[PATCH] D82293: [CodeMoverUtils][WIP] Move code motion related checks from LICM to CodeMoverUtils

[rithik sharma via Phabricator via llvm-commits]

RithikSharma updated this revision to Diff 273937.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82293/new/

https://reviews.llvm.org/D82293

Files:
  llvm/lib/Transforms/Scalar/LICM.cpp


Index: llvm/lib/Transforms/Scalar/LICM.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LICM.cpp
+++ llvm/lib/Transforms/Scalar/LICM.cpp
@@ -72,6 +72,7 @@
 #include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/AssumeBundleBuilder.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/CodeMoverUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/SSAUpdater.h"
@@ -985,19 +986,6 @@
 }
 
 namespace {
-/// Return true if-and-only-if we know how to (mechanically) both hoist and
-/// sink a given instruction out of a loop.  Does not address legality
-/// concerns such as aliasing or speculation safety.
-bool isHoistableAndSinkableInst(Instruction &I) {
-  // Only these instructions are hoistable/sinkable.
-  return (isa<LoadInst>(I) || isa<StoreInst>(I) || isa<CallInst>(I) ||
-          isa<FenceInst>(I) || isa<CastInst>(I) || isa<UnaryOperator>(I) ||
-          isa<BinaryOperator>(I) || isa<SelectInst>(I) ||
-          isa<GetElementPtrInst>(I) || isa<CmpInst>(I) ||
-          isa<InsertElementInst>(I) || isa<ExtractElementInst>(I) ||
-          isa<ShuffleVectorInst>(I) || isa<ExtractValueInst>(I) ||
-          isa<InsertValueInst>(I) || isa<FreezeInst>(I));
-}
 /// Return true if all of the alias sets within this AST are known not to
 /// contain a Mod, or if MSSA knows thare are no MemoryDefs in the loop.
 bool isReadOnly(AliasSetTracker *CurAST, const MemorySSAUpdater *MSSAU,
@@ -1041,19 +1029,15 @@
                               bool TargetExecutesOncePerLoop,
                               SinkAndHoistLICMFlags *Flags,
                               OptimizationRemarkEmitter *ORE) {
-  // If we don't understand the instruction, bail early.
-  if (!isHoistableAndSinkableInst(I))
-    return false;
-
   MemorySSA *MSSA = MSSAU ? MSSAU->getMemorySSA() : nullptr;
   if (MSSA)
     assert(Flags != nullptr && "Flags cannot be null.");
 
+  // Check code motion candidate
+  if (!isSafeToMove(I))
+    return false;
   // Loads have extra constraints we have to verify before we can hoist them.
   if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
-    if (!LI->isUnordered())
-      return false; // Don't sink/hoist volatile or ordered atomic loads!
-
     // Loads from constant memory are always safe to move, even if they end up
     // in the same alias set as something that ends up being modified.
     if (AA->pointsToConstantMemory(LI->getOperand(0)))
@@ -1087,14 +1071,6 @@
 
     return !Invalidated;
   } else if (CallInst *CI = dyn_cast<CallInst>(&I)) {
-    // Don't sink or hoist dbg info; it's legal, but not useful.
-    if (isa<DbgInfoIntrinsic>(I))
-      return false;
-
-    // Don't sink calls which can throw.
-    if (CI->mayThrow())
-      return false;
-
     using namespace PatternMatch;
     if (match(CI, m_Intrinsic<Intrinsic::assume>()))
       // Assumes don't actually alias anything or throw
@@ -1160,9 +1136,6 @@
     } else // MSSAU
       return isOnlyMemoryAccess(FI, CurLoop, MSSAU);
   } else if (auto *SI = dyn_cast<StoreInst>(&I)) {
-    if (!SI->isUnordered())
-      return false; // Don't sink/hoist volatile or ordered atomic store!
-
     // We can only hoist a store that we can prove writes a value which is not
     // read or overwritten within the loop.  For those cases, we fallback to
     // load store promotion instead.  TODO: We can extend this to cases where


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