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8182711: Re/Introduce private interface for HW-specific prefetch options in SPARC VM_Version

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Re/Introduce private interface for HW-specific prefetch options in SPARC VM_Version

Reviewed-by: kvn, neliasso
This commit is contained in:
Patric Hedlin 2017-06-27 15:22:23 +02:00 committed by Nils Eliasson
parent f525172036
commit 4ea55017ee
2 changed files with 58 additions and 34 deletions
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50
hotspot/src/cpu/sparc/vm/vm_version_sparc.cpp
View File

@ -38,46 +38,36 @@ void VM_Version::initialize() {
assert(_features != 0, "System pre-initialization is not complete.");
guarantee(VM_Version::has_v9(), "only SPARC v9 is supported");
if (FLAG_IS_DEFAULT(PrefetchCopyIntervalInBytes)) {
FLAG_SET_DEFAULT(PrefetchCopyIntervalInBytes, prefetch_copy_interval_in_bytes());
}
if (FLAG_IS_DEFAULT(PrefetchScanIntervalInBytes)) {
FLAG_SET_DEFAULT(PrefetchScanIntervalInBytes, prefetch_scan_interval_in_bytes());
}
if (FLAG_IS_DEFAULT(PrefetchFieldsAhead)) {
FLAG_SET_DEFAULT(PrefetchFieldsAhead, prefetch_fields_ahead());
}
PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
PrefetchFieldsAhead = prefetch_fields_ahead();
// Allocation prefetch settings
AllocatePrefetchDistance = allocate_prefetch_distance();
AllocatePrefetchStyle = allocate_prefetch_style();
intx cache_line_size = prefetch_data_size();
if (FLAG_IS_DEFAULT(AllocatePrefetchStepSize) &&
(cache_line_size > AllocatePrefetchStepSize)) {
FLAG_SET_DEFAULT(AllocatePrefetchStepSize, cache_line_size);
if (FLAG_IS_DEFAULT(AllocatePrefetchStepSize)) {
AllocatePrefetchStepSize = MAX2(AllocatePrefetchStepSize, cache_line_size);
}
if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
FLAG_SET_DEFAULT(AllocatePrefetchDistance, 512);
}
if ((AllocatePrefetchDistance == 0) && (AllocatePrefetchStyle != 0)) {
assert(!FLAG_IS_DEFAULT(AllocatePrefetchDistance), "default value should not be 0");
if (!FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
warning("AllocatePrefetchDistance is set to 0 which disable prefetching. Ignoring AllocatePrefetchStyle flag.");
}
FLAG_SET_DEFAULT(AllocatePrefetchStyle, 0);
}
if ((AllocatePrefetchInstr == 1) && (!has_blk_init() || cache_line_size <= 0)) {
if (!FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
if (AllocatePrefetchInstr == 1) {
if (!has_blk_init()) {
warning("BIS instructions required for AllocatePrefetchInstr 1 unavailable");
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 0);
}
if (cache_line_size <= 0) {
warning("Cache-line size must be known for AllocatePrefetchInstr 1 to work");
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 0);
}
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 0);
}
UseSSE = 0; // Only on x86 and x64
UseSSE = false; // Only used on x86 and x64.
_supports_cx8 = has_v9();
_supports_atomic_getset4 = true; // swap instruction
_supports_cx8 = true; // All SPARC V9 implementations.
_supports_atomic_getset4 = true; // Using the 'swap' instruction.
if (is_niagara()) {
// Indirect branch is the same cost as direct

42
hotspot/src/cpu/sparc/vm/vm_version_sparc.hpp
View File

@ -178,17 +178,51 @@ public:
// default prefetch block size on sparc
static intx prefetch_data_size() { return L2_data_cache_line_size(); }
// Prefetch
private:
// Prefetch policy and characteristics:
//
// These support routines are used in order to isolate any CPU/core specific
// logic from the actual flag/option processing. They should reflect the HW
// characteristics for the associated options on the current platform.
//
// The three Prefetch* options below (assigned -1 in the configuration) are
// treated according to (given the accepted range [-1..<maxint>]):
// -1: Determine a proper HW-specific value for the current HW.
// 0: Off
// >0: Command-line supplied value to use.
//
// FIXME: The documentation string in the configuration is wrong, saying that
// -1 is also interpreted as off.
//
static intx prefetch_copy_interval_in_bytes() {
return (has_v9() ? 512 : 0);
intx bytes = PrefetchCopyIntervalInBytes;
return bytes < 0 ? 512 : bytes;
}
static intx prefetch_scan_interval_in_bytes() {
return (has_v9() ? 512 : 0);
intx bytes = PrefetchScanIntervalInBytes;
return bytes < 0 ? 512 : bytes;
}
static intx prefetch_fields_ahead() {
return (is_ultra3() ? 1 : 0);
intx count = PrefetchFieldsAhead;
return count < 0 ? 0 : count;
}
// AllocatePrefetchDistance is treated under the same interpretation as the
// Prefetch* options above (i.e., -1, 0, >0).
static intx allocate_prefetch_distance() {
intx count = AllocatePrefetchDistance;
return count < 0 ? 512 : count;
}
// AllocatePrefetchStyle is guaranteed to be in range [0..3] defined by the
// configuration.
static intx allocate_prefetch_style() {
intx distance = allocate_prefetch_distance();
// Return 0 (off/none) if AllocatePrefetchDistance was not defined.
return distance > 0 ? AllocatePrefetchStyle : 0;
}
public:
// Assembler testing
static void allow_all();
static void revert();