No change in this commit, but clang was changed to also produce trivial comdats when
needed.
Original message:
Don't create new comdats in CodeGen.
This patch stops the implicit creation of comdats during codegen.
Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.
llvm-svn: 226467
return false;
}
+static bool hasImplicitComdat(size_t Val) {
+ switch (Val) {
+ default:
+ return false;
+ case 1: // Old WeakAnyLinkage
+ case 4: // Old LinkOnceAnyLinkage
+ case 10: // Old WeakODRLinkage
+ case 11: // Old LinkOnceODRLinkage
+ return true;
+ }
+}
+
static GlobalValue::LinkageTypes getDecodedLinkage(unsigned Val) {
switch (Val) {
default: // Map unknown/new linkages to external
case 0:
return GlobalValue::ExternalLinkage;
- case 1:
- return GlobalValue::WeakAnyLinkage;
case 2:
return GlobalValue::AppendingLinkage;
case 3:
return GlobalValue::InternalLinkage;
- case 4:
- return GlobalValue::LinkOnceAnyLinkage;
case 5:
return GlobalValue::ExternalLinkage; // Obsolete DLLImportLinkage
case 6:
return GlobalValue::CommonLinkage;
case 9:
return GlobalValue::PrivateLinkage;
- case 10:
- return GlobalValue::WeakODRLinkage;
- case 11:
- return GlobalValue::LinkOnceODRLinkage;
case 12:
return GlobalValue::AvailableExternallyLinkage;
case 13:
return GlobalValue::PrivateLinkage; // Obsolete LinkerPrivateWeakLinkage
case 15:
return GlobalValue::ExternalLinkage; // Obsolete LinkOnceODRAutoHideLinkage
+ case 1: // Old value with implicit comdat.
+ case 16:
+ return GlobalValue::WeakAnyLinkage;
+ case 10: // Old value with implicit comdat.
+ case 17:
+ return GlobalValue::WeakODRLinkage;
+ case 4: // Old value with implicit comdat.
+ case 18:
+ return GlobalValue::LinkOnceAnyLinkage;
+ case 11: // Old value with implicit comdat.
+ case 19:
+ return GlobalValue::LinkOnceODRLinkage;
}
}
Value *V = ValueList[ValueID];
V->setName(StringRef(ValueName.data(), ValueName.size()));
+ if (auto *GO = dyn_cast<GlobalObject>(V)) {
+ if (GO->getComdat() == reinterpret_cast<Comdat *>(1))
+ GO->setComdat(TheModule->getOrInsertComdat(V->getName()));
+ }
ValueName.clear();
break;
}
Ty = cast<PointerType>(Ty)->getElementType();
bool isConstant = Record[1];
- GlobalValue::LinkageTypes Linkage = getDecodedLinkage(Record[3]);
+ uint64_t RawLinkage = Record[3];
+ GlobalValue::LinkageTypes Linkage = getDecodedLinkage(RawLinkage);
unsigned Alignment = (1 << Record[4]) >> 1;
std::string Section;
if (Record[5]) {
if (Record.size() > 10)
NewGV->setDLLStorageClass(GetDecodedDLLStorageClass(Record[10]));
else
- UpgradeDLLImportExportLinkage(NewGV, Record[3]);
+ UpgradeDLLImportExportLinkage(NewGV, RawLinkage);
ValueList.push_back(NewGV);
if (unsigned InitID = Record[2])
GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
- if (Record.size() > 11)
+ if (Record.size() > 11) {
if (unsigned ComdatID = Record[11]) {
assert(ComdatID <= ComdatList.size());
NewGV->setComdat(ComdatList[ComdatID - 1]);
}
+ } else if (hasImplicitComdat(RawLinkage)) {
+ NewGV->setComdat(reinterpret_cast<Comdat *>(1));
+ }
break;
}
// FUNCTION: [type, callingconv, isproto, linkage, paramattr,
Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
bool isProto = Record[2];
- Func->setLinkage(getDecodedLinkage(Record[3]));
+ uint64_t RawLinkage = Record[3];
+ Func->setLinkage(getDecodedLinkage(RawLinkage));
Func->setAttributes(getAttributes(Record[4]));
Func->setAlignment((1 << Record[5]) >> 1);
if (Record.size() > 11)
Func->setDLLStorageClass(GetDecodedDLLStorageClass(Record[11]));
else
- UpgradeDLLImportExportLinkage(Func, Record[3]);
+ UpgradeDLLImportExportLinkage(Func, RawLinkage);
- if (Record.size() > 12)
+ if (Record.size() > 12) {
if (unsigned ComdatID = Record[12]) {
assert(ComdatID <= ComdatList.size());
Func->setComdat(ComdatList[ComdatID - 1]);
}
+ } else if (hasImplicitComdat(RawLinkage)) {
+ Func->setComdat(reinterpret_cast<Comdat *>(1));
+ }
if (Record.size() > 13 && Record[13] != 0)
FunctionPrefixes.push_back(std::make_pair(Func, Record[13]-1));
case GlobalValue::ExternalLinkage:
return 0;
case GlobalValue::WeakAnyLinkage:
- return 1;
+ return 16;
case GlobalValue::AppendingLinkage:
return 2;
case GlobalValue::InternalLinkage:
return 3;
case GlobalValue::LinkOnceAnyLinkage:
- return 4;
+ return 18;
case GlobalValue::ExternalWeakLinkage:
return 7;
case GlobalValue::CommonLinkage:
case GlobalValue::PrivateLinkage:
return 9;
case GlobalValue::WeakODRLinkage:
- return 10;
+ return 17;
case GlobalValue::LinkOnceODRLinkage:
- return 11;
+ return 19;
case GlobalValue::AvailableExternallyLinkage:
return 12;
}
Log2_32_Ceil(MaxGlobalType+1)));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constant.
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Initializer.
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // Linkage.
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
if (MaxAlignment == 0) // Alignment.
Abbv->Add(BitCodeAbbrevOp(0));
else {
// If this global is linkonce/weak and the target handles this by emitting it
// into a 'uniqued' section name, create and return the section now.
- if ((GV->isWeakForLinker() || EmitUniquedSection || GV->hasComdat()) &&
- !Kind.isCommon()) {
+ if ((EmitUniquedSection && !Kind.isCommon()) || GV->hasComdat()) {
StringRef Prefix = getSectionPrefixForGlobal(Kind);
SmallString<128> Name(Prefix);
StringRef Group = "";
unsigned Flags = getELFSectionFlags(Kind);
- if (GV->isWeakForLinker() || GV->hasComdat()) {
- if (const Comdat *C = getELFComdat(GV))
- Group = C->getName();
- else
- Group = Name.substr(Prefix.size());
+ if (const Comdat *C = getELFComdat(GV)) {
Flags |= ELF::SHF_GROUP;
+ Group = C->getName();
}
return getContext().getELFSection(Name.str(),
unsigned Characteristics = getCOFFSectionFlags(Kind);
StringRef Name = GV->getSection();
StringRef COMDATSymName = "";
- if ((GV->isWeakForLinker() || GV->hasComdat()) && !Kind.isCommon()) {
+ if (GV->hasComdat()) {
Selection = getSelectionForCOFF(GV);
const GlobalValue *ComdatGV;
if (Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
else
EmitUniquedSection = TM.getDataSections();
- // If this global is linkonce/weak and the target handles this by emitting it
- // into a 'uniqued' section name, create and return the section now.
- // Section names depend on the name of the symbol which is not feasible if the
- // symbol has private linkage.
- if ((GV->isWeakForLinker() || EmitUniquedSection || GV->hasComdat()) &&
- !Kind.isCommon()) {
+ if ((EmitUniquedSection && !Kind.isCommon()) || GV->hasComdat()) {
const char *Name = getCOFFSectionNameForUniqueGlobal(Kind);
unsigned Characteristics = getCOFFSectionFlags(Kind);
OutContext));
if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
GV->hasCommonLinkage()) {
- // TODO Use COMDAT groups for LinkOnceLinkage
OutStreamer.EmitSymbolAttribute(SymGlob, MCSA_Weak);
}
}
emitArrayBound(GVSym, GV);
OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
- // TODO Use COMDAT groups for LinkOnceLinkage
if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
GV->hasCommonLinkage())
OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
; CHECK: @available_externally.var = available_externally constant i32 0{{$}}
@linkonce.var = linkonce constant i32 0
-; CHECK: @linkonce.var = linkonce constant i32 0{{$}}
+; CHECK: @linkonce.var = linkonce constant i32 0, comdat{{$}}
@weak.var = weak constant i32 0
-; CHECK: @weak.var = weak constant i32 0{{$}}
+; CHECK: @weak.var = weak constant i32 0, comdat{{$}}
@linkonce_odr.var = linkonce_odr constant i32 0
-; CHECK: @linkonce_odr.var = linkonce_odr constant i32 0{{$}}
+; CHECK: @linkonce_odr.var = linkonce_odr constant i32 0, comdat{{$}}
@linkonce_odr_auto_hide.var = linkonce_odr_auto_hide constant i32 0
; CHECK: @linkonce_odr_auto_hide.var = constant i32 0{{$}}
}
define linkonce void @linkonce()
-; CHECK: define linkonce void @linkonce() {
+; CHECK: define linkonce void @linkonce() comdat {
{
ret void
}
define weak void @weak()
-; CHECK: define weak void @weak() {
+; CHECK: define weak void @weak() comdat {
{
ret void
}
define linkonce_odr void @linkonce_odr()
-; CHECK: define linkonce_odr void @linkonce_odr() {
+; CHECK: define linkonce_odr void @linkonce_odr() comdat {
{
ret void
}
+++ /dev/null
-; RUN: llc < %s -mtriple=arm-linux-gnueabi | FileCheck %s -check-prefix=ARMGNUEABI
-
-; Checking that a comdat group gets generated correctly for a static member
-; of instantiated C++ templates.
-; see http://sourcery.mentor.com/public/cxx-abi/abi.html#vague-itemplate
-; section 5.2.6 Instantiated templates
-; "Any static member data object is emitted in a COMDAT identified by its mangled
-; name, in any object file with a reference to its name symbol."
-
-; Case 1: variable is not explicitly initialized, and ends up in a .bss section
-; ARMGNUEABI: .section .bss._ZN1CIiE1iE,"aGw",%nobits,_ZN1CIiE1iE,comdat
-@_ZN1CIiE1iE = weak_odr global i32 0, align 4
-
-; Case 2: variable is explicitly initialized, and ends up in a .data section
-; ARMGNUEABI: .section .data._ZN1CIiE1jE,"aGw",%progbits,_ZN1CIiE1jE,comdat
-@_ZN1CIiE1jE = weak_odr global i32 12, align 4
ret void
}
-; CHECK: .section .text.test3,"axG",%progbits,test3,comdat
+; CHECK: .text
; CHECK: .weak test3
; CHECK: .type test3,%function
define linkonce_odr void @test3() {
ret void
}
-; CHECK: .section .text,"xr",discard,lnk1
; CHECK: .globl lnk1
define linkonce_odr dllexport void @lnk1() {
ret void
}
-; CHECK: .section .text,"xr",discard,lnk2
; CHECK: .globl lnk2
define linkonce_odr dllexport void @lnk2() alwaysinline {
ret void
}
-; CHECK: .section .text,"xr",discard,weak1
; CHECK: .globl weak1
define weak_odr dllexport void @weak1() {
ret void
; CHECK: .comm Var3
@Var3 = common dllexport global i32 0, align 4
-; CHECK: .section .data,"wd",discard,WeakVar1
; CHECK: .globl WeakVar1
@WeakVar1 = weak_odr dllexport global i32 1, align 4
-; CHECK: .section .rdata,"rd",discard,WeakVar2
; CHECK: .globl WeakVar2
@WeakVar2 = weak_odr dllexport unnamed_addr constant i32 1
ret void
}
-; CHECK: .section .text,"xr",discard,_lnk1
; CHECK: .globl _lnk1
define linkonce_odr dllexport void @lnk1() {
ret void
}
-; CHECK: .section .text,"xr",discard,_lnk2
; CHECK: .globl _lnk2
define linkonce_odr dllexport void @lnk2() alwaysinline {
ret void
}
-; CHECK: .section .text,"xr",discard,_weak1
; CHECK: .globl _weak1
define weak_odr dllexport void @weak1() {
ret void
; CHECK: .comm _Var3
@Var3 = common dllexport global i32 0, align 4
-; CHECK: .section .data,"wd",discard,_WeakVar1
; CHECK: .globl _WeakVar1
@WeakVar1 = weak_odr dllexport global i32 1, align 4
-; CHECK: .section .rdata,"rd",discard,_WeakVar2
; CHECK: .globl _WeakVar2
@WeakVar2 = weak_odr dllexport unnamed_addr constant i32 1
@"foo bar" = linkonce global i32 42
; LINUX: .type "foo bar",@object
-; LINUX: .section ".data.foo bar","aGw",@progbits,"foo bar",comdat
; LINUX: .weak "foo bar"
; LINUX: "foo bar":
@G6 = weak_odr unnamed_addr constant [1 x i8] c"\01"
; LINUX: .type G6,@object
-; LINUX: .section .rodata.G6,"aG",@progbits,G6,comdat
; LINUX: .weak G6
; LINUX: G6:
; LINUX: .byte 1
+++ /dev/null
-; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s -check-prefix=X86LINUX
-
-; Checking that a comdat group gets generated correctly for a static member
-; of instantiated C++ templates.
-; see http://sourcery.mentor.com/public/cxx-abi/abi.html#vague-itemplate
-; section 5.2.6 Instantiated templates
-; "Any static member data object is emitted in a COMDAT identified by its mangled
-; name, in any object file with a reference to its name symbol."
-
-; Case 1: variable is not explicitly initialized, and ends up in a .bss section
-; X86LINUX: .section .bss._ZN1CIiE1iE,"aGw",@nobits,_ZN1CIiE1iE,comdat
-@_ZN1CIiE1iE = weak_odr global i32 0, align 4
-
-; Case 2: variable is explicitly initialized, and ends up in a .data section
-; X86LINUX: .section .data._ZN1CIiE1jE,"aGw",@progbits,_ZN1CIiE1jE,comdat
-@_ZN1CIiE1jE = weak_odr global i32 12, align 4
declare void @_Z3bari(i32)
-; CHECK-LINUX: .text._Z3fooILi1EEvi,"axG",@progbits,_Z3fooILi1EEvi,comdat
+; CHECK-LINUX: _Z3fooILi1EEvi:
define linkonce void @_Z3fooILi1EEvi(i32 %Y) nounwind {
entry:
; CHECK: L0$pb
@"\01?thingy@@3Ufoo@@B" = global %struct.foo zeroinitializer, align 4
; CHECK: .bss
-@thingy_linkonce = linkonce_odr global %struct.foo zeroinitializer, align 4
+$thingy_linkonce = comdat any
+@thingy_linkonce = linkonce_odr global %struct.foo zeroinitializer, comdat, align 4
; CHECK: .section .bss,"wb",discard,_thingy_linkonce
; CHECK: .section .CRT$XLB,"rd"
@weak_array = weak_odr unnamed_addr constant [1 x i8*] [i8* bitcast (void ()* @f to i8*)]
-; CHECK: .section .rdata,"rd",discard,weak_array
+; CHECK: .section .rdata,"rd"
+++ /dev/null
-; Test that weak functions and globals are placed into selectany COMDAT\r
-; sections with the mangled name as suffix. Ensure that the weak linkage\r
-; type is not ignored by the backend if the section was specialized.\r
-;\r
-; RUN: llc -mtriple=i686-pc-win32 %s -o - | FileCheck %s --check-prefix=X86\r
-; RUN: llc -mtriple=i686-pc-mingw32 %s -o - | FileCheck %s --check-prefix=X86\r
-; RUN: llc -mtriple=x86_64-pc-win32 %s -o - | FileCheck %s --check-prefix=X64\r
-; RUN: llc -mtriple=x86_64-pc-mingw32 %s -o - | FileCheck %s --check-prefix=X64\r
-\r
-; Mangled function\r
-; X86: .section .text,"xr",discard,__Z3foo\r
-; X86: .globl __Z3foo\r
-;\r
-; X64: .section .text,"xr",discard,_Z3foo\r
-; X64: .globl _Z3foo\r
-define weak void @_Z3foo() {\r
- ret void\r
-}\r
-\r
-; Unmangled function\r
-; X86: .section .sect,"xr",discard,_f\r
-; X86: .globl _f\r
-;\r
-; X64: .section .sect,"xr",discard,f\r
-; X64: .globl f\r
-define weak void @f() section ".sect" {\r
- ret void\r
-}\r
-\r
-; Weak global\r
-; X86: .section .data,"rd",discard,_a\r
-; X86: .globl _a\r
-; X86: .zero 12\r
-;\r
-; X64: .section .data,"rd",discard,a\r
-; X64: .globl a\r
-; X64: .zero 12\r
-@a = weak unnamed_addr constant { i32, i32, i32 } { i32 0, i32 0, i32 0}, section ".data"\r
-\r
-; X86: .section .tls$,"wd",discard,_b\r
-; X86: .globl _b\r
-; X86: .long 0\r
-;\r
-; X64: .section .tls$,"wd",discard,b\r
-; X64: .globl b\r
-; X64: .long 0\r
-\r
-@b = weak_odr thread_local global i32 0, align 4\r