[PM] Port IndVarSimplify to the new pass manager

Summary:
There are some rough corners, since the new pass manager doesn't have
(as far as I can tell) LoopSimplify and LCSSA, so I've updated the
tests to run them separately in the old pass manager in the lit tests.
We also don't have an equivalent for AU.setPreservesCFG() in the new
pass manager, so I've left a FIXME.

Reviewers: bogner, chandlerc, davide

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20783

llvm-svn: 271846

include/llvm/Transforms/Scalar/IndVarSimplify.h

@@ -0,0 +1,29 @@
+//===- IndVarSimplify.h - Induction Variable Simplification -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides the interface for the Induction Variable
+// Simplification pass.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_SCALAR_INDVARSIMPLIFY_H
+#define LLVM_TRANSFORMS_SCALAR_INDVARSIMPLIFY_H
+
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+class IndVarSimplifyPass : public PassInfoMixin<IndVarSimplifyPass> {
+public:
+  PreservedAnalyses run(Loop &L, AnalysisManager<Loop> &AM);
+};
+}
+
+#endif // LLVM_TRANSFORMS_SCALAR_INDVARSIMPLIFY_H

lib/Passes/PassBuilder.cpp

@@ -72,6 +72,7 @@
 #include "llvm/Transforms/Scalar/EarlyCSE.h"
 #include "llvm/Transforms/Scalar/GuardWidening.h"
 #include "llvm/Transforms/Scalar/GVN.h"
+#include "llvm/Transforms/Scalar/IndVarSimplify.h"
 #include "llvm/Transforms/Scalar/LoopRotation.h"
 #include "llvm/Transforms/Scalar/LoopSimplifyCFG.h"
 #include "llvm/Transforms/Scalar/LowerAtomic.h"

lib/Passes/PassRegistry.def

@@ -164,4 +164,5 @@ LOOP_PASS("rotate", LoopRotatePass())
 LOOP_PASS("no-op-loop", NoOpLoopPass())
 LOOP_PASS("print", PrintLoopPass(dbgs()))
 LOOP_PASS("simplify-cfg", LoopSimplifyCFGPass())
+LOOP_PASS("indvars", IndVarSimplifyPass())
 #undef LOOP_PASS

lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -24,12 +24,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#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/TargetLibraryInfo.h"
@@ -2212,6 +2214,31 @@ bool IndVarSimplify::run(Loop *L) {
   return Changed;
 }
 
+PreservedAnalyses IndVarSimplifyPass::run(Loop &L, AnalysisManager<Loop> &AM) {
+  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+  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);
+  if (!IVS.run(&L))
+    return PreservedAnalyses::all();
+
+  // FIXME: once we have an equivalent of AU.setPreservesCFG() in the
+  // new pass manager, we should use that here.
+  return getLoopPassPreservedAnalyses();
+}
+
 namespace {
 struct IndVarSimplifyLegacyPass : public LoopPass {
   static char ID; // Pass identification, replacement for typeid

test/Transforms/IndVarSimplify/backedge-on-min-max.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -indvars -S | FileCheck %s
+; RUN: opt -lcssa -loop-simplify -S < %s | opt -S -passes='require<targetir>,require<scalar-evolution>,require<domtree>,loop(indvars)'
 
 ;; --- signed ---
 

test/Transforms/IndVarSimplify/iv-widen.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -indvars -S | FileCheck %s
+; RUN: opt -lcssa -loop-simplify -S < %s | opt -S -passes='require<targetir>,require<scalar-evolution>,require<domtree>,loop(indvars)'
 
 ; Provide legal integer types.
 target datalayout = "n8:16:32:64"

test/Transforms/IndVarSimplify/sharpen-range.ll

@@ -1,4 +1,5 @@
 ;; RUN: opt -S < %s -indvars | FileCheck %s
+; RUN: opt -lcssa -loop-simplify -S < %s | opt -S -passes='require<targetir>,require<scalar-evolution>,require<domtree>,loop(indvars)'
 
 ;; Check if llvm can narrow !range metadata based on loop entry
 ;; predicates.