Merge pull request swiftlang#60857 from meg-gupta/fixmem2regsbi2

Fix store_borrow multi block handling in mem2reg

Author: swift-ci

lib/SILOptimizer/Transforms/SILMem2Reg.cpp

@@ -420,8 +420,8 @@ beginLexicalLifetimeAfterStore(AllocStackInst *asi, SILInstruction *inst) {
     if (isGuaranteedLexicalValue(sbi->getSrc())) {
       return {{stored, SILValue(), SILValue()}, /*isStorageValid*/ true};
     }
-    auto *borrow = SILBuilderWithScope(sbi).createBeginBorrow(
-        loc, stored, /*isLexical*/ true);
+    auto *borrow = SILBuilderWithScope(sbi->getNextInstruction())
+                       .createBeginBorrow(loc, stored, /*isLexical*/ true);
     return {{stored, borrow, SILValue()}, /*isStorageValid*/ true};
   }
   BeginBorrowInst *bbi = nullptr;
@@ -794,6 +794,11 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
       if (!sbi) {
         continue;
       }
+      if (sbi->getDest() != asi) {
+        continue;
+      }
+      assert(!deinitializationPoints[blockPromotingWithin]);
+      deinitializationPoints[blockPromotingWithin] = inst;
       if (!runningVals.hasValue()) {
         continue;
       }
@@ -802,8 +807,6 @@ SILInstruction *StackAllocationPromoter::promoteAllocationInBlock(
       }
       // Mark storage as invalid and mark end_borrow as a deinit point.
       runningVals->isStorageValid = false;
-      assert(!deinitializationPoints[blockPromotingWithin]);
-      deinitializationPoints[blockPromotingWithin] = inst;
       if (!canEndLexicalLifetime(runningVals->value)) {
         continue;
       }

test/SILOptimizer/mem2reg_lifetime_borrows.sil

@@ -484,3 +484,20 @@ bb3:
   return %r : $()
 }
 
+// CHECK-NOT: alloc_stack [lexical]
+// CHECK-LABEL: } // end sil function 'storeborrow_multi_only_lexicalallocas'
+sil [ossa] @storeborrow_multi_only_lexicalallocas : $@convention(thin) (@in_guaranteed Klass) -> () {
+bb0(%0 : $*Klass):
+  %l = load_borrow %0 : $*Klass
+  %1 = alloc_stack [lexical] $Klass
+  %sb = store_borrow %l to %1 : $*Klass
+  br bb1
+
+bb1:
+  end_borrow %sb : $*Klass
+  end_borrow %l : $Klass
+  dealloc_stack %1 : $*Klass
+  %6 = tuple ()
+  return %6 : $()
+}
+