Optimize trivial regexp disjunctions

test/cctest/test-heap.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 1729 matching lines @@
 
   v8::V8::Initialize();
 
   Isolate* isolate = CcTest::i_isolate();
   HandleScope scope(isolate);
 
   LocalContext context;
 
   // Adjust source below and this check to match
   // RegExpImple::kRegExpTooLargeToOptimize.
-  DCHECK_EQ(i::RegExpImpl::kRegExpTooLargeToOptimize, 10 * KB);
+  DCHECK_EQ(i::RegExpImpl::kRegExpTooLargeToOptimize, 20 * KB);
 
   // Compile a regexp that is much larger if we are using regexp optimizations.
   CompileRun(
       "var reg_exp_source = '(?:a|bc|def|ghij|klmno|pqrstu)';"
       "var half_size_reg_exp;"
-      "while (reg_exp_source.length < 10 * 1024) {"
+      "while (reg_exp_source.length < 20 * 1024) {"
       "  half_size_reg_exp = reg_exp_source;"
       "  reg_exp_source = reg_exp_source + reg_exp_source;"
       "}"
       // Flatten string.
       "reg_exp_source.match(/f/);");
 
   // Get initial heap size after several full GCs, which will stabilize
   // the heap size and return with sweeping finished completely.
   CcTest::heap()->CollectAllGarbage();
   CcTest::heap()->CollectAllGarbage();
@@ skipping 4186 matching lines @@
   size_t counter2 = 2000;
   tracer->SampleAllocation(time2, counter2, counter2);
   size_t throughput = tracer->AllocationThroughputInBytesPerMillisecond(100);
   CHECK_EQ(2 * (counter2 - counter1) / (time2 - time1), throughput);
   int time3 = 1000;
   size_t counter3 = 30000;
   tracer->SampleAllocation(time3, counter3, counter3);
   throughput = tracer->AllocationThroughputInBytesPerMillisecond(100);
   CHECK_EQ(2 * (counter3 - counter1) / (time3 - time1), throughput);
 }