Remove unnecessary code for non-zero-length global regexps.

src/x64/regexp-macro-assembler-x64.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 908 matching lines @@
       __ movq(rbx, Operand(rbp, kRegisterOutput));
       __ movq(rcx, Operand(rbp, kInputEnd));
       __ subq(rcx, Operand(rbp, kInputStart));
       if (mode_ == UC16) {
         __ lea(rcx, Operand(rcx, rdx, times_2, 0));
       } else {
         __ addq(rcx, rdx);
       }
       for (int i = 0; i < num_saved_registers_; i++) {
         __ movq(rax, register_location(i));
-        if (i == 0 && global()) {
+        if (i == 0 && global_with_zero_length_match()) {
           // Keep capture start in rdx for the zero-length check later.
           __ movq(rdx, rax);
         }
         __ addq(rax, rcx);  // Convert to index from start, not end.
         if (mode_ == UC16) {
           __ sar(rax, Immediate(1));  // Convert byte index to character index.
         }
         __ movl(Operand(rbx, i * kIntSize), rax);
       }
     }
@@ skipping 11 matching lines @@
       __ j(less, &exit_label_);
 
       __ movq(Operand(rbp, kNumOutputRegisters), rcx);
       // Advance the location for output.
       __ addq(Operand(rbp, kRegisterOutput),
               Immediate(num_saved_registers_ * kIntSize));
 
       // Prepare rax to initialize registers with its value in the next run.
       __ movq(rax, Operand(rbp, kInputStartMinusOne));
 
-      // Special case for zero-length matches.
-      // rdx: capture start index
-      __ cmpq(rdi, rdx);
-      // Not a zero-length match, restart.
-      __ j(not_equal, &load_char_start_regexp);
-      // rdi (offset from the end) is zero if we already reached the end.
-      __ testq(rdi, rdi);
-      __ j(zero, &exit_label_, Label::kNear);
-      // Advance current position after a zero-length match.
-      if (mode_ == UC16) {
-        __ addq(rdi, Immediate(2));
-      } else {
-        __ incq(rdi);
+      if (global_with_zero_length_match()) {
+        // Special case for zero-length matches.
+        // rdx: capture start index
+        __ cmpq(rdi, rdx);
+        // Not a zero-length match, restart.
+        __ j(not_equal, &load_char_start_regexp);
+        // rdi (offset from the end) is zero if we already reached the end.
+        __ testq(rdi, rdi);
+        __ j(zero, &exit_label_, Label::kNear);
+        // Advance current position after a zero-length match.
+        if (mode_ == UC16) {
+          __ addq(rdi, Immediate(2));
+        } else {
+          __ incq(rdi);
+        }
       }
+
       __ jmp(&load_char_start_regexp);
     } else {
       __ movq(rax, Immediate(SUCCESS));
     }
   }
 
   __ bind(&exit_label_);
   if (global()) {
     // Return the number of successful captures.
     __ movq(rax, Operand(rbp, kSuccessfulCaptures));
@@ skipping 546 matching lines @@
   }
 }
 
 #undef __
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }}  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64