LPM: Stop threading `Pass *` through all of the loop utility APIs. NFC

A large number of loop utility functions take a `Pass *` and reach
into it to find out which analyses to preserve. There are a number of
problems with this:

- The APIs have access to pretty well any Pass state they want, so
  it's hard to tell what they may or may not do.

- Other APIs have copied these and pass around a `Pass *` even though
  they don't even use it. Some of these just hand a nullptr to the API
  since the callers don't even have a pass available.

- Passes in the new pass manager don't work like the current ones, so
  the APIs can't be used as is there.

Instead, we should explicitly thread the analysis results that we
actually care about through these APIs. This is both simpler and more
reusable.

llvm-svn: 255669

1 files changed, 24 insertions, 26 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 2a2fbc8..f50ab1c 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -1776,18 +1776,16 @@ class LSRInstance {
   void RewriteForPHI(PHINode *PN, const LSRFixup &LF,
                      const Formula &F,
                      SCEVExpander &Rewriter,
-                     SmallVectorImpl<WeakVH> &DeadInsts,
-                     Pass *P) const;
+                     SmallVectorImpl<WeakVH> &DeadInsts) const;
   void Rewrite(const LSRFixup &LF,
                const Formula &F,
                SCEVExpander &Rewriter,
-               SmallVectorImpl<WeakVH> &DeadInsts,
-               Pass *P) const;
-  void ImplementSolution(const SmallVectorImpl<const Formula *> &Solution,
-                         Pass *P);
+               SmallVectorImpl<WeakVH> &DeadInsts) const;
+  void ImplementSolution(const SmallVectorImpl<const Formula *> &Solution);
 
 public:
-  LSRInstance(Loop *L, Pass *P);
+  LSRInstance(Loop *L, IVUsers &IU, ScalarEvolution &SE, DominatorTree &DT,
+              LoopInfo &LI, const TargetTransformInfo &TTI);
 
   bool getChanged() const { return Changed; }
 
@@ -4634,8 +4632,7 @@ void LSRInstance::RewriteForPHI(PHINode *PN,
                                 const LSRFixup &LF,
                                 const Formula &F,
                                 SCEVExpander &Rewriter,
-                                SmallVectorImpl<WeakVH> &DeadInsts,
-                                Pass *P) const {
+                                SmallVectorImpl<WeakVH> &DeadInsts) const {
   DenseMap<BasicBlock *, Value *> Inserted;
   for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
     if (PN->getIncomingValue(i) == LF.OperandValToReplace) {
@@ -4709,12 +4706,11 @@ void LSRInstance::RewriteForPHI(PHINode *PN,
 void LSRInstance::Rewrite(const LSRFixup &LF,
                           const Formula &F,
                           SCEVExpander &Rewriter,
-                          SmallVectorImpl<WeakVH> &DeadInsts,
-                          Pass *P) const {
+                          SmallVectorImpl<WeakVH> &DeadInsts) const {
   // First, find an insertion point that dominates UserInst. For PHI nodes,
   // find the nearest block which dominates all the relevant uses.
   if (PHINode *PN = dyn_cast<PHINode>(LF.UserInst)) {
-    RewriteForPHI(PN, LF, F, Rewriter, DeadInsts, P);
+    RewriteForPHI(PN, LF, F, Rewriter, DeadInsts);
   } else {
     Value *FullV =
         Expand(LF, F, LF.UserInst->getIterator(), Rewriter, DeadInsts);
@@ -4744,9 +4740,8 @@ void LSRInstance::Rewrite(const LSRFixup &LF,
 
 /// Rewrite all the fixup locations with new values, following the chosen
 /// solution.
-void
-LSRInstance::ImplementSolution(const SmallVectorImpl<const Formula *> &Solution,
-                               Pass *P) {
+void LSRInstance::ImplementSolution(
+    const SmallVectorImpl<const Formula *> &Solution) {
   // Keep track of instructions we may have made dead, so that
   // we can remove them after we are done working.
   SmallVector<WeakVH, 16> DeadInsts;
@@ -4768,7 +4763,7 @@ LSRInstance::ImplementSolution(const SmallVectorImpl<const Formula *> &Solution,
 
   // Expand the new value definitions and update the users.
   for (const LSRFixup &Fixup : Fixups) {
-    Rewrite(Fixup, *Solution[Fixup.LUIdx], Rewriter, DeadInsts, P);
+    Rewrite(Fixup, *Solution[Fixup.LUIdx], Rewriter, DeadInsts);
 
     Changed = true;
   }
@@ -4784,14 +4779,11 @@ LSRInstance::ImplementSolution(const SmallVectorImpl<const Formula *> &Solution,
   Changed |= DeleteTriviallyDeadInstructions(DeadInsts);
 }
 
-LSRInstance::LSRInstance(Loop *L, Pass *P)
-    : IU(P->getAnalysis<IVUsers>()),
-      SE(P->getAnalysis<ScalarEvolutionWrapperPass>().getSE()),
-      DT(P->getAnalysis<DominatorTreeWrapperPass>().getDomTree()),
-      LI(P->getAnalysis<LoopInfoWrapperPass>().getLoopInfo()),
-      TTI(P->getAnalysis<TargetTransformInfoWrapperPass>().getTTI(
-          *L->getHeader()->getParent())),
-      L(L), Changed(false), IVIncInsertPos(nullptr) {
+LSRInstance::LSRInstance(Loop *L, IVUsers &IU, ScalarEvolution &SE,
+                         DominatorTree &DT, LoopInfo &LI,
+                         const TargetTransformInfo &TTI)
+    : IU(IU), SE(SE), DT(DT), LI(LI), TTI(TTI), L(L), Changed(false),
+      IVIncInsertPos(nullptr) {
   // If LoopSimplify form is not available, stay out of trouble.
   if (!L->isLoopSimplifyForm())
     return;
@@ -4882,7 +4874,7 @@ LSRInstance::LSRInstance(Loop *L, Pass *P)
 #endif
 
   // Now that we've decided what we want, make it so.
-  ImplementSolution(Solution, P);
+  ImplementSolution(Solution);
 }
 
 void LSRInstance::print_factors_and_types(raw_ostream &OS) const {
@@ -4998,10 +4990,16 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager & /*LPM*/) {
   if (skipOptnoneFunction(L))
     return false;
 
+  auto &IU = getAnalysis<IVUsers>();
+  auto &SE = getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+  auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+  auto &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  const auto &TTI = getAnalysis<TargetTransformInfoWrapperPass>().getTTI(
+      *L->getHeader()->getParent());
   bool Changed = false;
 
   // Run the main LSR transformation.
-  Changed |= LSRInstance(L, this).getChanged();
+  Changed |= LSRInstance(L, IU, SE, DT, LI, TTI).getChanged();
 
   // Remove any extra phis created by processing inner loops.
   Changed |= DeleteDeadPHIs(L->getHeader());