Add AddDiscriminatorsPass to NPM default O0 pipeline

[ychen]

Summary

AddDiscriminatorsPass is in Legacy PM's O0 pipeline. This patch did the same
for NPM O0 pipeline.

[aeubanks]

lgtm

[MaskRay]

I assume this will make sample PGO usable with -O0?

[ychen]

In D105650#2865669, @MaskRay wrote:

I assume this will make sample PGO usable with -O0?

That's right. The issue was found while trying to use sample PGO with O0.

llvm/lib/Passes/PassBuilder.cpp

if (PGOOpt && (PGOOpt->Action == PGOOptions::IRInstr ||
                  PGOOpt->Action == PGOOptions::IRUse))
     addPGOInstrPassesForO0(
         MPM,
         /* RunProfileGen */ (PGOOpt->Action == PGOOptions::IRInstr),
         /* IsCS */ false, PGOOpt->ProfileFile, PGOOpt->ProfileRemappingFile);
 
   for (auto &C : PipelineStartEPCallbacks)
     C(MPM, Level);
+
+  if (PGOOpt && PGOOpt->DebugInfoForProfiling)
+    MPM.addPass(createModuleToFunctionPassAdaptor(AddDiscriminatorsPass()));
+
   for (auto &C : PipelineEarlySimplificationEPCallbacks)
     C(MPM, Level);
 
   // Build a minimal pipeline based on the semantics required by LLVM,
   // which is just that always inlining occurs. Further, disable generating
   // lifetime intrinsics to avoid enabling further optimizations during
   // code generation.
   // However, we need to insert lifetime intrinsics to avoid invalid access

llvm/test/Other/new-pm-O0-defaults.ll

 ; The IR below was crafted so as:
 ; 1) To have a loop, so we create a loop pass manager
 ; 2) To be "immutable" in the sense that no pass in the standard
 ;    pipeline will modify it.
 ; Since no transformations take place, we don't expect any analyses
 ; to be invalidated.
 ; Any invalidation that shows up here is a bug, unless we started modifying
 ; the IR, in which case we need to make it immutable harder.
 
 ; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager \
 ; RUN:     -passes='default<O0>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-DEFAULT
 ; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager -enable-matrix \
 ; RUN:     -passes='default<O0>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-DEFAULT,CHECK-MATRIX
+; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager -new-pm-debug-info-for-profiling \
+; RUN:     -passes='default<O0>' -S %s 2>&1 \
+; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-DIS
 ; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager \
 ; RUN:     -passes='thinlto-pre-link<O0>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-DEFAULT,CHECK-PRE-LINK
 ; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager \
 ; RUN:     -passes='lto-pre-link<O0>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-DEFAULT,CHECK-PRE-LINK
 ; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager \
 ; RUN:     -passes='thinlto<O0>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-THINLTO
 ; RUN: opt -disable-verify -verify-cfg-preserved=0 -debug-pass-manager \
 ; RUN:     -passes='lto<O0>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-LTO
 
+; CHECK-DIS: Running analysis: InnerAnalysisManagerProxy
+; CHECK-DIS-NEXT: Running pass: AddDiscriminatorsPass
+; CHECK-DIS-NEXT: Running pass: AlwaysInlinerPass
+; CHECK-DIS-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-DEFAULT: Running pass: AlwaysInlinerPass
 ; CHECK-DEFAULT-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-DEFAULT-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-MATRIX: Running pass: LowerMatrixIntrinsicsPass
 ; CHECK-MATRIX-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-PRE-LINK: Running pass: CanonicalizeAliasesPass
 ; CHECK-PRE-LINK-NEXT: Running pass: NameAnonGlobalPass
 ; CHECK-THINLTO: Running pass: Annotation2MetadataPass