[Interpreter] Allocate registers used as call arguments on-demand.

test/unittests/interpreter/bytecode-register-allocator-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "test/unittests/test-utils.h"
 
@@ skipping 73 matching lines @@
   CHECK_EQ(allocator()->maximum_register_count(), 6);
   CHECK_EQ(allocator()->next_register_index(), 3);
 
   RegisterList empty_reg_list = allocator()->NewRegisterList(0);
   CHECK_EQ(empty_reg_list.first_register().index(), 0);
   CHECK_EQ(empty_reg_list.register_count(), 0);
   CHECK_EQ(allocator()->maximum_register_count(), 6);
   CHECK_EQ(allocator()->next_register_index(), 3);
 }
 
+TEST_F(BytecodeRegisterAllocatorTest, GrowableRegisterListAllocations) {
+  CHECK_EQ(allocator()->maximum_register_count(), 0);
+  Register reg = allocator()->NewRegister();
+  CHECK_EQ(reg.index(), 0);
+  RegisterList reg_list = allocator()->NewGrowableRegisterList();
+  CHECK_EQ(reg_list.register_count(), 0);
+  allocator()->GrowRegisterList(&reg_list);
+  allocator()->GrowRegisterList(&reg_list);
+  allocator()->GrowRegisterList(&reg_list);
+  CHECK_EQ(reg_list.register_count(), 3);
+  CHECK_EQ(reg_list[0].index(), 1);
+  CHECK_EQ(reg_list[1].index(), 2);
+  CHECK_EQ(reg_list[2].index(), 3);
+  CHECK_EQ(allocator()->maximum_register_count(), 4);
+  CHECK_EQ(allocator()->next_register_index(), 4);
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8