ARM64: use direct conditional branches for regexp

src/arm64/regexp-macro-assembler-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/code-stubs.h"
 #include "src/cpu-profiler.h"
@@ skipping 1443 matching lines @@
     if (to == NULL) {
       Backtrack();
       return;
     }
     __ B(to);
     return;
   }
   if (to == NULL) {
     to = &backtrack_label_;
   }
-  // TODO(ulan): do direct jump when jump distance is known and fits in imm19.
-  Condition inverted_condition = NegateCondition(condition);
-  Label no_branch;
-  __ B(inverted_condition, &no_branch);
-  __ B(to);
-  __ Bind(&no_branch);
+  __ B(condition, to);
 }
 
 void RegExpMacroAssemblerARM64::CompareAndBranchOrBacktrack(Register reg,
                                                             int immediate,
                                                             Condition condition,
                                                             Label* to) {
   if ((immediate == 0) && ((condition == eq) || (condition == ne))) {
     if (to == NULL) {
       to = &backtrack_label_;
     }
-    // TODO(ulan): do direct jump when jump distance is known and fits in imm19.
-    Label no_branch;
     if (condition == eq) {
-      __ Cbnz(reg, &no_branch);
+      __ Cbz(reg, to);
     } else {
-      __ Cbz(reg, &no_branch);
+      __ Cbnz(reg, to);
     }
-    __ B(to);
-    __ Bind(&no_branch);
   } else {
     __ Cmp(reg, immediate);
     BranchOrBacktrack(condition, to);
   }
 }
 
 
 void RegExpMacroAssemblerARM64::CheckPreemption() {
   // Check for preemption.
   ExternalReference stack_limit =
@@ skipping 200 matching lines @@
       __ Ldrh(current_character(), MemOperand(input_end(), offset, SXTW));
     }
   }
 }
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }}  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64