[CodeGen] Disable aggressive structor optimizations at -O0, take 2

The first version of the patch (r332228) was flawed because it was
putting structors into C5/D5 comdats very eagerly. This is correct only
if we can ensure the comdat contains all required versions of the
structor (which wasn't the case). This version uses a more nuanced
approach:
- for local structor symbols we use an alias because we don't have to
  worry about comdats or other compilation units.
- linkonce symbols are emitted separately, as we cannot guarantee we
  will have all symbols we need to form a comdat (they are emitted
  lazily, only when referenced).
- available_externally symbols are also emitted separately, as the code
  seemed to be worried about emitting an alias in this case.
- other linkage types are not affected by the optimization level. They
  either get put into a comdat (weak) or get aliased (external).

Reviewers: rjmccall, aprantl

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D46685

llvm-svn: 332839

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/test/CodeGenCXX/float16-declarations.cpp b/clang/test/CodeGenCXX/float16-declarations.cpp
index e82c05ec8c8..1d6999fef07 100644
--- a/clang/test/CodeGenCXX/float16-declarations.cpp
+++ b/clang/test/CodeGenCXX/float16-declarations.cpp
@@ -103,7 +103,7 @@ int main(void) {
 
   C1 c1(f1l);
 // CHECK-DAG:  [[F1L:%[a-z0-9]+]] = load half, half* %{{.*}}, align 2
-// CHECK-DAG:  call void @_ZN2C1C2EDF16_(%class.C1* %{{.*}}, half %{{.*}})
+// CHECK-DAG:  call void @_ZN2C1C1EDF16_(%class.C1* %{{.*}}, half %{{.*}})
 
   S1<_Float16> s1 = { 132.f16 };
 // CHECK-DAG: @_ZZ4mainE2s1 = private unnamed_addr constant %struct.S1 { half 0xH5820 }, align 2