Recognize List constructor and turn it into CreateArray ...

runtime/vm/stub_code_arm64.cc

 // Copyright (c) 2014, 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/globals.h"
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 599 matching lines @@
 //   R1: array element type (either NULL or an instantiated type).
 // NOTE: R2 cannot be clobbered here as the caller relies on it being saved.
 // The newly allocated object is returned in R0.
 void StubCode::GenerateAllocateArrayStub(Assembler* assembler) {
   Label slow_case;
   if (FLAG_inline_alloc) {
     // Compute the size to be allocated, it is based on the array length
     // and is computed as:
     // RoundedAllocationSize((array_length * kwordSize) + sizeof(RawArray)).
     // Assert that length is a Smi.
+
+    // TODO(zra): Fix code below before enabling.
+    __ b(&slow_case);
     __ tsti(R2, kSmiTagMask);
     if (FLAG_use_slow_path) {
       __ b(&slow_case);
     } else {
       __ b(&slow_case, NE);
     }
+    __ cmp(R2, Operand(0));
+    __ b(&slow_case, LT);
     __ LoadFieldFromOffset(R8, CTX, Context::isolate_offset(), kNoPP);
     __ LoadFromOffset(R8, R8, Isolate::heap_offset(), kNoPP);
     __ LoadFromOffset(R8, R8, Heap::new_space_offset(), kNoPP);
 
     // Calculate and align allocation size.
     // Load new object start and calculate next object start.
     // R1: array element type.
     // R2: array length as Smi.
     // R8: points to new space object.
     __ LoadFromOffset(R0, R8, Scavenger::top_offset(), kNoPP);
     intptr_t fixed_size = sizeof(RawArray) + kObjectAlignment - 1;
     __ LoadImmediate(R3, fixed_size, kNoPP);
     __ add(R3, R3, Operand(R2, LSL, 2));  // R2 is Smi.
     ASSERT(kSmiTagShift == 1);
     __ andi(R3, R3, ~(kObjectAlignment - 1));
-    __ add(R7, R3, Operand(R0));
+    __ adds(R7, R3, Operand(R0));
+    __ b(&slow_case, VS);
 
     // Check if the allocation fits into the remaining space.
     // R0: potential new object start.
     // R1: array element type.
     // R2: array length as Smi.
     // R3: array size.
     // R7: potential next object start.
     // R8: points to new space object.
     __ LoadFromOffset(TMP, R8, Scavenger::end_offset(), kNoPP);
     __ CompareRegisters(R7, TMP);
@@ skipping 1261 matching lines @@
   const Register right = R0;
   __ LoadFromOffset(left, SP, 1 * kWordSize, kNoPP);
   __ LoadFromOffset(right, SP, 0 * kWordSize, kNoPP);
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64