--- a/hotspot/src/share/vm/runtime/commandLineFlagConstraintsCompiler.cpp	Mon Jul 27 09:42:23 2015 +0200
+++ b/hotspot/src/share/vm/runtime/commandLineFlagConstraintsCompiler.cpp	Mon Jul 27 13:44:07 2015 +0200
@@ -42,3 +42,45 @@
   }
   return Flag::SUCCESS;
 }
+
+/**
+ * Validate the minimum number of compiler threads needed to run the
+ * JVM. The following configurations are possible.
+ *
+ * 1) The JVM is build using an interpreter only. As a result, the minimum number of
+ *    compiler threads is 0.
+ * 2) The JVM is build using the compiler(s) and tiered compilation is disabled. As
+ *    a result, either C1 or C2 is used, so the minimum number of compiler threads is 1.
+ * 3) The JVM is build using the compiler(s) and tiered compilation is enabled. However,
+ *    the option "TieredStopAtLevel < CompLevel_full_optimization". As a result, only
+ *    C1 can be used, so the minimum number of compiler threads is 1.
+ * 4) The JVM is build using the compilers and tiered compilation is enabled. The option
+ *    'TieredStopAtLevel = CompLevel_full_optimization' (the default value). As a result,
+ *    the minimum number of compiler threads is 2.
+ */
+Flag::Error CICompilerCountConstraintFunc(bool verbose, intx* value) {
+  int min_number_of_compiler_threads = 0;
+#if !defined(COMPILER1) && !defined(COMPILER2) && !defined(SHARK)
+  // case 1
+#else
+  if (!TieredCompilation || (TieredStopAtLevel < CompLevel_full_optimization)) {
+    min_number_of_compiler_threads = 1; // case 2 or case 3
+  } else {
+    min_number_of_compiler_threads = 2;   // case 4 (tiered)
+  }
+#endif
+
+  // The default CICompilerCount's value is CI_COMPILER_COUNT.
+  assert(min_number_of_compiler_threads <= CI_COMPILER_COUNT, "minimum should be less or equal default number");
+
+  if (*value < (intx)min_number_of_compiler_threads) {
+    if (verbose == true) {
+      jio_fprintf(defaultStream::error_stream(),
+                  "CICompilerCount=" INTX_FORMAT " must be at least %d \n",
+                  *value, min_number_of_compiler_threads);
+    }
+    return Flag::VIOLATES_CONSTRAINT;
+  } else {
+    return Flag::SUCCESS;
+  }
+}