Merge pull request swiftlang#81861 from kavon/kavon/avoid-double-copy

SILGen: avoid double copies with 'copy' expr

Author: kavon

lib/SILGen/SILGenExpr.cpp

@@ -7222,7 +7222,9 @@ RValue RValueEmitter::visitCopyExpr(CopyExpr *E, SGFContext C) {
   }
 
   if (subType.isLoadable(SGF.F)) {
-    ManagedValue mv = SGF.emitRValue(subExpr).getAsSingleValue(SGF, subExpr);
+    ManagedValue mv =
+      SGF.emitRValue(subExpr, SGFContext::AllowImmediatePlusZero)
+         .getAsSingleValue(SGF, subExpr);
     if (mv.getType().isTrivial(SGF.F))
       return RValue(SGF, {mv}, subType.getASTType());
     {

test/SILGen/copy_expr.swift

@@ -29,8 +29,7 @@ struct ContainKlass {
 // CHECK: [[X:%.*]] = apply {{%.*}}({{%.*}}) : $@convention(method) (@thin ContainKlass.Type) -> @owned ContainKlass
 // CHECK: [[MOVE:%.*]] = move_value [lexical] [var_decl] [[X]]
 // CHECK: [[BORROW:%.*]] = begin_borrow [[MOVE]]
-// CHECK: [[COPY_BORROW:%.*]] = copy_value [[BORROW]]
-// CHECK: explicit_copy_value [[COPY_BORROW]]
+// CHECK: [[COPY_BORROW:%.*]] = explicit_copy_value [[BORROW]]
 // CHECK: } // end sil function '$s9copy_expr22testCopyLoadableRValueyyF'
 func testCopyLoadableRValue() {
   let x = ContainKlass()
@@ -121,43 +120,35 @@ func testCopyAddressOnlyLValueArg<T : P>(_ x: inout T) {
 // CHECK: [[X:%.*]] = begin_borrow [[MOVE]]
 //
 // Calling consumeFunc.
-// CHECK: [[COPY_X:%.*]] = copy_value [[X]]
-// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[COPY_X]]
+// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[X]]
 // CHECK: [[FUNC:%.*]] = function_ref @$s9copy_expr12ContainKlassV11consumeFuncyyF : $@convention(method) (@owned ContainKlass) -> ()
 // CHECK: apply [[FUNC]]([[EXPLICIT_COPY_X]])
-// CHECK: destroy_value [[COPY_X]]
 //
 // Calling borrowingFunc.
 // CHECK: [[X:%.*]] = begin_borrow [[MOVE]]
-// CHECK: [[COPY_X:%.*]] = copy_value [[X]]
-// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[COPY_X]]
+// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[X]]
 // CHECK: [[FUNC:%.*]] = function_ref @$s9copy_expr12ContainKlassV13borrowingFuncyyF : $@convention(method) (@guaranteed ContainKlass) -> ()
 // CHECK: apply [[FUNC]]([[EXPLICIT_COPY_X]])
 // CHECK: destroy_value [[EXPLICIT_COPY_X]]
-// CHECK: destroy_value [[COPY_X]]
 //
 // Calling computedK. It is borrowed.
 // CHECK: [[X:%.*]] = begin_borrow [[MOVE]]
-// CHECK: [[COPY_X:%.*]] = copy_value [[X]]
-// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[COPY_X]]
+// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[X]]
 // CHECK: [[BORROW_EXPLICIT_COPY_X:%.*]] = begin_borrow [[EXPLICIT_COPY_X]]
 // CHECK: [[FUNC:%.*]] = function_ref @$s9copy_expr12ContainKlassV9computedKAA0D0Cvg : $@convention(method) (@guaranteed ContainKlass) -> @owned Klass
 // CHECK: apply [[FUNC]]([[BORROW_EXPLICIT_COPY_X]])
 // CHECK: end_borrow [[BORROW_EXPLICIT_COPY_X]]
 // CHECK: destroy_value [[EXPLICIT_COPY_X]]
-// CHECK: destroy_value [[COPY_X]]
 //
 // Calling computed getter.
 // CHECK: [[X:%.*]] = begin_borrow [[MOVE]]
-// CHECK: [[COPY_X:%.*]] = copy_value [[X]]
-// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[COPY_X]]
+// CHECK: [[EXPLICIT_COPY_X:%.*]] = explicit_copy_value [[X]]
 // CHECK: [[BORROW_EXPLICIT_COPY_X:%.*]] = begin_borrow [[EXPLICIT_COPY_X]]
 // CHECK: [[COPY_BORROW_EXPLICIT_COPY_X:%.*]] = copy_value [[BORROW_EXPLICIT_COPY_X]]
 // CHECK: [[FUNC:%.*]] = function_ref @$s9copy_expr12ContainKlassV18consumingComputedKAA0D0Cvg : $@convention(method) (@owned ContainKlass) -> @owned Klass
 // CHECK: apply [[FUNC]]([[COPY_BORROW_EXPLICIT_COPY_X]])
 // CHECK: end_borrow [[BORROW_EXPLICIT_COPY_X]]
 // CHECK: destroy_value [[EXPLICIT_COPY_X]]
-// CHECK: destroy_value [[COPY_X]]
 // CHECK: } // end sil function '$s9copy_expr31testCallMethodOnLoadableLetCopyyyF'
 func testCallMethodOnLoadableLetCopy() {
   let x = ContainKlass()

test/SILGen/copy_operator.swift

@@ -11,18 +11,14 @@ class Klass {}
 // CHECK-LABEL: sil [ossa] @$s8moveonly7useCopyyAA5KlassCADF : {{.*}} {
 // CHECK:       bb0([[ARG:%.*]] :
 // CHECK-NEXT:    debug_value
-// CHECK-NEXT:    [[COPY:%[^,]+]] = copy_value [[ARG]]
-// CHECK-NEXT:    [[EXPLICIT_COPY:%[^,]+]] = explicit_copy_value [[COPY]]
-// CHECK-NEXT:    destroy_value [[COPY]]
+// CHECK-NEXT:    [[EXPLICIT_COPY:%[^,]+]] = explicit_copy_value [[ARG]]
 // CHECK-NEXT:    return [[EXPLICIT_COPY]]
 // CHECK-LABEL: } // end sil function '$s8moveonly7useCopyyAA5KlassCADF'
 
 // CHECK-SIL-LABEL: sil @$s8moveonly7useCopyyAA5KlassCADF : {{.*}} {
 // CHECK-SIL:       bb0([[ARG:%.*]] : $Klass):
 // CHECK-SIL-NEXT:    debug_value
 // CHECK-SIL-NEXT:    strong_retain [[ARG]]
-// CHECK-SIL-NEXT:    strong_retain [[ARG]]
-// CHECK-SIL-NEXT:    strong_release [[ARG]]
 // CHECK-SIL-NEXT:    return [[ARG]] : $Klass
 // CHECK-SIL-LABEL: } // end sil function '$s8moveonly7useCopyyAA5KlassCADF'
 
@@ -39,18 +35,14 @@ public func useCopy(_ k: Klass) -> Klass {
 // CHECK-LABEL: sil [ossa] @$s8moveonly7useCopyyxxRlzClF : $@convention(thin) <T where T : AnyObject> (@guaranteed T) -> @owned T {
 // CHECK:       bb0([[ARG:%.*]] :
 // CHECK-NEXT:    debug_value
-// CHECK-NEXT:    [[COPY:%[^,]+]] = copy_value [[ARG]]
-// CHECK-NEXT:    [[EXPLICIT_COPY:%[^,]+]] = explicit_copy_value [[COPY]]
-// CHECK-NEXT:    destroy_value [[COPY]]
+// CHECK-NEXT:    [[EXPLICIT_COPY:%[^,]+]] = explicit_copy_value [[ARG]]
 // CHECK-NEXT:    return [[EXPLICIT_COPY]]
 // CHECK-LABEL: } // end sil function '$s8moveonly7useCopyyxxRlzClF'
 
 // CHECK-SIL-LABEL: sil @$s8moveonly7useCopyyxxRlzClF : {{.*}} {
 // CHECK-SIL:       bb0([[ARG:%.*]] :
 // CHECK-SIL-NEXT:    debug_value
 // CHECK-SIL-NEXT:    strong_retain [[ARG]]
-// CHECK-SIL-NEXT:    strong_retain [[ARG]]
-// CHECK-SIL-NEXT:    strong_release [[ARG]]
 // CHECK-SIL-NEXT:    return [[ARG]]
 // CHECK-SIL-LABEL: } // end sil function '$s8moveonly7useCopyyxxRlzClF'