IRGen, LLVMPasses: Switch from obsoleted nocapture to captures(none)

Per 29441e4f5fa5f5c7709f7cf180815ba97f611297 (llvm-project).

Author: AnthonyLatsis

lib/IRGen/CallEmission.h

@@ -152,11 +152,12 @@ class CallEmission {
                        WitnessMetadata *witnessMetadata);
   virtual Address getCalleeErrorSlot(SILType errorType, bool isCalleeAsync) = 0;
 
-  void addFnAttribute(llvm::Attribute::AttrKind Attr);
+  void addFnAttribute(llvm::Attribute::AttrKind kind);
 
   void setIndirectReturnAddress(Address addr) { indirectReturnAddress = addr; }
 
-  void addParamAttribute(unsigned ParamIndex, llvm::Attribute::AttrKind Attr);
+  void addParamAttribute(unsigned paramIndex, llvm::Attribute::AttrKind kind);
+  void addParamAttribute(unsigned paramIndex, llvm::Attribute attr);
 
   void emitToMemory(Address addr, const LoadableTypeInfo &substResultTI,
                     bool isOutlined);

lib/IRGen/GenCall.cpp

@@ -317,7 +317,7 @@ static void addIndirectValueParameterAttributes(IRGenModule &IGM,
   // Bitwise takable value types are guaranteed not to capture
   // a pointer into itself.
   if (!addressable && ti.isBitwiseTakable(ResilienceExpansion::Maximal))
-    b.addAttribute(llvm::Attribute::NoCapture);
+    b.addCapturesAttr(llvm::CaptureInfo::none());
   // The parameter must reference dereferenceable memory of the type.
   addDereferenceableAttributeToBuilder(IGM, b, ti);
 
@@ -330,7 +330,7 @@ static void addPackParameterAttributes(IRGenModule &IGM,
                                        unsigned argIndex) {
   llvm::AttrBuilder b(IGM.getLLVMContext());
   // Pack parameter pointers can't alias.
-  // Note: they are not marked `nocapture` as one
+  // Note: they are not marked `captures(none)` as one
   // pack parameter could be a value type (e.g. a C++ type)
   // that captures its own pointer in itself.
   b.addAttribute(llvm::Attribute::NoAlias);
@@ -357,7 +357,7 @@ static void addInoutParameterAttributes(IRGenModule &IGM, SILType paramSILType,
   // Bitwise takable value types are guaranteed not to capture
   // a pointer into itself.
   if (!addressable && ti.isBitwiseTakable(ResilienceExpansion::Maximal))
-    b.addAttribute(llvm::Attribute::NoCapture);
+    b.addCapturesAttr(llvm::CaptureInfo::none());
   // The inout must reference dereferenceable memory of the type.
   addDereferenceableAttributeToBuilder(IGM, b, ti);
 
@@ -411,7 +411,7 @@ static void addIndirectResultAttributes(IRGenModule &IGM,
   // Bitwise takable value types are guaranteed not to capture
   // a pointer into itself.
   if (typeInfo.isBitwiseTakable(ResilienceExpansion::Maximal))
-    b.addAttribute(llvm::Attribute::NoCapture);
+    b.addCapturesAttr(llvm::CaptureInfo::none());
   if (allowSRet) {
     assert(storageType);
     b.addStructRetAttr(storageType);
@@ -530,7 +530,7 @@ void IRGenModule::addSwiftErrorAttributes(llvm::AttributeList &attrs,
   // The error result should not be aliased, captured, or pointed at invalid
   // addresses regardless.
   b.addAttribute(llvm::Attribute::NoAlias);
-  b.addAttribute(llvm::Attribute::NoCapture);
+  b.addCapturesAttr(llvm::CaptureInfo::none());
   b.addDereferenceableAttr(getPointerSize().getValue());
 
   attrs = attrs.addParamAttributes(this->getLLVMContext(), argIndex, b);
@@ -2854,7 +2854,9 @@ class SyncCallEmission final : public CallEmission {
         }
       }
       Args[--LastArgWritten] = errorResultSlot.getAddress();
-      addParamAttribute(LastArgWritten, llvm::Attribute::NoCapture);
+      addParamAttribute(LastArgWritten, llvm::Attribute::getWithCaptureInfo(
+                                            IGF.IGM.getLLVMContext(),
+                                            llvm::CaptureInfo::none()));
       IGF.IGM.addSwiftErrorAttributes(CurCallee.getMutableAttributes(),
                                       LastArgWritten);
 
@@ -5577,14 +5579,20 @@ void CallEmission::setArgs(Explosion &adjusted, bool isOutlined,
   }
 }
 
-void CallEmission::addFnAttribute(llvm::Attribute::AttrKind attr) {
+void CallEmission::addFnAttribute(llvm::Attribute::AttrKind kind) {
   assert(state == State::Emitting);
   auto &attrs = CurCallee.getMutableAttributes();
-  attrs = attrs.addFnAttribute(IGF.IGM.getLLVMContext(), attr);
+  attrs = attrs.addFnAttribute(IGF.IGM.getLLVMContext(), kind);
 }
 
 void CallEmission::addParamAttribute(unsigned paramIndex,
-                                     llvm::Attribute::AttrKind attr) {
+                                     llvm::Attribute::AttrKind kind) {
+  addParamAttribute(paramIndex,
+                    llvm::Attribute::get(IGF.IGM.getLLVMContext(), kind));
+}
+
+void CallEmission::addParamAttribute(unsigned paramIndex,
+                                     llvm::Attribute attr) {
   assert(state == State::Emitting);
   auto &attrs = CurCallee.getMutableAttributes();
   attrs = attrs.addParamAttribute(IGF.IGM.getLLVMContext(), paramIndex, attr);

lib/LLVMPasses/ARCEntryPointBuilder.h

@@ -252,11 +252,16 @@ class ARCEntryPointBuilder {
 
     auto *ObjectPtrTy = getObjectPtrTy();
     auto &M = getModule();
-    auto AttrList = AttributeList::get(M.getContext(), 1, Attribute::NoCapture);
-    AttrList = AttrList.addFnAttribute(M.getContext(), Attribute::NoUnwind);
+    auto &C = M.getContext();
+
+    AttributeList AttrList;
+    AttrList = AttrList.addFnAttribute(C, Attribute::NoUnwind);
+    AttrList = AttrList.addParamAttribute(
+        C, 0, Attribute::getWithCaptureInfo(C, llvm::CaptureInfo::none()));
+
     CheckUnowned = cast<llvm::Function>(
         M.getOrInsertFunction("swift_checkUnowned", AttrList,
-                              Type::getVoidTy(M.getContext()), ObjectPtrTy)
+                              Type::getVoidTy(C), ObjectPtrTy)
             .getCallee());
     if (llvm::Triple(M.getTargetTriple()).isOSBinFormatCOFF() &&
         !llvm::Triple(M.getTargetTriple()).isOSCygMing())

test/AutoDiff/IRGen/differentiable_function.sil

@@ -33,7 +33,7 @@ bb0:
   return %result : $@differentiable(reverse) @callee_guaranteed (Float) -> Float
 }
 
-// CHECK-LABEL: define{{.*}}test_form_diff_func(ptr noalias nocapture sret(<{ %swift.function, %swift.function, %swift.function }>)
+// CHECK-LABEL: define{{.*}}test_form_diff_func(ptr noalias captures(none) sret(<{ %swift.function, %swift.function, %swift.function }>)
 // CHECK-SAME: [[OUT:%.*]])
 // CHECK:   [[OUT_ORIG:%.*]] = getelementptr{{.*}}[[OUT]], i32 0, i32 0
 // CHECK:   [[OUT_ORIG_FN:%.*]] = getelementptr{{.*}}[[OUT_ORIG]], i32 0, i32 0
@@ -60,7 +60,7 @@ bb0(%0 : $@differentiable(reverse) @callee_guaranteed (Float) -> Float):
   return %result : $(@callee_guaranteed (Float) -> Float, @callee_guaranteed (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float), @callee_guaranteed (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float))
 }
 
-// CHECK-LABEL: define{{.*}}@test_extract_components(ptr noalias nocapture sret(<{ %swift.function, %swift.function, %swift.function }>)
+// CHECK-LABEL: define{{.*}}@test_extract_components(ptr noalias captures(none) sret(<{ %swift.function, %swift.function, %swift.function }>)
 // CHECK-SAME: [[OUT:%.*]], ptr{{.*}}[[IN:%.*]])
 // CHECK:   [[ORIG:%.*]] = getelementptr{{.*}}[[IN]], i32 0, i32 0
 // CHECK:   [[ORIG_FN_ADDR:%.*]] = getelementptr{{.*}}[[ORIG]], i32 0, i32 0

test/DebugInfo/ErrorVar.swift

@@ -14,7 +14,7 @@ func simple(_ placeholder: Int64) throws -> () {
   // CHECK: define {{.*}}void @"$s8ErrorVar6simpleyys5Int64VKF"(
   // CHECK-SAME: i64
   // CHECK-SAME: %swift.refcounted* {{.*}}swiftself
-  // CHECK-SAME: %swift.error** noalias nocapture dereferenceable(4)
+  // CHECK-SAME: %swift.error** noalias captures(none) dereferenceable(4)
   // CHECK: #dbg_declare
   // CHECK: #dbg_declare({{.*}}, ![[ERROR:[0-9]+]], !DIExpression(DW_OP_deref)
   // CHECK-DAG: ![[ERRTY:.*]] = !DICompositeType({{.*}}identifier: "$ss5Error_pD"

test/Distributed/distributed_actor_accessor_thunks_32bit.swift

@@ -94,7 +94,7 @@ public distributed actor MyOtherActor {
 
 // CHECK: define hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7simple1yySiYaKFTE"
 
-// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7simple1yySiYaKFTETF"(%swift.context* swiftasync %0, %swift.opaque* nocapture %1, i8* %2, i8* %3, {{.*}}, %T27distributed_actor_accessors7MyActorC* [[ACTOR:%.*]], %swift.type* [[DECODER_TYPE:%.*]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
+// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7simple1yySiYaKFTETF"(%swift.context* swiftasync %0, %swift.opaque* captures(none) %1, i8* %2, i8* %3, {{.*}}, %T27distributed_actor_accessors7MyActorC* [[ACTOR:%.*]], %swift.type* [[DECODER_TYPE:%.*]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
 
 /// Read the current offset and cast an element to `Int`
 
@@ -119,7 +119,7 @@ public distributed actor MyOtherActor {
 // CHECK: missing-witness1:
 // CHECK-NEXT: call void @llvm.trap()
 // CHECK-NEXT: unreachable
-// CHECK: call swiftcc void @"$s27FakeDistributedActorSystems0A17InvocationDecoderC18decodeNextArgumentxyKSeRzSERzlF"(%swift.opaque* noalias nocapture sret(%swift.opaque) [[ARG_0_RES_SLOT]], %swift.type* %arg_type, i8** [[ENCODABLE_WITNESS]], i8** [[DECODABLE_WITNESS]], %T27FakeDistributedActorSystems0A17InvocationDecoderC* swiftself [[DECODER]], %swift.error** noalias nocapture dereferenceable(4) %swifterror)
+// CHECK: call swiftcc void @"$s27FakeDistributedActorSystems0A17InvocationDecoderC18decodeNextArgumentxyKSeRzSERzlF"(%swift.opaque* noalias captures(none) sret(%swift.opaque) [[ARG_0_RES_SLOT]], %swift.type* %arg_type, i8** [[ENCODABLE_WITNESS]], i8** [[DECODABLE_WITNESS]], %T27FakeDistributedActorSystems0A17InvocationDecoderC* swiftself [[DECODER]], %swift.error** noalias captures(none) dereferenceable(4) %swifterror)
 
 // CHECK: store %swift.error* null, %swift.error** %swifterror
 // CHECK-NEXT: [[ARG_0_VAL_ADDR:%.*]] = bitcast i8* [[ARG_0_VALUE_BUF]] to %TSi*
@@ -196,7 +196,7 @@ public distributed actor MyOtherActor {
 // CHECK: define hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7simple3ySiSSYaKFTE"
 
 /// !!! in `simple3` interesting bits are: argument value extraction (because string is exploded into N arguments) and call to distributed thunk
-// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7simple3ySiSSYaKFTETF"(%swift.context* swiftasync %0, %swift.opaque* nocapture [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR]], %swift.type* [[DECODER_TYPE:%.*]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
+// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7simple3ySiSSYaKFTETF"(%swift.context* swiftasync %0, %swift.opaque* captures(none) [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR]], %swift.type* [[DECODER_TYPE:%.*]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
 
 
 // CHECK: [[TYPED_RESULT_BUFF:%.*]] = bitcast i8* [[RESULT_BUFF]] to %TSi*
@@ -260,7 +260,7 @@ public distributed actor MyOtherActor {
 
 // CHECK: define hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC16single_case_enumyAA7SimpleEOAFYaKFTE"
 
-// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC16single_case_enumyAA7SimpleEOAFYaKFTETF"(%swift.context* swiftasync %0, %swift.opaque* nocapture [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR]], %swift.type* [[DECODER_TYPE]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
+// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC16single_case_enumyAA7SimpleEOAFYaKFTETF"(%swift.context* swiftasync %0, %swift.opaque* captures(none) [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR]], %swift.type* [[DECODER_TYPE]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
 
 /// Let's check that the call doesn't have any arguments and returns nothing.
 
@@ -307,7 +307,7 @@ public distributed actor MyOtherActor {
 
 // CHECK: define hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7complexyAA11LargeStructVSaySiG_AA3ObjCSSSgAFtYaKFTE"
 
-// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7complexyAA11LargeStructVSaySiG_AA3ObjCSSSgAFtYaKFTETF"(%swift.context* swiftasync {{.*}}, %swift.opaque* nocapture [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR]], %swift.type* [[DECODER_TYPE:%.*]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
+// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC7complexyAA11LargeStructVSaySiG_AA3ObjCSSSgAFtYaKFTETF"(%swift.context* swiftasync {{.*}}, %swift.opaque* captures(none) [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR]], %swift.type* [[DECODER_TYPE:%.*]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
 
 /// First, let's check that all of the different argument types here are loaded correctly.
 
@@ -366,7 +366,7 @@ public distributed actor MyOtherActor {
 
 /// ---> Accessor for `genericArgs`
 
-// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC11genericArgsyyx_Sayq_GtYaKSeRzSERzSeR_SER_r0_lFTETF"(%swift.context* swiftasync %0, %swift.opaque*  nocapture [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUF:%.*]], i8* [[GENERIC_SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR:%.*]], %swift.type* [[DECODER_TYPE:%.*]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
+// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors7MyActorC11genericArgsyyx_Sayq_GtYaKSeRzSERzSeR_SER_r0_lFTETF"(%swift.context* swiftasync %0, %swift.opaque*  captures(none) [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUF:%.*]], i8* [[GENERIC_SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors7MyActorC* [[ACTOR:%.*]], %swift.type* [[DECODER_TYPE:%.*]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
 
 /// ---> Load `T`
 
@@ -422,7 +422,7 @@ public distributed actor MyOtherActor {
 
 /// Let's check that there is argument decoding since parameter list is empty
 
-// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors12MyOtherActorC5emptyyyYaKFTETF"(%swift.context* swiftasync {{.*}}, %swift.opaque* nocapture [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors12MyOtherActorC* {{.*}}, %swift.type* [[DECODER_TYPE:%.*]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
+// CHECK: define linkonce_odr hidden swift{{(tail)?}}cc void @"$s27distributed_actor_accessors12MyOtherActorC5emptyyyYaKFTETF"(%swift.context* swiftasync {{.*}}, %swift.opaque* captures(none) [[ARG_DECODER:%.*]], i8* [[ARG_TYPES:%.*]], i8* [[RESULT_BUFF:%.*]], i8* [[SUBS:%.*]], i8* [[WITNESS_TABLES:%.*]], i32 [[NUM_WITNESS_TABLES:%.*]], %T27distributed_actor_accessors12MyOtherActorC* {{.*}}, %swift.type* [[DECODER_TYPE:%.*]], %swift.type* [[ACTOR_TYPE]], i8** [[DECODER_PROTOCOL_WITNESS:%.*]])
 // CHECK-NEXT: entry:
 // CHECK-NEXT: {{.*}} = alloca %swift.context*
 // CHECK-NEXT: %swifterror = alloca %swift.error*

test/Distributed/distributed_actor_accessor_thunks_64bit.swift

@@ -116,7 +116,7 @@ public distributed actor MyOtherActor {
 // CHECK: missing-witness1:
 // CHECK-NEXT: call void @llvm.trap()
 // CHECK-NEXT: unreachable
-// CHECK: call swiftcc void @"$s27FakeDistributedActorSystems0A17InvocationDecoderC18decodeNextArgumentxyKSeRzSERzlF"(ptr noalias sret(%swift.opaque) [[ARG_0_VALUE_BUF]], ptr %arg_type, ptr [[ENCODABLE_WITNESS]], ptr [[DECODABLE_WITNESS]], ptr swiftself [[DECODER]], ptr noalias nocapture swifterror dereferenceable(8) %swifterror)
+// CHECK: call swiftcc void @"$s27FakeDistributedActorSystems0A17InvocationDecoderC18decodeNextArgumentxyKSeRzSERzlF"(ptr noalias sret(%swift.opaque) [[ARG_0_VALUE_BUF]], ptr %arg_type, ptr [[ENCODABLE_WITNESS]], ptr [[DECODABLE_WITNESS]], ptr swiftself [[DECODER]], ptr noalias captures(none) swifterror dereferenceable(8) %swifterror)
 
 // CHECK: store ptr null, ptr %swifterror
 // CHECK-NEXT: %._value = getelementptr inbounds %TSi, ptr [[ARG_0_VALUE_BUF]], i32 0, i32 0

test/IRGen/abi_v7k.swift

@@ -296,7 +296,7 @@ func testRet3() -> MyRect2 {
 }
 
 // Returning tuple?: (Int x 6)?
-// CHECK-LABEL: define hidden swiftcc void @"$s8test_v7k7minMax2{{.*}}"(ptr noalias nocapture sret({{.*}}) %0, i32 %1, i32 %2)
+// CHECK-LABEL: define hidden swiftcc void @"$s8test_v7k7minMax2{{.*}}"(ptr noalias captures(none) sret({{.*}}) %0, i32 %1, i32 %2)
 // V7K-LABEL: _$s8test_v7k7minMax2
 // We will indirectly return an optional with the address in r0, input parameters will be in r1 and r2
 // V7K: str r0, [sp, [[IDX:#[0-9]+]]]
@@ -324,7 +324,7 @@ func minMax2(x : Int, y : Int) -> (min: Int, max: Int, min2: Int, max2: Int, min
 }
 
 // Returning struct?: {Int x 6}?
-// CHECK-LABEL: define hidden swiftcc void @"$s8test_v7k7minMax3{{.*}}"(ptr noalias nocapture sret({{.*}}) %0, i32 %1, i32 %2)
+// CHECK-LABEL: define hidden swiftcc void @"$s8test_v7k7minMax3{{.*}}"(ptr noalias captures(none) sret({{.*}}) %0, i32 %1, i32 %2)
 // V7K-LABEL: _$s8test_v7k7minMax3
 struct Ret {
   var min:Int