Generated code for substring slices in x64 and arm.

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3233 matching lines @@
 
   // Check whether the string is sequential. The only non-sequential
   // shapes we support have just been unwrapped above.
   __ bind(&check_sequential);
   STATIC_ASSERT(kSeqStringTag == 0);
   __ testb(result, Immediate(kStringRepresentationMask));
   __ j(not_zero, deferred->entry());
 
   // Dispatch on the encoding: ASCII or two-byte.
   Label ascii_string;
-  STATIC_ASSERT(kAsciiStringTag != 0);
+  STATIC_ASSERT((kStringEncodingMask & kAsciiStringTag) != 0);
+  STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
   __ testb(result, Immediate(kStringEncodingMask));
   __ j(not_zero, &ascii_string, Label::kNear);
 
   // Two-byte string.
   // Load the two-byte character code into the result register.
   Label done;
   STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
   __ movzxwl(result, FieldOperand(string,
                                   index,
                                   times_2,
@@ skipping 881 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64