Microoptimization to regexps.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
===================================================================
--- src/mips/code-stubs-mips.cc	(revision 12500)
+++ src/mips/code-stubs-mips.cc	(working copy)
@@ -5405,12 +5405,12 @@
   // Set FixedArray length.
   __ sll(t2, t1, kSmiTagSize);
   __ sw(t2, FieldMemOperand(a3, FixedArray::kLengthOffset));
-  // Fill contents of fixed-array with the-hole.
-  __ li(a2, Operand(masm->isolate()->factory()->the_hole_value()));
+  // Fill contents of fixed-array with undefined.
+  __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
   __ Addu(a3, a3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  // Fill fixed array elements with hole.
+  // Fill fixed array elements with undefined.
   // v0: JSArray, tagged.
-  // a2: the hole.
+  // a2: undefined.
   // a3: Start of elements in FixedArray.
   // t1: Number of elements to fill.
   Label loop;