[CodeMoverUtils] Make specific analysis dependent checks optional

Summary: This patch makes code motion checks optional which are dependent on
specific analysis example, dominator tree, post dominator tree and dependence
info. The aim is to make the adoption of CodeMoverUtils easier for clients that
don't use analysis which were strictly required by CodeMoverUtils. This will
also help in diversifying code motion checks using other analysis example MSSA.
Authored By: RithikSharma
Reviewer: Whitney, bmahjour, etiotto
Reviewed By: Whitney
Subscribers: Prazek, hiraditya, george.burgess.iv, asbirlea, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D82566

1 files changed, 12 insertions, 8 deletions

diff --git a/llvm/lib/Transforms/Utils/CodeMoverUtils.cpp b/llvm/lib/Transforms/Utils/CodeMoverUtils.cpp
index 4583ff7..11a740f 100644
--- a/llvm/lib/Transforms/Utils/CodeMoverUtils.cpp
+++ b/llvm/lib/Transforms/Utils/CodeMoverUtils.cpp
@@ -297,8 +297,12 @@ collectInstructionsInBetween(Instruction &StartInst, const Instruction &EndInst,
 }
 
 bool llvm::isSafeToMoveBefore(Instruction &I, Instruction &InsertPoint,
-                              DominatorTree &DT, const PostDominatorTree &PDT,
-                              DependenceInfo &DI) {
+                              DominatorTree &DT, const PostDominatorTree *PDT,
+                              DependenceInfo *DI) {
+  // Skip tests when we don't have PDT or DI
+  if (!PDT || !DI)
+    return false;
+
   // Cannot move itself before itself.
   if (&I == &InsertPoint)
     return false;
@@ -314,7 +318,7 @@ bool llvm::isSafeToMoveBefore(Instruction &I, Instruction &InsertPoint,
     return reportInvalidCandidate(I, NotMovedTerminator);
 
   // TODO remove this limitation.
-  if (!isControlFlowEquivalent(I, InsertPoint, DT, PDT))
+  if (!isControlFlowEquivalent(I, InsertPoint, DT, *PDT))
     return reportInvalidCandidate(I, NotControlFlowEquivalent);
 
   if (!DT.dominates(&InsertPoint, &I))
@@ -363,7 +367,7 @@ bool llvm::isSafeToMoveBefore(Instruction &I, Instruction &InsertPoint,
   // StartInst to \p EndInst.
   if (std::any_of(InstsToCheck.begin(), InstsToCheck.end(),
                   [&DI, &I](Instruction *CurInst) {
-                    auto DepResult = DI.depends(&I, CurInst, true);
+                    auto DepResult = DI->depends(&I, CurInst, true);
                     if (DepResult &&
                         (DepResult->isOutput() || DepResult->isFlow() ||
                          DepResult->isAnti()))
@@ -376,8 +380,8 @@ bool llvm::isSafeToMoveBefore(Instruction &I, Instruction &InsertPoint,
 }
 
 bool llvm::isSafeToMoveBefore(BasicBlock &BB, Instruction &InsertPoint,
-                              DominatorTree &DT, const PostDominatorTree &PDT,
-                              DependenceInfo &DI) {
+                              DominatorTree &DT, const PostDominatorTree *PDT,
+                              DependenceInfo *DI) {
   return llvm::all_of(BB, [&](Instruction &I) {
     if (BB.getTerminator() == &I)
       return true;
@@ -396,7 +400,7 @@ void llvm::moveInstructionsToTheBeginning(BasicBlock &FromBB, BasicBlock &ToBB,
     // Increment the iterator before modifying FromBB.
     ++It;
 
-    if (isSafeToMoveBefore(I, *MovePos, DT, PDT, DI))
+    if (isSafeToMoveBefore(I, *MovePos, DT, &PDT, &DI))
       I.moveBefore(MovePos);
   }
 }
@@ -408,7 +412,7 @@ void llvm::moveInstructionsToTheEnd(BasicBlock &FromBB, BasicBlock &ToBB,
   Instruction *MovePos = ToBB.getTerminator();
   while (FromBB.size() > 1) {
     Instruction &I = FromBB.front();
-    if (isSafeToMoveBefore(I, *MovePos, DT, PDT, DI))
+    if (isSafeToMoveBefore(I, *MovePos, DT, &PDT, &DI))
       I.moveBefore(MovePos);
   }
 }