Improve code generation for thread_local variables:

Summary:
 * Don't bother using a thread wrapper when the variable is known to
   have constant initialization.
 * Emit the thread wrapper as discardable-if-unused in TUs that don't
   contain a definition of the thread_local variable.
 * Don't emit the thread wrapper at all if the thread_local variable
   is unused and discardable; it will be emitted by all TUs that need
   it.

Reviewers: rjmccall, jdoerfert

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67429

llvm-svn: 371767

1 files changed, 11 insertions, 26 deletions

diff --git a/clang/test/OpenMP/parallel_copyin_codegen.cpp b/clang/test/OpenMP/parallel_copyin_codegen.cpp
index 87c11f04061..60cbf71010e 100644
--- a/clang/test/OpenMP/parallel_copyin_codegen.cpp
+++ b/clang/test/OpenMP/parallel_copyin_codegen.cpp
@@ -101,8 +101,7 @@ int main() {
   // LAMBDA: define{{.*}} internal{{.*}} void [[OUTER_LAMBDA]](
   // LAMBDA: call {{.*}}void {{.+}} @__kmpc_fork_call({{.+}}, i32 0, {{.+}}* [[OMP_REGION:@.+]] to {{.+}})
 
-  // TLS-LAMBDA:     [[G_CPY_VAL:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR:@.+]]()
-  // TLS-LAMBDA:     call {{.*}}void {{.+}} @__kmpc_fork_call({{.+}}, i32 1, {{.+}}* [[OMP_REGION:@.+]] to {{.+}}, i32* [[G_CPY_VAL]])
+  // TLS-LAMBDA:     call {{.*}}void {{.+}} @__kmpc_fork_call({{.+}}, i32 1, {{.+}}* [[OMP_REGION:@.+]] to {{.+}}, i32* @g)
 
 #pragma omp parallel copyin(g)
   {
@@ -120,14 +119,12 @@ int main() {
     // LAMBDA: [[DONE]]
 
     // TLS-LAMBDA-DAG: [[G_CAPTURE_SRC:%.+]] = load i{{[0-9]+}}*, i{{[0-9]+}}** %
-    // TLS-LAMBDA-DAG: [[G_CAPTURE_DST:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR]]()
     // TLS-LAMBDA-DAG: [[G_CAPTURE_SRCC:%.+]] = ptrtoint i{{[0-9]+}}* [[G_CAPTURE_SRC]] to i{{[0-9]+}}
-    // TLS-LAMBDA-DAG: [[G_CAPTURE_DSTC:%.+]] = ptrtoint i{{[0-9]+}}* [[G_CAPTURE_DST]] to i{{[0-9]+}}
-    // TLS-LAMBDA: icmp ne i{{[0-9]+}} {{%.+}}, {{%.+}}
+    // TLS-LAMBDA: icmp ne i{{[0-9]+}} {{%.+}}, ptrtoint (i{{[0-9]+}}* @g to i{{[0-9]+}})
     // TLS-LAMBDA: br i1 %{{.+}}, label %[[NOT_MASTER:.+]], label %[[DONE:.+]]
     // TLS-LAMBDA: [[NOT_MASTER]]
     // TLS-LAMBDA: load i{{[0-9]+}}, i{{[0-9]+}}* [[G_CAPTURE_SRC]],
-    // TLS-LAMBDA: store volatile i{{[0-9]+}} %{{.+}}, i{{[0-9]+}}* [[G_CAPTURE_DST]], align 128
+    // TLS-LAMBDA: store volatile i{{[0-9]+}} %{{.+}}, i{{[0-9]+}}* @g, align 128
     // TLS-LAMBDA: [[DONE]]
 
     // LAMBDA: call {{.*}}void @__kmpc_barrier(
@@ -136,18 +133,13 @@ int main() {
     // LAMBDA: call{{.*}} void [[INNER_LAMBDA:@.+]](%{{.+}}*
     // TLS-LAMBDA: call{{.*}} void [[INNER_LAMBDA:@.+]](%{{.+}}*
 
-    // TLS-LAMBDA:     define {{.*}}i{{[0-9]+}}* [[G_CTOR]]()
-    // TLS-LAMBDA:     ret i{{[0-9]+}}* [[G]]
-    // TLS-LAMBDA:     }
-
     [&]() {
       // LAMBDA: define {{.+}} void [[INNER_LAMBDA]](%{{.+}}* [[ARG_PTR:%.+]])
       // LAMBDA: store %{{.+}}* [[ARG_PTR]], %{{.+}}** [[ARG_PTR_REF:%.+]],
       g = 2;
       // LAMBDA: [[ARG_PTR:%.+]] = load %{{.+}}*, %{{.+}}** [[ARG_PTR_REF]]
 
-      // TLS-LAMBDA: [[G_CAPTURE_DST:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR]]()
-      // TLS-LAMBDA: store volatile i{{[0-9]+}} 2, i{{[0-9]+}}* [[G_CAPTURE_DST]], align 128
+      // TLS-LAMBDA: store volatile i{{[0-9]+}} 2, i{{[0-9]+}}* @g, align 128
     }();
   }
   }();
@@ -164,8 +156,7 @@ int main() {
   // BLOCKS: define{{.*}} internal{{.*}} void {{.+}}(i8*
   // BLOCKS: call {{.*}}void {{.+}} @__kmpc_fork_call({{.+}}, i32 0, {{.+}}* [[OMP_REGION:@.+]] to {{.+}})
 
-  // TLS-BLOCKS:     [[G_CPY_VAL:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR:@.+]]()
-  // TLS-BLOCKS:     call {{.*}}void {{.+}} @__kmpc_fork_call({{.+}}, i32 1, {{.+}}* [[OMP_REGION:@.+]] to {{.+}}, i32* [[G_CPY_VAL]])
+  // TLS-BLOCKS:     call {{.*}}void {{.+}} @__kmpc_fork_call({{.+}}, i32 1, {{.+}}* [[OMP_REGION:@.+]] to {{.+}}, i32* @g)
 
 #pragma omp parallel copyin(g)
   {
@@ -183,14 +174,12 @@ int main() {
     // BLOCKS: [[DONE]]
 
     // TLS-BLOCKS-DAG: [[G_CAPTURE_SRC:%.+]] = load i{{[0-9]+}}*, i{{[0-9]+}}** %
-    // TLS-BLOCKS-DAG: [[G_CAPTURE_DST:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR]]()
     // TLS-BLOCKS-DAG: [[G_CAPTURE_SRCC:%.+]] = ptrtoint i{{[0-9]+}}* [[G_CAPTURE_SRC]] to i{{[0-9]+}}
-    // TLS-BLOCKS-DAG: [[G_CAPTURE_DSTC:%.+]] = ptrtoint i{{[0-9]+}}* [[G_CAPTURE_DST]] to i{{[0-9]+}}
-    // TLS-BLOCKS: icmp ne i{{[0-9]+}} {{%.+}}, {{%.+}}
+    // TLS-BLOCKS: icmp ne i{{[0-9]+}} {{%.+}}, ptrtoint (i{{[0-9]+}}* @g to i{{[0-9]+}})
     // TLS-BLOCKS: br i1 %{{.+}}, label %[[NOT_MASTER:.+]], label %[[DONE:.+]]
     // TLS-BLOCKS: [[NOT_MASTER]]
     // TLS-BLOCKS: load i{{[0-9]+}}, i{{[0-9]+}}* [[G_CAPTURE_SRC]],
-    // TLS-BLOCKS: store volatile i{{[0-9]+}} %{{.+}}, i{{[0-9]+}}* [[G_CAPTURE_DST]], align 128
+    // TLS-BLOCKS: store volatile i{{[0-9]+}} %{{.+}}, i{{[0-9]+}}* @g, align 128
     // TLS-BLOCKS: [[DONE]]
 
     // BLOCKS: call {{.*}}void @__kmpc_barrier(
@@ -200,14 +189,10 @@ int main() {
     // BLOCKS-NOT: [[G]]{{[[^:word:]]}}
     // BLOCKS: call {{.*}}void {{%.+}}(i8
 
-    // TLS-BLOCKS: [[G_CAPTURE_DST:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR]]()
-    // TLS-BLOCKS: store volatile i{{[0-9]+}} 1, i{{[0-9]+}}* [[G_CAPTURE_DST]]
+    // TLS-BLOCKS: store volatile i{{[0-9]+}} 1, i{{[0-9]+}}* @g
     // TLS-BLOCKS-NOT: [[G]]{{[[^:word:]]}}
     // TLS-BLOCKS: call {{.*}}void {{%.+}}(i8
 
-    // TLS-BLOCKS:     define {{.*}}i{{[0-9]+}}* [[G_CTOR]]()
-    // TLS-BLOCKS:     ret i{{[0-9]+}}* [[G]]
-    // TLS-BLOCKS:     }
     ^{
       // BLOCKS: define {{.+}} void {{@.+}}(i8*
       // TLS-BLOCKS: define {{.+}} void {{@.+}}(i8*
@@ -219,8 +204,7 @@ int main() {
       // BLOCKS: ret
 
       // TLS-BLOCKS-NOT: [[G]]{{[[^:word:]]}}
-      // TLS-BLOCKS: [[G_CAPTURE_DST:%.+]] = call{{( cxx_fast_tlscc)?}} i{{[0-9]+}}* [[G_CTOR]]()
-      // TLS-BLOCKS: store volatile i{{[0-9]+}} 2, i{{[0-9]+}}* [[G_CAPTURE_DST]]
+      // TLS-BLOCKS: store volatile i{{[0-9]+}} 2, i{{[0-9]+}}* @g
       // TLS-BLOCKS-NOT: [[G]]{{[[^:word:]]}}
       // TLS-BLOCKS: ret
     }();
@@ -524,7 +508,8 @@ void array_func() {
   ;
 }
 #elif defined(NESTED)
-int t;
+int t_init();
+int t = t_init();
 #pragma omp threadprivate(t)
 // NESTED: foo
 void foo() {