[ThinLTO] Import virtual method with single implementation in hybrid mode
Differential revision: https://reviews.llvm.org/D68782
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375083 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/WholeProgramDevirt.cpp b/lib/Transforms/IPO/WholeProgramDevirt.cpp
index e1578cc..ec54e52 100644
--- a/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -383,11 +383,6 @@
!SummaryTypeCheckedLoadUsers.empty();
}
- void markSummaryHasTypeTestAssumeUsers() {
- SummaryHasTypeTestAssumeUsers = true;
- AllCallSitesDevirted = false;
- }
-
void addSummaryTypeCheckedLoadUser(FunctionSummary *FS) {
SummaryTypeCheckedLoadUsers.push_back(FS);
AllCallSitesDevirted = false;
@@ -395,7 +390,8 @@
void addSummaryTypeTestAssumeUser(FunctionSummary *FS) {
SummaryTypeTestAssumeUsers.push_back(FS);
- markSummaryHasTypeTestAssumeUsers();
+ SummaryHasTypeTestAssumeUsers = true;
+ AllCallSitesDevirted = false;
}
void markDevirt() {
@@ -504,7 +500,8 @@
void applySingleImplDevirt(VTableSlotInfo &SlotInfo, Constant *TheFn,
bool &IsExported);
- bool trySingleImplDevirt(MutableArrayRef<VirtualCallTarget> TargetsForSlot,
+ bool trySingleImplDevirt(ModuleSummaryIndex *ExportSummary,
+ MutableArrayRef<VirtualCallTarget> TargetsForSlot,
VTableSlotInfo &SlotInfo,
WholeProgramDevirtResolution *Res);
@@ -923,9 +920,38 @@
Apply(P.second);
}
+static bool AddCalls(VTableSlotInfo &SlotInfo, const ValueInfo &Callee) {
+ // We can't add calls if we haven't seen a definition
+ if (Callee.getSummaryList().empty())
+ return false;
+
+ // Insert calls into the summary index so that the devirtualized targets
+ // are eligible for import.
+ // FIXME: Annotate type tests with hotness. For now, mark these as hot
+ // to better ensure we have the opportunity to inline them.
+ bool IsExported = false;
+ auto &S = Callee.getSummaryList()[0];
+ CalleeInfo CI(CalleeInfo::HotnessType::Hot, /* RelBF = */ 0);
+ auto AddCalls = [&](CallSiteInfo &CSInfo) {
+ for (auto *FS : CSInfo.SummaryTypeCheckedLoadUsers) {
+ FS->addCall({Callee, CI});
+ IsExported |= S->modulePath() != FS->modulePath();
+ }
+ for (auto *FS : CSInfo.SummaryTypeTestAssumeUsers) {
+ FS->addCall({Callee, CI});
+ IsExported |= S->modulePath() != FS->modulePath();
+ }
+ };
+ AddCalls(SlotInfo.CSInfo);
+ for (auto &P : SlotInfo.ConstCSInfo)
+ AddCalls(P.second);
+ return IsExported;
+}
+
bool DevirtModule::trySingleImplDevirt(
- MutableArrayRef<VirtualCallTarget> TargetsForSlot,
- VTableSlotInfo &SlotInfo, WholeProgramDevirtResolution *Res) {
+ ModuleSummaryIndex *ExportSummary,
+ MutableArrayRef<VirtualCallTarget> TargetsForSlot, VTableSlotInfo &SlotInfo,
+ WholeProgramDevirtResolution *Res) {
// See if the program contains a single implementation of this virtual
// function.
Function *TheFn = TargetsForSlot[0].Fn;
@@ -965,6 +991,10 @@
TheFn->setVisibility(GlobalValue::HiddenVisibility);
TheFn->setName(NewName);
}
+ if (ValueInfo TheFnVI = ExportSummary->getValueInfo(TheFn->getGUID()))
+ // Any needed promotion of 'TheFn' has already been done during
+ // LTO unit split, so we can ignore return value of AddCalls.
+ AddCalls(SlotInfo, TheFnVI);
Res->TheKind = WholeProgramDevirtResolution::SingleImpl;
Res->SingleImplName = TheFn->getName();
@@ -1000,27 +1030,7 @@
DevirtTargets.insert(TheFn);
auto &S = TheFn.getSummaryList()[0];
- bool IsExported = false;
-
- // Insert calls into the summary index so that the devirtualized targets
- // are eligible for import.
- // FIXME: Annotate type tests with hotness. For now, mark these as hot
- // to better ensure we have the opportunity to inline them.
- CalleeInfo CI(CalleeInfo::HotnessType::Hot, /* RelBF = */ 0);
- auto AddCalls = [&](CallSiteInfo &CSInfo) {
- for (auto *FS : CSInfo.SummaryTypeCheckedLoadUsers) {
- FS->addCall({TheFn, CI});
- IsExported |= S->modulePath() != FS->modulePath();
- }
- for (auto *FS : CSInfo.SummaryTypeTestAssumeUsers) {
- FS->addCall({TheFn, CI});
- IsExported |= S->modulePath() != FS->modulePath();
- }
- };
- AddCalls(SlotInfo.CSInfo);
- for (auto &P : SlotInfo.ConstCSInfo)
- AddCalls(P.second);
-
+ bool IsExported = AddCalls(SlotInfo, TheFn);
if (IsExported)
ExportedGUIDs.insert(TheFn.getGUID());
@@ -1847,8 +1857,7 @@
// FIXME: Only add live functions.
for (FunctionSummary::VFuncId VF : FS->type_test_assume_vcalls()) {
for (Metadata *MD : MetadataByGUID[VF.GUID]) {
- CallSlots[{MD, VF.Offset}]
- .CSInfo.markSummaryHasTypeTestAssumeUsers();
+ CallSlots[{MD, VF.Offset}].CSInfo.addSummaryTypeTestAssumeUser(FS);
}
}
for (FunctionSummary::VFuncId VF : FS->type_checked_load_vcalls()) {
@@ -1861,7 +1870,7 @@
for (Metadata *MD : MetadataByGUID[VC.VFunc.GUID]) {
CallSlots[{MD, VC.VFunc.Offset}]
.ConstCSInfo[VC.Args]
- .markSummaryHasTypeTestAssumeUsers();
+ .addSummaryTypeTestAssumeUser(FS);
}
}
for (const FunctionSummary::ConstVCall &VC :
@@ -1893,7 +1902,7 @@
cast<MDString>(S.first.TypeID)->getString())
.WPDRes[S.first.ByteOffset];
- if (!trySingleImplDevirt(TargetsForSlot, S.second, Res)) {
+ if (!trySingleImplDevirt(ExportSummary, TargetsForSlot, S.second, Res)) {
DidVirtualConstProp |=
tryVirtualConstProp(TargetsForSlot, S.second, Res, S.first);
diff --git a/test/ThinLTO/X86/Inputs/devirt_single_hybrid_bar.ll b/test/ThinLTO/X86/Inputs/devirt_single_hybrid_bar.ll
new file mode 100644
index 0000000..414e7d5
--- /dev/null
+++ b/test/ThinLTO/X86/Inputs/devirt_single_hybrid_bar.ll
@@ -0,0 +1,58 @@
+; ModuleID = 'bar.cpp'
+source_filename = "bar.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.A = type { i32 (...)** }
+
+$_ZNK1A1fEv = comdat any
+
+$_ZTV1A = comdat any
+
+$_ZTS1A = comdat any
+
+$_ZTI1A = comdat any
+
+@_ZTV1A = linkonce_odr hidden unnamed_addr constant { [3 x i8*] } { [3 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*), i8* bitcast (i32 (%struct.A*)* @_ZNK1A1fEv to i8*)] }, comdat, align 8, !type !0, !type !1
+@_ZTVN10__cxxabiv117__class_type_infoE = external dso_local global i8*
+@_ZTS1A = linkonce_odr hidden constant [3 x i8] c"1A\00", comdat, align 1
+@_ZTI1A = linkonce_odr hidden constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([3 x i8], [3 x i8]* @_ZTS1A, i32 0, i32 0) }, comdat, align 8
+
+; Function Attrs: uwtable
+define hidden i32 @_Z3barv() local_unnamed_addr #0 {
+entry:
+ %b = alloca %struct.A, align 8
+ %0 = bitcast %struct.A* %b to i8*
+ call void @llvm.lifetime.start.p0i8(i64 8, i8* nonnull %0)
+ %1 = getelementptr inbounds %struct.A, %struct.A* %b, i64 0, i32 0
+ store i32 (...)** bitcast (i8** getelementptr inbounds ({ [3 x i8*] }, { [3 x i8*] }* @_ZTV1A, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %1, align 8, !tbaa !4
+ %call = call i32 @_Z3fooP1A(%struct.A* nonnull %b)
+ %add = add nsw i32 %call, 10
+ call void @llvm.lifetime.end.p0i8(i64 8, i8* nonnull %0) #4
+ ret i32 %add
+}
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)
+
+declare dso_local i32 @_Z3fooP1A(%struct.A*) local_unnamed_addr
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture)
+
+; Function Attrs: nounwind uwtable
+define linkonce_odr hidden i32 @_ZNK1A1fEv(%struct.A* %this) unnamed_addr comdat align 2 {
+entry:
+ ret i32 3
+}
+
+!llvm.module.flags = !{!2}
+!llvm.ident = !{!3}
+
+!0 = !{i64 16, !"_ZTS1A"}
+!1 = !{i64 16, !"_ZTSM1AKFivE.virtual"}
+!2 = !{i32 1, !"wchar_size", i32 4}
+!3 = !{!"clang version 10.0.0 (trunk 373596)"}
+!4 = !{!5, !5, i64 0}
+!5 = !{!"vtable pointer", !6, i64 0}
+!6 = !{!"Simple C++ TBAA"}
diff --git a/test/ThinLTO/X86/Inputs/devirt_single_hybrid_foo.ll b/test/ThinLTO/X86/Inputs/devirt_single_hybrid_foo.ll
new file mode 100644
index 0000000..d29f74b
--- /dev/null
+++ b/test/ThinLTO/X86/Inputs/devirt_single_hybrid_foo.ll
@@ -0,0 +1,35 @@
+; ModuleID = 'foo.cpp'
+source_filename = "foo.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.A = type { i32 (...)** }
+
+; Function Attrs: uwtable
+define hidden i32 @_Z3fooP1A(%struct.A* %pA) local_unnamed_addr {
+entry:
+ %0 = bitcast %struct.A* %pA to i32 (%struct.A*)***
+ %vtable = load i32 (%struct.A*)**, i32 (%struct.A*)*** %0, align 8, !tbaa !2
+ %1 = bitcast i32 (%struct.A*)** %vtable to i8*
+ %2 = tail call i1 @llvm.type.test(i8* %1, metadata !"_ZTS1A")
+ tail call void @llvm.assume(i1 %2)
+ %3 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable, align 8
+ %call = tail call i32 %3(%struct.A* %pA)
+ %add = add nsw i32 %call, 10
+ ret i32 %add
+}
+
+; Function Attrs: nounwind readnone willreturn
+declare i1 @llvm.type.test(i8*, metadata)
+
+; Function Attrs: nounwind willreturn
+declare void @llvm.assume(i1)
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 10.0.0 (trunk 373596)"}
+!2 = !{!3, !3, i64 0}
+!3 = !{!"vtable pointer", !4, i64 0}
+!4 = !{!"Simple C++ TBAA"}
diff --git a/test/ThinLTO/X86/devirt_single_hybrid.ll b/test/ThinLTO/X86/devirt_single_hybrid.ll
new file mode 100644
index 0000000..5b2df6c
--- /dev/null
+++ b/test/ThinLTO/X86/devirt_single_hybrid.ll
@@ -0,0 +1,55 @@
+; Check that we import and inline virtual method with single implementation
+; when we're running hybrid LTO.
+;
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit %s -o %t-main.bc
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit %p/Inputs/devirt_single_hybrid_foo.ll -o %t-foo.bc
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit %p/Inputs/devirt_single_hybrid_bar.ll -o %t-bar.bc
+; RUN: llvm-lto2 run -save-temps %t-main.bc %t-foo.bc %t-bar.bc -pass-remarks=. -o %t \
+; RUN: -r=%t-foo.bc,_Z3fooP1A,pl \
+; RUN: -r=%t-main.bc,main,plx \
+; RUN: -r=%t-main.bc,_Z3barv,l \
+; RUN: -r=%t-bar.bc,_Z3barv,pl \
+; RUN: -r=%t-bar.bc,_Z3fooP1A, \
+; RUN: -r=%t-bar.bc,_ZNK1A1fEv,pl \
+; RUN: -r=%t-bar.bc,_ZTV1A,l \
+; RUN: -r=%t-bar.bc,_ZTVN10__cxxabiv117__class_type_infoE, \
+; RUN: -r=%t-bar.bc,_ZTS1A,pl \
+; RUN: -r=%t-bar.bc,_ZTI1A,pl \
+; RUN: -r=%t-bar.bc,_ZNK1A1fEv, \
+; RUN: -r=%t-bar.bc,_ZTV1A,pl \
+; RUN: -r=%t-bar.bc,_ZTI1A, 2>&1 | FileCheck %s --check-prefix=REMARK
+; RUN: llvm-dis %t.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT
+; RUN: llvm-dis %t.1.5.precodegen.bc -o - | FileCheck %s --check-prefix=CODEGEN
+
+; REMARK-COUNT-3: single-impl: devirtualized a call to _ZNK1A1fEv
+
+; IMPORT: define available_externally hidden i32 @_ZNK1A1fEv(%struct.A* %this)
+; IMPORT-NEXT: entry:
+; IMPORT-NEXT: ret i32 3
+
+; CODEGEN: define hidden i32 @main()
+; CODEGEN-NEXT: entry:
+; CODEGEN-NEXT: ret i32 23
+
+; Virtual method should have been optimized out
+; CODEGEN-NOT: _ZNK1A1fEv
+
+; ModuleID = 'main.cpp'
+source_filename = "main.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: norecurse uwtable
+define hidden i32 @main() local_unnamed_addr {
+entry:
+ %call = tail call i32 @_Z3barv()
+ ret i32 %call
+}
+
+declare dso_local i32 @_Z3barv() local_unnamed_addr
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 10.0.0 (trunk 373596)"}
