[VM DBC compiler and simulator] Support reified generic functions.

runtime/vm/simulator_dbc.cc

Index: runtime/vm/simulator_dbc.cc
diff --git a/runtime/vm/simulator_dbc.cc b/runtime/vm/simulator_dbc.cc
index 9a8838fa60dac34fdb0d0ea8b5d2f66fd2e77820..432815f81796518fc0da8ece43be47efda42a126 100644
--- a/runtime/vm/simulator_dbc.cc
+++ b/runtime/vm/simulator_dbc.cc
@@ -835,7 +835,11 @@ DART_FORCE_INLINE void Simulator::InstanceCall1(Thread* thread,
   RawObject** args = call_base;
   RawArray* cache = icdata->ptr()->ic_data_->ptr();
 
-  RawSmi* receiver_cid = SimulatorHelpers::GetClassIdAsSmi(args[0]);
+  const intptr_t type_args_len = Smi::Value(*reinterpret_cast<RawSmi**>(
+      reinterpret_cast<uword>(icdata->ptr()->args_descriptor_->ptr()) +
+      Array::element_offset(ArgumentsDescriptor::kTypeArgsLenIndex)));
+  const intptr_t receiver_idx = type_args_len > 0 ? 1 : 0;
+  RawSmi* receiver_cid = SimulatorHelpers::GetClassIdAsSmi(args[receiver_idx]);
 
   bool found = false;
   const intptr_t length = Smi::Value(cache->length_);
@@ -853,8 +857,8 @@ DART_FORCE_INLINE void Simulator::InstanceCall1(Thread* thread,
       SimulatorHelpers::IncrementICUsageCount(cache->data(), i, kCheckedArgs);
     }
   } else {
-    InlineCacheMiss(kCheckedArgs, thread, icdata, call_base, top, *pc, *FP,
-                    *SP);
+    InlineCacheMiss(kCheckedArgs, thread, icdata, call_base + receiver_idx, top,
+                    *pc, *FP, *SP);
   }
 
   *argdesc = icdata->ptr()->args_descriptor_;
@@ -877,8 +881,12 @@ DART_FORCE_INLINE void Simulator::InstanceCall2(Thread* thread,
   RawObject** args = call_base;
   RawArray* cache = icdata->ptr()->ic_data_->ptr();
 
-  RawSmi* receiver_cid = SimulatorHelpers::GetClassIdAsSmi(args[0]);
-  RawSmi* arg0_cid = SimulatorHelpers::GetClassIdAsSmi(args[1]);
+  const intptr_t type_args_len = Smi::Value(*reinterpret_cast<RawSmi**>(

[zra, 2017/08/08 17:47:18]

Maybe pull the type_args_len calculation out into SimulatorHelpers instead of
duplicating it.

[regis, 2017/08/08 22:58:28]

Done.

+      reinterpret_cast<uword>(icdata->ptr()->args_descriptor_->ptr()) +
+      Array::element_offset(ArgumentsDescriptor::kTypeArgsLenIndex)));
+  const intptr_t receiver_idx = type_args_len > 0 ? 1 : 0;
+  RawSmi* receiver_cid = SimulatorHelpers::GetClassIdAsSmi(args[receiver_idx]);
+  RawSmi* arg0_cid = SimulatorHelpers::GetClassIdAsSmi(args[receiver_idx + 1]);
 
   bool found = false;
   const intptr_t length = Smi::Value(cache->length_);
@@ -897,8 +905,8 @@ DART_FORCE_INLINE void Simulator::InstanceCall2(Thread* thread,
       SimulatorHelpers::IncrementICUsageCount(cache->data(), i, kCheckedArgs);
     }
   } else {
-    InlineCacheMiss(kCheckedArgs, thread, icdata, call_base, top, *pc, *FP,
-                    *SP);
+    InlineCacheMiss(kCheckedArgs, thread, icdata, call_base + receiver_idx, top,
+                    *pc, *FP, *SP);
   }
 
   *argdesc = icdata->ptr()->args_descriptor_;
@@ -1261,6 +1269,7 @@ RawObject* Simulator::Call(const Code& code,
 
   // Load argument descriptor.
   argdesc = arguments_descriptor.raw();
+  ASSERT(ArgumentsDescriptor(arguments_descriptor).TypeArgsLen() == 0);
 
   // Ready to start executing bytecode. Load entry point and corresponding
   // object pool.
@@ -1432,7 +1441,7 @@ RawObject* Simulator::Call(const Code& code,
 
       // Process the list of default values encoded as a sequence of
       // LoadConstant instructions after EntryOpt bytecode.
-      // Execute only those that correspond to parameters the were not passed.
+      // Execute only those that correspond to parameters that were not passed.
       for (intptr_t i = pos_count - num_fixed_params; i < num_opt_pos_params;
            i++) {
         const uint32_t load_value = pc[i];
@@ -1553,6 +1562,32 @@ RawObject* Simulator::Call(const Code& code,
     DISPATCH();
   }
 
+  {
+    BYTECODE(CheckFunctionTypeArgs, A_D);
+    const uint16_t declared_type_args_len = rA;
+    const uint16_t first_stack_local_index = rD;
+
+    // Decode arguments descriptor's type args len.
+    const intptr_t type_args_len = Smi::Value(*reinterpret_cast<RawSmi**>(
+        reinterpret_cast<uword>(argdesc->ptr()) +
+        Array::element_offset(ArgumentsDescriptor::kTypeArgsLenIndex)));
+    if (type_args_len > 0) {
+      // Decode arguments descriptor's argument count (excluding type args).
+      const intptr_t arg_count = Smi::Value(*reinterpret_cast<RawSmi**>(
+          reinterpret_cast<uword>(argdesc->ptr()) +
+          Array::element_offset(ArgumentsDescriptor::kCountIndex)));
+      // Copy passed-in type args to first local slot.
+      FP[first_stack_local_index] = *FrameArguments(FP, arg_count + 1);
+    } else {
+      FP[first_stack_local_index] = Object::null();
+    }
+
+    // TODO(regis): Verify that type_args_len is correct.
+    USE(declared_type_args_len);
+
+    DISPATCH();
+  }
+
   {
     BYTECODE(DebugStep, A);
     if (thread->isolate()->single_step()) {