diff options
Diffstat (limited to 'llvm')
3 files changed, 133 insertions, 8 deletions
diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp index 3aa06a91b84..5ccfb29b01a 100644 --- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp +++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp @@ -843,18 +843,13 @@ bool DevirtIndex::tryFindVirtualCallTargets( std::vector<ValueInfo> &TargetsForSlot, const TypeIdCompatibleVtableInfo TIdInfo, uint64_t ByteOffset) { for (const TypeIdOffsetVtableInfo &P : TIdInfo) { - // Ensure that we have at most one external linkage vtable initializer. - assert(P.VTableVI.getSummaryList().size() == 1 || - llvm::count_if( - P.VTableVI.getSummaryList(), - [&](const std::unique_ptr<GlobalValueSummary> &Summary) { - return GlobalValue::isExternalLinkage(Summary->linkage()); - }) <= 1); // Find the first non-available_externally linkage vtable initializer. // We can have multiple available_externally, linkonce_odr and weak_odr // vtable initializers, however we want to skip available_externally as they // do not have type metadata attached, and therefore the summary will not - // contain any vtable functions. + // contain any vtable functions. We can also have multiple external + // vtable initializers in the case of comdats, which we cannot check here. + // The linker should give an error in this case. // // Also, handle the case of same-named local Vtables with the same path // and therefore the same GUID. This can happen if there isn't enough diff --git a/llvm/test/ThinLTO/X86/Inputs/devirt_external_comdat_same_guid.ll b/llvm/test/ThinLTO/X86/Inputs/devirt_external_comdat_same_guid.ll new file mode 100644 index 00000000000..a2556392601 --- /dev/null +++ b/llvm/test/ThinLTO/X86/Inputs/devirt_external_comdat_same_guid.ll @@ -0,0 +1,43 @@ +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-grtev4-linux-gnu" + +source_filename = "-" + +%struct.A = type { i32 (...)** } +%struct.B = type { %struct.A } + +$_ZTV1B = comdat any + +@_ZTV1B = constant { [4 x i8*] } { [4 x i8*] [i8* null, i8* undef, i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1fEi to i8*), i8* bitcast (i32 (%struct.A*, i32)* @_ZN1A1nEi to i8*)] }, comdat, !type !0, !type !1 + +define i32 @_ZN1B1fEi(%struct.B* %this, i32 %a) #0 comdat($_ZTV1B) { + ret i32 0; +} + +define i32 @_ZN1A1nEi(%struct.A* %this, i32 %a) #0 comdat($_ZTV1B) { + ret i32 0; +} + +define i32 @test2(%struct.B* %obj, i32 %a) { +entry: + %0 = bitcast %struct.B* %obj to i8*** + %vtable2 = load i8**, i8*** %0 + %1 = bitcast i8** %vtable2 to i8* + %p2 = call i1 @llvm.type.test(i8* %1, metadata !"_ZTS1B") + call void @llvm.assume(i1 %p2) + + %fptrptr = getelementptr i8*, i8** %vtable2, i32 1 + %2 = bitcast i8** %fptrptr to i32 (%struct.B*, i32)** + %fptr33 = load i32 (%struct.B*, i32)*, i32 (%struct.B*, i32)** %2, align 8 + + %call4 = tail call i32 %fptr33(%struct.B* nonnull %obj, i32 %a) + ret i32 %call4 +} + +attributes #0 = { noinline optnone } + +declare i1 @llvm.type.test(i8*, metadata) +declare void @llvm.assume(i1) + +!0 = !{i64 16, !"_ZTS1A"} +!1 = !{i64 16, !"_ZTS1B"} diff --git a/llvm/test/ThinLTO/X86/devirt_external_comdat_same_guid.ll b/llvm/test/ThinLTO/X86/devirt_external_comdat_same_guid.ll new file mode 100644 index 00000000000..18482a051e2 --- /dev/null +++ b/llvm/test/ThinLTO/X86/devirt_external_comdat_same_guid.ll @@ -0,0 +1,87 @@ +; REQUIRES: x86-registered-target + +; Test that index-based devirtualization in the presence of external +; vtables with the same name (with comdat) succeeds. + +; Generate unsplit module with summary for ThinLTO index-based WPD. +; RUN: opt -thinlto-bc -o %t3.o %s +; RUN: opt -thinlto-bc -o %t4.o %p/Inputs/devirt_external_comdat_same_guid.ll + +; RUN: llvm-lto2 run %t3.o %t4.o -save-temps -use-new-pm -pass-remarks=. \ +; RUN: -wholeprogramdevirt-print-index-based \ +; RUN: -o %t5 \ +; RUN: -r=%t3.o,use_B,px \ +; RUN: -r=%t3.o,test,px \ +; RUN: -r=%t3.o,_ZTV1B,px \ +; RUN: -r=%t3.o,_ZN1B1fEi,px \ +; RUN: -r=%t3.o,_ZN1B1nEi,px \ +; RUN: -r=%t4.o,_ZTV1B,x \ +; RUN: -r=%t4.o,_ZN1B1fEi,x \ +; RUN: -r=%t4.o,_ZN1A1nEi,x \ +; RUN: -r=%t4.o,test2,px \ +; RUN: 2>&1 | FileCheck %s --check-prefix=REMARK --check-prefix=PRINT +; RUN: llvm-dis %t5.1.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR1 +; RUN: llvm-dis %t5.2.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR2 + +; PRINT-DAG: Devirtualized call to {{.*}} (_ZN1A1nEi) + +; REMARK-DAG: single-impl: devirtualized a call to _ZN1A1nEi + +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-grtev4-linux-gnu" + +source_filename = "-" + +%struct.A = type { i32 (...)** } +%struct.B = type { %struct.A } + +$_ZTV1B = comdat any + +@_ZTV1B = constant { [4 x i8*] } { [4 x i8*] [i8* null, i8* undef, i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1fEi to i8*), i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1nEi to i8*)] }, comdat, !type !0, !type !1 + +define i32 @_ZN1B1fEi(%struct.B* %this, i32 %a) #0 comdat($_ZTV1B) { + ret i32 0; +} + +define i32 @_ZN1B1nEi(%struct.B* %this, i32 %a) #0 comdat($_ZTV1B) { + ret i32 0; +} + +; Ensures that vtable of B is live so that we will attempt devirt. +define dso_local i32 @use_B(%struct.B* %a) { +entry: + %0 = bitcast %struct.B* %a to i32 (...)*** + store i32 (...)** bitcast (i8** getelementptr inbounds ({ [4 x i8*] }, { [4 x i8*] }* @_ZTV1B, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8 + ret i32 0 +} + +; CHECK-IR1: define i32 @test( +define i32 @test(%struct.A* %obj, i32 %a) { +entry: + %0 = bitcast %struct.A* %obj to i8*** + %vtable = load i8**, i8*** %0 + %1 = bitcast i8** %vtable to i8* + %p = call i1 @llvm.type.test(i8* %1, metadata !"_ZTS1A") + call void @llvm.assume(i1 %p) + %fptrptr = getelementptr i8*, i8** %vtable, i32 1 + %2 = bitcast i8** %fptrptr to i32 (%struct.A*, i32)** + %fptr1 = load i32 (%struct.A*, i32)*, i32 (%struct.A*, i32)** %2, align 8 + + ; Check that the call was devirtualized. + ; CHECK-IR1: tail call i32 {{.*}}@_ZN1A1nEi + %call = tail call i32 %fptr1(%struct.A* nonnull %obj, i32 %a) + + ret i32 %call +} + +; CHECK-IR2: define i32 @test2 +; Check that the call was devirtualized. +; CHECK-IR2: tail call i32 @_ZN1A1nEi + +declare i1 @llvm.type.test(i8*, metadata) +declare void @llvm.assume(i1) + +attributes #0 = { noinline optnone } + +!0 = !{i64 16, !"_ZTS1A"} +!1 = !{i64 16, !"_ZTS1B"} |
