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

src/x64/regexp-macro-assembler-x64.cc

Index: src/x64/regexp-macro-assembler-x64.cc
diff --git a/src/x64/regexp-macro-assembler-x64.cc b/src/x64/regexp-macro-assembler-x64.cc
index 13a4caa3fbca8862aa3efc18fca1fde18d1727a6..2db5e7ac45ad2d81b553bc93ae13942acc59e578 100644
--- a/src/x64/regexp-macro-assembler-x64.cc
+++ b/src/x64/regexp-macro-assembler-x64.cc
@@ -926,7 +926,7 @@ Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
       }
       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);
         }
@@ -958,20 +958,23 @@ Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
       // 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));