Implement a simple register allocator that tries to keep instruction results in registers.

runtime/vm/flow_graph_compiler_ia32.cc

 // Copyright (c) 2012, 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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 77 matching lines @@
   __ movsd(FieldAddress(EAX, Double::value_offset()), XMM0);
   __ jmp(done);
   __ Bind(&smi_to_double);
   __ SmiUntag(EAX);
   __ cvtsi2sd(XMM1, EAX);
   __ jmp(&double_op);
   __ Bind(&call_method);
 }
 
 
+void FlowGraphCompiler::GenerateCall(intptr_t token_index,
+                                     intptr_t try_index,
+                                     const ExternalLabel* label,
+                                     PcDescriptors::Kind kind) {
+  ASSERT(frame_register_allocator()->IsSpilled());
+  __ call(label);
+  AddCurrentDescriptor(kind, AstNode::kNoId, token_index, try_index);
+}
+
+
 void FlowGraphCompiler::GenerateCallRuntime(intptr_t cid,
                                             intptr_t token_index,
                                             intptr_t try_index,
                                             const RuntimeEntry& entry) {
+  ASSERT(frame_register_allocator()->IsSpilled());
   __ CallRuntime(entry);
   AddCurrentDescriptor(PcDescriptors::kOther, cid, token_index, try_index);
 }
 
 
 void FlowGraphCompiler::CopyParameters() {
   const Function& function = parsed_function().function();
   LocalScope* scope = parsed_function().node_sequence()->scope();
   const int num_fixed_params = function.num_fixed_parameters();
   const int num_opt_params = function.num_optional_parameters();
@@ skipping 295 matching lines @@
                                            intptr_t argument_count) {
   __ LoadObject(ECX, function);
   __ LoadObject(EDX, arguments_descriptor);
   __ call(&StubCode::CallStaticFunctionLabel());
   const intptr_t descr_offset = assembler()->CodeSize();
   __ Drop(argument_count);
   return descr_offset;
 }
 
 
-void FlowGraphCompiler::GenerateCall(intptr_t token_index,
-                                     intptr_t try_index,
-                                     const ExternalLabel* label,
-                                     PcDescriptors::Kind kind) {
-  __ call(label);
-  AddCurrentDescriptor(kind, AstNode::kNoId, token_index, try_index);
-}
-
-
 // Fall through if bool_register contains null.
 void FlowGraphCompiler::GenerateBoolToJump(Register bool_register,
                                            Label* is_true,
                                            Label* is_false) {
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   Label fall_through;
   __ cmpl(bool_register, raw_null);
   __ j(EQUAL, &fall_through, Assembler::kNearJump);
   __ CompareObject(bool_register, bool_true());
@@ skipping 528 matching lines @@
   __ Bind(&is_assignable);
   __ popl(EDX);  // Remove pushed instantiator type arguments..
   __ popl(ECX);  // Remove pushed instantiator.
 }
 
 
 void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
   LocationSummary* locs = instr->locs();
   ASSERT(locs != NULL);
 
-  locs->AllocateRegisters();
+  frame_register_allocator()->AllocateRegisters(instr);
 
-  // Load instruction inputs into allocated registers.
-  for (intptr_t i = locs->input_count() - 1; i >= 0; i--) {
-    Location loc = locs->in(i);
-    ASSERT(loc.kind() == Location::kRegister);
-    __ popl(loc.reg());
-  }
+  // TODO(vegorov): adjust assertion when we start removing comparison from the
+  // graph when it is merged with a branch.
+  ASSERT(locs->is_call() ||
+         (instr->IsBranch() && instr->AsBranch()->is_fused_with_comparison()) ||
+         (locs->input_count() == instr->InputCount()));
 }
 
 
 // Checks class id of instance against all 'class_ids'. Jump to 'deopt' label
 // if no match or instance is Smi.
 void FlowGraphCompiler::EmitClassChecksNoSmi(
     const ZoneGrowableArray<intptr_t>& class_ids,
     Register instance_reg,
     Register temp_reg,
     Label* deopt) {
@@ skipping 38 matching lines @@
   __ cvtsi2sd(result, temp);
   __ Bind(&done);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32