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[WholeProgramDevirt] Don't process declarations when building type id map
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Authored by evgeny777 on Sep 17 2018, 8:14 AM.

Reviewers

tejohnson
pcc

Commits

Summary

IRMover can sometimes copy GV attributes, but not initialiser. In particular this happens when GV is marked dead in combined summary.

In your summary, I think you mean it can copy metadata (not attributes)?

Otherwise LGTM

This revision is now accepted and ready to land.Sep 19 2018, 8:28 AM

This revision was automatically updated to reflect the committed changes.

Path

Size

lib/

Transforms/

IPO/

2 lines

test/

Transforms/

WholeProgramDevirt/

25 lines

Show First 20 Lines • Show All 659 Lines • ▼ Show 20 Lines	void DevirtModule::buildTypeIdentifierMap(
std::vector<VTableBits> &Bits,		std::vector<VTableBits> &Bits,
DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap) {		DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap) {
DenseMap<GlobalVariable , VTableBits > GVToBits;		DenseMap<GlobalVariable , VTableBits > GVToBits;
Bits.reserve(M.getGlobalList().size());		Bits.reserve(M.getGlobalList().size());
SmallVector<MDNode *, 2> Types;		SmallVector<MDNode *, 2> Types;
for (GlobalVariable &GV : M.globals()) {		for (GlobalVariable &GV : M.globals()) {
Types.clear();		Types.clear();
GV.getMetadata(LLVMContext::MD_type, Types);		GV.getMetadata(LLVMContext::MD_type, Types);
if (Types.empty())		if (GV.isDeclaration() \|\| Types.empty())
continue;		continue;

VTableBits *&BitsPtr = GVToBits[&GV];		VTableBits *&BitsPtr = GVToBits[&GV];
if (!BitsPtr) {		if (!BitsPtr) {
Bits.emplace_back();		Bits.emplace_back();
Bits.back().GV = &GV;		Bits.back().GV = &GV;
Bits.back().ObjectSize =		Bits.back().ObjectSize =
M.getDataLayout().getTypeAllocSize(GV.getInitializer()->getType());		M.getDataLayout().getTypeAllocSize(GV.getInitializer()->getType());
▲ Show 20 Lines • Show All 1,013 Lines • Show Last 20 Lines

				; Check that we don't crash when processing declaration with type metadata
				; RUN: opt -S -wholeprogramdevirt %s

				target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
				target triple = "x86_64-none-linux-gnu"

				declare i1 @llvm.type.test(i8*, metadata)
				declare void @llvm.assume(i1)

				@_ZTVN3foo3barE = external dso_local unnamed_addr constant { [8 x i8*] }, align 8, !type !0

				define i1 @call1(i8* %obj) {
				%vtableptr = bitcast i8* %obj to [3 x i8]*
				%vtable = load [3 x i8], [3 x i8]* %vtableptr
				%vtablei8 = bitcast [3 x i8] %vtable to i8*
				%p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid")
				call void @llvm.assume(i1 %p)
				%fptrptr = getelementptr [3 x i8], [3 x i8]* %vtable, i32 0, i32 0
				%fptr = load i8, i8* %fptrptr
				%fptr_casted = bitcast i8* %fptr to i1 (i8)
				%result = call i1 %fptr_casted(i8* %obj)
				ret i1 %result
				}

				!0 = !{i64 16, !"_ZTSN3foo3barE"}