81   }
  82 
  83   if (ShenandoahRegionSampling && FLAG_IS_DEFAULT(PerfDataMemorySize)) {
  84     // When sampling is enabled, max out the PerfData memory to get more
  85     // Shenandoah data in, including Matrix.
  86     FLAG_SET_DEFAULT(PerfDataMemorySize, 2048*K);
  87   }
  88 
  89 #ifdef COMPILER2
  90   // Shenandoah cares more about pause times, rather than raw throughput.
  91   if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) {
  92     FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true);
  93     if (FLAG_IS_DEFAULT(LoopStripMiningIter)) {
  94       FLAG_SET_DEFAULT(LoopStripMiningIter, 1000);
  95     }
  96   }
  97 #ifdef ASSERT
  98   // C2 barrier verification is only reliable when all default barriers are enabled
  99   if (ShenandoahVerifyOptoBarriers &&
 100           (!FLAG_IS_DEFAULT(ShenandoahSATBBarrier)            ||
 101            !FLAG_IS_DEFAULT(ShenandoahConditionalSATBBarrier) ||
 102            !FLAG_IS_DEFAULT(ShenandoahKeepAliveBarrier)       ||
 103            !FLAG_IS_DEFAULT(ShenandoahWriteBarrier)           ||
 104            !FLAG_IS_DEFAULT(ShenandoahReadBarrier)            ||
 105            !FLAG_IS_DEFAULT(ShenandoahStoreValEnqueueBarrier) ||
 106            !FLAG_IS_DEFAULT(ShenandoahStoreValWriteBarrier)   ||
 107            !FLAG_IS_DEFAULT(ShenandoahStoreValReadBarrier)    ||
 108            !FLAG_IS_DEFAULT(ShenandoahCASBarrier)             ||
 109            !FLAG_IS_DEFAULT(ShenandoahAcmpBarrier)            ||
 110            !FLAG_IS_DEFAULT(ShenandoahCloneBarrier)
 111           )) {
 112     warning("Unusual barrier configuration, disabling C2 barrier verification");
 113     FLAG_SET_DEFAULT(ShenandoahVerifyOptoBarriers, false);
 114   }
 115 #else
 116   guarantee(!ShenandoahVerifyOptoBarriers, "Should be disabled");
 117 #endif // ASSERT
 118 #endif // COMPILER2
 119 
 120   if (AlwaysPreTouch) {
 121     // Shenandoah handles pre-touch on its own. It does not let the
 122     // generic storage code to do the pre-touch before Shenandoah has
 123     // a chance to do it on its own.
 124     FLAG_SET_DEFAULT(AlwaysPreTouch, false);
 125     FLAG_SET_DEFAULT(ShenandoahAlwaysPreTouch, true);
 126   }

  81   }
  82 
  83   if (ShenandoahRegionSampling && FLAG_IS_DEFAULT(PerfDataMemorySize)) {
  84     // When sampling is enabled, max out the PerfData memory to get more
  85     // Shenandoah data in, including Matrix.
  86     FLAG_SET_DEFAULT(PerfDataMemorySize, 2048*K);
  87   }
  88 
  89 #ifdef COMPILER2
  90   // Shenandoah cares more about pause times, rather than raw throughput.
  91   if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) {
  92     FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true);
  93     if (FLAG_IS_DEFAULT(LoopStripMiningIter)) {
  94       FLAG_SET_DEFAULT(LoopStripMiningIter, 1000);
  95     }
  96   }
  97 #ifdef ASSERT
  98   // C2 barrier verification is only reliable when all default barriers are enabled
  99   if (ShenandoahVerifyOptoBarriers &&
 100           (!FLAG_IS_DEFAULT(ShenandoahSATBBarrier)            ||

 101            !FLAG_IS_DEFAULT(ShenandoahKeepAliveBarrier)       ||
 102            !FLAG_IS_DEFAULT(ShenandoahWriteBarrier)           ||
 103            !FLAG_IS_DEFAULT(ShenandoahReadBarrier)            ||
 104            !FLAG_IS_DEFAULT(ShenandoahStoreValEnqueueBarrier) ||

 105            !FLAG_IS_DEFAULT(ShenandoahStoreValReadBarrier)    ||
 106            !FLAG_IS_DEFAULT(ShenandoahCASBarrier)             ||
 107            !FLAG_IS_DEFAULT(ShenandoahAcmpBarrier)            ||
 108            !FLAG_IS_DEFAULT(ShenandoahCloneBarrier)
 109           )) {
 110     warning("Unusual barrier configuration, disabling C2 barrier verification");
 111     FLAG_SET_DEFAULT(ShenandoahVerifyOptoBarriers, false);
 112   }
 113 #else
 114   guarantee(!ShenandoahVerifyOptoBarriers, "Should be disabled");
 115 #endif // ASSERT
 116 #endif // COMPILER2
 117 
 118   if (AlwaysPreTouch) {
 119     // Shenandoah handles pre-touch on its own. It does not let the
 120     // generic storage code to do the pre-touch before Shenandoah has
 121     // a chance to do it on its own.
 122     FLAG_SET_DEFAULT(AlwaysPreTouch, false);
 123     FLAG_SET_DEFAULT(ShenandoahAlwaysPreTouch, true);
 124   }