Merge pull request #67687 from nate-chandler/opaque-values/20230802/1/no-temporary-for-lvalue-keypath-base

[OpaqueValues] Skip temporary when loading l-value base.

Author: nate-chandler

lib/SILGen/SILGenLValue.cpp

@@ -2180,10 +2180,15 @@ static ManagedValue
 makeBaseConsumableMaterializedRValue(SILGenFunction &SGF,
                                      SILLocation loc, ManagedValue base) {
   if (base.isLValue()) {
-    auto tmp = SGF.emitTemporaryAllocation(loc, base.getType());
-    SGF.B.createCopyAddr(loc, base.getValue(), tmp,
-                         IsNotTake, IsInitialization);
-    return SGF.emitManagedBufferWithCleanup(tmp);
+    if (SGF.useLoweredAddresses()) {
+      auto tmp = SGF.emitTemporaryAllocation(loc, base.getType());
+      SGF.B.createCopyAddr(loc, base.getValue(), tmp, IsNotTake,
+                           IsInitialization);
+      return SGF.emitManagedBufferWithCleanup(tmp);
+    }
+    return SGF.emitLoad(loc, base.getValue(),
+                        SGF.getTypeLowering(base.getType()), SGFContext(),
+                        IsNotTake);
   }
 
   bool isBorrowed = base.isPlusZeroRValueOrTrivial()

test/SILGen/opaque_values_silgen.swift

@@ -6,6 +6,10 @@
 
 class C {}
 
+struct MyInt {
+  var int: Int
+}
+
 func genericInout<T>(_: inout T) {}
 
 func hasVarArg(_ args: Any...) {}
@@ -678,3 +682,20 @@ func FormClassKeyPath() {
   }
   _ = \Q.q
 }
+
+// CHECK-LABEL: sil {{.*}}[ossa] @UseGetterOnInout : {{.*}} {
+// CHECK:       bb0([[CONTAINER_ADDR:%[^,]+]] :
+// CHECK:         [[KEYPATH:%[^,]+]] = keypath $WritableKeyPath<MyInt, Int>, (root $MyInt; stored_property #MyInt.int : $Int) 
+// CHECK:         [[CONTAINER_ACCESS:%[^,]+]] = begin_access [read] [unknown] [[CONTAINER_ADDR]]
+// CHECK:         [[KEYPATH_UP:%[^,]+]] = upcast [[KEYPATH]]
+// CHECK:         [[CONTAINER:%[^,]+]] = load [trivial] [[CONTAINER_ACCESS]]
+// CHECK:         [[GETTER:%[^,]+]] = function_ref @swift_getAtKeyPath
+// CHECK:         [[VALUE:%[^,]+]] = apply [[GETTER]]<MyInt, Int>([[CONTAINER]], [[KEYPATH_UP]])
+// CHECK:         end_access [[CONTAINER_ACCESS]]
+// CHECK:         destroy_value [[KEYPATH_UP]]
+// CHECK:         return [[VALUE]] : $Int                                
+// CHECK-LABEL: } // end sil function 'UseGetterOnInout'
+@_silgen_name("UseGetterOnInout")
+func getInout(_ i: inout MyInt) -> Int {
+  return i[keyPath: \MyInt.int]
+}