[clang][NewPM] Fix broken -O0 test from the AlwaysInliner

[leonardchan]

Summary

This contains the part of D62225 which prevents insertion of lifetime intrinsics when creating the AlwaysInliner. This fixes the following tests when the new PM is enabled by default:

Clang :: CodeGen/aarch64-neon-across.c
Clang :: CodeGen/aarch64-neon-fcvt-intrinsics.c
Clang :: CodeGen/aarch64-neon-fma.c
Clang :: CodeGen/aarch64-neon-perm.c
Clang :: CodeGen/aarch64-neon-tbl.c
Clang :: CodeGen/aarch64-poly128.c
Clang :: CodeGen/aarch64-v8.2a-neon-intrinsics.c
Clang :: CodeGen/arm-neon-fma.c
Clang :: CodeGen/arm-neon-numeric-maxmin.c
Clang :: CodeGen/arm-neon-vcvtX.c
Clang :: CodeGen/avx-builtins.c
Clang :: CodeGen/builtins-ppc-p9vector.c
Clang :: CodeGen/builtins-ppc-vsx.c
Clang :: CodeGen/lifetime.c
Clang :: CodeGen/sse-builtins.c
Clang :: CodeGen/sse2-builtins.c

[chandlerc]

Code change LGTM. Can you update at least one of the tests to explicitly run both PMs so that we'll notice if this breaks in some weird way? Feel free to submit with that change.

[leonardchan]

In D63153#1540920, @chandlerc wrote:

Code change LGTM. Can you update at least one of the tests to explicitly run both PMs so that we'll notice if this breaks in some weird way? Feel free to submit with that change.

Done

cfe/trunk/lib/CodeGen/BackendUtil.cpp

if (!CodeGenOpts.DisableLLVMPasses) {
     if (CodeGenOpts.OptimizationLevel == 0) {
       if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
         MPM.addPass(GCOVProfilerPass(*Options));
       if (Optional<InstrProfOptions> Options =
               getInstrProfOptions(CodeGenOpts, LangOpts))
         MPM.addPass(InstrProfiling(*Options, false));
 
       // Build a minimal pipeline based on the semantics required by Clang,
-      // which is just that always inlining occurs.
-      MPM.addPass(AlwaysInlinerPass());
+      // which is just that always inlining occurs. Further, disable generating
+      // lifetime intrinsics to avoid enabling further optimizations during
+      // code generation.
+      MPM.addPass(AlwaysInlinerPass(/*InsertLifetimeIntrinsics=*/false));
 
       // At -O0 we directly run necessary sanitizer passes.
       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
         MPM.addPass(createModuleToFunctionPassAdaptor(BoundsCheckingPass()));
 
       // Lastly, add semantically necessary passes for LTO.
       if (IsLTO || IsThinLTO) {
         MPM.addPass(CanonicalizeAliasesPass());

cfe/trunk/test/CodeGen/lifetime.c

-// RUN: %clang -S -emit-llvm -o - -O0 %s | FileCheck %s -check-prefix=O0
+// RUN: %clang -S -emit-llvm -o - -O0 -fno-experimental-new-pass-manager %s | FileCheck %s -check-prefix=O0
 // RUN: %clang -S -emit-llvm -o - -O1 -fno-experimental-new-pass-manager %s | FileCheck %s -check-prefix=O1
 // RUN: %clang -S -emit-llvm -o - -O2 -fno-experimental-new-pass-manager %s | FileCheck %s -check-prefix=O2
 // RUN: %clang -S -emit-llvm -o - -O3 -fno-experimental-new-pass-manager %s | FileCheck %s -check-prefix=O3
+// RUN: %clang -S -emit-llvm -o - -O0 -fexperimental-new-pass-manager %s | FileCheck %s -check-prefix=O0
 
 extern void use(char *a);
 
 __attribute__((always_inline)) void helper_no_markers() {
   char a;
   use(&a);
 }