[NPM] Fix LoopNestPasses in -print-pipeline-passes

Fix printing of LoopNestPasses when using the opt pipeline printer
option -print-pipeline-passes.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D114771

Author: markuslavin

llvm/lib/Transforms/Scalar/LoopPassManager.cpp

@@ -49,9 +49,17 @@ 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();
-    P->printPipeline(OS, MapClassName2PassName);
+  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 << ",";
   }

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

@@ -69,3 +69,7 @@
 
 ; 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))