[PM] Separate the LoopAnalysisManager from the LoopPassManager and move

the latter to the Transforms library.

While the loop PM uses an analysis to form the IR units, the current
plan is to have the PM itself establish and enforce both loop simplified
form and LCSSA. This would be a layering violation in the analysis
library.

Fundamentally, the idea behind the loop PM is to *transform* loops in
addition to running passes over them, so it really seemed like the most
natural place to sink this was into the transforms library.

We can't just move *everything* because we also have loop analyses that
rely on a subset of the invariants. So this patch splits the the loop
infrastructure into the analysis management that has to be part of the
analysis library, and the transform-aware pass manager.

This also required splitting the loop analyses' printer passes out to
the transforms library, which makes sense to me as running these will
transform the code into LCSSA in theory.

I haven't split the unittest though because testing one component
without the other seems nearly intractable.

Differential Revision: https://reviews.llvm.org/D28452

llvm-svn: 291662

15 files changed, 154 insertions, 19 deletions

diff --git a/llvm/lib/Transforms/Scalar/CMakeLists.txt b/llvm/lib/Transforms/Scalar/CMakeLists.txt
index 56df77f0302..06d3d6a7395 100644
--- a/llvm/lib/Transforms/Scalar/CMakeLists.txt
+++ b/llvm/lib/Transforms/Scalar/CMakeLists.txt
@@ -13,10 +13,12 @@ add_llvm_library(LLVMScalarOpts
   GuardWidening.cpp
   GVN.cpp
   GVNHoist.cpp
+  IVUsersPrinter.cpp
   InductiveRangeCheckElimination.cpp
   IndVarSimplify.cpp
   JumpThreading.cpp
   LICM.cpp
+  LoopAccessAnalysisPrinter.cpp
   LoopSink.cpp
   LoadCombine.cpp
   LoopDeletion.cpp
@@ -26,6 +28,7 @@ add_llvm_library(LLVMScalarOpts
   LoopInstSimplify.cpp
   LoopInterchange.cpp
   LoopLoadElimination.cpp
+  LoopPassManager.cpp
   LoopRerollPass.cpp
   LoopRotation.cpp
   LoopSimplifyCFG.cpp
diff --git a/llvm/lib/Transforms/Scalar/IVUsersPrinter.cpp b/llvm/lib/Transforms/Scalar/IVUsersPrinter.cpp
new file mode 100644
index 00000000000..80759337928
--- /dev/null
+++ b/llvm/lib/Transforms/Scalar/IVUsersPrinter.cpp
@@ -0,0 +1,22 @@
+//===- IVUsersPrinter.cpp - Induction Variable Users Printer ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Scalar/IVUsersPrinter.h"
+#include "llvm/Analysis/IVUsers.h"
+#include "llvm/Support/Debug.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "iv-users"
+
+PreservedAnalyses IVUsersPrinterPass::run(Loop &L, LoopAnalysisManager &AM,
+                                          LoopStandardAnalysisResults &AR,
+                                          LPMUpdater &U) {
+  AM.getResult<IVUsersAnalysis>(L, AR).print(OS);
+  return PreservedAnalyses::all();
+}
diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 10975cd7951..1752fb75eb1 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -25,15 +25,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar/IndVarSimplify.h"
-#include "llvm/Transforms/Scalar.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
-#include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
+#include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/BasicBlock.h"
@@ -49,6 +47,8 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 24d1356ca5e..4c15c8a32be 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -41,7 +41,6 @@
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/OptimizationDiagnosticInfo.h"
 #include "llvm/Analysis/ScalarEvolution.h"
@@ -62,6 +61,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/SSAUpdater.h"
diff --git a/llvm/lib/Transforms/Scalar/LoopAccessAnalysisPrinter.cpp b/llvm/lib/Transforms/Scalar/LoopAccessAnalysisPrinter.cpp
new file mode 100644
index 00000000000..a64c99117d6
--- /dev/null
+++ b/llvm/lib/Transforms/Scalar/LoopAccessAnalysisPrinter.cpp
@@ -0,0 +1,25 @@
+//===- LoopAccessAnalysisPrinter.cpp - Loop Access Analysis Printer --------==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Scalar/LoopAccessAnalysisPrinter.h"
+#include "llvm/Analysis/LoopAccessAnalysis.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "loop-accesses"
+
+PreservedAnalyses
+LoopAccessInfoPrinterPass::run(Loop &L, LoopAnalysisManager &AM,
+                               LoopStandardAnalysisResults &AR, LPMUpdater &) {
+  Function &F = *L.getHeader()->getParent();
+  auto &LAI = AM.getResult<LoopAccessAnalysis>(L, AR);
+  OS << "Loop access info in function '" << F.getName() << "':\n";
+  OS.indent(2) << L.getHeader()->getName() << ":\n";
+  LAI.print(OS, 4);
+  return PreservedAnalyses::all();
+}
diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index d79edd3f064..cca75a36502 100644
--- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -19,9 +19,9 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 using namespace llvm;
 
diff --git a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
index 1336b05239e..19716b28ad6 100644
--- a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
@@ -31,13 +31,13 @@
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopAccessAnalysis.h"
 #include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/OptimizationDiagnosticInfo.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index 89f5a45e696..5fec51c095d 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -46,7 +46,6 @@
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopAccessAnalysis.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
 #include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
@@ -61,6 +60,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/BuildLibCalls.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
diff --git a/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp b/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp
index 3e5640826b2..69102d10ff6 100644
--- a/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp
@@ -18,7 +18,6 @@
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/DataLayout.h"
@@ -26,6 +25,7 @@
 #include "llvm/IR/Instructions.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 using namespace llvm;
diff --git a/llvm/lib/Transforms/Scalar/LoopPassManager.cpp b/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
new file mode 100644
index 00000000000..028f4bba8b1
--- /dev/null
+++ b/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
@@ -0,0 +1,85 @@
+//===- LoopPassManager.cpp - Loop pass management -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
+#include "llvm/Analysis/LoopInfo.h"
+
+using namespace llvm;
+
+// Explicit template instantiations and specialization defininitions for core
+// template typedefs.
+namespace llvm {
+template class PassManager<Loop, LoopAnalysisManager,
+                           LoopStandardAnalysisResults &, LPMUpdater &>;
+
+/// Explicitly specialize the pass manager's run method to handle loop nest
+/// structure updates.
+template <>
+PreservedAnalyses
+PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
+            LPMUpdater &>::run(Loop &L, LoopAnalysisManager &AM,
+                               LoopStandardAnalysisResults &AR, LPMUpdater &U) {
+  PreservedAnalyses PA = PreservedAnalyses::all();
+
+  if (DebugLogging)
+    dbgs() << "Starting Loop pass manager run.\n";
+
+  for (auto &Pass : Passes) {
+    if (DebugLogging)
+      dbgs() << "Running pass: " << Pass->name() << " on " << L;
+
+    PreservedAnalyses PassPA = Pass->run(L, AM, AR, U);
+
+    // If the loop was deleted, abort the run and return to the outer walk.
+    if (U.skipCurrentLoop()) {
+      PA.intersect(std::move(PassPA));
+      break;
+    }
+
+    // Update the analysis manager as each pass runs and potentially
+    // invalidates analyses.
+    AM.invalidate(L, PassPA);
+
+    // Finally, we intersect the final preserved analyses to compute the
+    // aggregate preserved set for this pass manager.
+    PA.intersect(std::move(PassPA));
+
+    // FIXME: Historically, the pass managers all called the LLVM context's
+    // yield function here. We don't have a generic way to acquire the
+    // context and it isn't yet clear what the right pattern is for yielding
+    // in the new pass manager so it is currently omitted.
+    // ...getContext().yield();
+  }
+
+  // Invalidation for the current loop should be handled above, and other loop
+  // analysis results shouldn't be impacted by runs over this loop. Therefore,
+  // the remaining analysis results in the AnalysisManager are preserved. We
+  // mark this with a set so that we don't need to inspect each one
+  // individually.
+  // FIXME: This isn't correct! This loop and all nested loops' analyses should
+  // be preserved, but unrolling should invalidate the parent loop's analyses.
+  PA.preserveSet<AllAnalysesOn<Loop>>();
+
+  if (DebugLogging)
+    dbgs() << "Finished Loop pass manager run.\n";
+
+  return PA;
+}
+}
+
+PrintLoopPass::PrintLoopPass() : OS(dbgs()) {}
+PrintLoopPass::PrintLoopPass(raw_ostream &OS, const std::string &Banner)
+    : OS(OS), Banner(Banner) {}
+
+PreservedAnalyses PrintLoopPass::run(Loop &L, LoopAnalysisManager &,
+                                     LoopStandardAnalysisResults &,
+                                     LPMUpdater &) {
+  printLoop(L, OS, Banner);
+  return PreservedAnalyses::all();
+}
diff --git a/llvm/lib/Transforms/Scalar/LoopRotation.cpp b/llvm/lib/Transforms/Scalar/LoopRotation.cpp
index 87f5f8b27a6..cc83069d5f5 100644
--- a/llvm/lib/Transforms/Scalar/LoopRotation.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopRotation.cpp
@@ -14,13 +14,12 @@
 #include "llvm/Transforms/Scalar/LoopRotation.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/CodeMetrics.h"
-#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
@@ -34,6 +33,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
diff --git a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index 30d683611fc..16061212ba3 100644
--- a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -18,18 +18,18 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/DependenceAnalysis.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 using namespace llvm;
diff --git a/llvm/lib/Transforms/Scalar/LoopSink.cpp b/llvm/lib/Transforms/Scalar/LoopSink.cpp
index 800a9b4c69c..f3f415275c0 100644
--- a/llvm/lib/Transforms/Scalar/LoopSink.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSink.cpp
@@ -38,7 +38,6 @@
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
 #include "llvm/IR/Dominators.h"
@@ -47,6 +46,7 @@
 #include "llvm/IR/Metadata.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 using namespace llvm;
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 5356835ab74..a1561fc0a6c 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -59,16 +59,15 @@
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallBitVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/Analysis/IVUsers.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
@@ -80,13 +79,13 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Module.h"
 #include "llvm/IR/OperandTraits.h"
 #include "llvm/IR/Operator.h"
-#include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
 #include "llvm/IR/ValueHandle.h"
@@ -99,6 +98,7 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include <algorithm>
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index a31514b1b77..c7f91226d22 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -19,7 +19,6 @@
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/LoopUnrollAnalyzer.h"
 #include "llvm/Analysis/OptimizationDiagnosticInfo.h"
 #include "llvm/Analysis/ScalarEvolution.h"
@@ -33,6 +32,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/UnrollLoop.h"
 #include <climits>