Simplify handling of IC and megamorphic cache misses.

runtime/vm/stub_code_ia32.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_IA32)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 378 matching lines @@
   __ movl(EAX, Address(EBX, 0));
   __ movl(Address(ECX, 0), EAX);
   __ AddImmediate(ECX, Immediate(kWordSize));
   __ AddImmediate(EBX, Immediate(-kWordSize));
   __ Bind(&loop_condition);
   __ decl(EDX);
   __ j(POSITIVE, &loop, Assembler::kNearJump);
 }
 
 
-// Input parameters:
-//   ECX: ic-data.
-//   EDX: arguments descriptor array.
-// Note: The receiver object is the first argument to the function being
-//       called, the stub accesses the receiver from this location directly
-//       when trying to resolve the call.
-// Uses EDI.
-void StubCode::GenerateInstanceFunctionLookupStub(Assembler* assembler) {
-  __ EnterStubFrame();
-
-  const Immediate& raw_null =
-      Immediate(reinterpret_cast<intptr_t>(Object::null()));
-  __ pushl(raw_null);  // Space for the return value.
-
-  // Push the receiver as an argument.  Load the smi-tagged argument
-  // count into EDI to index the receiver in the stack.  There are
-  // three words (null, stub's pc marker, saved fp) above the return
-  // address.
-  __ movl(EDI, FieldAddress(EDX, ArgumentsDescriptor::count_offset()));
-  __ pushl(Address(ESP, EDI, TIMES_2, (3 * kWordSize)));
-
-  __ pushl(ECX);  // Pass IC data object.
-  __ pushl(EDX);  // Pass arguments descriptor array.
-
-  // Pass the call's arguments array.
-  __ movl(EDX, EDI);  // Smi-tagged arguments array length.
-  PushArgumentsArray(assembler);
-
-  __ CallRuntime(kInstanceFunctionLookupRuntimeEntry, 4);
-
-  // Remove arguments.
-  __ Drop(4);
-  __ popl(EAX);  // Get result into EAX.
-  __ LeaveFrame();
-  __ ret();
-}
-
-
 DECLARE_LEAF_RUNTIME_ENTRY(intptr_t, DeoptimizeCopyFrame,
                            intptr_t deopt_reason,
                            uword saved_registers_address);
 
 DECLARE_LEAF_RUNTIME_ENTRY(void, DeoptimizeFillFrame, uword last_fp);
 
 
 // Used by eager and lazy deoptimization. Preserve result in EAX if necessary.
 // This stub translates optimized frame into unoptimized frame. The optimized
 // frame can contain values in registers and on stack, the unoptimized
@@ skipping 129 matching lines @@
       Immediate(reinterpret_cast<intptr_t>(Instructions::null()));
   __ pushl(raw_null);  // Space for the result of the runtime call.
   __ pushl(EAX);  // Pass receiver.
   __ pushl(ECX);  // Pass IC data.
   __ pushl(EDX);  // Pass arguments descriptor.
   __ CallRuntime(kMegamorphicCacheMissHandlerRuntimeEntry, 3);
   // Discard arguments.
   __ popl(EAX);
   __ popl(EAX);
   __ popl(EAX);
-  __ popl(EAX);  // Return value from the runtime call (instructions).
+  __ popl(EAX);  // Return value from the runtime call (function).
   __ popl(EDX);  // Restore arguments descriptor.
   __ popl(ECX);  // Restore IC data.
   __ LeaveFrame();
 
-  Label lookup;
-  __ cmpl(EAX, raw_null);
-  __ j(EQUAL, &lookup, Assembler::kNearJump);
-  __ addl(EAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
-  __ jmp(EAX);
-
-  __ Bind(&lookup);
-  __ jmp(&StubCode::InstanceFunctionLookupLabel());
+  __ movl(EBX, FieldAddress(EAX, Function::code_offset()));
+  __ movl(EBX, FieldAddress(EBX, Code::instructions_offset()));
+  __ addl(EBX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ jmp(EBX);
 }
 
 
 // Called for inline allocation of arrays.
 // Input parameters:
 //   EDX : Array length as Smi.
 //   ECX : array element type (either NULL or an instantiated type).
 // Uses EAX, EBX, ECX, EDI  as temporary registers.
 // NOTE: EDX cannot be clobbered here as the caller relies on it being saved.
 // The newly allocated object is returned in EAX.
@@ skipping 846 matching lines @@
   for (intptr_t i = 0; i < num_args; i++) {
     __ movl(EBX, Address(EAX, -kWordSize * i));
     __ pushl(EBX);
   }
   __ pushl(ECX);  // Pass IC data object.
   __ CallRuntime(handle_ic_miss, num_args + 1);
   // Remove the call arguments pushed earlier, including the IC data object.
   for (intptr_t i = 0; i < num_args + 1; i++) {
     __ popl(EAX);
   }
-  __ popl(EAX);  // Pop returned code object into EAX (null if not found).
+  __ popl(EAX);  // Pop returned function object into EAX.
   __ popl(ECX);  // Restore IC data array.
   __ popl(EDX);  // Restore arguments descriptor array.
   __ LeaveFrame();
   Label call_target_function;
-  __ cmpl(EAX, raw_null);
-  __ j(NOT_EQUAL, &call_target_function, Assembler::kNearJump);
-  // NoSuchMethod or closure.
-  // Mark IC call that it may be a closure call that does not collect
-  // type feedback.
-  __ movb(FieldAddress(ECX, ICData::is_closure_call_offset()), Immediate(1));
-  __ jmp(&StubCode::InstanceFunctionLookupLabel());
+  __ jmp(&call_target_function);
 
   __ Bind(&found);
   // EBX: Pointer to an IC data check group.
   const intptr_t target_offset = ICData::TargetIndexFor(num_args) * kWordSize;
   const intptr_t count_offset = ICData::CountIndexFor(num_args) * kWordSize;
   __ movl(EAX, Address(EBX, target_offset));
   __ addl(Address(EBX, count_offset), Immediate(Smi::RawValue(1)));
   __ j(NO_OVERFLOW, &call_target_function, Assembler::kNearJump);
   __ movl(Address(EBX, count_offset),
           Immediate(Smi::RawValue(Smi::kMaxValue)));
@@ skipping 499 matching lines @@
   const Register temp = ECX;
   __ movl(left, Address(ESP, 2 * kWordSize));
   __ movl(right, Address(ESP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32