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6821700: tune VM flags for peak performance

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Tune C2 flags default values for performance.

Reviewed-by: never, phh, iveresov, jmasa, ysr
This commit is contained in:
Vladimir Kozlov 2009-03-30 18:19:31 -07:00
parent 99aa7292a3
commit 705188bb7b
6 changed files with 23 additions and 6 deletions
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14
hotspot/src/cpu/sparc/vm/vm_version_sparc.cpp
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@ -62,7 +62,7 @@ void VM_Version::initialize() {
if (is_niagara1()) {
// Indirect branch is the same cost as direct
if (FLAG_IS_DEFAULT(UseInlineCaches)) {
UseInlineCaches = false;
FLAG_SET_DEFAULT(UseInlineCaches, false);
}
#ifdef _LP64
// Single issue niagara1 is slower for CompressedOops
@ -79,15 +79,19 @@ void VM_Version::initialize() {
#ifdef COMPILER2
// Indirect branch is the same cost as direct
if (FLAG_IS_DEFAULT(UseJumpTables)) {
UseJumpTables = true;
FLAG_SET_DEFAULT(UseJumpTables, true);
}
// Single-issue, so entry and loop tops are
// aligned on a single instruction boundary
if (FLAG_IS_DEFAULT(InteriorEntryAlignment)) {
InteriorEntryAlignment = 4;
FLAG_SET_DEFAULT(InteriorEntryAlignment, 4);
}
if (FLAG_IS_DEFAULT(OptoLoopAlignment)) {
OptoLoopAlignment = 4;
FLAG_SET_DEFAULT(OptoLoopAlignment, 4);
}
if (is_niagara1_plus() && FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
// Use smaller prefetch distance on N2
FLAG_SET_DEFAULT(AllocatePrefetchDistance, 256);
}
#endif
}
@ -95,7 +99,7 @@ void VM_Version::initialize() {
// Use hardware population count instruction if available.
if (has_hardware_popc()) {
if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
UsePopCountInstruction = true;
FLAG_SET_DEFAULT(UsePopCountInstruction, true);
}
}