Revert "VM: New calling convention for generated code."

runtime/vm/flow_graph_compiler_mips.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"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 78 matching lines @@
 
   // Emit all kMaterializeObject instructions describing objects to be
   // materialized on the deoptimization as a prefix to the deoptimization info.
   EmitMaterializations(deopt_env_, builder);
 
   // The real frame starts here.
   builder->MarkFrameStart();
 
   Zone* zone = compiler->zone();
 
+  // Current PP, FP, and PC.
   builder->AddPp(current->function(), slot_ix++);
-  builder->AddPcMarker(Function::Handle(zone), slot_ix++);
   builder->AddCallerFp(slot_ix++);
   builder->AddReturnAddress(current->function(), deopt_id(), slot_ix++);
 
+  // Callee's PC marker is not used anymore. Pass Code::null() to set to 0.
+  builder->AddPcMarker(Function::Handle(zone), slot_ix++);
 
   // Emit all values that are needed for materialization as a part of the
   // expression stack for the bottom-most frame. This guarantees that GC
   // will be able to find them during materialization.
   slot_ix = builder->EmitMaterializationArguments(slot_ix);
 
   // For the innermost environment, set outgoing arguments and the locals.
   for (intptr_t i = current->Length() - 1;
        i >= current->fixed_parameter_count();
        i--) {
     builder->AddCopy(current->ValueAt(i), current->LocationAt(i), slot_ix++);
   }
 
   Environment* previous = current;
   current = current->outer();
   while (current != NULL) {
+    // PP, FP, and PC.
     builder->AddPp(current->function(), slot_ix++);
-    builder->AddPcMarker(previous->function(), slot_ix++);
     builder->AddCallerFp(slot_ix++);
 
     // For any outer environment the deopt id is that of the call instruction
     // which is recorded in the outer environment.
     builder->AddReturnAddress(
         current->function(),
         Isolate::ToDeoptAfter(current->deopt_id()),
         slot_ix++);
 
+    // PC marker.
+    builder->AddPcMarker(previous->function(), slot_ix++);
+
     // The values of outgoing arguments can be changed from the inlined call so
     // we must read them from the previous environment.
     for (intptr_t i = previous->fixed_parameter_count() - 1; i >= 0; i--) {
       builder->AddCopy(previous->ValueAt(i),
                        previous->LocationAt(i),
                        slot_ix++);
     }
 
     // Set the locals, note that outgoing arguments are not in the environment.
     for (intptr_t i = current->Length() - 1;
          i >= current->fixed_parameter_count();
          i--) {
       builder->AddCopy(current->ValueAt(i),
                        current->LocationAt(i),
                        slot_ix++);
     }
 
     // Iterate on the outer environment.
     previous = current;
     current = current->outer();
   }
   // The previous pointer is now the outermost environment.
   ASSERT(previous != NULL);
 
-  // Set slots for the outermost environment.
+  // For the outermost environment, set caller PC, caller PP, and caller FP.
   builder->AddCallerPp(slot_ix++);
-  builder->AddPcMarker(previous->function(), slot_ix++);
   builder->AddCallerFp(slot_ix++);
   builder->AddCallerPc(slot_ix++);
 
+  // PC marker.
+  builder->AddPcMarker(previous->function(), slot_ix++);
+
   // For the outermost environment, set the incoming arguments.
   for (intptr_t i = previous->fixed_parameter_count() - 1; i >= 0; i--) {
     builder->AddCopy(previous->ValueAt(i), previous->LocationAt(i), slot_ix++);
   }
 
   return builder->CreateDeoptInfo(deopt_table);
 }
 
 
 void CompilerDeoptInfoWithStub::GenerateCode(FlowGraphCompiler* compiler,
                                              intptr_t stub_ix) {
   // Calls do not need stubs, they share a deoptimization trampoline.
   ASSERT(reason() != ICData::kDeoptAtCall);
   Assembler* assem = compiler->assembler();
 #define __ assem->
   __ Comment("%s", Name());
   __ Bind(entry_label());
   if (FLAG_trap_on_deoptimization) {
     __ break_(0);
   }
 
   ASSERT(deopt_env() != NULL);
-  __ Push(CODE_REG);
+
   __ BranchLink(*StubCode::Deoptimize_entry());
   set_pc_offset(assem->CodeSize());
 #undef __
 }
 
 
 #define __ assembler()->
 
 
 // Fall through if bool_register contains null.
@@ skipping 720 matching lines @@
     if (check_correct_named_args) {
       __ lw(T1, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
       __ SmiUntag(T1);
       // Check that T2 equals T1, i.e. no named arguments passed.
       __ beq(T2, T1, &all_arguments_processed);
     }
   }
 
   __ Bind(&wrong_num_arguments);
   if (function.IsClosureFunction()) {
-    __ LeaveDartFrame(kKeepCalleePP);  // Arguments are still on the stack.
+    __ LeaveDartFrame();  // The arguments are still on the stack.
     __ Branch(*StubCode::CallClosureNoSuchMethod_entry());
     // The noSuchMethod call may return to the caller, but not here.
   } else if (check_correct_named_args) {
     __ Stop("Wrong arguments");
   }
 
   __ Bind(&all_arguments_processed);
   // Nullify originally passed arguments only after they have been copied and
   // checked, otherwise noSuchMethod would not see their original values.
   // This step can be skipped in case we decide that formal parameters are
@@ skipping 37 matching lines @@
   // Sequence node has one store node and one return NULL node.
   __ Comment("Inlined Setter");
   __ lw(T0, Address(SP, 1 * kWordSize));  // Receiver.
   __ lw(T1, Address(SP, 0 * kWordSize));  // Value.
   __ StoreIntoObjectOffset(T0, offset, T1);
   __ LoadObject(V0, Object::null_object());
   __ Ret();
 }
 
 
-static const Register new_pp = T7;
-
-
 void FlowGraphCompiler::EmitFrameEntry() {
   const Function& function = parsed_function().function();
   if (CanOptimizeFunction() &&
       function.IsOptimizable() &&
       (!is_optimizing() || may_reoptimize())) {
     const Register function_reg = T0;
 
+    __ GetNextPC(T2, TMP);
+
+    // Calculate offset of pool pointer from the PC.
+    const intptr_t object_pool_pc_dist =
+       Instructions::HeaderSize() - Instructions::object_pool_offset() +
+       assembler()->CodeSize() - 1 * Instr::kInstrSize;
+
+    // Preserve PP of caller.
+    __ mov(T1, PP);
     // Temporarily setup pool pointer for this dart function.
-    __ LoadPoolPointer(new_pp);
+    __ lw(PP, Address(T2, -object_pool_pc_dist));
     // Load function object from object pool.
-    __ LoadFunctionFromCalleePool(function_reg, function, new_pp);
+    __ LoadObject(function_reg, function);  // Uses PP.
+    // Restore PP of caller.
+    __ mov(PP, T1);
+
+    // Patch point is after the eventually inlined function object.
+    entry_patch_pc_offset_ = assembler()->CodeSize();
 
     __ lw(T1, FieldAddress(function_reg, Function::usage_counter_offset()));
     // Reoptimization of an optimized function is triggered by counting in
     // IC stubs, but not at the entry of the function.
     if (!is_optimizing()) {
       __ addiu(T1, T1, Immediate(1));
       __ sw(T1, FieldAddress(function_reg, Function::usage_counter_offset()));
     }
 
     // Skip Branch if T1 is less than the threshold.
     Label dont_branch;
     __ BranchSignedLess(
         T1, Immediate(GetOptimizationThreshold()), &dont_branch);
 
     ASSERT(function_reg == T0);
-    __ Branch(*StubCode::OptimizeFunction_entry(), new_pp);
+    __ Branch(*StubCode::OptimizeFunction_entry());
 
     __ Bind(&dont_branch);
+
+  } else if (!flow_graph().IsCompiledForOsr()) {
+    entry_patch_pc_offset_ = assembler()->CodeSize();
   }
   __ Comment("Enter frame");
   if (flow_graph().IsCompiledForOsr()) {
     intptr_t extra_slots = StackSize()
         - flow_graph().num_stack_locals()
         - flow_graph().num_copied_params();
     ASSERT(extra_slots >= 0);
     __ EnterOsrFrame(extra_slots * kWordSize);
   } else {
     ASSERT(StackSize() >= 0);
@@ skipping 40 matching lines @@
       Label correct_num_arguments, wrong_num_arguments;
       __ lw(T0, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
       __ BranchNotEqual(T0, Immediate(Smi::RawValue(num_fixed_params)),
                         &wrong_num_arguments);
 
       __ lw(T1, FieldAddress(S4,
                              ArgumentsDescriptor::positional_count_offset()));
       __ beq(T0, T1, &correct_num_arguments);
       __ Bind(&wrong_num_arguments);
       if (function.IsClosureFunction()) {
-        __ LeaveDartFrame(kKeepCalleePP);  // Arguments are still on the stack.
+        __ LeaveDartFrame();  // The arguments are still on the stack.
         __ Branch(*StubCode::CallClosureNoSuchMethod_entry());
         // The noSuchMethod call may return to the caller, but not here.
       } else {
         __ Stop("Wrong number of arguments");
       }
       __ Bind(&correct_num_arguments);
     }
   } else if (!flow_graph().IsCompiledForOsr()) {
     CopyParameters();
   }
@@ skipping 32 matching lines @@
         ASSERT(num_locals > 1);
         __ sw(V0, Address(FP, (slot_base - i) * kWordSize));
       }
     }
   }
 
   VisitBlocks();
 
   __ break_(0);
   GenerateDeferredCode();
+  // Emit function patching code. This will be swapped with the first 5 bytes
+  // at entry point.
+  patch_code_pc_offset_ = assembler()->CodeSize();
+  __ BranchPatchable(*StubCode::FixCallersTarget_entry());
 
   if (is_optimizing()) {
     lazy_deopt_pc_offset_ = assembler()->CodeSize();
     __ Branch(*StubCode::DeoptimizeLazy_entry());
   }
 }
 
 
 void FlowGraphCompiler::GenerateCall(intptr_t token_pos,
                                      const StubEntry& stub_entry,
@@ skipping 696 matching lines @@
   __ AddImmediate(SP, kDoubleSize);
 }
 
 
 #undef __
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS