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[memprof] Teach extractCallsFromIR to look into inline stacks #115441

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Merged
merged 4 commits into from
Nov 9, 2024
Merged

[memprof] Teach extractCallsFromIR to look into inline stacks #115441

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887d8ca
[memprof] Teach extractCallsFromIR to look into inline stacks
kazutakahirata Nov 7, 2024
cf2948f
Address comments.
kazutakahirata Nov 8, 2024
fb8fd7a
Simplify the inline stack traversal.
kazutakahirata Nov 8, 2024
c9ce780
Add an assert.
kazutakahirata Nov 8, 2024
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20 changes: 11 additions & 9 deletions llvm/lib/Transforms/Instrumentation/MemProfiler.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -810,10 +810,6 @@ memprof::extractCallsFromIR(Module &M) {

for (auto &BB : F) {
for (auto &I : BB) {
const DILocation *DIL = I.getDebugLoc();
if (!DIL)
continue;

if (!isa<CallBase>(&I) || isa<IntrinsicInst>(&I))
continue;

Expand All @@ -824,11 +820,17 @@ memprof::extractCallsFromIR(Module &M) {
continue;

StringRef CalleeName = CalledFunction->getName();
uint64_t CallerGUID =
IndexedMemProfRecord::getGUID(DIL->getSubprogramLinkageName());
uint64_t CalleeGUID = IndexedMemProfRecord::getGUID(CalleeName);
LineLocation Loc = {GetOffset(DIL), DIL->getColumn()};
Calls[CallerGUID].emplace_back(Loc, CalleeGUID);
for (const DILocation *DIL = I.getDebugLoc(); DIL;
DIL = DIL->getInlinedAt()) {
StringRef CallerName = DIL->getSubprogramLinkageName();
assert(!CallerName.empty() &&
"Be sure to enable -fdebug-info-for-profiling");
uint64_t CallerGUID = IndexedMemProfRecord::getGUID(CallerName);
uint64_t CalleeGUID = IndexedMemProfRecord::getGUID(CalleeName);
LineLocation Loc = {GetOffset(DIL), DIL->getColumn()};
Calls[CallerGUID].emplace_back(Loc, CalleeGUID);
CalleeName = CallerName;
}
}
}
}
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119 changes: 119 additions & 0 deletions llvm/unittests/Transforms/Instrumentation/MemProfUseTest.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -101,4 +101,123 @@ declare !dbg !19 void @_Z2f3v()
EXPECT_THAT(CallSites[2],
Pair(FieldsAre(2U, 9U), IndexedMemProfRecord::getGUID("_Z2f3v")));
}

TEST(MemProf, ExtractDirectCallsFromIRInline) {
// The following IR is generated from:
//
// void f1();
// static inline void f2() {
// // For an interesting line number.
// f1();
// }
// static inline void f3() {
// /****/ f2(); // For an interesting column number.
// }
//
// void g1();
// void g2();
// static inline void g3() {
// /**/ g1(); // For an interesting column number.
// g2();
// }
//
// void foo() {
// f3();
// /***/ g3(); // For an interesting column number.
// }
StringRef IR = R"IR(
define dso_local void @_Z3foov() local_unnamed_addr !dbg !10 {
entry:
tail call void @_Z2f1v(), !dbg !13
tail call void @_Z2g1v(), !dbg !18
tail call void @_Z2g2v(), !dbg !21
ret void, !dbg !22
}

declare !dbg !23 void @_Z2f1v() local_unnamed_addr

declare !dbg !24 void @_Z2g1v() local_unnamed_addr

declare !dbg !25 void @_Z2g2v() local_unnamed_addr

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8}
!llvm.ident = !{!9}

!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, splitDebugInlining: false, debugInfoForProfiling: true, nameTableKind: None)
!1 = !DIFile(filename: "foobar.cc", directory: "/")
!2 = !{i32 7, !"Dwarf Version", i32 5}
!3 = !{i32 2, !"Debug Info Version", i32 3}
!4 = !{i32 1, !"wchar_size", i32 4}
!5 = !{i32 1, !"MemProfProfileFilename", !"memprof.profraw"}
!6 = !{i32 8, !"PIC Level", i32 2}
!7 = !{i32 7, !"PIE Level", i32 2}
!8 = !{i32 7, !"uwtable", i32 2}
!9 = !{!"clang"}
!10 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: !1, file: !1, line: 17, type: !11, scopeLine: 17, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!11 = !DISubroutineType(types: !12)
!12 = !{}
!13 = !DILocation(line: 4, column: 3, scope: !14, inlinedAt: !15)
!14 = distinct !DISubprogram(name: "f2", linkageName: "_ZL2f2v", scope: !1, file: !1, line: 2, type: !11, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!15 = distinct !DILocation(line: 7, column: 10, scope: !16, inlinedAt: !17)
!16 = distinct !DISubprogram(name: "f3", linkageName: "_ZL2f3v", scope: !1, file: !1, line: 6, type: !11, scopeLine: 6, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!17 = distinct !DILocation(line: 18, column: 3, scope: !10)
!18 = !DILocation(line: 13, column: 8, scope: !19, inlinedAt: !20)
!19 = distinct !DISubprogram(name: "g3", linkageName: "_ZL2g3v", scope: !1, file: !1, line: 12, type: !11, scopeLine: 12, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!20 = distinct !DILocation(line: 19, column: 9, scope: !10)
!21 = !DILocation(line: 14, column: 3, scope: !19, inlinedAt: !20)
!22 = !DILocation(line: 20, column: 1, scope: !10)
!23 = !DISubprogram(name: "f1", linkageName: "_Z2f1v", scope: !1, file: !1, line: 1, type: !11, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
!24 = !DISubprogram(name: "g1", linkageName: "_Z2g1v", scope: !1, file: !1, line: 10, type: !11, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
!25 = !DISubprogram(name: "g2", linkageName: "_Z2g2v", scope: !1, file: !1, line: 11, type: !11, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
)IR";

LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M = parseAssemblyString(IR, Err, Ctx);
ASSERT_TRUE(M);

auto Calls = extractCallsFromIR(*M);

// Expect exactly 4 callers.
ASSERT_THAT(Calls, SizeIs(4));

// Verify each key-value pair.

auto FooIt = Calls.find(IndexedMemProfRecord::getGUID("_Z3foov"));
ASSERT_NE(FooIt, Calls.end());
const auto &[FooCallerGUID, FooCallSites] = *FooIt;
EXPECT_EQ(FooCallerGUID, IndexedMemProfRecord::getGUID("_Z3foov"));
ASSERT_THAT(FooCallSites, SizeIs(2));
EXPECT_THAT(FooCallSites[0], Pair(FieldsAre(1U, 3U),
IndexedMemProfRecord::getGUID("_ZL2f3v")));
EXPECT_THAT(FooCallSites[1], Pair(FieldsAre(2U, 9U),
IndexedMemProfRecord::getGUID("_ZL2g3v")));

auto F2It = Calls.find(IndexedMemProfRecord::getGUID("_ZL2f2v"));
ASSERT_NE(F2It, Calls.end());
const auto &[F2CallerGUID, F2CallSites] = *F2It;
EXPECT_EQ(F2CallerGUID, IndexedMemProfRecord::getGUID("_ZL2f2v"));
ASSERT_THAT(F2CallSites, SizeIs(1));
EXPECT_THAT(F2CallSites[0],
Pair(FieldsAre(2U, 3U), IndexedMemProfRecord::getGUID("_Z2f1v")));

auto F3It = Calls.find(IndexedMemProfRecord::getGUID("_ZL2f3v"));
ASSERT_NE(F3It, Calls.end());
const auto &[F3CallerGUID, F3CallSites] = *F3It;
EXPECT_EQ(F3CallerGUID, IndexedMemProfRecord::getGUID("_ZL2f3v"));
ASSERT_THAT(F3CallSites, SizeIs(1));
EXPECT_THAT(F3CallSites[0], Pair(FieldsAre(1U, 10U),
IndexedMemProfRecord::getGUID("_ZL2f2v")));

auto G3It = Calls.find(IndexedMemProfRecord::getGUID("_ZL2g3v"));
ASSERT_NE(G3It, Calls.end());
const auto &[G3CallerGUID, G3CallSites] = *G3It;
EXPECT_EQ(G3CallerGUID, IndexedMemProfRecord::getGUID("_ZL2g3v"));
ASSERT_THAT(G3CallSites, SizeIs(2));
EXPECT_THAT(G3CallSites[0],
Pair(FieldsAre(1U, 8U), IndexedMemProfRecord::getGUID("_Z2g1v")));
EXPECT_THAT(G3CallSites[1],
Pair(FieldsAre(2U, 3U), IndexedMemProfRecord::getGUID("_Z2g2v")));
}
} // namespace
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