Remove all trivial extend_lifetime instructions

during the MoveOnlyWrappedTypeEliminator pass.

Such instructions are only valid in RAW SIL. This pass generally removes marker
instructions that are only used for ownership diagnostics.

Fixes rdar://139450982 ([GH:#77451] Assert failure on
`extend_lifetime` verify with `onone-simplification` pass disabled)

Author: atrick

lib/SILOptimizer/Mandatory/MoveOnlyWrappedTypeEliminator.cpp

@@ -311,19 +311,6 @@ bool SILMoveOnlyWrappedTypeEliminator::process() {
   // - record its users for later visitation
   auto visitValue = [&touchedInsts, fn = fn,
                      trivialOnly = trivialOnly](SILValue value) -> bool {
-    // Trivial move_value instructions are relevant. After they are stripped,
-    // any extend_lifetime uses are also stripped.
-    if (isa<MoveValueInst>(value)
-        && value->getOwnershipKind() == OwnershipKind::None) {
-      for (auto *use : value->getNonTypeDependentUses()) {
-        auto *user = use->getUser();
-        if (isa<ExtendLifetimeInst>(user)) {
-          touchedInsts.insert(user);
-        }
-      }
-      return true;
-    }
-
     if (!value->getType().hasAnyMoveOnlyWrapping(fn))
       return false;
 
@@ -366,6 +353,10 @@ bool SILMoveOnlyWrappedTypeEliminator::process() {
 
         touched = true;
       }
+      // delete trivial move_value and extend_lifetime instructions.
+      if (isa<MoveValueInst>(ii) || isa<ExtendLifetimeInst>(ii)) {
+        touched = true;
+      }
       if (!touched)
         continue;
       touchedInsts.insert(&ii);

test/SILOptimizer/moveonly_type_eliminator.sil

@@ -637,3 +637,40 @@ bb0:
   %13 = tuple ()
   return %13 : $()
 }
+
+// Remove trivial move_value + extend_lifetime
+//
+// CHECK-LABEL: sil [ossa] @move_extend_lifetime : $@convention(thin) (@thin Trivial.Type) -> () {
+// CHECK: bb0(%0 : $@thin Trivial.Type):
+// CHECK-NOT: move_value
+// CHECK-NOT: extend_lifetime
+// CHECK-LABEL: } // end sil function 'move_extend_lifetime'
+sil [ossa] @move_extend_lifetime : $@convention(thin) (@thin Trivial.Type) -> () {
+bb0(%0 : $@thin Trivial.Type):
+  %mv = move_value [var_decl] %0 : $@thin Trivial.Type
+  extend_lifetime %mv : $@thin Trivial.Type
+  %13 = tuple ()
+  return %13 : $()
+}
+
+sil @captureType : $@convention(thin) (@thin Trivial.Type) -> ()
+sil @takeClosure : $@convention(thin) (@guaranteed @noescape @callee_guaranteed () -> ()) -> ()
+
+// SILGen pattern binding can (incorrectly) create a local variable to hold the value a function argument. This results
+// in an extend_lifetime that directly uses the argument value. Ensure that MoveOnlyTypeEliminator erases the
+// extend_lifetime.
+//
+// CHECK-LABEL: sil [ossa] @arg_extend_lifetime : $@convention(thin) (@thin Trivial.Type) -> () {
+// CHECK-NOT: extend_lifetime
+// CHECK-LABEL: } // end sil function 'arg_extend_lifetime'
+sil [ossa] @arg_extend_lifetime : $@convention(thin) (@thin Trivial.Type) -> () {
+bb0(%0 : $@thin Trivial.Type):
+  %cf = function_ref @captureType : $@convention(thin) (@thin Trivial.Type) -> ()
+  %closure = partial_apply [callee_guaranteed] [on_stack] %cf(%0) : $@convention(thin) (@thin Trivial.Type) -> ()
+  %f = function_ref @takeClosure : $@convention(thin) (@guaranteed @noescape @callee_guaranteed () -> ()) -> ()
+  %6 = apply %f(%closure) : $@convention(thin) (@guaranteed @noescape @callee_guaranteed () -> ()) -> ()
+  destroy_value %closure : $@noescape @callee_guaranteed () -> ()
+  extend_lifetime %0 : $@thin Trivial.Type
+  %13 = tuple ()
+  return %13 : $()
+}