Skeleton of a linear scan register allocator.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
diff --git a/runtime/vm/intermediate_language_x64.cc b/runtime/vm/intermediate_language_x64.cc
index ba50319b5fd7ef0b43a8d69e7c5603b7c255d4e0..2ff995e80f9aafafeb650f1fab12f9e0465765f9 100644
--- a/runtime/vm/intermediate_language_x64.cc
+++ b/runtime/vm/intermediate_language_x64.cc
@@ -32,7 +32,7 @@ LocationSummary* Computation::MakeCallSummary() {
 
 void BindInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   computation()->EmitNativeCode(compiler);
-  if (is_used() && locs()->out().kind() == Location::kRegister) {
+  if (is_used() && locs()->out().IsRegister()) {
     // TODO(vegorov): this should really happen only for comparisons fused
     // with branches.  Currrently IR does not provide an easy way to remove
     // instructions from the graph so we just leave fused comparison in it
@@ -155,12 +155,7 @@ LocationSummary* ConstantVal::MakeLocationSummary() const {
 
 void ConstantVal::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register result = locs()->out().reg();
-  if (value().IsSmi()) {
-    int64_t imm = reinterpret_cast<int64_t>(value().raw());
-    __ movq(result, Immediate(imm));
-  } else {
-    __ LoadObject(result, value());
-  }
+  __ LoadObject(result, value());
 }
 
 
@@ -448,7 +443,7 @@ LocationSummary* RelationalOpComp::MakeLocationSummary() const {
     const intptr_t kNumTemps = 1;
     LocationSummary* summary = new LocationSummary(kNumInputs,
                                                    kNumTemps,
-                                                   LocationSummary::kCall,
+                                                   LocationSummary::kNoCall,
                                                    contains_branch);
     summary->set_in(0, Location::RequiresRegister());
     summary->set_in(1, Location::RequiresRegister());
@@ -1981,6 +1976,7 @@ void PolymorphicInstanceCallComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ Bind(&done);
 }
 
+
 }  // namespace dart
 
 #undef __