VM: Clean up generated code for NoSuchMethod invocation of closures.

runtime/vm/stub_code_arm.cc

 // Copyright (c) 2013, 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"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 1137 matching lines @@
   __ Ret();
 }
 
 
 // Called for invoking "dynamic noSuchMethod(Invocation invocation)" function
 // from the entry code of a dart function after an error in passed argument
 // name or number is detected.
 // Input parameters:
 //  LR : return address.
 //  SP : address of last argument.
-//  R5: inline cache data object.
 //  R4: arguments descriptor array.
 void StubCode::GenerateCallNoSuchMethodFunctionStub(Assembler* assembler) {
   __ EnterStubFrame();
 
   // Load the receiver.
   __ ldr(R2, FieldAddress(R4, ArgumentsDescriptor::count_offset()));
   __ add(IP, FP, Operand(R2, LSL, 1));  // R2 is Smi.
   __ ldr(R6, Address(IP, kParamEndSlotFromFp * kWordSize));
 
   // Push space for the return value.
   // Push the receiver.
   // Push IC data object.

[Vyacheslav Egorov (Google), 2014/09/02 22:28:04]

comment is obsolete, update

[Florian Schneider, 2014/09/03 09:05:00]

Done.

   // Push arguments descriptor array.
   __ LoadImmediate(IP, reinterpret_cast<intptr_t>(Object::null()));
-  __ PushList((1 << R4) | (1 << R5) | (1 << R6) | (1 << IP));
+  __ PushList((1 << R4) | (1 << R6) | (1 << IP));
 
   // R2: Smi-tagged arguments array length.
   PushArgumentsArray(assembler);
 
-  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, 4);
+  const intptr_t kNumArgs = 3;

[Vyacheslav Egorov (Google), 2014/09/02 22:28:04]

this 3 is related to the number of bits set in the list above. I wonder if this
can be unified somehow.

[Florian Schneider, 2014/09/03 09:05:00]

It's a little tricky to generate the push-list - maybe some macro-magic could
help out, but I'd rather do this in a separate CL. IP (=null) contains the slot
for the result

+  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, kNumArgs);
   // Remove arguments.
-  __ Drop(4);
+  __ Drop(kNumArgs);
   __ Pop(R0);  // Get result into R0.
   __ LeaveStubFrame();

[Vyacheslav Egorov (Google), 2014/09/02 22:28:04]

something is off here: three things were pushed and you dropped three things.
where does the result come from?

[Florian Schneider, 2014/09/03 09:05:00]

I'm sure PushArgumentsArray is the missing piece here.

   __ Ret();
 }
 
 
 //  R6: function object.
 //  R5: inline cache data object.
 // Cannot use function object from ICData as it may be the inlined
 // function and not the top-scope function.
 void StubCode::GenerateOptimizedUsageCounterIncrement(Assembler* assembler) {
   Register ic_reg = R5;
@@ skipping 763 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM