Change comparison-to-branch fusion to actually remove comparison from the graph.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 152 matching lines @@
 void CreateArrayComp::SetInputAt(intptr_t i, Value* value) {
   if (i == 0) {
     inputs_[0] = value;
   } else {
     (*elements_)[i - 1] = value;
   }
 }
 
 
 intptr_t BranchInstr::InputCount() const {
-  return 1;
+  return is_fused_with_comparison() ? fused_with_comparison_->InputCount() : 1;
 }
 
 
 Value* BranchInstr::InputAt(intptr_t i) const {
+  if (is_fused_with_comparison()) {
+    return fused_with_comparison_->InputAt(i);
+  }
   if (i == 0) return value();
   UNREACHABLE();
   return NULL;
 }
 
 
 void BranchInstr::SetInputAt(intptr_t i, Value* value) {
+  ASSERT(!is_fused_with_comparison());
   if (i == 0) {
     value_ = value;
     return;
   }
   UNREACHABLE();
 }
 
 
 intptr_t ParallelMoveInstr::InputCount() const {
   UNREACHABLE();
@@ skipping 783 matching lines @@
   compiler->GenerateCallRuntime(cid(),
                                 token_pos(),
                                 try_index(),
                                 kReThrowRuntimeEntry);
   __ int3();
 }
 
 
 LocationSummary* BranchInstr::MakeLocationSummary() const {
   if (is_fused_with_comparison()) {
-    return LocationSummary::Make(0,
-                                 Location::NoLocation(),
-                                 LocationSummary::kNoCall,
-                                 LocationSummary::kBranch);
+    return fused_with_comparison_->locs();
   } else {
     const int kNumInputs = 1;
     const int kNumTemps = 0;
     LocationSummary* locs = new LocationSummary(kNumInputs,
                                                 kNumTemps,
-                                                LocationSummary::kNoCall,
-                                                LocationSummary::kBranch);
+                                                LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresRegister());
     return locs;
   }
 }
 
 
 void BranchInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  // If branch was fused with a comparision then no code needs to be emitted.
-  if (!is_fused_with_comparison()) {
+  if (is_fused_with_comparison()) {
+    fused_with_comparison_->EmitNativeCode(compiler);
+  } else {
     Register value = locs()->in(0).reg();
     __ CompareObject(value, compiler->bool_true());
     EmitBranchOnCondition(compiler, EQUAL);
   }
 }
 
 
 static Condition NegateCondition(Condition condition) {
   switch (condition) {
     case EQUAL:         return NOT_EQUAL;
@@ skipping 56 matching lines @@
   ASSERT(locs()->in(0).reg() == CTX);
 }
 
 
 LocationSummary* StrictCompareComp::MakeLocationSummary() const {
   if (is_fused_with_branch()) {
     const intptr_t kNumInputs = 2;
     const intptr_t kNumTemps = 0;
     LocationSummary* locs = new LocationSummary(kNumInputs,
                                                 kNumTemps,
-                                                LocationSummary::kNoCall,
-                                                LocationSummary::kBranch);
+                                                LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresRegister());
     locs->set_in(1, Location::RequiresRegister());
     return locs;
   } else {
     return LocationSummary::Make(2, Location::SameAsFirstInput());
   }
 }
 
 
 void StrictCompareComp::EmitNativeCode(FlowGraphCompiler* compiler) {
@@ skipping 212 matching lines @@
   const ExternalLabel label(closure_function.ToCString(), stub.EntryPoint());
   compiler->GenerateCall(token_pos(), try_index(), &label,
                          PcDescriptors::kOther);
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 
 #undef __
 
 }  // namespace dart