Regexp: Improve the speed that we scan for an initial point where a non-anchored

src/x64/regexp-macro-assembler-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 524 matching lines @@
 void RegExpMacroAssemblerX64::CheckNotCharacter(uint32_t c,
                                                 Label* on_not_equal) {
   __ cmpl(current_character(), Immediate(c));
   BranchOrBacktrack(not_equal, on_not_equal);
 }
 
 
 void RegExpMacroAssemblerX64::CheckCharacterAfterAnd(uint32_t c,
                                                      uint32_t mask,
                                                      Label* on_equal) {
-  __ movl(rax, current_character());
-  __ and_(rax, Immediate(mask));
-  __ cmpl(rax, Immediate(c));
+  if (c == 0) {
+    __ testl(current_character(), Immediate(mask));
+  } else {
+    __ movl(rax, Immediate(mask));
+    __ and_(rax, current_character());
+    __ cmpl(rax, Immediate(c));
+  }
   BranchOrBacktrack(equal, on_equal);
 }
 
 
 void RegExpMacroAssemblerX64::CheckNotCharacterAfterAnd(uint32_t c,
                                                         uint32_t mask,
                                                         Label* on_not_equal) {
-  __ movl(rax, current_character());
-  __ and_(rax, Immediate(mask));
-  __ cmpl(rax, Immediate(c));
+  if (c == 0) {
+    __ testl(current_character(), Immediate(mask));
+  } else {
+    __ movl(rax, Immediate(mask));
+    __ and_(rax, current_character());
+    __ cmpl(rax, Immediate(c));
+  }
   BranchOrBacktrack(not_equal, on_not_equal);
 }
 
 
 void RegExpMacroAssemblerX64::CheckNotCharacterAfterMinusAnd(
     uc16 c,
     uc16 minus,
     uc16 mask,
     Label* on_not_equal) {
   ASSERT(minus < String::kMaxUtf16CodeUnit);
@@ skipping 884 matching lines @@
   }
 }
 
 #undef __
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }}  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64