkEqualDI(CachedDIFinder->getSecond(), ExpectedDIFinder);
+}
+
+class DebugInfoCacheTest : public testing::Test {
+protected:
+  LLVMContext C;
+
+  std::unique_ptr<Module> makeModule(StringRef IR) {
+    SMDiagnostic Err;
+    auto M = parseAssemblyString(IR, Err, C);
+    if (!M)
+      Err.print("DebugInfoCacheTest", errs());
+
+    verifyModule(*M, &errs());
+    return M;
+  }
+};
+
+TEST_F(DebugInfoCacheTest, TestEmpty) {
+  auto M = makeModule("");
+  DebugInfoCache DIC{*M};
+  EXPECT_EQ(DIC.Result.size(), 0u);
+}
+
+TEST_F(DebugInfoCacheTest, TestMultiCU) {
+  auto M = makeModule(MultiCUModule);
+  DebugInfoCache DIC{*M};
+  EXPECT_EQ(DIC.Result.size(), 2u);
+
+  checkCachedDISameAsFromScratch(*M, DIC, "file1.cpp");
+  checkCachedDISameAsFromScratch(*M, DIC, "file2.cpp");
+}
+
+/* Generated roughly by
+file1.cpp:
+struct file1_extern_type1;
+struct file1_extern_type2;
+
+namespace file1 {
+typedef struct file1_type1 { int x; float y; } file1_type1;
+file1_type1 global{0, 1.};
+} // file1
+
+extern struct file1_extern_type1 *file1_extern_func1(struct
+file1_extern_type2*);
+
+file1::file1_type1 file1_func1(file1::file1_type1 x) { return x; }
+--------
+file2.cpp:
+struct file2_extern_type1;
+struct file2_extern_type2;
+
+namespace file2 {
+typedef struct file2_type1 { float x; float y; } file2_type1;
+enum class file2_type2 { opt1, opt2 };
+
+namespace inner {
+file2_type2 inner_global{file2_type2::opt2};
+} // inner
+} // file2
+
+extern struct file2_extern_type1 *file2_extern_func1(struct
+file2_extern_type2*);
+
+file2::file2_type1 file2_func1(file2::file2_type1 x, file2::file2_type2 y) {
+return x; }
+--------
+$ clang -S -emit-llvm file*.cpp
+$ llvm-link -S -o single.ll file*.ll
+*/
+StringRef MultiCUModule = R"""(
+%"struct.file1::file1_type1" = type { i32, float }
+%"struct.file2::file2_type1" = type { float, float }
+
+@_ZN5file16globalE = dso_local global %"struct.file1::file1_type1" { i32 0, float 1.000000e+00 }, align 4, !dbg !0
+@_ZN5file25inner12inner_globalE = dso_local global i32 1, align 4, !dbg !11
+
+define dso_local i64 @_Z11file1_func1N5file111file1_type1E(i64 %0) !dbg !33 {
+  %2 = alloca %"struct.file1::file1_type1", align 4
+  %3 = alloca %"struct.file1::file1_type1", align 4
+  store i64 %0, ptr %3, align 4
+    #dbg_declare(ptr %3, !37, !DIExpression(), !38)
+  call void @llvm.memcpy.p0.p0.i64(ptr align 4 %2, ptr align 4 %3, i64 8, i1 false), !dbg !39
+  %4 = load i64, ptr %2, align 4, !dbg !40
+  ret i64 %4, !dbg !40
+}
+
+declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg)
+
+define dso_local <2 x float> @_Z11file2_func1N5file211file2_type1ENS_11file2_type2E(<2 x float> %0, i32 noundef %1) !dbg !41 {
+  %3 = alloca %"struct.file2::file2_type1", align 4
+  %4 = alloca %"struct.file2::file2_type1", align 4
+  %5 = alloca i32, align 4
+  store <2 x float> %0, ptr %4, align 4
+    #dbg_declare(ptr %4, !49, !DIExpression(), !50)
+  store i32 %1, ptr %5, align 4
+    #dbg_declare(ptr %5, !51, !DIExpression(), !52)
+  call void @llvm.memcpy.p0.p0.i64(ptr align 4 %3, ptr align 4 %4, i64 8, i1 false), !dbg !53
+  %6 = load <2 x float>, ptr %3, align 4, !dbg !54
+  ret <2 x float> %6, !dbg !54
+}
+
+!llvm.dbg.cu = !{!20, !22}
+!llvm.ident = !{!25, !25}
+!llvm.module.flags = !{!26, !27, !28, !29, !30, !31, !32}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "global", linkageName: "_ZN5file16globalE", scope: !2, file: !3, line: 6, type: !4, isLocal: false, isDefinition: true)
+!2 = !DINamespace(name: "file1", scope: null)
+!3 = !DIFile(filename: "file1.cpp", directory: "")
+!4 = !DIDerivedType(tag: DW_TAG_typedef, name: "file1_type1", scope: !2, file: !3, line: 5, baseType: !5)
+!5 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "file1_type1", scope: !2, file: !3, line: 5, size: 64, flags: DIFlagTypePassByValue, elements: !6, identifier: "_ZTSN5file111file1_type1E")
+!6 = !{!7, !9}
+!7 = !DIDerivedType(tag: DW_TAG_member, name: "x", scope: !5, file: !3, line: 5, baseType: !8, size: 32)
+!8 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!9 = !DIDerivedType(tag: DW_TAG_member, name: "y", scope: !5, file: !3, line: 5, baseType: !10, size: 32, offset: 32)
+!10 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float)
+!11 = !DIGlobalVariableExpression(var: !12, expr: !DIExpression())
+!12 = distinct !DIGlobalVariable(name: "inner_global", linkageName: "_ZN5file25inner12inner_globalE", scope: !13, file: !15, line: 9, type: !16, isLocal: false, isDefinition: true)
+!13 = !DINamespace(name: "inner", scope: !14)
+!14 = !DINamespace(name: "file2", scope: null)
+!15 = !DIFile(filename: "file2.cpp", directory: "")
+!16 = distinct !DICompositeType(tag: DW_TAG_enumeration_type, name: "file2_type2", scope: !14, file: !15, line: 6, baseType: !8, size: 32, flags: DIFlagEnumClass, elements: !17, identifier: "_ZTSN5file211file2_type2E")
+!17 = !{!18, !19}
+!18 = !DIEnumerator(name: "opt1", value: 0)
+!19 = !DIEnumerator(name: "opt2", value: 1)
+!20 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !3, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !21, splitDebugInlining: false, nameTableKind: None)
+!21 = !{!0}
+!22 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !15, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !23, globals: !24, splitDebugInlining: false, nameTableKind: None)
+!23 = !{!16}
+!24 = !{!11}
+!25 = !{!"clang"}
+!26 = !{i32 7, !"Dwarf Version", i32 5}
+!27 = !{i32 2, !"Debug Info Version", i32 3}
+!28 = !{i32 1, !"wchar_size", i32 4}
+!29 = !{i32 8, !"PIC Level", i32 2}
+!30 = !{i32 7, !"PIE Level", i32 2}
+!31 = !{i32 7, !"uwtable", i32 2}
+!32 = !{i32 7, !"frame-pointer", i32 2}
+!33 = distinct !DISubprogram(name: "file1_func1", linkageName: "_Z11file1_func1N5file111file1_type1E", scope: !3, file: !3, line: 11, type: !34, scopeLine: 11, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !20, retainedNodes: !36)
+!34 = !DISubroutineType(types: !35)
+!35 = !{!4, !4}
+!36 = !{}
+!37 = !DILocalVariable(name: "x", arg: 1, scope: !33, file: !3, line: 11, type: !4)
+!38 = !DILocation(line: 11, column: 51, scope: !33)
+!39 = !DILocation(line: 11, column: 63, scope: !33)
+!40 = !DILocation(line: 11, column: 56, scope: !33)
+!41 = distinct !DISubprogram(name: "file2_func1", linkageName: "_Z11file2_func1N5file211file2_type1ENS_11file2_type2E", scope: !15, file: !15, line: 15, type: !42, scopeLine: 15, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !22, retainedNodes: !36)
+!42 = !DISubroutineType(types: !43)
+!43 = !{!44, !44, !16}
+!44 = !DIDerivedType(tag: DW_TAG_typedef, name: "file2_type1", scope: !14, file: !15, line: 5, baseType: !45)
+!45 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "file2_type1", scope: !14, file: !15, line: 5, size: 64, flags: DIFlagTypePassByValue, elements: !46, identifier: "_ZTSN5file211file2_type1E")
+!46 = !{!47, !48}
+!47 = !DIDerivedType(tag: DW_TAG_member, name: "x", scope: !45, file: !15, line: 5, baseType: !10, size: 32)
+!48 = !DIDerivedType(tag: DW_TAG_member, name: "y", scope: !45, file: !15, line: 5, baseType: !10, size: 32, offset: 32)
+!49 = !DILocalVariable(name: "x", arg: 1, scope: !41, file: !15, line: 15, type: !44)
+!50 = !DILocation(line: 15, column: 51, scope: !41)
+!51 = !DILocalVariable(name: "y", arg: 2, scope: !41, file: !15, line: 15, type: !16)
+!52 = !DILocation(line: 15, column: 73, scope: !41)
+!53 = !DILocation(line: 15, column: 85, scope: !41)
+!54 = !DILocation(line: 15, column: 78, scope: !41)
+)""";
+} // namespace
+} // namespace llvm