[Debugify] Don't apply DI before the bitcode writer pass

Applying synthetic debug info before the bitcode writer pass has no
testing-related purpose. This commit prevents that from happening.

It also adds tests which check that IR produced with/without
-debugify-each enabled is identical after stripping. This makes it
possible to check that individual passes (or full pipelines) are
invariant to debug info.

llvm-svn: 333861

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp
index 09f3ac82428..f1221819f62 100644
--- a/llvm/tools/opt/opt.cpp
+++ b/llvm/tools/opt/opt.cpp
@@ -269,8 +269,8 @@ public:
   using super = legacy::PassManager;
 
   void add(Pass *P) override {
-    bool WrapWithDebugify =
-        DebugifyEach && !P->getAsImmutablePass() && !isIRPrintingPass(P);
+    bool WrapWithDebugify = DebugifyEach && !P->getAsImmutablePass() &&
+                            !isIRPrintingPass(P) && !isBitcodeWriterPass(P);
     if (!WrapWithDebugify) {
       super::add(P);
       return;