--- a/hotspot/src/share/vm/runtime/commandLineFlagConstraintsCompiler.cpp Tue Jan 26 14:04:01 2016 +0000
+++ b/hotspot/src/share/vm/runtime/commandLineFlagConstraintsCompiler.cpp Thu Jan 28 08:33:45 2016 +0100
@@ -118,27 +118,46 @@
}
Flag::Error AllocatePrefetchStepSizeConstraintFunc(intx value, bool verbose) {
- if (value < 1 || value > max_jint) {
+ intx max_value = 512;
+ if (value < 1 || value > max_value) {
CommandLineError::print(verbose,
"AllocatePrefetchStepSize (" INTX_FORMAT ") "
"must be between 1 and %d\n",
AllocatePrefetchStepSize,
- max_jint);
+ max_value);
return Flag::VIOLATES_CONSTRAINT;
}
if (AllocatePrefetchDistance % AllocatePrefetchStepSize != 0) {
- CommandLineError::print(verbose,
- "AllocatePrefetchDistance (" INTX_FORMAT ") "
- "%% AllocatePrefetchStepSize (" INTX_FORMAT ") "
- "= " INTX_FORMAT " "
- "must be 0\n",
- AllocatePrefetchDistance, AllocatePrefetchStepSize,
- AllocatePrefetchDistance % AllocatePrefetchStepSize);
- return Flag::VIOLATES_CONSTRAINT;
- }
+ CommandLineError::print(verbose,
+ "AllocatePrefetchDistance (" INTX_FORMAT ") "
+ "%% AllocatePrefetchStepSize (" INTX_FORMAT ") "
+ "= " INTX_FORMAT " "
+ "must be 0\n",
+ AllocatePrefetchDistance, AllocatePrefetchStepSize,
+ AllocatePrefetchDistance % AllocatePrefetchStepSize);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
- return Flag::SUCCESS;
+ /* The limit of 64 for the quotient of AllocatePrefetchDistance and AllocatePrefetchSize
+ * originates from the limit of 64 for AllocatePrefetchLines/AllocateInstancePrefetchLines.
+ * If AllocatePrefetchStyle == 2, the quotient from above is used in PhaseMacroExpand::prefetch_allocation()
+ * to determine the number of lines to prefetch. For other values of AllocatePrefetchStyle,
+ * AllocatePrefetchDistance and AllocatePrefetchSize is used. For consistency, all these
+ * quantities must have the same limit (64 in this case).
+ */
+ if (AllocatePrefetchDistance / AllocatePrefetchStepSize > 64) {
+ CommandLineError::print(verbose,
+ "AllocatePrefetchDistance (" INTX_FORMAT ") too large or "
+ "AllocatePrefetchStepSize (" INTX_FORMAT ") too small; "
+ "try decreasing/increasing values so that "
+ "AllocatePrefetchDistance / AllocatePrefetchStepSize <= 64\n",
+ AllocatePrefetchDistance, AllocatePrefetchStepSize,
+ AllocatePrefetchDistance % AllocatePrefetchStepSize);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+
+ return Flag::SUCCESS;
}
Flag::Error CompileThresholdConstraintFunc(intx value, bool verbose) {