[TLS] move setting tls_guard in tls_init.

We used to emit the store prior to branch in the entry block. To make it more
efficient, this commit moves it to the init block. We still mark as initialized
before initializing anything else.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@252777 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index e74467bb1410246069192d5ee54a4c525576339d..df75045c789712b642a45e6d4b3f88692ae8c178 100644 (file)
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/lib/CodeGen/CGDeclCXX.cpp
@@ -518,14 +518,14 @@ CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
       llvm::Value *GuardVal = Builder.CreateLoad(Guard);
       llvm::Value *Uninit = Builder.CreateIsNull(GuardVal,
                                                  "guard.uninitialized");
-      // Mark as initialized before initializing anything else. If the
-      // initializers use previously-initialized thread_local vars, that's
-      // probably supposed to be OK, but the standard doesn't say.
-      Builder.CreateStore(llvm::ConstantInt::get(GuardVal->getType(),1), Guard);
       llvm::BasicBlock *InitBlock = createBasicBlock("init");
       ExitBlock = createBasicBlock("exit");
       Builder.CreateCondBr(Uninit, InitBlock, ExitBlock);
       EmitBlock(InitBlock);
+      // Mark as initialized before initializing anything else. If the
+      // initializers use previously-initialized thread_local vars, that's
+      // probably supposed to be OK, but the standard doesn't say.
+      Builder.CreateStore(llvm::ConstantInt::get(GuardVal->getType(),1), Guard);
     }
 
     RunCleanupsScope Scope(*this);

diff --git a/test/CodeGenCXX/cxx11-thread-local.cpp b/test/CodeGenCXX/cxx11-thread-local.cpp
index e28447e01eb32aad1c6fef5214e72b5ae47ac545..9d9d255dcb028fb44f0c20653ace0a3604696ceb 100644 (file)
--- a/test/CodeGenCXX/cxx11-thread-local.cpp
+++ b/test/CodeGenCXX/cxx11-thread-local.cpp
@@ -173,9 +173,9 @@ void set_anon_i() {
 // CHECK: define {{.*}}@__tls_init()
 // CHECK: load i8, i8* @__tls_guard
 // CHECK: %[[NEED_TLS_INIT:.*]] = icmp eq i8 %{{.*}}, 0
-// CHECK: store i8 1, i8* @__tls_guard
 // CHECK: br i1 %[[NEED_TLS_INIT]],
 // init:
+// CHECK: store i8 1, i8* @__tls_guard
 // CHECK: call void @[[A_INIT]]()
 // CHECK: call void @[[D_INIT]]()
 // CHECK: call void @[[U_M_INIT]]()

diff --git a/test/OpenMP/threadprivate_codegen.cpp b/test/OpenMP/threadprivate_codegen.cpp
index 97678b4b66626a4219b005916ea2e96ba1fab81b..53d7ef7083850a7033995234a804d78f5dfbe573 100644 (file)
--- a/test/OpenMP/threadprivate_codegen.cpp
+++ b/test/OpenMP/threadprivate_codegen.cpp
@@ -939,9 +939,9 @@ int foobar() {
 // CHECK-TLS:      define internal void @__tls_init()
 // CHECK-TLS:      [[GRD:%.*]] = load i8, i8* @__tls_guard
 // CHECK-TLS-NEXT: [[IS_INIT:%.*]] = icmp eq i8 [[GRD]], 0
-// CHECK-TLS-NEXT: store i8 1, i8* @__tls_guard
 // CHECK-TLS-NEXT: br i1 [[IS_INIT]], label %[[INIT_LABEL:[^,]+]], label %[[DONE_LABEL:[^,]+]]{{.*}}
 // CHECK-TLS:      [[INIT_LABEL]]
+// CHECK-TLS-NEXT: store i8 1, i8* @__tls_guard
 // CHECK-TLS:      call void [[GS1_CXX_INIT]]
 // CHECK-TLS-NOT:  call void [[GS2_CXX_INIT]]
 // CHECK-TLS:      call void [[ARR_X_CXX_INIT]]