r252814 - [TLS on Darwin] change how we handle globals with linkonce or weak linkage.
Manman Ren via cfe-commits
cfe-commits at lists.llvm.org
Wed Nov 11 14:42:31 PST 2015
Author: mren
Date: Wed Nov 11 16:42:31 2015
New Revision: 252814
URL: http://llvm.org/viewvc/llvm-project?rev=252814&view=rev
Log:
[TLS on Darwin] change how we handle globals with linkonce or weak linkage.
This is about how we handle static member of a template. Before this commit,
we use internal linkage for the IR thread-local variable, which is inefficient.
With this commit, we will start to follow Itanium C++ ABI.
rdar://problem/23415206
Reviewed by John McCall.
Modified:
cfe/trunk/lib/CodeGen/CodeGenModule.cpp
cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
cfe/trunk/test/CodeGenCXX/cxx11-thread-local-reference.cpp
cfe/trunk/test/CodeGenCXX/cxx11-thread-local.cpp
cfe/trunk/test/CodeGenCXX/tls-init-funcs.cpp
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=252814&r1=252813&r2=252814&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Wed Nov 11 16:42:31 2015
@@ -2315,12 +2315,17 @@ void CodeGenModule::EmitGlobalVarDefinit
llvm::GlobalValue::LinkageTypes Linkage =
getLLVMLinkageVarDefinition(D, GV->isConstant());
- // On Darwin, the backing variable for a C++11 thread_local variable always
- // has internal linkage; all accesses should just be calls to the
+ // On Darwin, if the normal linkage of a C++ thread_local variable is
+ // LinkOnce or Weak, we keep the normal linkage to prevent multiple
+ // copies within a linkage unit; otherwise, the backing variable has
+ // internal linkage and all accesses should just be calls to the
// Itanium-specified entry point, which has the normal linkage of the
- // variable.
+ // variable. This is to preserve the ability to change the implementation
+ // behind the scenes.
if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
- Context.getTargetInfo().getTriple().isMacOSX())
+ Context.getTargetInfo().getTriple().isMacOSX() &&
+ !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
+ !llvm::GlobalVariable::isWeakLinkage(Linkage))
Linkage = llvm::GlobalValue::InternalLinkage;
GV->setLinkage(Linkage);
Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=252814&r1=252813&r2=252814&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Wed Nov 11 16:42:31 2015
@@ -2163,12 +2163,10 @@ getThreadLocalWrapperLinkage(const VarDe
return VarLinkage;
// If the thread wrapper is replaceable, give it appropriate linkage.
- if (isThreadWrapperReplaceable(VD, CGM)) {
- if (llvm::GlobalVariable::isLinkOnceLinkage(VarLinkage) ||
- llvm::GlobalVariable::isWeakODRLinkage(VarLinkage))
- return llvm::GlobalVariable::WeakAnyLinkage;
- return VarLinkage;
- }
+ if (isThreadWrapperReplaceable(VD, CGM))
+ if (!llvm::GlobalVariable::isLinkOnceLinkage(VarLinkage) &&
+ !llvm::GlobalVariable::isWeakODRLinkage(VarLinkage))
+ return VarLinkage;
return llvm::GlobalValue::WeakODRLinkage;
}
@@ -2194,7 +2192,9 @@ ItaniumCXXABI::getOrCreateThreadLocalWra
llvm::Function::Create(FnTy, getThreadLocalWrapperLinkage(VD, CGM),
WrapperName.str(), &CGM.getModule());
// Always resolve references to the wrapper at link time.
- if (!Wrapper->hasLocalLinkage() && !isThreadWrapperReplaceable(VD, CGM))
+ if (!Wrapper->hasLocalLinkage() && !(isThreadWrapperReplaceable(VD, CGM) &&
+ !llvm::GlobalVariable::isLinkOnceLinkage(Wrapper->getLinkage()) &&
+ !llvm::GlobalVariable::isWeakODRLinkage(Wrapper->getLinkage())))
Wrapper->setVisibility(llvm::GlobalValue::HiddenVisibility);
return Wrapper;
}
Modified: cfe/trunk/test/CodeGenCXX/cxx11-thread-local-reference.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx11-thread-local-reference.cpp?rev=252814&r1=252813&r2=252814&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/cxx11-thread-local-reference.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/cxx11-thread-local-reference.cpp Wed Nov 11 16:42:31 2015
@@ -1,11 +1,14 @@
-// RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
+// RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck --check-prefix=CHECK --check-prefix=LINUX %s
+// RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple x86_64-apple-darwin12 | FileCheck --check-prefix=CHECK --check-prefix=DARWIN %s
int &f();
-// CHECK: @r = thread_local global i32* null
+// LINUX: @r = thread_local global i32* null
+// DARWIN: @r = internal thread_local global i32* null
thread_local int &r = f();
-// CHECK: @_ZTH1r = alias void (), void ()* @__tls_init
+// LINUX: @_ZTH1r = alias void (), void ()* @__tls_init
+// DARWIN: @_ZTH1r = internal alias void (), void ()* @__tls_init
int &g() { return r; }
@@ -17,7 +20,8 @@ int &g() { return r; }
// CHECK: call i32* @_ZTW1r()
// CHECK: ret i32* %{{.*}}
-// CHECK: define weak_odr hidden i32* @_ZTW1r() {
+// LINUX: define weak_odr hidden i32* @_ZTW1r() {
+// DARWIN: define i32* @_ZTW1r() {
// CHECK: call void @_ZTH1r()
// CHECK: load i32*, i32** @r, align 8
// CHECK: ret i32* %{{.*}}
Modified: cfe/trunk/test/CodeGenCXX/cxx11-thread-local.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx11-thread-local.cpp?rev=252814&r1=252813&r2=252814&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/cxx11-thread-local.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/cxx11-thread-local.cpp Wed Nov 11 16:42:31 2015
@@ -1,11 +1,13 @@
-// RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
+// RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck --check-prefix=CHECK --check-prefix=LINUX %s
// RUN: %clang_cc1 -std=c++11 -femulated-tls -emit-llvm %s -o - \
-// RUN: -triple x86_64-linux-gnu 2>&1 | FileCheck --check-prefix=CHECK %s
+// RUN: -triple x86_64-linux-gnu 2>&1 | FileCheck --check-prefix=CHECK --check-prefix=LINUX %s
+// RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple x86_64-apple-darwin12 | FileCheck --check-prefix=CHECK --check-prefix=DARWIN %s
int f();
int g();
-// CHECK: @a = thread_local global i32 0
+// LINUX: @a = thread_local global i32 0
+// DARWIN: @a = internal thread_local global i32 0
thread_local int a = f();
extern thread_local int b;
// CHECK: @c = global i32 0
@@ -14,7 +16,8 @@ int c = b;
static thread_local int d = g();
struct U { static thread_local int m; };
-// CHECK: @_ZN1U1mE = thread_local global i32 0
+// LINUX: @_ZN1U1mE = thread_local global i32 0
+// DARWIN: @_ZN1U1mE = internal thread_local global i32 0
thread_local int U::m = f();
template<typename T> struct V { static thread_local int m; };
@@ -45,9 +48,11 @@ int e = V<int>::m;
// CHECK: @llvm.global_ctors = appending global {{.*}} @[[GLOBAL_INIT:[^ ]*]]
-// CHECK: @_ZTH1a = alias void (), void ()* @__tls_init
+// LINUX: @_ZTH1a = alias void (), void ()* @__tls_init
+// DARWIN: @_ZTH1a = internal alias void (), void ()* @__tls_init
// CHECK: @_ZTHL1d = internal alias void (), void ()* @__tls_init
-// CHECK: @_ZTHN1U1mE = alias void (), void ()* @__tls_init
+// LINUX: @_ZTHN1U1mE = alias void (), void ()* @__tls_init
+// DARWIN: @_ZTHN1U1mE = internal alias void (), void ()* @__tls_init
// CHECK: @_ZTHN1VIiE1mE = linkonce_odr alias void (), void ()* @__tls_init
@@ -78,13 +83,15 @@ int f() {
// CHECK-NEXT: load i32, i32* %{{.*}}, align 4
// CHECK-NEXT: store i32 %{{.*}}, i32* @c, align 4
-// CHECK-LABEL: define weak_odr hidden i32* @_ZTW1b()
-// CHECK: br i1 icmp ne (void ()* @_ZTH1b, void ()* null),
+// LINUX-LABEL: define weak_odr hidden i32* @_ZTW1b()
+// LINUX: br i1 icmp ne (void ()* @_ZTH1b, void ()* null),
// not null:
-// CHECK: call void @_ZTH1b()
-// CHECK: br label
+// LINUX: call void @_ZTH1b()
+// LINUX: br label
// finally:
-// CHECK: ret i32* @b
+// LINUX: ret i32* @b
+// DARWIN-LABEL: declare i32* @_ZTW1b()
+// There is no definition of the thread wrapper on Darwin for external TLV.
// CHECK: define {{.*}} @[[D_INIT:.*]]()
// CHECK: call i32 @_Z1gv()
@@ -111,24 +118,28 @@ struct T { ~T(); };
void tls_dtor() {
// CHECK: load i8, i8* @_ZGVZ8tls_dtorvE1s
// CHECK: call void @_ZN1SC1Ev(%struct.S* @_ZZ8tls_dtorvE1s)
- // CHECK: call i32 @__cxa_thread_atexit({{.*}}@_ZN1SD1Ev {{.*}} @_ZZ8tls_dtorvE1s{{.*}} @__dso_handle
+ // LINUX: call i32 @__cxa_thread_atexit({{.*}}@_ZN1SD1Ev {{.*}} @_ZZ8tls_dtorvE1s{{.*}} @__dso_handle
+ // DARWIN: call i32 @_tlv_atexit({{.*}}@_ZN1SD1Ev {{.*}} @_ZZ8tls_dtorvE1s{{.*}} @__dso_handle
// CHECK: store i8 1, i8* @_ZGVZ8tls_dtorvE1s
static thread_local S s;
// CHECK: load i8, i8* @_ZGVZ8tls_dtorvE1t
// CHECK-NOT: _ZN1T
- // CHECK: call i32 @__cxa_thread_atexit({{.*}}@_ZN1TD1Ev {{.*}}@_ZZ8tls_dtorvE1t{{.*}} @__dso_handle
+ // LINUX: call i32 @__cxa_thread_atexit({{.*}}@_ZN1TD1Ev {{.*}}@_ZZ8tls_dtorvE1t{{.*}} @__dso_handle
+ // DARWIN: call i32 @_tlv_atexit({{.*}}@_ZN1TD1Ev {{.*}}@_ZZ8tls_dtorvE1t{{.*}} @__dso_handle
// CHECK: store i8 1, i8* @_ZGVZ8tls_dtorvE1t
static thread_local T t;
// CHECK: load i8, i8* @_ZGVZ8tls_dtorvE1u
// CHECK: call void @_ZN1SC1Ev(%struct.S* @_ZGRZ8tls_dtorvE1u_)
- // CHECK: call i32 @__cxa_thread_atexit({{.*}}@_ZN1SD1Ev {{.*}} @_ZGRZ8tls_dtorvE1u_{{.*}} @__dso_handle
+ // LINUX: call i32 @__cxa_thread_atexit({{.*}}@_ZN1SD1Ev {{.*}} @_ZGRZ8tls_dtorvE1u_{{.*}} @__dso_handle
+ // DARWIN: call i32 @_tlv_atexit({{.*}}@_ZN1SD1Ev {{.*}} @_ZGRZ8tls_dtorvE1u_{{.*}} @__dso_handle
// CHECK: store i8 1, i8* @_ZGVZ8tls_dtorvE1u
static thread_local const S &u = S();
}
-// CHECK: declare i32 @__cxa_thread_atexit(void (i8*)*, i8*, i8*)
+// LINUX: declare i32 @__cxa_thread_atexit(void (i8*)*, i8*, i8*)
+// DARWIN: declare i32 @_tlv_atexit(void (i8*)*, i8*, i8*)
// CHECK: define {{.*}} @_Z7PR15991v(
int PR15991() {
@@ -143,7 +154,8 @@ struct PR19254 {
};
// CHECK: define {{.*}} @_ZN7PR192541fEv(
int PR19254::f() {
- // CHECK: call void @_ZTHN7PR192541nE(
+ // LINUX: call void @_ZTHN7PR192541nE(
+ // DARWIN: call i32* @_ZTWN7PR192541nE(
return this->n;
}
@@ -182,19 +194,21 @@ void set_anon_i() {
// CHECK: call void @[[V_M_INIT]]()
-// CHECK: define weak_odr hidden i32* @_ZTW1a() {
+// LIUNX: define weak_odr hidden i32* @_ZTW1a() {
+// DARWIN: define i32* @_ZTW1a() {
// CHECK: call void @_ZTH1a()
// CHECK: ret i32* @a
// CHECK: }
-// CHECK: declare extern_weak void @_ZTH1b()
+// LINUX: declare extern_weak void @_ZTH1b()
// CHECK-LABEL: define internal i32* @_ZTWL1d()
// CHECK: call void @_ZTHL1d()
// CHECK: ret i32* @_ZL1d
-// CHECK-LABEL: define weak_odr hidden i32* @_ZTWN1U1mE()
+// LINUX-LABEL: define weak_odr hidden i32* @_ZTWN1U1mE()
+// DARWIN-LABEL: define i32* @_ZTWN1U1mE()
// CHECK: call void @_ZTHN1U1mE()
// CHECK: ret i32* @_ZN1U1mE
Modified: cfe/trunk/test/CodeGenCXX/tls-init-funcs.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/tls-init-funcs.cpp?rev=252814&r1=252813&r2=252814&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/tls-init-funcs.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/tls-init-funcs.cpp Wed Nov 11 16:42:31 2015
@@ -1,13 +1,13 @@
// RUN: %clang_cc1 -triple x86_64-apple-macosx10.8 -std=c++1y -S -emit-llvm %s -o - | FileCheck %s
// CHECK: @a = internal thread_local global
-// CHECK: @_Z2vtIiE = internal thread_local global i32 5
+// CHECK: @_Z2vtIiE = linkonce_odr thread_local global i32 5
// CHECK: @_ZZ3inlvE3loc = linkonce_odr thread_local global i32 0
// CHECK: @_tlv_atexit({{.*}}@_ZN1AD1Ev
// CHECK: call i32* @_ZTW3ext()
// CHECK: declare i32* @_ZTW3ext()
-// CHECK: define weak i32* @_ZTW2vtIiE()
-// CHECK: define weak i32* @_ZTW2vtIvE()
+// CHECK: define weak_odr hidden i32* @_ZTW2vtIiE()
+// CHECK: define weak_odr hidden i32* @_ZTW2vtIvE()
// CHECK: define {{.*}} @_ZTW1a
struct A {
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