Implement inline string compare on ARM.

src/arm/macro-assembler-arm.cc

 // Copyright 2006-2009 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 1203 matching lines @@
     }
     // The context may be an intermediate context, not a function context.
     ldr(dst, MemOperand(dst, Context::SlotOffset(Context::FCONTEXT_INDEX)));
   } else {  // Slot is in the current function context.
     // The context may be an intermediate context, not a function context.
     ldr(dst, MemOperand(cp, Context::SlotOffset(Context::FCONTEXT_INDEX)));
   }
 }
 
 
+void MacroAssembler::JumpIfNonSmisNotBothSequentialAsciiStrings(
+    Register first,
+    Register second,
+    Register scratch1,
+    Register scratch2,
+    Label* failure) {
+  // Test that both first and second are sequential ASCII strings.
+  // Assume that they are non-smis.
+  ldr(scratch1, FieldMemOperand(first, HeapObject::kMapOffset));
+  ldr(scratch2, FieldMemOperand(second, HeapObject::kMapOffset));
+  ldrb(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
+  ldrb(scratch2, FieldMemOperand(scratch2, Map::kInstanceTypeOffset));
+  int kFlatAsciiStringMask =
+      kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
+  int kFlatAsciiStringTag = ASCII_STRING_TYPE;
+  and_(scratch1, scratch1, Operand(kFlatAsciiStringMask));
+  and_(scratch2, scratch2, Operand(kFlatAsciiStringMask));
+  cmp(scratch1, Operand(kFlatAsciiStringTag));
+  // Ignore second test if first test failed.
+  cmp(scratch2, Operand(kFlatAsciiStringTag), eq);
+  b(ne, failure);
+}
+
+void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register first,
+                                                         Register second,
+                                                         Register scratch1,
+                                                         Register scratch2,
+                                                         Label* failure) {
+  // Check that neither is a smi.
+  ASSERT_EQ(0, kSmiTag);
+  and_(scratch1, first, Operand(second));
+  tst(scratch1, Operand(kSmiTagMask));
+  b(eq, failure);
+  JumpIfNonSmisNotBothSequentialAsciiStrings(first,
+                                             second,
+                                             scratch1,
+                                             scratch2,
+                                             failure);
+}
+
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 CodePatcher::CodePatcher(byte* address, int instructions)
     : address_(address),
       instructions_(instructions),
       size_(instructions * Assembler::kInstrSize),
       masm_(address, size_ + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.
@@ skipping 16 matching lines @@
 }
 
 
 void CodePatcher::Emit(Address addr) {
   masm()->emit(reinterpret_cast<Instr>(addr));
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal