Allow unaligned accesses for ARMv7.

src/arm/regexp-macro-assembler-arm.cc

 // Copyright 2012 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 1340 matching lines @@
   __ mov(code_pointer(), Operand(function));
   RegExpCEntryStub stub;
   __ CallStub(&stub);
   if (OS::ActivationFrameAlignment() != 0) {
     __ ldr(sp, MemOperand(sp, 0));
   }
   __ mov(code_pointer(), Operand(masm_->CodeObject()));
 }
 
 
+bool RegExpMacroAssemblerARM::CanReadUnaligned() {
+  return CpuFeatures::IsSupported(UNALIGNED_ACCESSES) && !slow_safe();
+}
+
+
 void RegExpMacroAssemblerARM::LoadCurrentCharacterUnchecked(int cp_offset,
                                                             int characters) {
   Register offset = current_input_offset();
   if (cp_offset != 0) {
     // r4 is not being used to store the capture start index at this point.
     __ add(r4, current_input_offset(), Operand(cp_offset * char_size()));
     offset = r4;
   }
   // The ldr, str, ldrh, strh instructions can do unaligned accesses, if the CPU
   // and the operating system running on the target allow it.
   // If unaligned load/stores are not supported then this function must only
   // be used to load a single character at a time.
-#if !V8_TARGET_CAN_READ_UNALIGNED
-  ASSERT(characters == 1);
-#endif
+  if (!CanReadUnaligned()) {
+    ASSERT(characters == 1);
+  }
 
   if (mode_ == ASCII) {
     if (characters == 4) {
       __ ldr(current_character(), MemOperand(end_of_input_address(), offset));
     } else if (characters == 2) {
       __ ldrh(current_character(), MemOperand(end_of_input_address(), offset));
     } else {
       ASSERT(characters == 1);
       __ ldrb(current_character(), MemOperand(end_of_input_address(), offset));
     }
@@ skipping 20 matching lines @@
   __ ldr(pc, MemOperand(sp, stack_alignment, PostIndex));
 }
 
 #undef __
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }}  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM