[SYCL][NewPM] Disable vectorization and loop transformation (#5305)

Port changes that disable vectorization and loop transformation passes
in optimization pipeline from legacy Pass Manager builder to new PM builder
(see commit ff6929e).
Also for those tests that fail without this fix after optimization by
the new Pass Manager add validation for both legacy and new PMs.

Signed-off-by: Mikhail Lychkov <[email protected]>

Author: mlychkov

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -223,6 +223,8 @@ extern cl::opt<bool> EnableMatrix;
 
 extern cl::opt<bool> DisablePreInliner;
 extern cl::opt<int> PreInlineThreshold;
+
+extern cl::opt<bool> SYCLOptimizationMode;
 } // namespace llvm
 
 void PassBuilder::invokePeepholeEPCallbacks(FunctionPassManager &FPM,
@@ -271,78 +273,88 @@ PassBuilder::buildO1FunctionSimplificationPipeline(OptimizationLevel Level,
   // Form canonically associated expression trees, and simplify the trees using
   // basic mathematical properties. For example, this will form (nearly)
   // minimal multiplication trees.
-  FPM.addPass(ReassociatePass());
-
-  // Add the primary loop simplification pipeline.
-  // FIXME: Currently this is split into two loop pass pipelines because we run
-  // some function passes in between them. These can and should be removed
-  // and/or replaced by scheduling the loop pass equivalents in the correct
-  // positions. But those equivalent passes aren't powerful enough yet.
-  // Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
-  // used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet to
-  // fully replace `SimplifyCFGPass`, and the closest to the other we have is
-  // `LoopInstSimplify`.
-  LoopPassManager LPM1, LPM2;
-
-  // Simplify the loop body. We do this initially to clean up after other loop
-  // passes run, either when iterating on a loop or on inner loops with
-  // implications on the outer loop.
-  LPM1.addPass(LoopInstSimplifyPass());
-  LPM1.addPass(LoopSimplifyCFGPass());
-
-  // Try to remove as much code from the loop header as possible,
-  // to reduce amount of IR that will have to be duplicated.
-  // TODO: Investigate promotion cap for O1.
-  LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
-
-  LPM1.addPass(LoopRotatePass(/* Disable header duplication */ true,
-                              isLTOPreLink(Phase)));
-  // TODO: Investigate promotion cap for O1.
-  LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
-  LPM1.addPass(SimpleLoopUnswitchPass());
-  if (EnableLoopFlatten)
-    LPM1.addPass(LoopFlattenPass());
-
-  LPM2.addPass(LoopIdiomRecognizePass());
-  LPM2.addPass(IndVarSimplifyPass());
-
-  for (auto &C : LateLoopOptimizationsEPCallbacks)
-    C(LPM2, Level);
-
-  LPM2.addPass(LoopDeletionPass());
-
-  if (EnableLoopInterchange)
-    LPM2.addPass(LoopInterchangePass());
-
-  // Do not enable unrolling in PreLinkThinLTO phase during sample PGO
-  // because it changes IR to makes profile annotation in back compile
-  // inaccurate. The normal unroller doesn't pay attention to forced full unroll
-  // attributes so we need to make sure and allow the full unroll pass to pay
-  // attention to it.
-  if (Phase != ThinOrFullLTOPhase::ThinLTOPreLink || !PGOOpt ||
-      PGOOpt->Action != PGOOptions::SampleUse)
-    LPM2.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
-                                    /* OnlyWhenForced= */ !PTO.LoopUnrolling,
-                                    PTO.ForgetAllSCEVInLoopUnroll));
-
-  for (auto &C : LoopOptimizerEndEPCallbacks)
-    C(LPM2, Level);
-
-  // We provide the opt remark emitter pass for LICM to use. We only need to do
-  // this once as it is immutable.
-  FPM.addPass(
-      RequireAnalysisPass<OptimizationRemarkEmitterAnalysis, Function>());
-  FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM1),
-                                              /*UseMemorySSA=*/true,
-                                              /*UseBlockFrequencyInfo=*/true));
-  FPM.addPass(SimplifyCFGPass());
-  FPM.addPass(InstCombinePass());
-  // The loop passes in LPM2 (LoopFullUnrollPass) do not preserve MemorySSA.
-  // *All* loop passes must preserve it, in order to be able to use it.
-  FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM2),
-                                              /*UseMemorySSA=*/false,
-                                              /*UseBlockFrequencyInfo=*/false));
+  if (!SYCLOptimizationMode) {
+    // FIXME: re-association increases variables liveness and therefore register
+    // pressure.
+    FPM.addPass(ReassociatePass());
+
+    // Do not run loop pass pipeline in "SYCL Optimization Mode". Loop
+    // optimizations rely on TTI, which is not accurate for SPIR target.
+
+    // Add the primary loop simplification pipeline.
+    // FIXME: Currently this is split into two loop pass pipelines because we
+    // run some function passes in between them. These can and should be removed
+    // and/or replaced by scheduling the loop pass equivalents in the correct
+    // positions. But those equivalent passes aren't powerful enough yet.
+    // Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
+    // used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet
+    // to fully replace `SimplifyCFGPass`, and the closest to the other we have
+    // is `LoopInstSimplify`.
+    LoopPassManager LPM1, LPM2;
+
+    // Simplify the loop body. We do this initially to clean up after other loop
+    // passes run, either when iterating on a loop or on inner loops with
+    // implications on the outer loop.
+    LPM1.addPass(LoopInstSimplifyPass());
+    LPM1.addPass(LoopSimplifyCFGPass());
+
+    // Try to remove as much code from the loop header as possible,
+    // to reduce amount of IR that will have to be duplicated.
+    // TODO: Investigate promotion cap for O1.
+    LPM1.addPass(
+        LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
+
+    LPM1.addPass(LoopRotatePass(/* Disable header duplication */ true,
+                                isLTOPreLink(Phase)));
+    // TODO: Investigate promotion cap for O1.
+    LPM1.addPass(
+        LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
+    LPM1.addPass(SimpleLoopUnswitchPass());
+    if (EnableLoopFlatten)
+      LPM1.addPass(LoopFlattenPass());
+
+    LPM2.addPass(LoopIdiomRecognizePass());
+    LPM2.addPass(IndVarSimplifyPass());
+
+    for (auto &C : LateLoopOptimizationsEPCallbacks)
+      C(LPM2, Level);
 
+    LPM2.addPass(LoopDeletionPass());
+
+    if (EnableLoopInterchange)
+      LPM2.addPass(LoopInterchangePass());
+
+    // Do not enable unrolling in PreLinkThinLTO phase during sample PGO
+    // because it changes IR to makes profile annotation in back compile
+    // inaccurate. The normal unroller doesn't pay attention to forced full
+    // unroll attributes so we need to make sure and allow the full unroll pass
+    // to pay attention to it.
+    if (Phase != ThinOrFullLTOPhase::ThinLTOPreLink || !PGOOpt ||
+        PGOOpt->Action != PGOOptions::SampleUse)
+      LPM2.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
+                                      /* OnlyWhenForced= */ !PTO.LoopUnrolling,
+                                      PTO.ForgetAllSCEVInLoopUnroll));
+
+    for (auto &C : LoopOptimizerEndEPCallbacks)
+      C(LPM2, Level);
+
+    // We provide the opt remark emitter pass for LICM to use. We only need to
+    // do this once as it is immutable.
+    FPM.addPass(
+        RequireAnalysisPass<OptimizationRemarkEmitterAnalysis, Function>());
+    FPM.addPass(
+        createFunctionToLoopPassAdaptor(std::move(LPM1),
+                                        /*UseMemorySSA=*/true,
+                                        /*UseBlockFrequencyInfo=*/true));
+    FPM.addPass(SimplifyCFGPass());
+    FPM.addPass(InstCombinePass());
+    // The loop passes in LPM2 (LoopFullUnrollPass) do not preserve MemorySSA.
+    // *All* loop passes must preserve it, in order to be able to use it.
+    FPM.addPass(
+        createFunctionToLoopPassAdaptor(std::move(LPM2),
+                                        /*UseMemorySSA=*/false,
+                                        /*UseBlockFrequencyInfo=*/false));
+  }
   // Delete small array after loop unroll.
   FPM.addPass(SROAPass());
 
@@ -443,81 +455,92 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
   // Form canonically associated expression trees, and simplify the trees using
   // basic mathematical properties. For example, this will form (nearly)
   // minimal multiplication trees.
-  FPM.addPass(ReassociatePass());
-
-  // Add the primary loop simplification pipeline.
-  // FIXME: Currently this is split into two loop pass pipelines because we run
-  // some function passes in between them. These can and should be removed
-  // and/or replaced by scheduling the loop pass equivalents in the correct
-  // positions. But those equivalent passes aren't powerful enough yet.
-  // Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
-  // used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet to
-  // fully replace `SimplifyCFGPass`, and the closest to the other we have is
-  // `LoopInstSimplify`.
-  LoopPassManager LPM1, LPM2;
-
-  // Simplify the loop body. We do this initially to clean up after other loop
-  // passes run, either when iterating on a loop or on inner loops with
-  // implications on the outer loop.
-  LPM1.addPass(LoopInstSimplifyPass());
-  LPM1.addPass(LoopSimplifyCFGPass());
-
-  // Try to remove as much code from the loop header as possible,
-  // to reduce amount of IR that will have to be duplicated.
-  // TODO: Investigate promotion cap for O1.
-  LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
+  if (!SYCLOptimizationMode) {
+    // FIXME: re-association increases variables liveness and therefore register
+    // pressure.
+    FPM.addPass(ReassociatePass());
+
+    // Do not run loop pass pipeline in "SYCL Optimization Mode". Loop
+    // optimizations rely on TTI, which is not accurate for SPIR target.
+
+    // Add the primary loop simplification pipeline.
+    // FIXME: Currently this is split into two loop pass pipelines because we
+    // run some function passes in between them. These can and should be removed
+    // and/or replaced by scheduling the loop pass equivalents in the correct
+    // positions. But those equivalent passes aren't powerful enough yet.
+    // Specifically, `SimplifyCFGPass` and `InstCombinePass` are currently still
+    // used. We have `LoopSimplifyCFGPass` which isn't yet powerful enough yet
+    // to fully replace `SimplifyCFGPass`, and the closest to the other we have
+    // is `LoopInstSimplify`.
+    LoopPassManager LPM1, LPM2;
+
+    // Simplify the loop body. We do this initially to clean up after other loop
+    // passes run, either when iterating on a loop or on inner loops with
+    // implications on the outer loop.
+    LPM1.addPass(LoopInstSimplifyPass());
+    LPM1.addPass(LoopSimplifyCFGPass());
+
+    // Try to remove as much code from the loop header as possible,
+    // to reduce amount of IR that will have to be duplicated.
+    // TODO: Investigate promotion cap for O1.
+    LPM1.addPass(
+        LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
+
+    // Disable header duplication in loop rotation at -Oz.
+    LPM1.addPass(
+        LoopRotatePass(Level != OptimizationLevel::Oz, isLTOPreLink(Phase)));
+    // TODO: Investigate promotion cap for O1.
+    LPM1.addPass(
+        LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
+    LPM1.addPass(SimpleLoopUnswitchPass(/* NonTrivial */ Level ==
+                                            OptimizationLevel::O3 &&
+                                        EnableO3NonTrivialUnswitching));
+    if (EnableLoopFlatten)
+      LPM1.addPass(LoopFlattenPass());
+
+    LPM2.addPass(LoopIdiomRecognizePass());
+    LPM2.addPass(IndVarSimplifyPass());
 
-  // Disable header duplication in loop rotation at -Oz.
-  LPM1.addPass(
-      LoopRotatePass(Level != OptimizationLevel::Oz, isLTOPreLink(Phase)));
-  // TODO: Investigate promotion cap for O1.
-  LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
-  LPM1.addPass(
-      SimpleLoopUnswitchPass(/* NonTrivial */ Level == OptimizationLevel::O3 &&
-                             EnableO3NonTrivialUnswitching));
-  if (EnableLoopFlatten)
-    LPM1.addPass(LoopFlattenPass());
-
-  LPM2.addPass(LoopIdiomRecognizePass());
-  LPM2.addPass(IndVarSimplifyPass());
-
-  for (auto &C : LateLoopOptimizationsEPCallbacks)
-    C(LPM2, Level);
-
-  LPM2.addPass(LoopDeletionPass());
-
-  if (EnableLoopInterchange)
-    LPM2.addPass(LoopInterchangePass());
-
-  // Do not enable unrolling in PreLinkThinLTO phase during sample PGO
-  // because it changes IR to makes profile annotation in back compile
-  // inaccurate. The normal unroller doesn't pay attention to forced full unroll
-  // attributes so we need to make sure and allow the full unroll pass to pay
-  // attention to it.
-  if (Phase != ThinOrFullLTOPhase::ThinLTOPreLink || !PGOOpt ||
-      PGOOpt->Action != PGOOptions::SampleUse)
-    LPM2.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
-                                    /* OnlyWhenForced= */ !PTO.LoopUnrolling,
-                                    PTO.ForgetAllSCEVInLoopUnroll));
-
-  for (auto &C : LoopOptimizerEndEPCallbacks)
-    C(LPM2, Level);
-
-  // We provide the opt remark emitter pass for LICM to use. We only need to do
-  // this once as it is immutable.
-  FPM.addPass(
-      RequireAnalysisPass<OptimizationRemarkEmitterAnalysis, Function>());
-  FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM1),
-                                              /*UseMemorySSA=*/true,
-                                              /*UseBlockFrequencyInfo=*/true));
-  FPM.addPass(SimplifyCFGPass());
-  FPM.addPass(InstCombinePass());
-  // The loop passes in LPM2 (LoopIdiomRecognizePass, IndVarSimplifyPass,
-  // LoopDeletionPass and LoopFullUnrollPass) do not preserve MemorySSA.
-  // *All* loop passes must preserve it, in order to be able to use it.
-  FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM2),
-                                              /*UseMemorySSA=*/false,
-                                              /*UseBlockFrequencyInfo=*/false));
+    for (auto &C : LateLoopOptimizationsEPCallbacks)
+      C(LPM2, Level);
+
+    LPM2.addPass(LoopDeletionPass());
+
+    if (EnableLoopInterchange)
+      LPM2.addPass(LoopInterchangePass());
+
+    // Do not enable unrolling in PreLinkThinLTO phase during sample PGO
+    // because it changes IR to makes profile annotation in back compile
+    // inaccurate. The normal unroller doesn't pay attention to forced full
+    // unroll attributes so we need to make sure and allow the full unroll pass
+    // to pay attention to it.
+    if (Phase != ThinOrFullLTOPhase::ThinLTOPreLink || !PGOOpt ||
+        PGOOpt->Action != PGOOptions::SampleUse)
+      LPM2.addPass(LoopFullUnrollPass(Level.getSpeedupLevel(),
+                                      /* OnlyWhenForced= */ !PTO.LoopUnrolling,
+                                      PTO.ForgetAllSCEVInLoopUnroll));
+
+    for (auto &C : LoopOptimizerEndEPCallbacks)
+      C(LPM2, Level);
+
+    // We provide the opt remark emitter pass for LICM to use. We only need to
+    // do this once as it is immutable.
+    FPM.addPass(
+        RequireAnalysisPass<OptimizationRemarkEmitterAnalysis, Function>());
+    FPM.addPass(
+        createFunctionToLoopPassAdaptor(std::move(LPM1),
+                                        /*UseMemorySSA=*/true,
+                                        /*UseBlockFrequencyInfo=*/true));
+    FPM.addPass(SimplifyCFGPass());
+    FPM.addPass(InstCombinePass());
+    // The loop passes in LPM2 (LoopIdiomRecognizePass, IndVarSimplifyPass,
+    // LoopDeletionPass and LoopFullUnrollPass) do not preserve MemorySSA.
+    // *All* loop passes must preserve it, in order to be able to use it.
+    FPM.addPass(
+        createFunctionToLoopPassAdaptor(std::move(LPM2),
+                                        /*UseMemorySSA=*/false,
+                                        /*UseBlockFrequencyInfo=*/false));
+  }
 
   // Delete small array after loop unroll.
   FPM.addPass(SROAPass());
@@ -1162,29 +1185,32 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
   for (auto &C : VectorizerStartEPCallbacks)
     C(OptimizePM, Level);
 
-  LoopPassManager LPM;
-  // First rotate loops that may have been un-rotated by prior passes.
-  // Disable header duplication at -Oz.
-  LPM.addPass(LoopRotatePass(Level != OptimizationLevel::Oz, LTOPreLink));
-  // Some loops may have become dead by now. Try to delete them.
-  // FIXME: see discussion in https://reviews.llvm.org/D112851,
-  //        this may need to be revisited once we run GVN before loop deletion
-  //        in the simplification pipeline.
-  LPM.addPass(LoopDeletionPass());
-  OptimizePM.addPass(createFunctionToLoopPassAdaptor(
-      std::move(LPM), /*UseMemorySSA=*/false, /*UseBlockFrequencyInfo=*/false));
-
-  // Distribute loops to allow partial vectorization.  I.e. isolate dependences
-  // into separate loop that would otherwise inhibit vectorization.  This is
-  // currently only performed for loops marked with the metadata
-  // llvm.loop.distribute=true or when -enable-loop-distribute is specified.
-  OptimizePM.addPass(LoopDistributePass());
-
-  // Populates the VFABI attribute with the scalar-to-vector mappings
-  // from the TargetLibraryInfo.
-  OptimizePM.addPass(InjectTLIMappings());
-
-  addVectorPasses(Level, OptimizePM, /* IsFullLTO */ false);
+  if (!SYCLOptimizationMode) {
+    LoopPassManager LPM;
+    // First rotate loops that may have been un-rotated by prior passes.
+    // Disable header duplication at -Oz.
+    LPM.addPass(LoopRotatePass(Level != OptimizationLevel::Oz, LTOPreLink));
+    // Some loops may have become dead by now. Try to delete them.
+    // FIXME: see discussion in https://reviews.llvm.org/D112851,
+    //        this may need to be revisited once we run GVN before loop deletion
+    //        in the simplification pipeline.
+    LPM.addPass(LoopDeletionPass());
+    OptimizePM.addPass(
+        createFunctionToLoopPassAdaptor(std::move(LPM), /*UseMemorySSA=*/false,
+                                        /*UseBlockFrequencyInfo=*/false));
+
+    // Distribute loops to allow partial vectorization. I.e. isolate dependences
+    // into separate loop that would otherwise inhibit vectorization. This is
+    // currently only performed for loops marked with the metadata
+    // llvm.loop.distribute=true or when -enable-loop-distribute is specified.
+    OptimizePM.addPass(LoopDistributePass());
+
+    // Populates the VFABI attribute with the scalar-to-vector mappings
+    // from the TargetLibraryInfo.
+    OptimizePM.addPass(InjectTLIMappings());
+
+    addVectorPasses(Level, OptimizePM, /* IsFullLTO */ false);
+  }
 
   // LoopSink pass sinks instructions hoisted by LICM, which serves as a
   // canonicalization pass that enables other optimizations. As a result,