Allow duplicating mark_dependence [nonescaping] on addresses

Author: meg-gupta

lib/SIL/IR/SILInstruction.cpp

@@ -1448,11 +1448,11 @@ bool SILInstruction::isTriviallyDuplicatable() const {
   if (auto *PA = dyn_cast<PartialApplyInst>(this)) {
     return !PA->isOnStack();
   }
-  // Like partial_apply [onstack], mark_dependence [nonescaping] creates a
-  // borrow scope. We currently assume that a set of dominated scope-ending uses
-  // can be found.
+  // Like partial_apply [onstack], mark_dependence [nonescaping] on values
+  // creates a borrow scope. We currently assume that a set of dominated
+  // scope-ending uses can be found.
   if (auto *MD = dyn_cast<MarkDependenceInst>(this)) {
-    return !MD->isNonEscaping();
+    return !MD->isNonEscaping() || MD->getType().isAddress();
   }
 
   if (isa<OpenExistentialAddrInst>(this) || isa<OpenExistentialRefInst>(this) ||

lib/SILOptimizer/Utils/LoopUtils.cpp

@@ -264,11 +264,11 @@ bool swift::canDuplicateLoopInstruction(SILLoop *L, SILInstruction *I) {
       return false;
     }
   }
-  // Like partial_apply [onstack], mark_dependence [nonescaping] creates a
-  // borrow scope. We currently assume that a set of dominated scope-ending uses
-  // can be found.
+  // Like partial_apply [onstack], mark_dependence [nonescaping] on values
+  // creates a borrow scope. We currently assume that a set of dominated
+  // scope-ending uses can be found.
   if (auto *MD = dyn_cast<MarkDependenceInst>(I)) {
-    return !MD->isNonEscaping();
+    return !MD->isNonEscaping() || MD->getType().isAddress();
   }
   // CodeGen can't build ssa for objc methods.
   if (auto *Method = dyn_cast<MethodInst>(I)) {