Recognize List constructor and turn it into CreateArray ...

runtime/vm/stub_code_arm.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/globals.h"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 595 matching lines @@
     // 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.
     __ tst(R2, ShifterOperand(kSmiTagMask));
     if (FLAG_use_slow_path) {
       __ b(&slow_case);
     } else {
       __ b(&slow_case, NE);
     }
+    __ cmp(R2, ShifterOperand(0));
+    __ b(&slow_case, LT);
+
+    // Check for maximum allowed length.
+    const intptr_t max_len =
+        reinterpret_cast<int32_t>(Smi::New(Array::kMaxElements));
+    __ CompareImmediate(R2, max_len);
+    __ b(&slow_case, GT);
+
     __ ldr(R8, FieldAddress(CTX, Context::isolate_offset()));
     __ LoadFromOffset(kWord, R8, R8, Isolate::heap_offset());
     __ LoadFromOffset(kWord, R8, R8, Heap::new_space_offset());
 
     // 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(kWord, R0, R8, Scavenger::top_offset());
     intptr_t fixed_size = sizeof(RawArray) + kObjectAlignment - 1;
     __ LoadImmediate(R3, fixed_size);
     __ add(R3, R3, ShifterOperand(R2, LSL, 1));  // R2 is Smi.
     ASSERT(kSmiTagShift == 1);
     __ bic(R3, R3, ShifterOperand(kObjectAlignment - 1));
-    __ add(R7, R3, ShifterOperand(R0));
+    __ adds(R7, R3, ShifterOperand(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(kWord, IP, R8, Scavenger::end_offset());
     __ cmp(R7, ShifterOperand(IP));
@@ skipping 1204 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM