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Differential D52175

[WholeProgramDevirt] Don't process declarations when building type id map
ClosedPublic

Authored by evgeny777 on Sep 17 2018, 8:14 AM.

Details

Reviewers
tejohnson
pcc
Commits
rG2b70d616f057: [WholeProgramDevirt] Don't process declarations when building type id map
rL342836: [WholeProgramDevirt] Don't process declarations when building type id map
Summary

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

Diff Detail

Repository
rL LLVM

Event Timeline

evgeny777 created this revision.Sep 17 2018, 8:14 AM
asl added a subscriber: asl.Sep 17 2018, 1:42 PM
tejohnson accepted this revision.Sep 19 2018, 8:28 AM

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
Closed by commit rL342836: [WholeProgramDevirt] Don't process declarations when building type id map (authored by evgeny777). · Explain WhySep 24 2018, 7:22 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
llvm/
trunk/
lib/
Transforms/
IPO/
2 lines
test/
Transforms/
WholeProgramDevirt/
25 lines

Diff 166668

llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp

Show First 20 Lines • Show All 659 Lines • ▼ Show 20 Linesvoid 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 1,012 Lines • Show Last 20 Lines

llvm/trunk/test/Transforms/WholeProgramDevirt/vtable-decl.ll

; 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"}