Simplify WPD test case for hybrid LTO and thinTLO.

[mingmingl]

Summary

1. remove verbose information (function linkage types, alignment, TBAA) 2) remove unused element or replace irrelevant element with null (as placeholders) in virtual table, remove unused definitions of deleted elements accordingly.

[mingmingl]

Hi Teresa,

I'm taking the liberty to create a separate revision for clean-ups.

[mingmingl]

resolve No newline at end of file by using a different editor

[tejohnson]

lgtm with another possible cleanup noted below.

llvm/test/ThinLTO/X86/Inputs/devirt_after_filtering_unreachable_lib.ll

37–38

I think the ".virtual" type metadata can also be removed here and below.

[mingmingl]

Remove ".virtual" type metadata.

[mingmingl]

thanks for review!

llvm/test/ThinLTO/X86/Inputs/devirt_after_filtering_unreachable_lib.ll

 ; ModuleID = 'lib.cc'
 source_filename = "lib.cc"
 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"
 
-%class.Derived = type { %class.Base }
-%class.Base = type { i32 (...)** }
+%Derived = type { %Base }
+%Base = type { i32 (...)** }
 
-$_ZN7DerivedD2Ev = comdat any
+@_ZTV7Derived = constant { [3 x i8*] } { [3 x i8*] [i8* null, i8* null, i8* bitcast (void (%Derived*)* @_ZN7DerivedD0Ev to i8*)] }, !type !0, !type !1, !vcall_visibility !2
+@_ZTV4Base = constant { [3 x i8*] } { [3 x i8*] [i8* null, i8* null, i8* bitcast (void (%Base*)* @_ZN4BaseD0Ev to i8*)] }, !type !0, !vcall_visibility !2
 
-$_ZN7DerivedD0Ev = comdat any
-
-$_ZN4BaseD2Ev = comdat any
-
-$_ZN4BaseD0Ev = comdat any
-
-$_ZTS4Base = comdat any
-
-$_ZTI4Base = comdat any
-
-$_ZTV4Base = comdat any
-
-@_ZTV7Derived = hidden unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8*, i8* }* @_ZTI7Derived to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7DerivedD2Ev to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7DerivedD0Ev to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7Derived1xEv to i8*)] }, align 8, !type !0, !type !1, !type !2, !type !3, !vcall_visibility !4
-@_ZTVN10__cxxabiv120__si_class_type_infoE = external dso_local global i8*
-@_ZTS7Derived = hidden constant [9 x i8] c"7Derived\00", align 1
-@_ZTVN10__cxxabiv117__class_type_infoE = external dso_local global i8*
-@_ZTS4Base = linkonce_odr hidden constant [6 x i8] c"4Base\00", comdat, align 1
-@_ZTI4Base = 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 ([6 x i8], [6 x i8]* @_ZTS4Base, i32 0, i32 0) }, comdat, align 8
-@_ZTI7Derived = hidden constant { i8*, i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv120__si_class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([9 x i8], [9 x i8]* @_ZTS7Derived, i32 0, i32 0), i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*) }, align 8
-@_ZTV4Base = linkonce_odr hidden unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD2Ev to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD0Ev to i8*), i8* bitcast (void ()* @__cxa_pure_virtual to i8*)] }, comdat, align 8, !type !0, !type !1, !vcall_visibility !4
-@str = private unnamed_addr constant [11 x i8] c"Derived::x\00", align 1
-@str.3 = private unnamed_addr constant [23 x i8] c"In Derived::~Derived()\00", align 1
-@str.4 = private unnamed_addr constant [17 x i8] c"In Base::~Base()\00", align 1
-
-; Function Attrs: mustprogress nofree nounwind uwtable
-define hidden void @_ZN7Derived1xEv(%class.Derived* nocapture nonnull readnone align 8 %this) unnamed_addr align 2 {
+define void @_Z3fooP4Base(%Base* %b) {
 entry:
-  %puts = tail call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([11 x i8], [11 x i8]* @str, i64 0, i64 0))
-  ret void
-}
-
-; Function Attrs: mustprogress nounwind uwtable
-define hidden void @_Z3fooP4Base(%class.Base* %b) local_unnamed_addr {
-entry:
-  %isnull = icmp eq %class.Base* %b, null
-  br i1 %isnull, label %delete.end, label %delete.notnull
-
-delete.notnull:                                   ; preds = %entry
-  %0 = bitcast %class.Base* %b to void (%class.Base*)***
-  %vtable = load void (%class.Base*)**, void (%class.Base*)*** %0, align 8, !tbaa !9
-  %1 = bitcast void (%class.Base*)** %vtable to i8*
+  %0 = bitcast %Base* %b to void (%Base*)***
+  %vtable = load void (%Base*)**, void (%Base*)*** %0
+  %1 = bitcast void (%Base*)** %vtable to i8*
   %2 = tail call i1 @llvm.type.test(i8* %1, metadata !"_ZTS4Base")
   tail call void @llvm.assume(i1 %2)
-  %vfn = getelementptr inbounds void (%class.Base*)*, void (%class.Base*)** %vtable, i64 1
-  %3 = load void (%class.Base*)*, void (%class.Base*)** %vfn, align 8
-  tail call void %3(%class.Base* nonnull align 8 dereferenceable(8) %b)
-  br label %delete.end
-
-delete.end:                                       ; preds = %delete.notnull, %entry
+  %vfn = getelementptr inbounds void (%Base*)*, void (%Base*)** %vtable, i64 0
+  %3 = load void (%Base*)*, void (%Base*)** %vfn
+  tail call void %3(%Base* %b)
   ret void
 }
 
 declare i1 @llvm.type.test(i8*, metadata)
 
-declare void @llvm.assume(i1 noundef)
-
-define linkonce_odr hidden void @_ZN7DerivedD2Ev(%class.Derived* nonnull align 8 dereferenceable(8) %this) unnamed_addr comdat align 2 {
-entry:
-  %0 = getelementptr inbounds %class.Derived, %class.Derived* %this, i64 0, i32 0, i32 0
-  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV7Derived, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8, !tbaa !9
-  %puts = tail call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([23 x i8], [23 x i8]* @str.3, i64 0, i64 0))
-  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV4Base, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8, !tbaa !9
-  %puts.i = tail call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @str.4, i64 0, i64 0))
-  ret void
-}
-
-; Function Attrs: nounwind uwtable
-define linkonce_odr hidden void @_ZN7DerivedD0Ev(%class.Derived* nonnull align 8 dereferenceable(8) %this) unnamed_addr comdat align 2 {
-entry:
-  %0 = getelementptr inbounds %class.Derived, %class.Derived* %this, i64 0, i32 0, i32 0
-  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV7Derived, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8, !tbaa !9
-  %puts.i = tail call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([23 x i8], [23 x i8]* @str.3, i64 0, i64 0))
-  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV4Base, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8, !tbaa !9
-  %puts.i.i = tail call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @str.4, i64 0, i64 0))
-  %1 = bitcast %class.Derived* %this to i8*
-  tail call void @_ZdlPv(i8* nonnull %1)
-  ret void
-}
+declare void @llvm.assume(i1)
 
-; Function Attrs: nounwind uwtable
-define linkonce_odr hidden void @_ZN4BaseD2Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr comdat align 2 {
-entry:
-  %0 = getelementptr inbounds %class.Base, %class.Base* %this, i64 0, i32 0
-  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV4Base, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8, !tbaa !9
-  %puts = tail call i32 @puts(i8* nonnull dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @str.4, i64 0, i64 0))
+define void @_ZN7DerivedD0Ev(%Derived* %this) {
   ret void
 }
 
-; Function Attrs: nounwind uwtable
-define linkonce_odr hidden void @_ZN4BaseD0Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr comdat align 2 {
-entry:
-  tail call void @llvm.trap()
+define void @_ZN4BaseD0Ev(%Base* %this) {
   unreachable
 }
 
-declare dso_local void @__cxa_pure_virtual() unnamed_addr
-
-declare void @llvm.trap()
-
-declare dso_local void @_ZdlPv(i8*) local_unnamed_addr
-
-declare noundef i32 @puts(i8* nocapture noundef readonly) local_unnamed_addr
-
-!llvm.module.flags = !{!5, !6, !7}
-
 !0 = !{i64 16, !"_ZTS4Base"}
-!1 = !{i64 32, !"_ZTSM4BaseFvvE.virtual"}
-!2 = !{i64 16, !"_ZTS7Derived"}
-!3 = !{i64 32, !"_ZTSM7DerivedFvvE.virtual"}
-!4 = !{i64 1}
-!5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{i32 1, !"Virtual Function Elim", i32 0}
-!7 = !{i32 7, !"uwtable", i32 1}
-!9 = !{!10, !10, i64 0}
-!10 = !{!"vtable pointer", !11, i64 0}
-!11 = !{!"Simple C++ TBAA"}
+!1 = !{i64 16, !"_ZTS7Derived"}
+!2 = !{i64 1}

llvm/test/ThinLTO/X86/devirt_after_filtering_unreachable.ll

 ; Test that unreachable functions are ignored by WPD in hybrid LTO, and thin LTO.
 ; In this test case, the unreachable function is the virtual deleting destructor of an abstract class.
 
 ; Generate split module with summary for hybrid Regular LTO WPD
 ; RUN: opt -thinlto-bc -thinlto-split-lto-unit %s -o %t-main.bc
 ; RUN: opt -thinlto-bc -thinlto-split-lto-unit %p/Inputs/devirt_after_filtering_unreachable_lib.ll -o %t-foo.bc
 
 ; Check that deleting destructor of pure virtual class is unreachable.
 
 ; Check that deleting destructor of pure virtual class is unreachable.
 ; RUN: llvm-modextract -b -n=0 %t-foo.bc -o %t-foo.bc.0
 ; RUN: llvm-dis -o - %t-foo.bc.0 | FileCheck %s --check-prefix=UNREACHABLEFLAG
 
 ; Tests that devirtualization happens.
 ; RUN: llvm-lto2 run -save-temps %t-main.bc %t-foo.bc -pass-remarks=. -o %t \
 ; RUN:   -whole-program-visibility \
-; RUN:   -r=%t-foo.bc,_ZN7Derived1xEv,pl \
-; RUN:   -r=%t-foo.bc,puts, \
 ; RUN:   -r=%t-foo.bc,_Z3fooP4Base,pl \
-; RUN:   -r=%t-foo.bc,_ZN7DerivedD2Ev,pl \
 ; RUN:   -r=%t-foo.bc,_ZN7DerivedD0Ev,pl \
-; RUN:   -r=%t-foo.bc,_ZN4BaseD2Ev,pl \
 ; RUN:   -r=%t-foo.bc,_ZN4BaseD0Ev,pl \
-; RUN:   -r=%t-foo.bc,__cxa_pure_virtual, \
-; RUN:   -r=%t-foo.bc,_ZdlPv, \
 ; RUN:   -r=%t-foo.bc,_ZTV7Derived,l \
-; RUN:   -r=%t-foo.bc,_ZTVN10__cxxabiv120__si_class_type_infoE, \
-; RUN:   -r=%t-foo.bc,_ZTS7Derived,pl \
-; RUN:   -r=%t-foo.bc,_ZTVN10__cxxabiv117__class_type_infoE, \
-; RUN:   -r=%t-foo.bc,_ZTS4Base,pl \
-; RUN:   -r=%t-foo.bc,_ZTI4Base,pl \
-; RUN:   -r=%t-foo.bc,_ZTI7Derived,pl \
 ; RUN:   -r=%t-foo.bc,_ZTV4Base,l \
-; RUN:   -r=%t-foo.bc,__cxa_pure_virtual, \
-; RUN:   -r=%t-foo.bc,_ZN7Derived1xEv, \
-; RUN:   -r=%t-foo.bc,_ZN7DerivedD2Ev, \
 ; RUN:   -r=%t-foo.bc,_ZN7DerivedD0Ev, \
-; RUN:   -r=%t-foo.bc,_ZN4BaseD2Ev, \
 ; RUN:   -r=%t-foo.bc,_ZN4BaseD0Ev, \
 ; RUN:   -r=%t-foo.bc,_ZTV7Derived,pl \
-; RUN:   -r=%t-foo.bc,_ZTI4Base, \
-; RUN:   -r=%t-foo.bc,_ZTI7Derived, \
 ; RUN:   -r=%t-foo.bc,_ZTV4Base,pl \
 ; RUN:   -r=%t-main.bc,main,plx \
 ; RUN:   -r=%t-main.bc,_Znwm,pl \
 ; RUN:   -r=%t-main.bc,_Z3fooP4Base, \
 ; RUN:   -r=%t-main.bc,_ZTV7Derived, 2>&1 | FileCheck %s --check-prefix=REMARK
  
 ; REMARK-COUNT-1: single-impl: devirtualized a call to _ZN7DerivedD0Ev
 
 ; Generate unsplit module with summary for ThinLTO index-based WPD.
 ; RUN: opt -thinlto-bc -o %t3.o %s
 
 ; Check that deleting destructor of pure virtual class is unreachable.
 ; RUN: opt -thinlto-bc -o %t4.o %p/Inputs/devirt_after_filtering_unreachable_lib.ll
 ; RUN: llvm-dis -o - %t4.o | FileCheck %s --check-prefix=UNREACHABLEFLAG
 
 ; UNREACHABLEFLAG: gv: (name: "_ZN4BaseD0Ev", {{.*}}, funcFlags: ({{.*}} mustBeUnreachable: 1
 
 ; Test that devirtualized happen in index based WPD
 ; RUN: llvm-lto2 run %t4.o %t3.o -save-temps -pass-remarks=. \
 ; RUN:   -whole-program-visibility \
 ; RUN:   -wholeprogramdevirt-print-index-based \
 ; RUN:   -o %t5 \
-; RUN:   -r=%t4.o,_ZN7Derived1xEv,pl \
-; RUN:   -r=%t4.o,puts, \
 ; RUN:   -r=%t4.o,_Z3fooP4Base,pl \
-; RUN:   -r=%t4.o,_ZN7DerivedD2Ev,pl \
 ; RUN:   -r=%t4.o,_ZN7DerivedD0Ev,pl \
-; RUN:   -r=%t4.o,_ZN4BaseD2Ev,pl \
 ; RUN:   -r=%t4.o,_ZN4BaseD0Ev,pl \
-; RUN:   -r=%t4.o,__cxa_pure_virtual, \
-; RUN:   -r=%t4.o,_ZdlPv, \
 ; RUN:   -r=%t4.o,_ZTV7Derived,pl \
-; RUN:   -r=%t4.o,_ZTVN10__cxxabiv120__si_class_type_infoE, \
-; RUN:   -r=%t4.o,_ZTS7Derived,pl \
-; RUN:   -r=%t4.o,_ZTVN10__cxxabiv117__class_type_infoE, \
-; RUN:   -r=%t4.o,_ZTS4Base,pl \
-; RUN:   -r=%t4.o,_ZTI4Base,pl \
-; RUN:   -r=%t4.o,_ZTI7Derived,pl \
 ; RUN:   -r=%t4.o,_ZTV4Base,pl \
 ; RUN:   -r=%t3.o,main,plx \
 ; RUN:   -r=%t3.o,_Znwm, \
 ; RUN:   -r=%t3.o,_Z3fooP4Base, \
 ; RUN:   -r=%t3.o,_ZTV7Derived,  2>&1 | FileCheck %s --check-prefix=THINREMARK
 
 ; THINREMARK: Devirtualized call to {{.*}} (_ZN7DerivedD0Ev)
 ; THINREMARK: single-impl: devirtualized a call to _ZN7DerivedD0Ev
 ; THINREMARK: single-impl: devirtualized a call to _ZN7DerivedD0Ev
 
 ; ModuleID = 'tmp.cc'
 source_filename = "tmp.cc"
 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"
 
-%class.Derived = type { %class.Base }
-%class.Base = type { i32 (...)** }
+%Derived = type { %Base }
+%Base = type { i32 (...)** }
 
-@_ZTV7Derived = external dso_local unnamed_addr constant { [5 x i8*] }, align 8
+@_ZTV7Derived = external constant { [5 x i8*] }
 
-define hidden i32 @main() local_unnamed_addr {
+define hidden i32 @main() {
 entry:
-  %call = tail call noalias nonnull dereferenceable(8) i8* @_Znwm(i64 8)
-  %0 = bitcast i8* %call to %class.Derived*
-  %1 = getelementptr inbounds %class.Derived, %class.Derived* %0, i64 0, i32 0, i32 0
-  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV7Derived, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %1, align 8, !tbaa !4
-  %2 = getelementptr %class.Derived, %class.Derived* %0, i64 0, i32 0
-  tail call void @_Z3fooP4Base(%class.Base* nonnull %2)
+  %call = tail call i8* @_Znwm(i64 8)
+  %0 = bitcast i8* %call to %Derived*
+  %1 = getelementptr inbounds %Derived, %Derived* %0, i64 0, i32 0, i32 0
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV7Derived, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %1
+  %2 = getelementptr %Derived, %Derived* %0, i64 0, i32 0
+  tail call void @_Z3fooP4Base(%Base* nonnull %2)
   ret i32 0
 }
 
-declare dso_local nonnull i8* @_Znwm(i64) local_unnamed_addr
+declare i8* @_Znwm(i64)
 
-declare dso_local void @_Z3fooP4Base(%class.Base*) local_unnamed_addr
-
-!llvm.module.flags = !{!0, !1, !2}
-
-!0 = !{i32 1, !"wchar_size", i32 4}
-!1 = !{i32 1, !"Virtual Function Elim", i32 0}
-!2 = !{i32 7, !"uwtable", i32 1}
-!4 = !{!5, !5, i64 0}
-!5 = !{!"vtable pointer", !6, i64 0}
-!6 = !{!"Simple C++ TBAA"}
+declare void @_Z3fooP4Base(%Base*)