---

yaml
---
r: 323515
b: refs/heads/tensorflow-next
c: fb5b4ff
h: refs/heads/master
i:
  323513: ba48007
  323511: e805524

Author: swift-ci

[refs]

@@ -1461,4 +1461,4 @@ refs/heads/master-rebranch: 86e95c23aa0d37f24ec138b7853146c1cead2e40
 refs/heads/rdar-53901732: 9bd06af3284e18a109cdbf9aa59d833b24eeca7b
 refs/heads/revert-26776-subst-always-returns-a-type: 1b8e18fdd391903a348970a4c848995d4cdd789c
 refs/heads/tensorflow-merge: 8b854f62f80d4476cb383d43c4aac2001dde3cec
-refs/heads/tensorflow-next: 6933de294b4691530af4e50880fa445daade4b8f
+refs/heads/tensorflow-next: fb5b4ffa5499715fbf5936c5acb0ff995002dcd3

branches/tensorflow-next/lib/SILOptimizer/ARC/ARCMatchingSet.cpp

@@ -77,7 +77,7 @@ ARCMatchingSetBuilder::matchIncrementsToDecrements() {
 
     bool BUCodeMotionSafe = (*BURefCountState)->second.isCodeMotionSafe();
     LLVM_DEBUG(llvm::dbgs() << "        BOTTOM UP CODEMOTIONSAFE: "
-                            << (BUIsKnownSafe ? "true" : "false") << "\n");
+                            << (BUCodeMotionSafe ? "true" : "false") << "\n");
     Flags.CodeMotionSafe &= BUCodeMotionSafe;
 
     // Now that we know we have an inst, grab the decrement.
@@ -161,7 +161,7 @@ ARCMatchingSetBuilder::matchDecrementsToIncrements() {
 
     bool TDCodeMotionSafe = (*TDRefCountState)->second.isCodeMotionSafe();
     LLVM_DEBUG(llvm::dbgs() << "        TOP DOWN CODEMOTIONSAFE: "
-                            << (TDIsKnownSafe ? "true" : "false") << "\n");
+                            << (TDCodeMotionSafe ? "true" : "false") << "\n");
     Flags.CodeMotionSafe &= TDCodeMotionSafe;
 
     // Now that we know we have an inst, grab the decrement.

branches/tensorflow-next/lib/SILOptimizer/Analysis/ARCAnalysis.cpp

@@ -459,6 +459,25 @@ valueHasARCDecrementOrCheckInInstructionRange(SILValue Op,
 bool
 swift::
 mayGuaranteedUseValue(SILInstruction *User, SILValue Ptr, AliasAnalysis *AA) {
+  // Instructions that check the ref count are modeled as both a potential
+  // decrement and a use.
+  if (mayCheckRefCount(User)) {
+    switch (User->getKind()) {
+    case SILInstructionKind::IsUniqueInst:
+      // This instruction takes the address of its referent, so there's no way
+      // for the optimizer to reuse the reference across it (it appears to
+      // mutate the reference itself). In fact it's operand's RC root would be
+      // the parent object. This means we can ignore it as a direct RC user.
+      return false;
+    case SILInstructionKind::IsEscapingClosureInst:
+      // FIXME: this is overly conservative. It should return true only of the
+      // RC identity of the single operand matches Ptr.
+      return true;
+    default:
+      llvm_unreachable("Unexpected check-ref-count instruction.");
+    }
+  }
+
   // Only full apply sites can require a guaranteed lifetime. If we don't have
   // one, bail.
   if (!isa<FullApplySite>(User))

branches/tensorflow-next/test/SILOptimizer/arcsequenceopts_uniquecheck.sil

@@ -104,3 +104,27 @@ bb0(%0 : $*C, %1 : $*C):
   strong_release %2 : $C
   return %4 : $Builtin.Int1
 }
+
+// Similarly, do not remove a retain/release pair that spans an
+// is_escaping_closure instruction. This would fail to catch closures
+// that are returned from the function.
+// <rdar://problem/52803634>
+
+// thunk for @callee_guaranteed () -> ()
+sil shared [transparent] [serializable] [reabstraction_thunk] [without_actually_escaping] @$sIg_Ieg_TR : $@convention(thin) (@noescape @callee_guaranteed () -> ()) -> () {
+bb0(%0 : $@noescape @callee_guaranteed () -> ()):
+  %1 = apply %0() : $@noescape @callee_guaranteed () -> ()
+  return %1 : $()
+}
+
+sil hidden [noinline] @testEscapingClosure : $@convention(thin) (@noescape @callee_guaranteed () -> ()) -> @owned @callee_guaranteed () -> () {
+bb0(%0 : $@noescape @callee_guaranteed () -> ()):
+  %1 = function_ref @$sIg_Ieg_TR : $@convention(thin) (@noescape @callee_guaranteed () -> ()) -> ()
+  %2 = partial_apply [callee_guaranteed] %1(%0) : $@convention(thin) (@noescape @callee_guaranteed () -> ()) -> ()
+  %3 = mark_dependence %2 : $@callee_guaranteed () -> () on %0 : $@noescape @callee_guaranteed () -> ()
+  strong_retain %3 : $@callee_guaranteed () -> ()
+  %5 = is_escaping_closure %3 : $@callee_guaranteed () -> ()
+  strong_release %3 : $@callee_guaranteed () -> ()
+  cond_fail %5 : $Builtin.Int1
+  return %3 : $@callee_guaranteed () -> ()
+}