Upgrade TypePromotionTransaction to be able to report changes in CodeGenPrepare

optimizeMemoryInst was reporting no change while still modifying the IR.
Inspect the status of TypePromotionTransaction to get a better status.

Related to https://reviews.llvm.org/D80916

Differential Revision: https://reviews.llvm.org/D81256

1 files changed, 14 insertions, 11 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 0d97a7f..8181c66 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -2822,8 +2822,9 @@ public:
   TypePromotionTransaction(SetOfInstrs &RemovedInsts)
       : RemovedInsts(RemovedInsts) {}
 
-  /// Advocate every changes made in that transaction.
-  void commit();
+  /// Advocate every changes made in that transaction. Return true if any change
+  /// happen.
+  bool commit();
 
   /// Undo all the changes made after the given point.
   void rollback(ConstRestorationPt Point);
@@ -2929,11 +2930,13 @@ TypePromotionTransaction::getRestorationPoint() const {
   return !Actions.empty() ? Actions.back().get() : nullptr;
 }
 
-void TypePromotionTransaction::commit() {
+bool TypePromotionTransaction::commit() {
   for (CommitPt It = Actions.begin(), EndIt = Actions.end(); It != EndIt;
        ++It)
     (*It)->commit();
+  bool Modified = !Actions.empty();
   Actions.clear();
+  return Modified;
 }
 
 void TypePromotionTransaction::rollback(
@@ -4959,7 +4962,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
     TPT.rollback(LastKnownGood);
     return false;
   }
-  TPT.commit();
+  bool Modified = TPT.commit();
 
   // Get the combined AddrMode (or the only AddrMode, if we only had one).
   ExtAddrMode AddrMode = AddrModes.getAddrMode();
@@ -4973,7 +4976,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
                   })) {
     LLVM_DEBUG(dbgs() << "CGP: Found      local addrmode: " << AddrMode
                       << "\n");
-    return false;
+    return Modified;
   }
 
   // Insert this computation right after this user.  Since our caller is
@@ -5014,7 +5017,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
       // We can't add more than one pointer together, nor can we scale a
       // pointer (both of which seem meaningless).
       if (ResultPtr || AddrMode.Scale != 1)
-        return false;
+        return Modified;
 
       ResultPtr = AddrMode.ScaledReg;
       AddrMode.Scale = 0;
@@ -5031,12 +5034,12 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
       Type *ScaledRegTy = AddrMode.ScaledReg->getType();
       if (cast<IntegerType>(IntPtrTy)->getBitWidth() >
           cast<IntegerType>(ScaledRegTy)->getBitWidth())
-        return false;
+        return Modified;
     }
 
     if (AddrMode.BaseGV) {
       if (ResultPtr)
-        return false;
+        return Modified;
 
       ResultPtr = AddrMode.BaseGV;
     }
@@ -5060,7 +5063,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
         !AddrMode.BaseReg && !AddrMode.Scale && !AddrMode.BaseOffs) {
       SunkAddr = Constant::getNullValue(Addr->getType());
     } else if (!ResultPtr) {
-      return false;
+      return Modified;
     } else {
       Type *I8PtrTy =
           Builder.getInt8PtrTy(Addr->getType()->getPointerAddressSpace());
@@ -5145,7 +5148,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
         (ScalePtrTy && DL->isNonIntegralPointerType(ScalePtrTy)) ||
         (AddrMode.BaseGV &&
          DL->isNonIntegralPointerType(AddrMode.BaseGV->getType())))
-      return false;
+      return Modified;
 
     LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode
                       << " for " << *MemoryInst << "\n");
@@ -5185,7 +5188,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
         Instruction *I = dyn_cast_or_null<Instruction>(Result);
         if (I && (Result != AddrMode.BaseReg))
           I->eraseFromParent();
-        return false;
+        return Modified;
       }
       if (AddrMode.Scale != 1)
         V = Builder.CreateMul(V, ConstantInt::get(IntPtrTy, AddrMode.Scale),