Index: include/llvm/Passes/PassBuilder.h =================================================================== --- include/llvm/Passes/PassBuilder.h +++ include/llvm/Passes/PassBuilder.h @@ -85,6 +85,9 @@ /// is that of the flag: `vectorize-slp`. bool SLPVectorization; + /// Tuning option to enable/disable loop unrolling. Its default value is true. + bool LoopUnrolling; + /// Tuning option to forget all SCEV loops in LoopUnroll. Its default value /// is that of the flag: `-forget-scev-loop-unroll`. bool ForgetAllSCEVInLoopUnroll; Index: lib/Passes/PassBuilder.cpp =================================================================== --- lib/Passes/PassBuilder.cpp +++ lib/Passes/PassBuilder.cpp @@ -215,6 +215,7 @@ LoopInterleaving = EnableLoopInterleaving; LoopVectorization = EnableLoopVectorization; SLPVectorization = RunSLPVectorization; + LoopUnrolling = true; ForgetAllSCEVInLoopUnroll = ForgetSCEVInLoopUnroll; LicmMssaOptCap = SetLicmMssaOptCap; LicmMssaNoAccForPromotionCap = SetLicmMssaNoAccForPromotionCap; @@ -458,8 +459,9 @@ // Do not enable unrolling in PreLinkThinLTO phase during sample PGO // because it changes IR to makes profile annotation in back compile // inaccurate. - if (Phase != ThinLTOPhase::PreLink || !PGOOpt || - PGOOpt->Action != PGOOptions::SampleUse) + if ((Phase != ThinLTOPhase::PreLink || !PGOOpt || + PGOOpt->Action != PGOOptions::SampleUse) && + PTO.LoopUnrolling) LPM2.addPass( LoopFullUnrollPass(Level, false, PTO.ForgetAllSCEVInLoopUnroll)); @@ -907,8 +909,9 @@ OptimizePM.addPass( createFunctionToLoopPassAdaptor(LoopUnrollAndJamPass(Level))); } - OptimizePM.addPass(LoopUnrollPass( - LoopUnrollOptions(Level, false, PTO.ForgetAllSCEVInLoopUnroll))); + if (PTO.LoopUnrolling) + OptimizePM.addPass(LoopUnrollPass( + LoopUnrollOptions(Level, false, PTO.ForgetAllSCEVInLoopUnroll))); OptimizePM.addPass(WarnMissedTransformationsPass()); OptimizePM.addPass(InstCombinePass()); OptimizePM.addPass(RequireAnalysisPass());