[LoopRotate][NPM] Disable header duplication under -Oz

It was already disabled under -Oz in
buildFunctionSimplificationPipeline(), but not in
buildModuleOptimizationPipeline()/addPGOInstrPasses().

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D89927

Author: aeubanks

llvm/lib/Passes/PassBuilder.cpp

@@ -677,7 +677,7 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
   LPM1.addPass(LoopInstSimplifyPass());
   LPM1.addPass(LoopSimplifyCFGPass());
 
-  // Rotate Loop - disable header duplication at -Oz
+  // Disable header duplication in loop rotation at -Oz.
   LPM1.addPass(LoopRotatePass(Level != OptimizationLevel::Oz));
   // TODO: Investigate promotion cap for O1.
   LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
@@ -833,8 +833,9 @@ void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM, bool DebugLogging,
   MPM.addPass(PGOInstrumentationGen(IsCS));
 
   FunctionPassManager FPM;
+  // Disable header duplication in loop rotation at -Oz.
   FPM.addPass(createFunctionToLoopPassAdaptor(
-      LoopRotatePass(), EnableMSSALoopDependency,
+      LoopRotatePass(Level != OptimizationLevel::Oz), EnableMSSALoopDependency,
       /*UseBlockFrequencyInfo=*/false, DebugLogging));
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
 
@@ -1164,8 +1165,9 @@ ModulePassManager PassBuilder::buildModuleOptimizationPipeline(
     C(OptimizePM, Level);
 
   // First rotate loops that may have been un-rotated by prior passes.
+  // Disable header duplication at -Oz.
   OptimizePM.addPass(createFunctionToLoopPassAdaptor(
-      LoopRotatePass(), EnableMSSALoopDependency,
+      LoopRotatePass(Level != OptimizationLevel::Oz), EnableMSSALoopDependency,
       /*UseBlockFrequencyInfo=*/false, DebugLogging));
 
   // Distribute loops to allow partial vectorization.  I.e. isolate dependences

llvm/test/Transforms/LoopRotate/oz-disable.ll

@@ -1,6 +1,8 @@
 ; REQUIRES: asserts
 ; RUN: opt < %s -S -Os -debug -debug-only=loop-rotate 2>&1 | FileCheck %s -check-prefix=OS
 ; RUN: opt < %s -S -Oz -debug -debug-only=loop-rotate 2>&1 | FileCheck %s -check-prefix=OZ
+; RUN: opt < %s -S -passes='default<Os>' -debug -debug-only=loop-rotate 2>&1 | FileCheck %s -check-prefix=OS
+; RUN: opt < %s -S -passes='default<Oz>' -debug -debug-only=loop-rotate 2>&1 | FileCheck %s -check-prefix=OZ
 
 ; Loop should be rotated for -Os but not for -Oz.
 ; OS: rotating Loop at depth 1