[PM] Rewrite the loop pass manager to use a worklist and augmented run

arguments much like the CGSCC pass manager.

This is a major redesign following the pattern establish for the CGSCC layer to
support updates to the set of loops during the traversal of the loop nest and
to support invalidation of analyses.

An additional significant burden in the loop PM is that so many passes require
access to a large number of function analyses. Manually ensuring these are
cached, available, and preserved has been a long-standing burden in LLVM even
with the help of the automatic scheduling in the old pass manager. And it made
the new pass manager extremely unweildy. With this design, we can package the
common analyses up while in a function pass and make them immediately available
to all the loop passes. While in some cases this is unnecessary, I think the
simplicity afforded is worth it.

This does not (yet) address loop simplified form or LCSSA form, but those are
the next things on my radar and I have a clear plan for them.

While the patch is very large, most of it is either mechanically updating loop
passes to the new API or the new testing for the loop PM. The code for it is
reasonably compact.

I have not yet updated all of the loop passes to correctly leverage the update
mechanisms demonstrated in the unittests. I'll do that in follow-up patches
along with improved FileCheck tests for those passes that ensure things work in
more realistic scenarios. In many cases, there isn't much we can do with these
until the loop simplified form and LCSSA form are in place.

Differential Revision: https://reviews.llvm.org/D28292

llvm-svn: 291651

11 files changed, 59 insertions, 133 deletions

diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 3829aba9c86..10975cd7951 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -2482,23 +2482,13 @@ bool IndVarSimplify::run(Loop *L) {
   return Changed;
 }
 
-PreservedAnalyses IndVarSimplifyPass::run(Loop &L, LoopAnalysisManager &AM) {
-  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+PreservedAnalyses IndVarSimplifyPass::run(Loop &L, LoopAnalysisManager &AM,
+                                          LoopStandardAnalysisResults &AR,
+                                          LPMUpdater &) {
   Function *F = L.getHeader()->getParent();
   const DataLayout &DL = F->getParent()->getDataLayout();
 
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-
-  assert((LI && SE && DT) &&
-         "Analyses required for indvarsimplify not available!");
-
-  // Optional analyses.
-  auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-
-  IndVarSimplify IVS(LI, SE, DT, DL, TLI, TTI);
+  IndVarSimplify IVS(&AR.LI, &AR.SE, &AR.DT, DL, &AR.TLI, &AR.TTI);
   if (!IVS.run(&L))
     return PreservedAnalyses::all();
 
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 26b3b14d186..24d1356ca5e 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -185,23 +185,20 @@ private:
 };
 }
 
-PreservedAnalyses LICMPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LICMPass::run(Loop &L, LoopAnalysisManager &AM,
+                                LoopStandardAnalysisResults &AR, LPMUpdater &) {
   const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+      AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR).getManager();
   Function *F = L.getHeader()->getParent();
 
-  auto *AA = FAM.getCachedResult<AAManager>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
   auto *ORE = FAM.getCachedResult<OptimizationRemarkEmitterAnalysis>(*F);
-  assert((AA && LI && DT && TLI && SE && ORE) &&
-         "Analyses for LICM not available");
+  // FIXME: This should probably be optional rather than required.
+  if (!ORE)
+    report_fatal_error("LICM: OptimizationRemarkEmitterAnalysis not "
+                       "cached at a higher level");
 
   LoopInvariantCodeMotion LICM;
-
-  if (!LICM.runOnLoop(&L, AA, LI, DT, TLI, SE, ORE, true))
+  if (!LICM.runOnLoop(&L, &AR.AA, &AR.LI, &AR.DT, &AR.TLI, &AR.SE, ORE, true))
     return PreservedAnalyses::all();
 
   // FIXME: There is no setPreservesCFG in the new PM. When that becomes
diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index 187e6e3073c..d79edd3f064 100644
--- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -215,15 +215,10 @@ bool LoopDeletionPass::runImpl(Loop *L, DominatorTree &DT, ScalarEvolution &SE,
   return Changed;
 }
 
-PreservedAnalyses LoopDeletionPass::run(Loop &L, LoopAnalysisManager &AM) {
-  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  auto &DT = *FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto &SE = *FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto &LI = *FAM.getCachedResult<LoopAnalysis>(*F);
-
-  bool Changed = runImpl(&L, DT, SE, LI);
+PreservedAnalyses LoopDeletionPass::run(Loop &L, LoopAnalysisManager &AM,
+                                        LoopStandardAnalysisResults &AR,
+                                        LPMUpdater &) {
+  bool Changed = runImpl(&L, AR.DT, AR.SE, AR.LI);
   if (!Changed)
     return PreservedAnalyses::all();
 
diff --git a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
index b2b2f72aa83..1336b05239e 100644
--- a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
@@ -946,10 +946,18 @@ PreservedAnalyses LoopDistributePass::run(Function &F,
   auto &SE = AM.getResult<ScalarEvolutionAnalysis>(F);
   auto &ORE = AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
 
+  // We don't directly need these analyses but they're required for loop
+  // analyses so provide them below.
+  auto &AA = AM.getResult<AAManager>(F);
+  auto &AC = AM.getResult<AssumptionAnalysis>(F);
+  auto &TTI = AM.getResult<TargetIRAnalysis>(F);
+  auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
+
   auto &LAM = AM.getResult<LoopAnalysisManagerFunctionProxy>(F).getManager();
   std::function<const LoopAccessInfo &(Loop &)> GetLAA =
       [&](Loop &L) -> const LoopAccessInfo & {
-    return LAM.getResult<LoopAccessAnalysis>(L);
+    LoopStandardAnalysisResults AR = {AA, AC, DT, LI, SE, TLI, TTI};
+    return LAM.getResult<LoopAccessAnalysis>(L, AR);
   };
 
   bool Changed = runImpl(F, &LI, &DT, &SE, &ORE, GetLAA);
diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index 2743574ecca..89f5a45e696 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -186,24 +186,12 @@ public:
 };
 } // End anonymous namespace.
 
-PreservedAnalyses LoopIdiomRecognizePass::run(Loop &L,
-                                              LoopAnalysisManager &AM) {
-  const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  // Use getCachedResult because Loop pass cannot trigger a function analysis.
-  auto *AA = FAM.getCachedResult<AAManager>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-  const auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
+PreservedAnalyses LoopIdiomRecognizePass::run(Loop &L, LoopAnalysisManager &AM,
+                                              LoopStandardAnalysisResults &AR,
+                                              LPMUpdater &) {
   const auto *DL = &L.getHeader()->getModule()->getDataLayout();
-  assert((AA && DT && LI && SE && TLI && TTI && DL) &&
-         "Analyses for Loop Idiom Recognition not available");
 
-  LoopIdiomRecognize LIR(AA, DT, LI, SE, TLI, TTI, DL);
+  LoopIdiomRecognize LIR(&AR.AA, &AR.DT, &AR.LI, &AR.SE, &AR.TLI, &AR.TTI, DL);
   if (!LIR.runOnLoop(&L))
     return PreservedAnalyses::all();
 
diff --git a/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp b/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp
index f6620ad1ade..3e5640826b2 100644
--- a/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp
@@ -183,20 +183,10 @@ public:
 };
 }
 
-PreservedAnalyses LoopInstSimplifyPass::run(Loop &L,
-                                            LoopAnalysisManager &AM) {
-  const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  // Use getCachedResult because Loop pass cannot trigger a function analysis.
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *AC = FAM.getCachedResult<AssumptionAnalysis>(*F);
-  const auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-  assert((LI && AC && TLI) && "Analyses for Loop Inst Simplify not available");
-
-  if (!SimplifyLoopInst(&L, DT, LI, AC, TLI))
+PreservedAnalyses LoopInstSimplifyPass::run(Loop &L, LoopAnalysisManager &AM,
+                                            LoopStandardAnalysisResults &AR,
+                                            LPMUpdater &) {
+  if (!SimplifyLoopInst(&L, &AR.DT, &AR.LI, &AR.AC, &AR.TLI))
     return PreservedAnalyses::all();
 
   return getLoopPassPreservedAnalyses();
diff --git a/llvm/lib/Transforms/Scalar/LoopRotation.cpp b/llvm/lib/Transforms/Scalar/LoopRotation.cpp
index 0225cc32570..87f5f8b27a6 100644
--- a/llvm/lib/Transforms/Scalar/LoopRotation.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopRotation.cpp
@@ -625,20 +625,11 @@ bool LoopRotate::processLoop(Loop *L) {
 LoopRotatePass::LoopRotatePass(bool EnableHeaderDuplication)
     : EnableHeaderDuplication(EnableHeaderDuplication) {}
 
-PreservedAnalyses LoopRotatePass::run(Loop &L, LoopAnalysisManager &AM) {
-  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  const auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  auto *AC = FAM.getCachedResult<AssumptionAnalysis>(*F);
-  assert((LI && TTI && AC) && "Analyses for loop rotation not available");
-
-  // Optional analyses.
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
+PreservedAnalyses LoopRotatePass::run(Loop &L, LoopAnalysisManager &AM,
+                                      LoopStandardAnalysisResults &AR,
+                                      LPMUpdater &) {
   int Threshold = EnableHeaderDuplication ? DefaultRotationThreshold : 0;
-  LoopRotate LR(Threshold, LI, TTI, AC, DT, SE);
+  LoopRotate LR(Threshold, &AR.LI, &AR.TTI, &AR.AC, &AR.DT, &AR.SE);
 
   bool Changed = LR.processLoop(&L);
   if (!Changed)
diff --git a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index d37339fc5fe..30d683611fc 100644
--- a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -64,16 +64,10 @@ static bool simplifyLoopCFG(Loop &L, DominatorTree &DT, LoopInfo &LI) {
   return Changed;
 }
 
-PreservedAnalyses LoopSimplifyCFGPass::run(Loop &L, LoopAnalysisManager &AM) {
-  const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  assert((LI && DT) && "Analyses for LoopSimplifyCFG not available");
-
-  if (!simplifyLoopCFG(L, *DT, *LI))
+PreservedAnalyses LoopSimplifyCFGPass::run(Loop &L, LoopAnalysisManager &AM,
+                                           LoopStandardAnalysisResults &AR,
+                                           LPMUpdater &) {
+  if (!simplifyLoopCFG(L, AR.DT, AR.LI))
     return PreservedAnalyses::all();
   return getLoopPassPreservedAnalyses();
 }
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index a61f646042a..5356835ab74 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -5052,21 +5052,11 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager & /*LPM*/) {
   return ReduceLoopStrength(L, IU, SE, DT, LI, TTI);
 }
 
-PreservedAnalyses LoopStrengthReducePass::run(Loop &L,
-                                              LoopAnalysisManager &AM) {
-  const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  auto &IU = AM.getResult<IVUsersAnalysis>(L);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  assert((SE && DT && LI && TTI) &&
-         "Analyses for Loop Strength Reduce not available");
-
-  if (!ReduceLoopStrength(&L, IU, *SE, *DT, *LI, *TTI))
+PreservedAnalyses LoopStrengthReducePass::run(Loop &L, LoopAnalysisManager &AM,
+                                              LoopStandardAnalysisResults &AR,
+                                              LPMUpdater &) {
+  if (!ReduceLoopStrength(&L, AM.getResult<IVUsersAnalysis>(L, AR), AR.SE,
+                          AR.DT, AR.LI, AR.TTI))
     return PreservedAnalyses::all();
 
   return getLoopPassPreservedAnalyses();
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index f66369b3036..a31514b1b77 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -1111,41 +1111,23 @@ Pass *llvm::createSimpleLoopUnrollPass() {
   return llvm::createLoopUnrollPass(-1, -1, 0, 0, 0);
 }
 
-PreservedAnalyses LoopUnrollPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LoopUnrollPass::run(Loop &L, LoopAnalysisManager &AM,
+                                      LoopStandardAnalysisResults &AR,
+                                      LPMUpdater &) {
   const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+      AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR).getManager();
   Function *F = L.getHeader()->getParent();
 
-
-  DominatorTree *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  LoopInfo *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  ScalarEvolution *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  auto *AC = FAM.getCachedResult<AssumptionAnalysis>(*F);
   auto *ORE = FAM.getCachedResult<OptimizationRemarkEmitterAnalysis>(*F);
-  if (!DT)
-    report_fatal_error(
-        "LoopUnrollPass: DominatorTreeAnalysis not cached at a higher level");
-  if (!LI)
-    report_fatal_error(
-        "LoopUnrollPass: LoopAnalysis not cached at a higher level");
-  if (!SE)
-    report_fatal_error(
-        "LoopUnrollPass: ScalarEvolutionAnalysis not cached at a higher level");
-  if (!TTI)
-    report_fatal_error(
-        "LoopUnrollPass: TargetIRAnalysis not cached at a higher level");
-  if (!AC)
-    report_fatal_error(
-        "LoopUnrollPass: AssumptionAnalysis not cached at a higher level");
+  // FIXME: This should probably be optional rather than required.
   if (!ORE)
     report_fatal_error("LoopUnrollPass: OptimizationRemarkEmitterAnalysis not "
                        "cached at a higher level");
 
-  bool Changed =
-      tryToUnrollLoop(&L, *DT, LI, SE, *TTI, *AC, *ORE, /*PreserveLCSSA*/ true,
-                      ProvidedCount, ProvidedThreshold, ProvidedAllowPartial,
-                      ProvidedRuntime, ProvidedUpperBound);
+  bool Changed = tryToUnrollLoop(&L, AR.DT, &AR.LI, &AR.SE, AR.TTI, AR.AC, *ORE,
+                                 /*PreserveLCSSA*/ true, ProvidedCount,
+                                 ProvidedThreshold, ProvidedAllowPartial,
+                                 ProvidedRuntime, ProvidedUpperBound);
 
   if (!Changed)
     return PreservedAnalyses::all();
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 578c65daf7c..c9819a8e270 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -7641,7 +7641,7 @@ PreservedAnalyses LoopVectorizePass::run(Function &F,
     auto &TTI = AM.getResult<TargetIRAnalysis>(F);
     auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
     auto &BFI = AM.getResult<BlockFrequencyAnalysis>(F);
-    auto *TLI = AM.getCachedResult<TargetLibraryAnalysis>(F);
+    auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
     auto &AA = AM.getResult<AAManager>(F);
     auto &AC = AM.getResult<AssumptionAnalysis>(F);
     auto &DB = AM.getResult<DemandedBitsAnalysis>(F);
@@ -7650,10 +7650,11 @@ PreservedAnalyses LoopVectorizePass::run(Function &F,
     auto &LAM = AM.getResult<LoopAnalysisManagerFunctionProxy>(F).getManager();
     std::function<const LoopAccessInfo &(Loop &)> GetLAA =
         [&](Loop &L) -> const LoopAccessInfo & {
-      return LAM.getResult<LoopAccessAnalysis>(L);
+      LoopStandardAnalysisResults AR = {AA, AC, DT, LI, SE, TLI, TTI};
+      return LAM.getResult<LoopAccessAnalysis>(L, AR);
     };
     bool Changed =
-        runImpl(F, SE, LI, TTI, DT, BFI, TLI, DB, AA, AC, GetLAA, ORE);
+        runImpl(F, SE, LI, TTI, DT, BFI, &TLI, DB, AA, AC, GetLAA, ORE);
     if (!Changed)
       return PreservedAnalyses::all();
     PreservedAnalyses PA;