VM: Remove PushTempInstr, simplify SSA renaming.

runtime/vm/flow_graph_builder.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/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/compiler.h"
@@ skipping 2229 matching lines @@
   return kFirstLocalSlotFromFp
       - owner()->num_stack_locals()
       - owner()->num_copied_params()
       - owner()->args_pushed()
       - owner()->temp_count() + 1;
 }
 
 
 LocalVariable* EffectGraphVisitor::EnterTempLocalScope(
     Value* value, TokenPosition token_pos) {
-  Do(new(Z) PushTempInstr(value));
-  owner()->AllocateTemp();
-
   ASSERT(value->definition()->temp_index() == (owner()->temp_count() - 1));
   intptr_t index = GetCurrentTempLocalIndex();
   char name[64];
   OS::SNPrint(name, 64, ":tmp_local%" Pd, index);
   LocalVariable*  var =
       new(Z) LocalVariable(TokenPosition::kNoSource,
                            String::ZoneHandle(Z, Symbols::New(T, name)),
                            *value->Type()->ToAbstractType());
   var->set_index(index);
   return var;
 }
 
 
 Definition* EffectGraphVisitor::ExitTempLocalScope(
     LocalVariable* var, TokenPosition token_pos) {
   Value* tmp = Bind(new(Z) LoadLocalInstr(*var, token_pos));
   owner()->DeallocateTemps(1);
   ASSERT(GetCurrentTempLocalIndex() == var->index());
   return new(Z) DropTempsInstr(1, tmp);
 }
 
 
 void EffectGraphVisitor::BuildLetTempExpressions(LetNode* node) {
   intptr_t num_temps = node->num_temps();
   for (intptr_t i = 0; i < num_temps; ++i) {
     ValueGraphVisitor for_value(owner());
     node->InitializerAt(i)->Visit(&for_value);
     Append(for_value);
-    Value* temp_val = for_value.value();
     ASSERT(!node->TempAt(i)->HasIndex() ||
            (node->TempAt(i)->index() == GetCurrentTempLocalIndex()));
     node->TempAt(i)->set_index(GetCurrentTempLocalIndex());
-    Do(new(Z) PushTempInstr(temp_val));
-    owner()->AllocateTemp();
   }
 }
 
 
 void EffectGraphVisitor::VisitLetNode(LetNode* node) {
   BuildLetTempExpressions(node);
 
   // Visit body.
   for (intptr_t i = 0; i < node->nodes().length(); ++i) {
     EffectGraphVisitor for_effect(owner());
@@ skipping 2319 matching lines @@
                    Script::Handle(function.script()),
                    function.token_pos(),
                    Report::AtLocation,
                    "FlowGraphBuilder Bailout: %s %s",
                    String::Handle(function.name()).ToCString(),
                    reason);
   UNREACHABLE();
 }
 
 }  // namespace dart