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

src/arm/regexp-macro-assembler-arm.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 778 matching lines @@
       __ add(r1, r1, Operand(r2));
       // r1 is length of string in characters.
 
       ASSERT_EQ(0, num_saved_registers_ % 2);
       // Always an even number of capture registers. This allows us to
       // unroll the loop once to add an operation between a load of a register
       // and the following use of that register.
       for (int i = 0; i < num_saved_registers_; i += 2) {
         __ ldr(r2, register_location(i));
         __ ldr(r3, register_location(i + 1));
-        if (global()) {
+        if (i == 0 && global_with_zero_length_match()) {
           // Keep capture start in r4 for the zero-length check later.
           __ mov(r4, r2);
         }
         if (mode_ == UC16) {
           __ add(r2, r1, Operand(r2, ASR, 1));
           __ add(r3, r1, Operand(r3, ASR, 1));
         } else {
           __ add(r2, r1, Operand(r2));
           __ add(r3, r1, Operand(r3));
         }
@@ skipping 17 matching lines @@
       __ cmp(r1, Operand(num_saved_registers_));
       __ b(lt, &return_r0);
 
       __ str(r1, MemOperand(frame_pointer(), kNumOutputRegisters));
       // Advance the location for output.
       __ add(r2, r2, Operand(num_saved_registers_ * kPointerSize));
       __ str(r2, MemOperand(frame_pointer(), kRegisterOutput));
 
       // Prepare r0 to initialize registers with its value in the next run.
       __ ldr(r0, MemOperand(frame_pointer(), kInputStartMinusOne));
-      // Special case for zero-length matches.
-      // r4: capture start index
-      __ cmp(current_input_offset(), r4);
-      // Not a zero-length match, restart.
-      __ b(ne, &load_char_start_regexp);
-      // Offset from the end is zero if we already reached the end.
-      __ cmp(current_input_offset(), Operand(0));
-      __ b(eq, &exit_label_);
-      // Advance current position after a zero-length match.
-      __ add(current_input_offset(),
-             current_input_offset(),
-             Operand((mode_ == UC16) ? 2 : 1));
+
+      if (global_with_zero_length_match()) {
+        // Special case for zero-length matches.
+        // r4: capture start index
+        __ cmp(current_input_offset(), r4);
+        // Not a zero-length match, restart.
+        __ b(ne, &load_char_start_regexp);
+        // Offset from the end is zero if we already reached the end.
+        __ cmp(current_input_offset(), Operand(0));
+        __ b(eq, &exit_label_);
+        // Advance current position after a zero-length match.
+        __ add(current_input_offset(),
+               current_input_offset(),
+               Operand((mode_ == UC16) ? 2 : 1));
+      }
+
       __ b(&load_char_start_regexp);
     } else {
       __ mov(r0, Operand(SUCCESS));
     }
   }
 
   // Exit and return r0
   __ bind(&exit_label_);
   if (global()) {
     __ ldr(r0, MemOperand(frame_pointer(), kSuccessfulCaptures));
@@ skipping 551 matching lines @@
   __ ldr(pc, MemOperand(sp, stack_alignment, PostIndex));
 }
 
 #undef __
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }}  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM