From c370f2625145aec2ac70a49c3b1ff5a82fc2f92f Mon Sep 17 00:00:00 2001
From: Pavel Labath <labath@google.com>
Date: Mon, 14 May 2018 11:35:44 +0000
Subject: [PATCH] Revert "[CodeGen] Disable aggressive structor optimizations
 at -O0"

It breaks the sanitizer build
<http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/23739>

This reverts commit r332228.

llvm-svn: 332232
---
 clang/lib/CodeGen/ItaniumCXXABI.cpp            | 14 +++++---------
 clang/test/CodeGenCXX/ctor-dtor-alias.cpp      |  9 ++++-----
 clang/test/CodeGenCXX/float16-declarations.cpp |  2 +-
 3 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 89a05769e033..e7d4d8ac295e 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -3630,16 +3630,12 @@ static StructorCodegen getCodegenToUse(CodeGenModule &CGM,
   }
   llvm::GlobalValue::LinkageTypes Linkage = CGM.getFunctionLinkage(AliasDecl);
 
-  // Only use RAUW in optimized code, as it makes the complete structor symbol
-  // disappear completely, which degrades debugging experience.
-  if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
-    if (llvm::GlobalValue::isDiscardableIfUnused(Linkage))
-      return StructorCodegen::RAUW;
+  if (llvm::GlobalValue::isDiscardableIfUnused(Linkage))
+    return StructorCodegen::RAUW;
 
-    // FIXME: Should we allow available_externally aliases?
-    if (!llvm::GlobalAlias::isValidLinkage(Linkage))
-      return StructorCodegen::RAUW;
-  }
+  // FIXME: Should we allow available_externally aliases?
+  if (!llvm::GlobalAlias::isValidLinkage(Linkage))
+    return StructorCodegen::RAUW;
 
   if (llvm::GlobalValue::isWeakForLinker(Linkage)) {
     // Only ELF and wasm support COMDATs with arbitrary names (C5/D5).
diff --git a/clang/test/CodeGenCXX/ctor-dtor-alias.cpp b/clang/test/CodeGenCXX/ctor-dtor-alias.cpp
index 4e830c159323..d72c5b48b3ad 100644
--- a/clang/test/CodeGenCXX/ctor-dtor-alias.cpp
+++ b/clang/test/CodeGenCXX/ctor-dtor-alias.cpp
@@ -77,12 +77,11 @@ namespace test4 {
   // CHECK1: call i32 @__cxa_atexit{{.*}}_ZN5test41AD2Ev
   // CHECK1: define linkonce_odr void @_ZN5test41AD2Ev({{.*}} comdat align
 
-  // test that we don't do this optimization at -O0 and call the complete
-  // destructor for B instead. This enables the debugger to see both
-  // destructors.
-  // NOOPT: @_ZN5test41BD1Ev = linkonce_odr alias void {{.*}} @_ZN5test41BD2Ev
+  // test that we don't do this optimization at -O0 so that the debugger can
+  // see both destructors.
   // NOOPT: define internal void @__cxx_global_var_init.2()
-  // NOOPT: call i32 @__cxa_atexit{{.*}}@_ZN5test41BD1Ev
+  // NOOPT: call i32 @__cxa_atexit{{.*}}@_ZN5test41BD2Ev
+  // NOOPT: define linkonce_odr void @_ZN5test41BD2Ev({{.*}} comdat align
   struct A {
     virtual ~A() {}
   };
diff --git a/clang/test/CodeGenCXX/float16-declarations.cpp b/clang/test/CodeGenCXX/float16-declarations.cpp
index 1d6999fef073..e82c05ec8c81 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 @_ZN2C1C1EDF16_(%class.C1* %{{.*}}, half %{{.*}})
+// CHECK-DAG:  call void @_ZN2C1C2EDF16_(%class.C1* %{{.*}}, half %{{.*}})
 
   S1<_Float16> s1 = { 132.f16 };
 // CHECK-DAG: @_ZZ4mainE2s1 = private unnamed_addr constant %struct.S1 { half 0xH5820 }, align 2