[SILGen] Forward addr self to borrow accessors.

Utilize and expand the pre-existing peephole.

rdar://127115078

Author: nate-chandler

lib/SILGen/SILGenApply.cpp

@@ -6858,22 +6858,21 @@ bool AccessorBaseArgPreparer::shouldLoadBaseAddress() const {
 ArgumentSource AccessorBaseArgPreparer::prepareAccessorAddressBaseArg() {
   // If the base is currently an address, we may have to copy it.
   if (shouldLoadBaseAddress()) {
-    if (selfParam.isConsumed() ||
-        (base.getType().isAddressOnly(SGF.F)
-         // If a move-only base is borrowed, then we have to try our best to
-         // borrow it in-place without copying.
-         // TODO: Can we avoid copying a non-move-only value too in this
-         // circumstance?
-         && !base.getType().isMoveOnly())) {
+    if (selfParam.isConsumed() || base.getType().isAddressOnly(SGF.F)) {
       // The load can only be a take if the base is a +1 rvalue.
       auto shouldTake = IsTake_t(base.hasCleanup());
 
+      auto isGuaranteed = selfParam.isGuaranteed();
+
+      auto context =
+          isGuaranteed ? SGFContext::AllowImmediatePlusZero : SGFContext();
+
       base = SGF.emitFormalAccessLoad(loc, base.forward(SGF),
                                       SGF.getTypeLowering(baseLoweredType),
-                                      SGFContext(), shouldTake);
+                                      context, shouldTake, isGuaranteed);
       return ArgumentSource(loc, RValue(SGF, loc, baseFormalType, base));
     }
-    
+
     // If the type is address-only, we can borrow the memory location as is.
     if (base.getType().isAddressOnly(SGF.F)) {
       return ArgumentSource(loc, RValue(SGF, loc, baseFormalType, base));

test/SILGen/boxed_existentials.swift

@@ -64,13 +64,10 @@ func test_property(_ x: Error) -> String {
 // CHECK-LABEL: sil hidden [ossa] @$s18boxed_existentials13test_propertyySSs5Error_pF
 // CHECK: bb0([[ARG:%.*]] : @guaranteed $any Error):
 // CHECK:         [[VALUE:%.*]] = open_existential_box [[ARG]] : $any Error to $*[[VALUE_TYPE:@opened\(.*, any Error\) Self]]
-// FIXME: Extraneous copy here
-// CHECK-NEXT:    [[COPY:%[0-9]+]] = alloc_stack $[[VALUE_TYPE]]
-// CHECK-NEXT:    copy_addr [[VALUE]] to [init] [[COPY]] : $*[[VALUE_TYPE]]
 // CHECK:         [[METHOD:%.*]] = witness_method $[[VALUE_TYPE]], #Error._domain!getter
 // -- self parameter of witness is @in_guaranteed; no need to copy since
 //    value in box is immutable and box is guaranteed
-// CHECK:         [[RESULT:%.*]] = apply [[METHOD]]<[[VALUE_TYPE]]>([[COPY]])
+// CHECK:         [[RESULT:%.*]] = apply [[METHOD]]<[[VALUE_TYPE]]>([[VALUE]])
 // CHECK-NOT:         destroy_value [[ARG]]
 // CHECK:         return [[RESULT]]
 
@@ -93,10 +90,8 @@ func test_property_of_lvalue(_ x: Error) -> String {
 // CHECK:         [[COPY:%.*]] = alloc_stack $[[VALUE_TYPE]]
 // CHECK:         copy_addr [[VALUE]] to [init] [[COPY]]
 // CHECK:         destroy_value [[VALUE_BOX]]
-// CHECK:         [[BORROW:%.*]] = alloc_stack $[[VALUE_TYPE]]
-// CHECK:         copy_addr [[COPY]] to [init] [[BORROW]]
 // CHECK:         [[METHOD:%.*]] = witness_method $[[VALUE_TYPE]], #Error._domain!getter
-// CHECK:         [[RESULT:%.*]] = apply [[METHOD]]<[[VALUE_TYPE]]>([[BORROW]])
+// CHECK:         [[RESULT:%.*]] = apply [[METHOD]]<[[VALUE_TYPE]]>([[COPY]])
 // CHECK:         destroy_addr [[COPY]]
 // CHECK:         dealloc_stack [[COPY]]
 // CHECK:         end_borrow [[VAR_LIFETIME]]

test/SILGen/copy_expr.swift

@@ -333,10 +333,8 @@ func testCallMethodOnLoadableGlobal() {
 // Calling computedK. It is borrowed.
 // CHECK: [[TEMP:%.*]] = alloc_stack $T
 // CHECK: explicit_copy_addr [[X]] to [init] [[TEMP]]
-// CHECK: [[TEMP2:%.*]] = alloc_stack $T
-// CHECK: copy_addr [[TEMP]] to [init] [[TEMP2]]
 // CHECK: [[FUNC:%.*]] = witness_method $T, #P.computedK!getter : <Self where Self : P> (Self) -> () -> Klass : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @owned Klass
-// CHECK: apply [[FUNC]]<(T)>([[TEMP2]])
+// CHECK: apply [[FUNC]]<(T)>([[TEMP]])
 //
 // Calling computed consuming getter.
 // CHECK: [[TEMP:%.*]] = alloc_stack $T
@@ -378,10 +376,8 @@ func testCallMethodOnAddressOnlyLetCopy<T : P>(_ t: T.Type) {
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK:   [[TEMP:%.*]] = alloc_stack $
 // CHECK:   explicit_copy_addr [[ACCESS]] to [init] [[TEMP]]
-// CHECK:   [[TEMP2:%.*]] = alloc_stack $
-// CHECK:   copy_addr [[TEMP]] to [init] [[TEMP2]]
 // CHECK:   [[FUNC:%.*]] = witness_method $T, #P.computedK!getter : <Self where Self : P> (Self) -> () -> Klass : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @owned Klass
-// CHECK:   apply [[FUNC]]<(T)>([[TEMP2]])
+// CHECK:   apply [[FUNC]]<(T)>([[TEMP]])
 //
 // Consuming computed getter.
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
@@ -423,10 +419,8 @@ func testCallMethodOnAddressOnlyVarCopy<T : P>(_ t: T.Type) {
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[ARG]]
 // CHECK:   [[TEMP:%.*]] = alloc_stack $
 // CHECK:   explicit_copy_addr [[ACCESS]] to [init] [[TEMP]]
-// CHECK:   [[TEMP2:%.*]] = alloc_stack $
-// CHECK:   copy_addr [[TEMP]] to [init] [[TEMP2]]
 // CHECK:   [[FUNC:%.*]] = witness_method $T, #P.computedK!getter : <Self where Self : P> (Self) -> () -> Klass : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @owned Klass
-// CHECK:   apply [[FUNC]]<(T)>([[TEMP2]])
+// CHECK:   apply [[FUNC]]<(T)>([[TEMP]])
 //
 // Consuming computed getter.
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[ARG]]

test/SILGen/dynamic_self.swift

@@ -96,27 +96,19 @@ func testExistentialDispatch(p: P) {
 
 // CHECK:   [[PCOPY_ADDR:%[0-9]+]] = open_existential_addr immutable_access [[P]] : $*any P to $*@opened([[N:".*"]], any P) Self
 // CHECK:   [[P_RESULT:%[0-9]+]] = alloc_stack $any P
-// CHECK:   [[PCOPY_ADDR_1:%[0-9]+]] = alloc_stack $@opened([[N]], any P) Self
-// CHECK:   copy_addr [[PCOPY_ADDR]] to [init] [[PCOPY_ADDR_1]] : $*@opened([[N]], any P) Self
 // CHECK:   [[P_P_GETTER:%[0-9]+]] = witness_method $@opened([[N]], any P) Self, #P.p!getter : {{.*}}, [[PCOPY_ADDR]]{{.*}} : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out τ_0_0
 // CHECK:   [[P_RESULT_ADDR2:%[0-9]+]] = init_existential_addr [[P_RESULT]] : $*any P, $@opened([[N]], any P) Self
-// CHECK:   apply [[P_P_GETTER]]<@opened([[N]], any P) Self>([[P_RESULT_ADDR2]], [[PCOPY_ADDR_1]]) : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out τ_0_0
-// CHECK:   destroy_addr [[PCOPY_ADDR_1]] : $*@opened([[N]], any P) Self
+// CHECK:   apply [[P_P_GETTER]]<@opened([[N]], any P) Self>([[P_RESULT_ADDR2]], [[PCOPY_ADDR]]) : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out τ_0_0
 // CHECK:   destroy_addr [[P_RESULT]] : $*any P
-// CHECK:   dealloc_stack [[PCOPY_ADDR_1]] : $*@opened([[N]], any P) Self
 // CHECK:   dealloc_stack [[P_RESULT]] : $*any P
   _ = p.p
 
 // CHECK:   [[PCOPY_ADDR:%[0-9]+]] = open_existential_addr immutable_access [[P]] : $*any P to $*@opened([[N:".*"]], any P) Self
 // CHECK:   [[P_RESULT:%[0-9]+]] = alloc_stack $any P
-// CHECK:   [[PCOPY_ADDR_1:%[0-9]+]] = alloc_stack $@opened([[N]], any P) Self
-// CHECK:   copy_addr [[PCOPY_ADDR]] to [init] [[PCOPY_ADDR_1]] : $*@opened([[N]], any P) Self
 // CHECK:   [[P_SUBSCRIPT_GETTER:%[0-9]+]] = witness_method $@opened([[N]], any P) Self, #P.subscript!getter : {{.*}}, [[PCOPY_ADDR]]{{.*}} : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out τ_0_0
 // CHECK:   [[P_RESULT_ADDR:%[0-9]+]] = init_existential_addr [[P_RESULT]] : $*any P, $@opened([[N]], any P) Self
-// CHECK:   apply [[P_SUBSCRIPT_GETTER]]<@opened([[N]], any P) Self>([[P_RESULT_ADDR]], [[PCOPY_ADDR_1]]) : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out τ_0_0
-// CHECK:   destroy_addr [[PCOPY_ADDR_1]] : $*@opened([[N]], any P) Self
+// CHECK:   apply [[P_SUBSCRIPT_GETTER]]<@opened([[N]], any P) Self>([[P_RESULT_ADDR]], [[PCOPY_ADDR]]) : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out τ_0_0
 // CHECK:   destroy_addr [[P_RESULT]] : $*any P
-// CHECK:   dealloc_stack [[PCOPY_ADDR_1]] : $*@opened([[N]], any P) Self
 // CHECK:   dealloc_stack [[P_RESULT]] : $*any P
   _ = p[]
 }