Refactor to support multiple outputs in location summary

runtime/vm/flow_graph_allocator.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/flow_graph_allocator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/intermediate_language.h"
 #include "vm/il_printer.h"
 #include "vm/flow_graph.h"
@@ skipping 840 matching lines @@
                                                BitVector* interference_set) {
   LocationSummary* locs = current->locs();
 
   Definition* def = current->AsDefinition();
   if ((def != NULL) && (def->AsConstant() != NULL)) {
     LiveRange* range = (def->ssa_temp_index() != -1) ?
         GetLiveRange(def->ssa_temp_index()) : NULL;
 
     // Drop definitions of constants that have no uses.
     if ((range == NULL) || (range->first_use() == NULL)) {
-      locs->set_out(Location::NoLocation());
+      locs->set_out(0, Location::NoLocation());
       return;
     }
 
     // If this constant has only unconstrained uses convert them all
     // to use the constant directly and drop this definition.
     // TODO(vegorov): improve allocation when we have enough registers to keep
     // constants used in the loop in them.
     if (HasOnlyUnconstrainedUses(range)) {
       const Object& value = def->AsConstant()->value();
       range->set_assigned_location(Location::Constant(value));
       range->set_spill_slot(Location::Constant(value));
       range->finger()->Initialize(range);
       ConvertAllUses(range);
 
-      locs->set_out(Location::NoLocation());
+      locs->set_out(0, Location::NoLocation());
       return;
     }
   }
 
   const intptr_t pos = current->lifetime_position();
   ASSERT(IsInstructionStartPosition(pos));
 
   // Number of input locations and number of input operands have to agree.
   ASSERT(locs->input_count() == current->InputCount());
 
   // Normalize same-as-first-input output if input is specified as
   // fixed register.
-  if (locs->out().IsUnallocated() &&
-      (locs->out().policy() == Location::kSameAsFirstInput) &&
+  if (locs->out(0).IsUnallocated() &&
+      (locs->out(0).policy() == Location::kSameAsFirstInput) &&
       (locs->in(0).IsMachineRegister())) {
-    locs->set_out(locs->in(0));
+    locs->set_out(0, locs->in(0));
   }
 
   const bool output_same_as_first_input =
-      locs->out().IsUnallocated() &&
-      (locs->out().policy() == Location::kSameAsFirstInput);
+      locs->out(0).IsUnallocated() &&
+      (locs->out(0).policy() == Location::kSameAsFirstInput);
 
   // Add uses from the deoptimization environment.
   if (current->env() != NULL) ProcessEnvironmentUses(block, current);
 
   // Process inputs.
   // Skip the first input if output is specified with kSameAsFirstInput policy,
   // they will be processed together at the very end.
   for (intptr_t j = output_same_as_first_input ? 1 : 0;
        j < current->InputCount();
        j++) {
@@ skipping 102 matching lines @@
     // locations.  Every register is blocked now so attempt to
     // allocate will not succeed.
     for (intptr_t j = 0; j < locs->temp_count(); j++) {
       ASSERT(!locs->temp(j).IsUnallocated());
     }
 
     for (intptr_t j = 0; j < locs->input_count(); j++) {
       ASSERT(!locs->in(j).IsUnallocated());
     }
 
-    ASSERT(!locs->out().IsUnallocated());
+    ASSERT(!locs->out(0).IsUnallocated());
 #endif
   }
 
   if (locs->can_call()) {
     safepoints_.Add(current);
   }
 
   if (def == NULL) {
-    ASSERT(locs->out().IsInvalid());
+    ASSERT(locs->out(0).IsInvalid());
     return;
   }
 
-  if (locs->out().IsInvalid()) {
+  if (locs->out(0).IsInvalid()) {
     ASSERT(def->ssa_temp_index() < 0);
     return;
   }
 
   // We might have a definition without use.  We do not assign SSA index to
   // such definitions.
   LiveRange* range = (def->ssa_temp_index() >= 0) ?
       GetLiveRange(def->ssa_temp_index()) :
       MakeLiveRangeForTemporary();
-  Location* out = locs->out_slot();
+  Location* out = locs->out_slot(0);
 
   // Process output and finalize its liverange.
   if (out->IsMachineRegister()) {
     // Fixed output location. Expected shape of live range:
     //
     //                    i  i' j  j'
     //    register        [--)
     //    output             [-------
     //
     BlockLocation(*out, pos, pos + 1);
@@ skipping 29 matching lines @@
     // start. Expected shape of live ranges:
     //
     //                 i  i'
     //    input #0   --*
     //    output       [----
     //
     ASSERT(locs->in(0).Equals(Location::RequiresRegister()) ||
            locs->in(0).Equals(Location::RequiresFpuRegister()));
 
     // Create move that will copy value between input and output.
-    locs->set_out(Location::RequiresRegister());
+    locs->set_out(0, Location::RequiresRegister());
     MoveOperands* move = AddMoveAt(pos,
                                    Location::RequiresRegister(),
                                    Location::Any());
 
     // Add uses to the live range of the input.
     Definition* input = current->InputAt(0)->definition();
     LiveRange* input_range =
         GetLiveRange(input->ssa_temp_index());
     input_range->AddUseInterval(block->start_pos(), pos);
     input_range->AddUse(pos, move->src_slot());
@@ skipping 10 matching lines @@
         interference_set->Contains(range->vreg())) {
       interference_set->Add(input->ssa_temp_index());
     }
   } else {
     // Normal unallocated location that requires a register. Expected shape of
     // live range:
     //
     //                    i  i'
     //    output          [-------
     //
-    ASSERT(locs->out().Equals(Location::RequiresRegister()) ||
-           locs->out().Equals(Location::RequiresFpuRegister()));
+    ASSERT(locs->out(0).Equals(Location::RequiresRegister()) ||
+           locs->out(0).Equals(Location::RequiresFpuRegister()));
 
     // Shorten live range to the point of definition and add use to be filled by
     // allocator.
     range->DefineAt(pos);
     range->AddUse(pos, out);
   }
 
   AssignSafepoints(range);
   CompleteRange(range, RegisterKindForResult(current));
 }
@@ skipping 1469 matching lines @@
     OS::Print("-- [after ssa allocator] ir [%s] -------------\n",
               function.ToFullyQualifiedCString());
     FlowGraphPrinter printer(flow_graph_, true);
     printer.PrintBlocks();
     OS::Print("----------------------------------------------\n");
   }
 }
 
 
 }  // namespace dart