Attempt to make \b\w+ faster. Slight performance increase on, e.g., string unpacking.

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

 // Copyright 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 441 matching lines @@
     Label* on_not_equal) {
   ASSERT(minus < String::kMaxUC16CharCode);
   __ sub(r0, current_character(), Operand(minus));
   __ and_(r0, r0, Operand(mask));
   __ cmp(r0, Operand(c));
   BranchOrBacktrack(ne, on_not_equal);
 }
 
 
 bool RegExpMacroAssemblerARM::CheckSpecialCharacterClass(uc16 type,
-                                                         int cp_offset,
-                                                         bool check_offset,
                                                          Label* on_no_match) {
   // Range checks (c in min..max) are generally implemented by an unsigned
   // (c - min) <= (max - min) check
   switch (type) {
   case 's':
     // Match space-characters
     if (mode_ == ASCII) {
       // ASCII space characters are '\t'..'\r' and ' '.
-      if (check_offset) {
-        LoadCurrentCharacter(cp_offset, on_no_match);
-      } else {
-        LoadCurrentCharacterUnchecked(cp_offset, 1);
-      }
       Label success;
       __ cmp(current_character(), Operand(' '));
       __ b(eq, &success);
       // Check range 0x09..0x0d
       __ sub(r0, current_character(), Operand('\t'));
       __ cmp(r0, Operand('\r' - '\t'));
       BranchOrBacktrack(hi, on_no_match);
       __ bind(&success);
       return true;
     }
     return false;
   case 'S':
     // Match non-space characters.
-    if (check_offset) {
-      LoadCurrentCharacter(cp_offset, on_no_match, 1);
-    } else {
-      LoadCurrentCharacterUnchecked(cp_offset, 1);
-    }
     if (mode_ == ASCII) {
       // ASCII space characters are '\t'..'\r' and ' '.
       __ cmp(current_character(), Operand(' '));
       BranchOrBacktrack(eq, on_no_match);
       __ sub(r0, current_character(), Operand('\t'));
       __ cmp(r0, Operand('\r' - '\t'));
       BranchOrBacktrack(ls, on_no_match);
       return true;
     }
     return false;
   case 'd':
     // Match ASCII digits ('0'..'9')
-    if (check_offset) {
-      LoadCurrentCharacter(cp_offset, on_no_match, 1);
-    } else {
-      LoadCurrentCharacterUnchecked(cp_offset, 1);
-    }
     __ sub(r0, current_character(), Operand('0'));
     __ cmp(current_character(), Operand('9' - '0'));
     BranchOrBacktrack(hi, on_no_match);
     return true;
   case 'D':
     // Match non ASCII-digits
-    if (check_offset) {
-      LoadCurrentCharacter(cp_offset, on_no_match, 1);
-    } else {
-      LoadCurrentCharacterUnchecked(cp_offset, 1);
-    }
     __ sub(r0, current_character(), Operand('0'));
     __ cmp(r0, Operand('9' - '0'));
     BranchOrBacktrack(ls, on_no_match);
     return true;
   case '.': {
     // Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
-    if (check_offset) {
-      LoadCurrentCharacter(cp_offset, on_no_match, 1);
-    } else {
-      LoadCurrentCharacterUnchecked(cp_offset, 1);
-    }
     __ eor(r0, current_character(), Operand(0x01));
     // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
     __ sub(r0, r0, Operand(0x0b));
     __ cmp(r0, Operand(0x0c - 0x0b));
     BranchOrBacktrack(ls, on_no_match);
     if (mode_ == UC16) {
       // Compare original value to 0x2028 and 0x2029, using the already
       // computed (current_char ^ 0x01 - 0x0b). I.e., check for
       // 0x201d (0x2028 - 0x0b) or 0x201e.
       __ sub(r0, r0, Operand(0x2028 - 0x0b));
       __ cmp(r0, Operand(1));
       BranchOrBacktrack(ls, on_no_match);
     }
     return true;
   }
+  case 'n': {
+      // Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
+      __ eor(r0, current_character(), Operand(0x01));
+      // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+      __ sub(r0, r0, Operand(0x0b));
+      __ cmp(r0, Operand(0x0c - 0x0b));
+      if (mode_ == ASCII) {
+        BranchOrBacktrack(hi, on_no_match);
+      } else {
+        Label done;
+        __ b(ls, &done);
+        // Compare original value to 0x2028 and 0x2029, using the already
+        // computed (current_char ^ 0x01 - 0x0b). I.e., check for
+        // 0x201d (0x2028 - 0x0b) or 0x201e.
+        __ sub(r0, r0, Operand(0x2028 - 0x0b));
+        __ cmp(r0, Operand(1));
+        BranchOrBacktrack(hi, on_no_match);
+        __ bind(&done);
+      }
+      return true;
+    }
+  case 'w': {
+    // Match word character (0-9, A-Z, a-z and _).
+    Label digits, done;
+    __ cmp(current_character(), Operand('9'));
+    __ b(ls, &digits);
+    __ cmp(current_character(), Operand('_'));
+    __ b(eq, &done);
+    __ orr(r0, current_character(), Operand(0x20));
+    __ sub(r0, r0, Operand('a'));
+    __ cmp(r0, Operand('z' - 'a'));
+    BranchOrBacktrack(hi, on_no_match);
+    __ jmp(&done);
+
+    __ bind(&digits);
+    __ cmp(current_character(), Operand('0'));
+    BranchOrBacktrack(lo, on_no_match);
+    __ bind(&done);
+
+    return true;
+  }
+  case 'W': {
+    // Match non-word character (not 0-9, A-Z, a-z and _).
+    Label digits, done;
+    __ cmp(current_character(), Operand('9'));
+    __ b(ls, &digits);
+    __ cmp(current_character(), Operand('_'));
+    BranchOrBacktrack(eq, on_no_match);
+    __ orr(r0, current_character(), Operand(0x20));
+    __ sub(r0, r0, Operand('a'));
+    __ cmp(r0, Operand('z' - 'a'));
+    BranchOrBacktrack(ls, on_no_match);
+    __ jmp(&done);
+
+    __ bind(&digits);
+    __ cmp(current_character(), Operand('0'));
+    BranchOrBacktrack(hs, on_no_match);
+    __ bind(&done);
+
+    return true;
+  }
   case '*':
     // Match any character.
-    if (check_offset) {
-      CheckPosition(cp_offset, on_no_match);
-    }
     return true;
-  // No custom implementation (yet): w, W, s(UC16), S(UC16).
+  // No custom implementation (yet): s(UC16), S(UC16).
   default:
     return false;
   }
 }
 
 
 void RegExpMacroAssemblerARM::Fail() {
   __ mov(r0, Operand(FAILURE));
   __ jmp(&exit_label_);
 }
@@ skipping 654 matching lines @@
   __ mov(r0, sp);
   __ Call(r5);
   __ ldr(pc, MemOperand(sp, stack_alignment, PostIndex));
 }
 
 #undef __
 
 #endif  // V8_NATIVE_REGEXP
 
 }}  // namespace v8::internal