[NPM] -print-pipeline-passes fix printing of LoopNestPasses

[markus]

Summary

Previously LoopNestPasses, like lnicm, were not printed correctly. The following patch tries to address that.

llvm/lib/Transforms/Scalar/LoopPassManager.cpp

PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
 
   return PA;
 }
 
 void PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
                  LPMUpdater &>::printPipeline(raw_ostream &OS,
                                               function_ref<StringRef(StringRef)>
                                                   MapClassName2PassName) {
-  for (unsigned Idx = 0, Size = LoopPasses.size(); Idx != Size; ++Idx) {
-    auto *P = LoopPasses[Idx].get();
+  assert(LoopPasses.size() + LoopNestPasses.size() == IsLoopNestPass.size());
+
+  unsigned IdxLP = 0, IdxLNP = 0;
+  for (unsigned Idx = 0, Size = IsLoopNestPass.size(); Idx != Size; ++Idx) {
+    if (IsLoopNestPass[Idx]) {
+      auto *P = LoopNestPasses[IdxLNP++].get();
+      P->printPipeline(OS, MapClassName2PassName);
+    } else {
+      auto *P = LoopPasses[IdxLP++].get();
       P->printPipeline(OS, MapClassName2PassName);
+    }
     if (Idx + 1 < Size)
       OS << ",";
   }
 }
 
 // Run both loop passes and loop-nest passes on top-level loop \p L.
 PreservedAnalyses
 LoopPassManager::runWithLoopNestPasses(Loop &L, LoopAnalysisManager &AM,

llvm/test/Other/new-pm-print-pipeline.ll

 ; RUN: opt -disable-output -disable-verify -print-pipeline-passes -passes='inliner-wrapper,inliner-wrapper-no-mandatory-first' < %s | FileCheck %s --match-full-lines --check-prefixes=CHECK-20
 ; CHECK-20: cgscc(inline<only-mandatory>,inline),cgscc(inline)
 
 ; RUN: opt -disable-output -disable-verify -print-pipeline-passes -passes='scc-oz-module-inliner' < %s | FileCheck %s --match-full-lines --check-prefixes=CHECK-21
 ; CHECK-21: require<globals-aa>,function(invalidate<aa>),require<profile-summary>,cgscc(devirt<4>(inline<only-mandatory>,inline,{{.*}},instcombine{{.*}}))
 
 ; RUN: opt -disable-output -disable-verify -print-pipeline-passes -passes='cgscc(function<eager-inv>(no-op-function)),function<eager-inv>(no-op-function)' < %s | FileCheck %s --match-full-lines --check-prefixes=CHECK-22
 ; CHECK-22: cgscc(function<eager-inv>(no-op-function)),function<eager-inv>(no-op-function)
+
+;; Test that the loop-nest-pass lnicm is printed with the other loop-passes in the pipeline.
+; RUN: opt -disable-output -disable-verify -print-pipeline-passes -passes='function(loop-mssa(licm,loop-rotate,loop-deletion,lnicm,loop-rotate))' < %s | FileCheck %s --match-full-lines --check-prefixes=CHECK-23
+; CHECK-23: function(loop-mssa(licm,loop-rotate,loop-deletion,lnicm,loop-rotate))