Get rid of isStorageValid flag on lastStoreInst

Author: meg-gupta

lib/SILOptimizer/Transforms/SILMem2Reg.cpp

@@ -655,7 +655,7 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
   Optional<StorageStateTracking<LiveValues>> runningVals;
   // Keep track of the last StoreInst that we found and the BeginBorrowInst and
   // CopyValueInst that we created in response if the alloc_stack was lexical.
-  Optional<StorageStateTracking<SILInstruction *>> lastStoreInst;
+  Optional<SILInstruction *> lastStoreInst;
 
   // For all instructions in the block.
   for (auto bbi = blockPromotingWithin->begin(),
@@ -683,8 +683,6 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
         }
         if (runningVals)
           runningVals->isStorageValid = false;
-        if (lastStoreInst)
-          lastStoreInst->isStorageValid = false;
       }
 
       if (runningVals) {
@@ -736,14 +734,14 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
 
       // If we met a store before this one, delete it.
       if (lastStoreInst) {
-        assert(cast<StoreInst>(lastStoreInst->value)->getOwnershipQualifier() !=
+        assert(cast<StoreInst>(*lastStoreInst)->getOwnershipQualifier() !=
                    StoreOwnershipQualifier::Assign &&
                "store [assign] to the stack location should have been "
                "transformed to a store [init]");
-        LLVM_DEBUG(llvm::dbgs() << "*** Removing redundant store: "
-                                << *lastStoreInst->value);
+        LLVM_DEBUG(llvm::dbgs()
+                   << "*** Removing redundant store: " << *lastStoreInst);
         ++NumInstRemoved;
-        prepareForDeletion(lastStoreInst->value, instructionsToDelete);
+        prepareForDeletion(*lastStoreInst, instructionsToDelete);
       }
 
       auto oldRunningVals = runningVals;
@@ -752,7 +750,7 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
                      /*isStorageValid=*/true};
       // The current store is now the lastStoreInst (until we see
       // another).
-      lastStoreInst = {inst, /*isStorageValid=*/true};
+      lastStoreInst = inst;
       if (shouldAddLexicalLifetime(asi)) {
         if (oldRunningVals && oldRunningVals->isStorageValid &&
             canEndLexicalLifetime(oldRunningVals->value)) {
@@ -770,17 +768,17 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
 
       // If we met a store before this one, delete it.
       if (lastStoreInst) {
-        LLVM_DEBUG(llvm::dbgs() << "*** Removing redundant store: "
-                                << *lastStoreInst->value);
+        LLVM_DEBUG(llvm::dbgs()
+                   << "*** Removing redundant store: " << *lastStoreInst);
         ++NumInstRemoved;
-        prepareForDeletion(lastStoreInst->value, instructionsToDelete);
+        prepareForDeletion(*lastStoreInst, instructionsToDelete);
       }
 
       // The stored value is the new running value.
       runningVals = {LiveValues::toReplace(asi, sbi->getSrc()),
                      /*isStorageValid=*/true};
       // The current store is now the lastStoreInst.
-      lastStoreInst = {inst, /*isStorageValid=*/true};
+      lastStoreInst = inst;
       if (shouldAddLexicalLifetime(asi)) {
         runningVals = beginLexicalLifetimeAfterStore(asi, inst);
       }
@@ -837,8 +835,6 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
                                             runningVals->value);
         }
         runningVals->isStorageValid = false;
-        if (lastStoreInst)
-          lastStoreInst->isStorageValid = false;
       } else {
         assert(!deinitializationPoints[blockPromotingWithin]);
         deinitializationPoints[blockPromotingWithin] = dai;
@@ -853,15 +849,15 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
     }
   }
 
-  if (lastStoreInst && lastStoreInst->isStorageValid) {
-    assert((isa<StoreBorrowInst>(lastStoreInst->value) ||
-            (cast<StoreInst>(lastStoreInst->value)->getOwnershipQualifier() !=
+  if (lastStoreInst && runningVals->isStorageValid) {
+    assert((isa<StoreBorrowInst>(*lastStoreInst) ||
+            (cast<StoreInst>(*lastStoreInst)->getOwnershipQualifier() !=
              StoreOwnershipQualifier::Assign)) &&
            "store [assign] to the stack location should have been "
            "transformed to a store [init]");
-    LLVM_DEBUG(llvm::dbgs() << "*** Finished promotion. Last store: "
-                            << *lastStoreInst->value);
-    return lastStoreInst->value;
+    LLVM_DEBUG(llvm::dbgs()
+               << "*** Finished promotion. Last store: " << *lastStoreInst);
+    return *lastStoreInst;
   }
 
   LLVM_DEBUG(llvm::dbgs() << "*** Finished promotion with no stores.\n");