Adding support for multiple returns in compiled functions.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 7200bf0e7a210e11016ff6e50e42a73bcd32710b..46efb4b75bc0b7680dc3a27fe5eabeca877a0c27 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -504,7 +504,7 @@ void InstructionSelector::VisitControl(BasicBlock* block) {
     }
     case BasicBlock::kReturn: {
       DCHECK_EQ(IrOpcode::kReturn, input->opcode());
-      return VisitReturn(input->InputAt(0));
+      return VisitReturn(input);
     }
     case BasicBlock::kDeoptimize: {
       // If the result itself is a return, return its input.
@@ -1009,15 +1009,20 @@ void InstructionSelector::VisitGoto(BasicBlock* target) {
 }
 
 
-void InstructionSelector::VisitReturn(Node* value) {
-  DCHECK_NOT_NULL(value);
+void InstructionSelector::VisitReturn(Node* ret) {
   OperandGenerator g(this);
   if (linkage()->GetIncomingDescriptor()->ReturnCount() == 0) {
     Emit(kArchRet, g.NoOutput());
   } else {
-    Emit(kArchRet, g.NoOutput(),
-         g.UseLocation(value, linkage()->GetReturnLocation(),
-                       linkage()->GetReturnType()));
+    const int ret_count = ret->op()->ValueInputCount();
+    auto value_locations = zone()->NewArray<InstructionOperand>(ret_count);
+    for (int i = 0; i < ret_count; ++i) {
+      DCHECK_NOT_NULL(ret->InputAt(i));

[titzer, 2015/10/08 17:18:17]

Superfluous DCHECK. We rely on the graph verifier to check the invariants we
expect, so that the rest of the code can be mostly DCHECK-free :-)

[bradn, 2015/10/08 17:20:02]

Done.

+      value_locations[i] =
+          g.UseLocation(ret->InputAt(i), linkage()->GetReturnLocation(i),
+                        linkage()->GetReturnType(i));
+    }
+    Emit(kArchRet, 0, nullptr, ret_count, value_locations);
   }
 }