Pass a second type argument vector to all type instantiation calls in the VM.

runtime/vm/flow_graph_compiler_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 184 matching lines @@
   __ b(&fall_through, EQ);
   __ CompareObject(bool_register, Bool::True());
   __ b(is_true, EQ);
   __ b(is_false);
   __ Bind(&fall_through);
 }
 
 
 // R0: instance (must be preserved).
 // R1: instantiator type arguments (if used).
+// R2: function type arguments (if used).
 RawSubtypeTestCache* FlowGraphCompiler::GenerateCallSubtypeTestStub(
     TypeTestStubKind test_kind,
     Register instance_reg,
-    Register type_arguments_reg,
+    Register instantiator_type_arguments_reg,
+    Register function_type_arguments_reg,
     Register temp_reg,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   ASSERT(instance_reg == R0);
-  ASSERT(temp_reg == kNoRegister);  // Unused on ARM.
+  ASSERT(temp_reg == kNoRegister);  // Unused on ARM64.
   const SubtypeTestCache& type_test_cache =
       SubtypeTestCache::ZoneHandle(zone(), SubtypeTestCache::New());
-  __ LoadUniqueObject(R2, type_test_cache);
+  __ LoadUniqueObject(R3, type_test_cache);
   if (test_kind == kTestTypeOneArg) {
-    ASSERT(type_arguments_reg == kNoRegister);
-    __ LoadObject(R1, Object::null_object());
+    ASSERT(instantiator_type_arguments_reg == kNoRegister);
+    ASSERT(function_type_arguments_reg == kNoRegister);
     __ BranchLink(*StubCode::Subtype1TestCache_entry());
   } else if (test_kind == kTestTypeTwoArgs) {
-    ASSERT(type_arguments_reg == kNoRegister);
-    __ LoadObject(R1, Object::null_object());
+    ASSERT(instantiator_type_arguments_reg == kNoRegister);
+    ASSERT(function_type_arguments_reg == kNoRegister);
     __ BranchLink(*StubCode::Subtype2TestCache_entry());
-  } else if (test_kind == kTestTypeThreeArgs) {
-    ASSERT(type_arguments_reg == R1);
-    __ BranchLink(*StubCode::Subtype3TestCache_entry());
+  } else if (test_kind == kTestTypeFourArgs) {
+    ASSERT(instantiator_type_arguments_reg == R1);
+    ASSERT(function_type_arguments_reg == R2);
+    __ BranchLink(*StubCode::Subtype4TestCache_entry());
   } else {
     UNREACHABLE();
   }
   // Result is in R1: null -> not found, otherwise Bool::True or Bool::False.
   GenerateBoolToJump(R1, is_instance_lbl, is_not_instance_lbl);
   return type_test_cache.raw();
 }
 
 
 // Jumps to labels 'is_instance' or 'is_not_instance' respectively, if
 // type test is conclusive, otherwise fallthrough if a type test could not
 // be completed.
 // R0: instance being type checked (preserved).
-// Clobbers R2.
+// Clobbers R1, R2.
 RawSubtypeTestCache*
 FlowGraphCompiler::GenerateInstantiatedTypeWithArgumentsTest(
     TokenPosition token_pos,
     const AbstractType& type,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   __ Comment("InstantiatedTypeWithArgumentsTest");
   ASSERT(type.IsInstantiated());
   const Class& type_class = Class::ZoneHandle(zone(), type.type_class());
   ASSERT(type.IsFunctionType() || (type_class.NumTypeArguments() > 0));
@@ skipping 43 matching lines @@
         const Type& object_type = Type::Handle(zone(), Type::ObjectType());
         if (object_type.IsSubtypeOf(tp_argument, NULL, NULL, Heap::kOld)) {
           // Instance class test only necessary.
           return GenerateSubtype1TestCacheLookup(
               token_pos, type_class, is_instance_lbl, is_not_instance_lbl);
         }
       }
     }
   }
   // Regular subtype test cache involving instance's type arguments.
-  const Register kTypeArgumentsReg = kNoRegister;
+  const Register kInstantiatorTypeArgumentsReg = kNoRegister;
+  const Register kFunctionTypeArgumentsReg = kNoRegister;
   const Register kTempReg = kNoRegister;
   // R0: instance (must be preserved).
   return GenerateCallSubtypeTestStub(kTestTypeTwoArgs, kInstanceReg,
-                                     kTypeArgumentsReg, kTempReg,
+                                     kInstantiatorTypeArgumentsReg,
+                                     kFunctionTypeArgumentsReg, kTempReg,
                                      is_instance_lbl, is_not_instance_lbl);
 }
 
 
 void FlowGraphCompiler::CheckClassIds(Register class_id_reg,
                                       const GrowableArray<intptr_t>& class_ids,
                                       Label* is_equal_lbl,
                                       Label* is_not_equal_lbl) {
   for (intptr_t i = 0; i < class_ids.length(); i++) {
     __ CompareImmediate(class_id_reg, class_ids[i]);
@@ skipping 86 matching lines @@
   __ Comment("Subtype1TestCacheLookup");
   const Register kInstanceReg = R0;
   __ LoadClass(R1, kInstanceReg);
   // R1: instance class.
   // Check immediate superclass equality.
   __ LoadFieldFromOffset(R2, R1, Class::super_type_offset());
   __ LoadFieldFromOffset(R2, R2, Type::type_class_id_offset());
   __ CompareImmediate(R2, Smi::RawValue(type_class.id()));
   __ b(is_instance_lbl, EQ);
 
-  const Register kTypeArgumentsReg = kNoRegister;
+  const Register kInstantiatorTypeArgumentsReg = kNoRegister;
+  const Register kFunctionTypeArgumentsReg = kNoRegister;
   const Register kTempReg = kNoRegister;
   return GenerateCallSubtypeTestStub(kTestTypeOneArg, kInstanceReg,
-                                     kTypeArgumentsReg, kTempReg,
+                                     kInstantiatorTypeArgumentsReg,
+                                     kFunctionTypeArgumentsReg, kTempReg,
                                      is_instance_lbl, is_not_instance_lbl);
 }
 
 
 // Generates inlined check if 'type' is a type parameter or type itself
 // R0: instance (preserved).
 RawSubtypeTestCache* FlowGraphCompiler::GenerateUninstantiatedTypeTest(
     TokenPosition token_pos,
     const AbstractType& type,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   __ Comment("UninstantiatedTypeTest");
   ASSERT(!type.IsInstantiated());
   // Skip check if destination is a dynamic type.
   if (type.IsTypeParameter()) {
     const TypeParameter& type_param = TypeParameter::Cast(type);
-    // Load instantiator type arguments on stack.
-    __ ldr(R1, Address(SP));  // Get instantiator type arguments.
+    __ ldr(R1, Address(SP, 1 * kWordSize));  // Get instantiator type args.

[zra, 2017/04/07 17:36:30]

ldp to load a pair.

[regis, 2017/04/11 04:23:07]

Done.

+    __ ldr(R2, Address(SP, 0 * kWordSize));  // Get function type args.
     // R1: instantiator type arguments.
+    // R2: function type arguments.
+    const Register kTypeArgumentsReg =
+        type_param.IsClassTypeParameter() ? R1 : R2;
     // Check if type arguments are null, i.e. equivalent to vector of dynamic.
-    __ CompareObject(R1, Object::null_object());
+    __ CompareObject(kTypeArgumentsReg, Object::null_object());
     __ b(is_instance_lbl, EQ);
-    __ LoadFieldFromOffset(R2, R1,
+    __ LoadFieldFromOffset(R3, kTypeArgumentsReg,
                            TypeArguments::type_at_offset(type_param.index()));
-    // R2: concrete type of type.
+    // R3: concrete type of type.
     // Check if type argument is dynamic.
-    __ CompareObject(R2, Object::dynamic_type());
+    __ CompareObject(R3, Object::dynamic_type());
     __ b(is_instance_lbl, EQ);
-    __ CompareObject(R2, Type::ZoneHandle(zone(), Type::ObjectType()));
+    __ CompareObject(R3, Type::ZoneHandle(zone(), Type::ObjectType()));
     __ b(is_instance_lbl, EQ);
+    // TODO(regis): Optimize void type as well once allowed as type argument.
 
     // For Smi check quickly against int and num interfaces.
     Label not_smi;
     __ tsti(R0, Immediate(kSmiTagMask));  // Value is Smi?
     __ b(&not_smi, NE);
-    __ CompareObject(R2, Type::ZoneHandle(zone(), Type::IntType()));
+    __ CompareObject(R3, Type::ZoneHandle(zone(), Type::IntType()));
     __ b(is_instance_lbl, EQ);
-    __ CompareObject(R2, Type::ZoneHandle(zone(), Type::Number()));
+    __ CompareObject(R3, Type::ZoneHandle(zone(), Type::Number()));
     __ b(is_instance_lbl, EQ);
     // Smi must be handled in runtime.
     Label fall_through;
     __ b(&fall_through);
 
     __ Bind(&not_smi);
     // R1: instantiator type arguments.
+    // R2: function type arguments.
     // R0: instance.
     const Register kInstanceReg = R0;
-    const Register kTypeArgumentsReg = R1;
+    const Register kInstantiatorTypeArgumentsReg = R1;
+    const Register kFunctionTypeArgumentsReg = R2;
     const Register kTempReg = kNoRegister;
     const SubtypeTestCache& type_test_cache = SubtypeTestCache::ZoneHandle(
         zone(), GenerateCallSubtypeTestStub(
-                    kTestTypeThreeArgs, kInstanceReg, kTypeArgumentsReg,
+                    kTestTypeFourArgs, kInstanceReg,
+                    kInstantiatorTypeArgumentsReg, kFunctionTypeArgumentsReg,
                     kTempReg, is_instance_lbl, is_not_instance_lbl));
     __ Bind(&fall_through);
     return type_test_cache.raw();
   }
   if (type.IsType()) {
     const Register kInstanceReg = R0;
-    const Register kTypeArgumentsReg = R1;
+    const Register kInstantiatorTypeArgumentsReg = R1;
+    const Register kFunctionTypeArgumentsReg = R2;
     __ tsti(kInstanceReg, Immediate(kSmiTagMask));  // Is instance Smi?
     __ b(is_not_instance_lbl, EQ);
-    __ ldr(kTypeArgumentsReg, Address(SP));  // Instantiator type args.
+    __ ldr(kInstantiatorTypeArgumentsReg, Address(SP, 1 * kWordSize));

[zra, 2017/04/07 17:36:30]

ditto

[regis, 2017/04/11 04:23:08]

Done.

+    __ ldr(kFunctionTypeArgumentsReg, Address(SP, 0 * kWordSize));
     // Uninstantiated type class is known at compile time, but the type
     // arguments are determined at runtime by the instantiator.
     const Register kTempReg = kNoRegister;
-    return GenerateCallSubtypeTestStub(kTestTypeThreeArgs, kInstanceReg,
-                                       kTypeArgumentsReg, kTempReg,
+    return GenerateCallSubtypeTestStub(kTestTypeFourArgs, kInstanceReg,
+                                       kInstantiatorTypeArgumentsReg,
+                                       kFunctionTypeArgumentsReg, kTempReg,
                                        is_instance_lbl, is_not_instance_lbl);
   }
   return SubtypeTestCache::null();
 }
 
 
 // Inputs:
 // - R0: instance being type checked (preserved).
 // - R1: optional instantiator type arguments (preserved).
-// Clobbers R2, R3.
+// - R2: optional function type arguments (preserved).
+// Clobbers R3, R4, R8, R9.
 // Returns:
-// - preserved instance in R0 and optional instantiator type arguments in R1.
+// - preserved instance in R0, optional instantiator type arguments in R1, and
+//   optional function type arguments in R2.
 // Note that this inlined code must be followed by the runtime_call code, as it
 // may fall through to it. Otherwise, this inline code will jump to the label
 // is_instance or to the label is_not_instance.
 RawSubtypeTestCache* FlowGraphCompiler::GenerateInlineInstanceof(
     TokenPosition token_pos,
     const AbstractType& type,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   __ Comment("InlineInstanceof");
   if (type.IsVoidType()) {
@@ skipping 28 matching lines @@
 
 
 // If instanceof type test cannot be performed successfully at compile time and
 // therefore eliminated, optimize it by adding inlined tests for:
 // - NULL -> return type == Null (type is not Object or dynamic).
 // - Smi -> compile time subtype check (only if dst class is not parameterized).
 // - Class equality (only if class is not parameterized).
 // Inputs:
 // - R0: object.
 // - R1: instantiator type arguments or raw_null.
+// - R2: function type arguments or raw_null.
 // Returns:
 // - true or false in R0.
 void FlowGraphCompiler::GenerateInstanceOf(TokenPosition token_pos,
                                            intptr_t deopt_id,
                                            const AbstractType& type,
                                            LocationSummary* locs) {
   ASSERT(type.IsFinalized() && !type.IsMalformed() && !type.IsMalbounded());
   ASSERT(!type.IsObjectType() && !type.IsDynamicType());
 
-  // Preserve instantiator type arguments (R1).
-  __ Push(R1);
+  __ Push(R1);  // Store instantiator type arguments.

[zra, 2017/04/07 17:36:30]

PushPair

[regis, 2017/04/11 04:23:08]

Done.

However, the argument names 'first' and 'second' of PushPair and PopPair are
very confusing. If the idea is to simulate 2 pushes, PushPair pushing 'first'
first and 'second' second, then PopPair should do the same: if PushPair(first,
second) === Push(first); Push(second) then I would expect to call PopPair(first,
second) == Pop(first); Pop(second), but PopPair(first, second) does actually
Pop(second); Pop(first).
So if I want to undo a PushPair(R1, R0), I have to do a PopPair(R1, R0) and not
a PopPair(R0, R1), despite the names of the arguments.
I wanted to rename the arguments to high and low, which are much less confusing
to me. But to keep the same order as for ldp(rt, rt2), I renamed them to low and
high, and fixed the single use of PushPair/PopPair I could find.

+  __ Push(R2);  // Store function type arguments.
 
   Label is_instance, is_not_instance;
   // If type is instantiated and non-parameterized, we can inline code
   // checking whether the tested instance is a Smi.
   if (type.IsInstantiated()) {
     // A null object is only an instance of Null, Object, and dynamic.
     // Object and dynamic have already been checked above (if the type is
     // instantiated). So we can return false here if the instance is null,
     // unless the type is Null (and if the type is instantiated).
     // We can only inline this null check if the type is instantiated at compile
     // time, since an uninstantiated type at compile time could be Null, Object,
     // or dynamic at run time.
     __ CompareObject(R0, Object::null_object());
     __ b(type.IsNullType() ? &is_instance : &is_not_instance, EQ);
   }
 
   // Generate inline instanceof test.
   SubtypeTestCache& test_cache = SubtypeTestCache::ZoneHandle(zone());
   test_cache =
       GenerateInlineInstanceof(token_pos, type, &is_instance, &is_not_instance);
 
   // test_cache is null if there is no fall-through.
   Label done;
   if (!test_cache.IsNull()) {
     // Generate runtime call.
     // Load instantiator (R2) and its type arguments (R1).
-    __ ldr(R1, Address(SP, 0 * kWordSize));
-    __ PushObject(Object::null_object());  // Make room for the result.
-    __ Push(R0);                           // Push the instance.
-    __ PushObject(type);                   // Push the type.
-    __ Push(R1);  // Push instantiator type arguments (R1).
+    __ ldr(R1, Address(SP, 1 * kWordSize));  // Get instantiator type args.

[zra, 2017/04/07 17:36:30]

ldp

[regis, 2017/04/11 04:23:08]

Done.

+    __ ldr(R2, Address(SP, 0 * kWordSize));  // Get function type args.
+    __ PushObject(Object::null_object());    // Make room for the result.
+    __ Push(R0);                             // Push the instance.
+    __ PushObject(type);                     // Push the type.
+    __ Push(R1);                             // Instantiator type arguments.

[zra, 2017/04/07 17:36:30]

PushPair

[regis, 2017/04/11 04:23:08]

Done.

+    __ Push(R2);                             // Function type arguments.
     __ LoadUniqueObject(R0, test_cache);
     __ Push(R0);
-    GenerateRuntimeCall(token_pos, deopt_id, kInstanceofRuntimeEntry, 4, locs);
+    GenerateRuntimeCall(token_pos, deopt_id, kInstanceofRuntimeEntry, 5, locs);
     // Pop the parameters supplied to the runtime entry. The result of the
     // instanceof runtime call will be left as the result of the operation.
-    __ Drop(4);
+    __ Drop(5);
     __ Pop(R0);
     __ b(&done);
   }
   __ Bind(&is_not_instance);
   __ LoadObject(R0, Bool::Get(false));
   __ b(&done);
 
   __ Bind(&is_instance);
   __ LoadObject(R0, Bool::Get(true));
   __ Bind(&done);
-  // Remove instantiator type arguments (R1).
-  __ Drop(1);
+  // Remove instantiator type arguments and function type arguments.
+  __ Drop(2);
 }
 
 
 // Optimize assignable type check by adding inlined tests for:
 // - NULL -> return NULL.
 // - Smi -> compile time subtype check (only if dst class is not parameterized).
 // - Class equality (only if class is not parameterized).
 // Inputs:
 // - R0: instance being type checked.
 // - R1: instantiator type arguments or raw_null.
+// - R2: function type arguments or raw_null.
 // Returns:
 // - object in R0 for successful assignable check (or throws TypeError).
 // Performance notes: positive checks must be quick, negative checks can be slow
 // as they throw an exception.
 void FlowGraphCompiler::GenerateAssertAssignable(TokenPosition token_pos,
                                                  intptr_t deopt_id,
                                                  const AbstractType& dst_type,
                                                  const String& dst_name,
                                                  LocationSummary* locs) {
   ASSERT(!TokenPosition(token_pos).IsClassifying());
   ASSERT(!dst_type.IsNull());
   ASSERT(dst_type.IsFinalized());
   // Assignable check is skipped in FlowGraphBuilder, not here.
   ASSERT(dst_type.IsMalformedOrMalbounded() ||
          (!dst_type.IsDynamicType() && !dst_type.IsObjectType()));
-  // Preserve instantiator type arguments (R1).
-  __ Push(R1);
+  __ Push(R1);  // Store instantiator type arguments.

[zra, 2017/04/07 17:36:30]

PushPair

[regis, 2017/04/11 04:23:08]

Done.

+  __ Push(R2);  // Store function type arguments.
   // A null object is always assignable and is returned as result.
   Label is_assignable, runtime_call;
   __ CompareObject(R0, Object::null_object());
   __ b(&is_assignable, EQ);
 
   // Generate throw new TypeError() if the type is malformed or malbounded.
   if (dst_type.IsMalformedOrMalbounded()) {
     __ PushObject(Object::null_object());  // Make room for the result.
     __ Push(R0);                           // Push the source object.
     __ PushObject(dst_name);               // Push the name of the destination.
     __ PushObject(dst_type);               // Push the type of the destination.
     GenerateRuntimeCall(token_pos, deopt_id, kBadTypeErrorRuntimeEntry, 3,
                         locs);
     // We should never return here.
     __ brk(0);
 
     __ Bind(&is_assignable);  // For a null object.
-    // Restore instantiator type arguments (R1).
-    __ Pop(R1);
+    __ Pop(R2);               // Remove pushed function type arguments.

[zra, 2017/04/07 17:36:30]

PopPair

[regis, 2017/04/11 04:23:08]

Done.

+    __ Pop(R1);               // Remove pushed instantiator type arguments.
     return;
   }
 
   // Generate inline type check, linking to runtime call if not assignable.
   SubtypeTestCache& test_cache = SubtypeTestCache::ZoneHandle(zone());
   test_cache = GenerateInlineInstanceof(token_pos, dst_type, &is_assignable,
                                         &runtime_call);
 
   __ Bind(&runtime_call);
-  __ ldr(R1, Address(SP));  // Load instantiator type arguments (R1).
-  __ PushObject(Object::null_object());  // Make room for the result.
-  __ Push(R0);                           // Push the source object.
-  __ PushObject(dst_type);               // Push the type of the destination.
-  __ Push(R1);              // Push instantiator type arguments (R1).
-  __ PushObject(dst_name);  // Push the name of the destination.
+  __ ldr(R1, Address(SP, 1 * kWordSize));  // Get instantiator type args.

[zra, 2017/04/07 17:36:30]

ldp

[regis, 2017/04/11 04:23:07]

Done.

+  __ ldr(R2, Address(SP, 0 * kWordSize));  // Get function type args.
+  __ PushObject(Object::null_object());    // Make room for the result.
+  __ Push(R0);                             // Push the source object.
+  __ PushObject(dst_type);                 // Push the type of the destination.
+  __ Push(R1);                             // Instantiator type arguments.

[zra, 2017/04/07 17:36:30]

PushPair

[regis, 2017/04/11 04:23:07]

Done.

+  __ Push(R2);                             // Function type arguments.
+  __ PushObject(dst_name);                 // Push the name of the destination.
   __ LoadUniqueObject(R0, test_cache);
   __ Push(R0);
-  GenerateRuntimeCall(token_pos, deopt_id, kTypeCheckRuntimeEntry, 5, locs);
+  GenerateRuntimeCall(token_pos, deopt_id, kTypeCheckRuntimeEntry, 6, locs);
   // Pop the parameters supplied to the runtime entry. The result of the
   // type check runtime call is the checked value.
-  __ Drop(5);
+  __ Drop(6);
   __ Pop(R0);
 
   __ Bind(&is_assignable);
-  // Restore instantiator type arguments (R1).
-  __ Pop(R1);
+  __ Pop(R2);  // Remove pushed function type arguments.

[zra, 2017/04/07 17:36:30]

PopPair

[regis, 2017/04/11 04:23:08]

Done.

+  __ Pop(R1);  // Remove pushed instantiator type arguments.
 }
 
 
 void FlowGraphCompiler::EmitInstructionEpilogue(Instruction* instr) {
   if (is_optimizing()) {
     return;
   }
   Definition* defn = instr->AsDefinition();
   if ((defn != NULL) && defn->HasTemp()) {
     __ Push(defn->locs()->out(0).reg());
@@ skipping 1144 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64