hotspot/src/cpu/sparc/vm/vm_version_sparc.cpp - edge/openjdk - Git at Google

 /*
  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 #include "precompiled.hpp"
 #include "asm/macroAssembler.inline.hpp"
 #include "memory/resourceArea.hpp"
 #include "runtime/java.hpp"
 #include "runtime/stubCodeGenerator.hpp"
 #include "vm_version_sparc.hpp"
 #ifdef TARGET_OS_FAMILY_linux
 # include "os_linux.inline.hpp"
 #endif
 #ifdef TARGET_OS_FAMILY_solaris
 # include "os_solaris.inline.hpp"
 #endif

 int VM_Version::_features = VM_Version::unknown_m;
 const char* VM_Version::_features_str = "";
 unsigned int VM_Version::_L2_data_cache_line_size = 0;

 void VM_Version::initialize() {

   assert(_features != VM_Version::unknown_m, "System pre-initialization is not complete.");
   guarantee(VM_Version::has_v9(), "only SPARC v9 is supported");

   PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
   PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
   PrefetchFieldsAhead         = prefetch_fields_ahead();

   assert(0 <= AllocatePrefetchInstr && AllocatePrefetchInstr <= 1, "invalid value");
   if( AllocatePrefetchInstr < 0 ) AllocatePrefetchInstr = 0;
   if( AllocatePrefetchInstr > 1 ) AllocatePrefetchInstr = 0;

   // Allocation prefetch settings
   intx cache_line_size = prefetch_data_size();
   if( cache_line_size > AllocatePrefetchStepSize )
     AllocatePrefetchStepSize = cache_line_size;

   assert(AllocatePrefetchLines > 0, "invalid value");
   if( AllocatePrefetchLines < 1 )     // set valid value in product VM
     AllocatePrefetchLines = 3;
   assert(AllocateInstancePrefetchLines > 0, "invalid value");
   if( AllocateInstancePrefetchLines < 1 ) // set valid value in product VM
     AllocateInstancePrefetchLines = 1;

   AllocatePrefetchDistance = allocate_prefetch_distance();
   AllocatePrefetchStyle    = allocate_prefetch_style();

   assert((AllocatePrefetchDistance % AllocatePrefetchStepSize) == 0 &&
          (AllocatePrefetchDistance > 0), "invalid value");
   if ((AllocatePrefetchDistance % AllocatePrefetchStepSize) != 0 ||
       (AllocatePrefetchDistance <= 0)) {
     AllocatePrefetchDistance = AllocatePrefetchStepSize;
   }

   if (AllocatePrefetchStyle == 3 && !has_blk_init()) {
     warning("BIS instructions are not available on this CPU");
     FLAG_SET_DEFAULT(AllocatePrefetchStyle, 1);
   }

   assert(ArraycopySrcPrefetchDistance < 4096, "invalid value");
   if (ArraycopySrcPrefetchDistance >= 4096)
     ArraycopySrcPrefetchDistance = 4064;
   assert(ArraycopyDstPrefetchDistance < 4096, "invalid value");
   if (ArraycopyDstPrefetchDistance >= 4096)
     ArraycopyDstPrefetchDistance = 4064;

   UseSSE = 0; // Only on x86 and x64

   _supports_cx8 = has_v9();
   _supports_atomic_getset4 = true; // swap instruction

   // There are Fujitsu Sparc64 CPUs which support blk_init as well so
   // we have to take this check out of the 'is_niagara()' block below.
   if (has_blk_init()) {
     // When using CMS or G1, we cannot use memset() in BOT updates
     // because the sun4v/CMT version in libc_psr uses BIS which
     // exposes "phantom zeros" to concurrent readers. See 6948537.
     if (FLAG_IS_DEFAULT(UseMemSetInBOT) && (UseConcMarkSweepGC || UseG1GC)) {
       FLAG_SET_DEFAULT(UseMemSetInBOT, false);
     }
     // Issue a stern warning if the user has explicitly set
     // UseMemSetInBOT (it is known to cause issues), but allow
     // use for experimentation and debugging.
     if (UseConcMarkSweepGC || UseG1GC) {
       if (UseMemSetInBOT) {
         assert(!FLAG_IS_DEFAULT(UseMemSetInBOT), "Error");
         warning("Experimental flag -XX:+UseMemSetInBOT is known to cause instability"
                 " on sun4v; please understand that you are using at your own risk!");
       }
     }
   }

   if (is_niagara()) {
     // Indirect branch is the same cost as direct
     if (FLAG_IS_DEFAULT(UseInlineCaches)) {
       FLAG_SET_DEFAULT(UseInlineCaches, false);
     }
     // Align loops on a single instruction boundary.
     if (FLAG_IS_DEFAULT(OptoLoopAlignment)) {
       FLAG_SET_DEFAULT(OptoLoopAlignment, 4);
     }
 #ifdef _LP64
     // 32-bit oops don't make sense for the 64-bit VM on sparc
     // since the 32-bit VM has the same registers and smaller objects.
     Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
     Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 #endif // _LP64
 #ifdef COMPILER2
     // Indirect branch is the same cost as direct
     if (FLAG_IS_DEFAULT(UseJumpTables)) {
       FLAG_SET_DEFAULT(UseJumpTables, true);
     }
     // Single-issue, so entry and loop tops are
     // aligned on a single instruction boundary
     if (FLAG_IS_DEFAULT(InteriorEntryAlignment)) {
       FLAG_SET_DEFAULT(InteriorEntryAlignment, 4);
     }
     if (is_niagara_plus()) {
       if (has_blk_init() && UseTLAB &&
           FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
         // Use BIS instruction for TLAB allocation prefetch.
         FLAG_SET_ERGO(intx, AllocatePrefetchInstr, 1);
         if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
           FLAG_SET_ERGO(intx, AllocatePrefetchStyle, 3);
         }
         if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
           // Use smaller prefetch distance with BIS
           FLAG_SET_DEFAULT(AllocatePrefetchDistance, 64);
         }
       }
       if (is_T4()) {
         // Double number of prefetched cache lines on T4
         // since L2 cache line size is smaller (32 bytes).
         if (FLAG_IS_DEFAULT(AllocatePrefetchLines)) {
           FLAG_SET_ERGO(intx, AllocatePrefetchLines, AllocatePrefetchLines*2);
         }
         if (FLAG_IS_DEFAULT(AllocateInstancePrefetchLines)) {
           FLAG_SET_ERGO(intx, AllocateInstancePrefetchLines, AllocateInstancePrefetchLines*2);
         }
       }
       if (AllocatePrefetchStyle != 3 && FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
         // Use different prefetch distance without BIS
         FLAG_SET_DEFAULT(AllocatePrefetchDistance, 256);
       }
       if (AllocatePrefetchInstr == 1) {
         // Need a space at the end of TLAB for BIS since it
         // will fault when accessing memory outside of heap.

         // +1 for rounding up to next cache line, +1 to be safe
         int lines = AllocatePrefetchLines + 2;
         int step_size = AllocatePrefetchStepSize;
         int distance = AllocatePrefetchDistance;
         _reserve_for_allocation_prefetch = (distance + step_size*lines)/(int)HeapWordSize;
       }
     }
 #endif
   }

   // Use hardware population count instruction if available.
   if (has_hardware_popc()) {
     if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
       FLAG_SET_DEFAULT(UsePopCountInstruction, true);
     }
   } else if (UsePopCountInstruction) {
     warning("POPC instruction is not available on this CPU");
     FLAG_SET_DEFAULT(UsePopCountInstruction, false);
   }

   // T4 and newer Sparc cpus have new compare and branch instruction.
   if (has_cbcond()) {
     if (FLAG_IS_DEFAULT(UseCBCond)) {
       FLAG_SET_DEFAULT(UseCBCond, true);
     }
   } else if (UseCBCond) {
     warning("CBCOND instruction is not available on this CPU");
     FLAG_SET_DEFAULT(UseCBCond, false);
   }

   assert(BlockZeroingLowLimit > 0, "invalid value");
   if (has_block_zeroing() && cache_line_size > 0) {
     if (FLAG_IS_DEFAULT(UseBlockZeroing)) {
       FLAG_SET_DEFAULT(UseBlockZeroing, true);
     }
   } else if (UseBlockZeroing) {
     warning("BIS zeroing instructions are not available on this CPU");
     FLAG_SET_DEFAULT(UseBlockZeroing, false);
   }

   assert(BlockCopyLowLimit > 0, "invalid value");
   if (has_block_zeroing() && cache_line_size > 0) { // has_blk_init() && is_T4(): core's local L2 cache
     if (FLAG_IS_DEFAULT(UseBlockCopy)) {
       FLAG_SET_DEFAULT(UseBlockCopy, true);
     }
   } else if (UseBlockCopy) {
     warning("BIS instructions are not available or expensive on this CPU");
     FLAG_SET_DEFAULT(UseBlockCopy, false);
   }

 #ifdef COMPILER2
   // T4 and newer Sparc cpus have fast RDPC.
   if (has_fast_rdpc() && FLAG_IS_DEFAULT(UseRDPCForConstantTableBase)) {
     FLAG_SET_DEFAULT(UseRDPCForConstantTableBase, true);
   }

   // Currently not supported anywhere.
   FLAG_SET_DEFAULT(UseFPUForSpilling, false);

   MaxVectorSize = 8;

   assert((InteriorEntryAlignment % relocInfo::addr_unit()) == 0, "alignment is not a multiple of NOP size");
 #endif

   assert((CodeEntryAlignment % relocInfo::addr_unit()) == 0, "alignment is not a multiple of NOP size");
   assert((OptoLoopAlignment % relocInfo::addr_unit()) == 0, "alignment is not a multiple of NOP size");

   char buf[512];
   jio_snprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
                (has_v9() ? ", v9" : (has_v8() ? ", v8" : "")),
                (has_hardware_popc() ? ", popc" : ""),
                (has_vis1() ? ", vis1" : ""),
                (has_vis2() ? ", vis2" : ""),
                (has_vis3() ? ", vis3" : ""),
                (has_blk_init() ? ", blk_init" : ""),
                (has_cbcond() ? ", cbcond" : ""),
                (has_aes() ? ", aes" : ""),
                (has_sha1() ? ", sha1" : ""),
                (has_sha256() ? ", sha256" : ""),
                (has_sha512() ? ", sha512" : ""),
                (is_ultra3() ? ", ultra3" : ""),
                (is_sun4v() ? ", sun4v" : ""),
                (is_niagara_plus() ? ", niagara_plus" : (is_niagara() ? ", niagara" : "")),
                (is_sparc64() ? ", sparc64" : ""),
                (!has_hardware_mul32() ? ", no-mul32" : ""),
                (!has_hardware_div32() ? ", no-div32" : ""),
                (!has_hardware_fsmuld() ? ", no-fsmuld" : ""));

   // buf is started with ", " or is empty
   _features_str = strdup(strlen(buf) > 2 ? buf + 2 : buf);

   // UseVIS is set to the smallest of what hardware supports and what
   // the command line requires.  I.e., you cannot set UseVIS to 3 on
   // older UltraSparc which do not support it.
   if (UseVIS > 3) UseVIS=3;
   if (UseVIS < 0) UseVIS=0;
   if (!has_vis3()) // Drop to 2 if no VIS3 support
     UseVIS = MIN2((intx)2,UseVIS);
   if (!has_vis2()) // Drop to 1 if no VIS2 support
     UseVIS = MIN2((intx)1,UseVIS);
   if (!has_vis1()) // Drop to 0 if no VIS1 support
     UseVIS = 0;

   // SPARC T4 and above should have support for AES instructions
   if (has_aes()) {
     if (UseVIS > 2) { // AES intrinsics use MOVxTOd/MOVdTOx which are VIS3
       if (FLAG_IS_DEFAULT(UseAES)) {
         FLAG_SET_DEFAULT(UseAES, true);
       }
       if (FLAG_IS_DEFAULT(UseAESIntrinsics)) {
         FLAG_SET_DEFAULT(UseAESIntrinsics, true);
       }
       // we disable both the AES flags if either of them is disabled on the command line
       if (!UseAES || !UseAESIntrinsics) {
         FLAG_SET_DEFAULT(UseAES, false);
         FLAG_SET_DEFAULT(UseAESIntrinsics, false);
       }
     } else {
         if (UseAES || UseAESIntrinsics) {
           warning("SPARC AES intrinsics require VIS3 instruction support. Intrinsics will be disabled.");
           if (UseAES) {
             FLAG_SET_DEFAULT(UseAES, false);
           }
           if (UseAESIntrinsics) {
             FLAG_SET_DEFAULT(UseAESIntrinsics, false);
           }
         }
     }
   } else if (UseAES || UseAESIntrinsics) {
     warning("AES instructions are not available on this CPU");
     if (UseAES) {
       FLAG_SET_DEFAULT(UseAES, false);
     }
     if (UseAESIntrinsics) {
       FLAG_SET_DEFAULT(UseAESIntrinsics, false);
     }
   }

   // SHA1, SHA256, and SHA512 instructions were added to SPARC T-series at different times
   if (has_sha1() || has_sha256() || has_sha512()) {
     if (UseVIS > 0) { // SHA intrinsics use VIS1 instructions
       if (FLAG_IS_DEFAULT(UseSHA)) {
         FLAG_SET_DEFAULT(UseSHA, true);
       }
     } else {
       if (UseSHA) {
         warning("SPARC SHA intrinsics require VIS1 instruction support. Intrinsics will be disabled.");
         FLAG_SET_DEFAULT(UseSHA, false);
       }
     }
   } else if (UseSHA) {
     warning("SHA instructions are not available on this CPU");
     FLAG_SET_DEFAULT(UseSHA, false);
   }

   if (!UseSHA) {
     FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
     FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
     FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
   } else {
     if (has_sha1()) {
       if (FLAG_IS_DEFAULT(UseSHA1Intrinsics)) {
         FLAG_SET_DEFAULT(UseSHA1Intrinsics, true);
       }
     } else if (UseSHA1Intrinsics) {
       warning("SHA1 instruction is not available on this CPU.");
       FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
     }
     if (has_sha256()) {
       if (FLAG_IS_DEFAULT(UseSHA256Intrinsics)) {
         FLAG_SET_DEFAULT(UseSHA256Intrinsics, true);
       }
     } else if (UseSHA256Intrinsics) {
       warning("SHA256 instruction (for SHA-224 and SHA-256) is not available on this CPU.");
       FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
     }

     if (has_sha512()) {
       if (FLAG_IS_DEFAULT(UseSHA512Intrinsics)) {
         FLAG_SET_DEFAULT(UseSHA512Intrinsics, true);
       }
     } else if (UseSHA512Intrinsics) {
       warning("SHA512 instruction (for SHA-384 and SHA-512) is not available on this CPU.");
       FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
     }
     if (!(UseSHA1Intrinsics || UseSHA256Intrinsics || UseSHA512Intrinsics)) {
       FLAG_SET_DEFAULT(UseSHA, false);
     }
   }

   if (FLAG_IS_DEFAULT(ContendedPaddingWidth) &&
     (cache_line_size > ContendedPaddingWidth))
     ContendedPaddingWidth = cache_line_size;

 #ifndef PRODUCT
   if (PrintMiscellaneous && Verbose) {
     tty->print_cr("L2 data cache line size: %u", L2_data_cache_line_size());
     tty->print("Allocation");
     if (AllocatePrefetchStyle <= 0) {
       tty->print_cr(": no prefetching");
     } else {
       tty->print(" prefetching: ");
       if (AllocatePrefetchInstr == 0) {
           tty->print("PREFETCH");
       } else if (AllocatePrefetchInstr == 1) {
           tty->print("BIS");
       }
       if (AllocatePrefetchLines > 1) {
         tty->print_cr(" at distance %d, %d lines of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchLines, (int) AllocatePrefetchStepSize);
       } else {
         tty->print_cr(" at distance %d, one line of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchStepSize);
       }
     }
     if (PrefetchCopyIntervalInBytes > 0) {
       tty->print_cr("PrefetchCopyIntervalInBytes %d", (int) PrefetchCopyIntervalInBytes);
     }
     if (PrefetchScanIntervalInBytes > 0) {
       tty->print_cr("PrefetchScanIntervalInBytes %d", (int) PrefetchScanIntervalInBytes);
     }
     if (PrefetchFieldsAhead > 0) {
       tty->print_cr("PrefetchFieldsAhead %d", (int) PrefetchFieldsAhead);
     }
     if (ContendedPaddingWidth > 0) {
       tty->print_cr("ContendedPaddingWidth %d", (int) ContendedPaddingWidth);
     }
   }
 #endif // PRODUCT
 }

 void VM_Version::print_features() {
   tty->print_cr("Version:%s", cpu_features());
 }

 int VM_Version::determine_features() {
   if (UseV8InstrsOnly) {
     NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-V8");)
     return generic_v8_m;
   }

   int features = platform_features(unknown_m); // platform_features() is os_arch specific

   if (features == unknown_m) {
     features = generic_v9_m;
     warning("Cannot recognize SPARC version. Default to V9");
   }

   assert(is_T_family(features) == is_niagara(features), "Niagara should be T series");
   if (UseNiagaraInstrs) { // Force code generation for Niagara
     if (is_T_family(features)) {
       // Happy to accomodate...
     } else {
       NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Niagara");)
       features |= T_family_m;
     }
   } else {
     if (is_T_family(features) && !FLAG_IS_DEFAULT(UseNiagaraInstrs)) {
       NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Not-Niagara");)
       features &= ~(T_family_m | T1_model_m);
     } else {
       // Happy to accomodate...
     }
   }

   return features;
 }

 static int saved_features = 0;

 void VM_Version::allow_all() {
   saved_features = _features;
   _features      = all_features_m;
 }

 void VM_Version::revert() {
   _features = saved_features;
 }

 unsigned int VM_Version::calc_parallel_worker_threads() {
   unsigned int result;
   if (is_M_series()) {
     // for now, use same gc thread calculation for M-series as for niagara-plus
     // in future, we may want to tweak parameters for nof_parallel_worker_thread
     result = nof_parallel_worker_threads(5, 16, 8);
   } else if (is_niagara_plus()) {
     result = nof_parallel_worker_threads(5, 16, 8);
   } else {
     result = nof_parallel_worker_threads(5, 8, 8);
   }
   return result;
 }
	/*
	* Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#include "precompiled.hpp"
	#include "asm/macroAssembler.inline.hpp"
	#include "memory/resourceArea.hpp"
	#include "runtime/java.hpp"
	#include "runtime/stubCodeGenerator.hpp"
	#include "vm_version_sparc.hpp"
	#ifdef TARGET_OS_FAMILY_linux
	# include "os_linux.inline.hpp"
	#endif
	#ifdef TARGET_OS_FAMILY_solaris
	# include "os_solaris.inline.hpp"
	#endif

	int VM_Version::_features = VM_Version::unknown_m;
	const char* VM_Version::_features_str = "";
	unsigned int VM_Version::_L2_data_cache_line_size = 0;

	void VM_Version::initialize() {

	assert(_features != VM_Version::unknown_m, "System pre-initialization is not complete.");
	guarantee(VM_Version::has_v9(), "only SPARC v9 is supported");

	PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
	PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
	PrefetchFieldsAhead = prefetch_fields_ahead();

	assert(0 <= AllocatePrefetchInstr && AllocatePrefetchInstr <= 1, "invalid value");
	if( AllocatePrefetchInstr < 0 ) AllocatePrefetchInstr = 0;
	if( AllocatePrefetchInstr > 1 ) AllocatePrefetchInstr = 0;

	// Allocation prefetch settings
	intx cache_line_size = prefetch_data_size();
	if( cache_line_size > AllocatePrefetchStepSize )
	AllocatePrefetchStepSize = cache_line_size;

	assert(AllocatePrefetchLines > 0, "invalid value");
	if( AllocatePrefetchLines < 1 ) // set valid value in product VM
	AllocatePrefetchLines = 3;
	assert(AllocateInstancePrefetchLines > 0, "invalid value");
	if( AllocateInstancePrefetchLines < 1 ) // set valid value in product VM
	AllocateInstancePrefetchLines = 1;

	AllocatePrefetchDistance = allocate_prefetch_distance();
	AllocatePrefetchStyle = allocate_prefetch_style();

	assert((AllocatePrefetchDistance % AllocatePrefetchStepSize) == 0 &&
	(AllocatePrefetchDistance > 0), "invalid value");
	if ((AllocatePrefetchDistance % AllocatePrefetchStepSize) != 0 \|\|
	(AllocatePrefetchDistance <= 0)) {
	AllocatePrefetchDistance = AllocatePrefetchStepSize;
	}

	if (AllocatePrefetchStyle == 3 && !has_blk_init()) {
	warning("BIS instructions are not available on this CPU");
	FLAG_SET_DEFAULT(AllocatePrefetchStyle, 1);
	}

	assert(ArraycopySrcPrefetchDistance < 4096, "invalid value");
	if (ArraycopySrcPrefetchDistance >= 4096)
	ArraycopySrcPrefetchDistance = 4064;
	assert(ArraycopyDstPrefetchDistance < 4096, "invalid value");
	if (ArraycopyDstPrefetchDistance >= 4096)
	ArraycopyDstPrefetchDistance = 4064;

	UseSSE = 0; // Only on x86 and x64

	_supports_cx8 = has_v9();
	_supports_atomic_getset4 = true; // swap instruction

	// There are Fujitsu Sparc64 CPUs which support blk_init as well so
	// we have to take this check out of the 'is_niagara()' block below.
	if (has_blk_init()) {
	// When using CMS or G1, we cannot use memset() in BOT updates
	// because the sun4v/CMT version in libc_psr uses BIS which
	// exposes "phantom zeros" to concurrent readers. See 6948537.
	if (FLAG_IS_DEFAULT(UseMemSetInBOT) && (UseConcMarkSweepGC \|\| UseG1GC)) {
	FLAG_SET_DEFAULT(UseMemSetInBOT, false);
	}
	// Issue a stern warning if the user has explicitly set
	// UseMemSetInBOT (it is known to cause issues), but allow
	// use for experimentation and debugging.
	if (UseConcMarkSweepGC \|\| UseG1GC) {
	if (UseMemSetInBOT) {
	assert(!FLAG_IS_DEFAULT(UseMemSetInBOT), "Error");
	warning("Experimental flag -XX:+UseMemSetInBOT is known to cause instability"
	" on sun4v; please understand that you are using at your own risk!");
	}
	}
	}

	if (is_niagara()) {
	// Indirect branch is the same cost as direct
	if (FLAG_IS_DEFAULT(UseInlineCaches)) {
	FLAG_SET_DEFAULT(UseInlineCaches, false);
	}
	// Align loops on a single instruction boundary.
	if (FLAG_IS_DEFAULT(OptoLoopAlignment)) {
	FLAG_SET_DEFAULT(OptoLoopAlignment, 4);
	}
	#ifdef _LP64
	// 32-bit oops don't make sense for the 64-bit VM on sparc
	// since the 32-bit VM has the same registers and smaller objects.
	Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
	Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
	#endif // _LP64
	#ifdef COMPILER2
	// Indirect branch is the same cost as direct
	if (FLAG_IS_DEFAULT(UseJumpTables)) {
	FLAG_SET_DEFAULT(UseJumpTables, true);
	}
	// Single-issue, so entry and loop tops are
	// aligned on a single instruction boundary
	if (FLAG_IS_DEFAULT(InteriorEntryAlignment)) {
	FLAG_SET_DEFAULT(InteriorEntryAlignment, 4);
	}
	if (is_niagara_plus()) {
	if (has_blk_init() && UseTLAB &&
	FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
	// Use BIS instruction for TLAB allocation prefetch.
	FLAG_SET_ERGO(intx, AllocatePrefetchInstr, 1);
	if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
	FLAG_SET_ERGO(intx, AllocatePrefetchStyle, 3);
	}
	if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
	// Use smaller prefetch distance with BIS
	FLAG_SET_DEFAULT(AllocatePrefetchDistance, 64);
	}
	}
	if (is_T4()) {
	// Double number of prefetched cache lines on T4
	// since L2 cache line size is smaller (32 bytes).
	if (FLAG_IS_DEFAULT(AllocatePrefetchLines)) {
	FLAG_SET_ERGO(intx, AllocatePrefetchLines, AllocatePrefetchLines*2);
	}
	if (FLAG_IS_DEFAULT(AllocateInstancePrefetchLines)) {
	FLAG_SET_ERGO(intx, AllocateInstancePrefetchLines, AllocateInstancePrefetchLines*2);
	}
	}
	if (AllocatePrefetchStyle != 3 && FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
	// Use different prefetch distance without BIS
	FLAG_SET_DEFAULT(AllocatePrefetchDistance, 256);
	}
	if (AllocatePrefetchInstr == 1) {
	// Need a space at the end of TLAB for BIS since it
	// will fault when accessing memory outside of heap.

	// +1 for rounding up to next cache line, +1 to be safe
	int lines = AllocatePrefetchLines + 2;
	int step_size = AllocatePrefetchStepSize;
	int distance = AllocatePrefetchDistance;
	_reserve_for_allocation_prefetch = (distance + step_size*lines)/(int)HeapWordSize;
	}
	}
	#endif
	}

	// Use hardware population count instruction if available.
	if (has_hardware_popc()) {
	if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
	FLAG_SET_DEFAULT(UsePopCountInstruction, true);
	}
	} else if (UsePopCountInstruction) {
	warning("POPC instruction is not available on this CPU");
	FLAG_SET_DEFAULT(UsePopCountInstruction, false);
	}

	// T4 and newer Sparc cpus have new compare and branch instruction.
	if (has_cbcond()) {
	if (FLAG_IS_DEFAULT(UseCBCond)) {
	FLAG_SET_DEFAULT(UseCBCond, true);
	}
	} else if (UseCBCond) {
	warning("CBCOND instruction is not available on this CPU");
	FLAG_SET_DEFAULT(UseCBCond, false);
	}

	assert(BlockZeroingLowLimit > 0, "invalid value");
	if (has_block_zeroing() && cache_line_size > 0) {
	if (FLAG_IS_DEFAULT(UseBlockZeroing)) {
	FLAG_SET_DEFAULT(UseBlockZeroing, true);
	}
	} else if (UseBlockZeroing) {
	warning("BIS zeroing instructions are not available on this CPU");
	FLAG_SET_DEFAULT(UseBlockZeroing, false);
	}

	assert(BlockCopyLowLimit > 0, "invalid value");
	if (has_block_zeroing() && cache_line_size > 0) { // has_blk_init() && is_T4(): core's local L2 cache
	if (FLAG_IS_DEFAULT(UseBlockCopy)) {
	FLAG_SET_DEFAULT(UseBlockCopy, true);
	}
	} else if (UseBlockCopy) {
	warning("BIS instructions are not available or expensive on this CPU");
	FLAG_SET_DEFAULT(UseBlockCopy, false);
	}

	#ifdef COMPILER2
	// T4 and newer Sparc cpus have fast RDPC.
	if (has_fast_rdpc() && FLAG_IS_DEFAULT(UseRDPCForConstantTableBase)) {
	FLAG_SET_DEFAULT(UseRDPCForConstantTableBase, true);
	}

	// Currently not supported anywhere.
	FLAG_SET_DEFAULT(UseFPUForSpilling, false);

	MaxVectorSize = 8;

	assert((InteriorEntryAlignment % relocInfo::addr_unit()) == 0, "alignment is not a multiple of NOP size");
	#endif

	assert((CodeEntryAlignment % relocInfo::addr_unit()) == 0, "alignment is not a multiple of NOP size");
	assert((OptoLoopAlignment % relocInfo::addr_unit()) == 0, "alignment is not a multiple of NOP size");

	char buf[512];
	jio_snprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
	(has_v9() ? ", v9" : (has_v8() ? ", v8" : "")),
	(has_hardware_popc() ? ", popc" : ""),
	(has_vis1() ? ", vis1" : ""),
	(has_vis2() ? ", vis2" : ""),
	(has_vis3() ? ", vis3" : ""),
	(has_blk_init() ? ", blk_init" : ""),
	(has_cbcond() ? ", cbcond" : ""),
	(has_aes() ? ", aes" : ""),
	(has_sha1() ? ", sha1" : ""),
	(has_sha256() ? ", sha256" : ""),
	(has_sha512() ? ", sha512" : ""),
	(is_ultra3() ? ", ultra3" : ""),
	(is_sun4v() ? ", sun4v" : ""),
	(is_niagara_plus() ? ", niagara_plus" : (is_niagara() ? ", niagara" : "")),
	(is_sparc64() ? ", sparc64" : ""),
	(!has_hardware_mul32() ? ", no-mul32" : ""),
	(!has_hardware_div32() ? ", no-div32" : ""),
	(!has_hardware_fsmuld() ? ", no-fsmuld" : ""));

	// buf is started with ", " or is empty
	_features_str = strdup(strlen(buf) > 2 ? buf + 2 : buf);

	// UseVIS is set to the smallest of what hardware supports and what
	// the command line requires. I.e., you cannot set UseVIS to 3 on
	// older UltraSparc which do not support it.
	if (UseVIS > 3) UseVIS=3;
	if (UseVIS < 0) UseVIS=0;
	if (!has_vis3()) // Drop to 2 if no VIS3 support
	UseVIS = MIN2((intx)2,UseVIS);
	if (!has_vis2()) // Drop to 1 if no VIS2 support
	UseVIS = MIN2((intx)1,UseVIS);
	if (!has_vis1()) // Drop to 0 if no VIS1 support
	UseVIS = 0;

	// SPARC T4 and above should have support for AES instructions
	if (has_aes()) {
	if (UseVIS > 2) { // AES intrinsics use MOVxTOd/MOVdTOx which are VIS3
	if (FLAG_IS_DEFAULT(UseAES)) {
	FLAG_SET_DEFAULT(UseAES, true);
	}
	if (FLAG_IS_DEFAULT(UseAESIntrinsics)) {
	FLAG_SET_DEFAULT(UseAESIntrinsics, true);
	}
	// we disable both the AES flags if either of them is disabled on the command line
	if (!UseAES \|\| !UseAESIntrinsics) {
	FLAG_SET_DEFAULT(UseAES, false);
	FLAG_SET_DEFAULT(UseAESIntrinsics, false);
	}
	} else {
	if (UseAES \|\| UseAESIntrinsics) {
	warning("SPARC AES intrinsics require VIS3 instruction support. Intrinsics will be disabled.");
	if (UseAES) {
	FLAG_SET_DEFAULT(UseAES, false);
	}
	if (UseAESIntrinsics) {
	FLAG_SET_DEFAULT(UseAESIntrinsics, false);
	}
	}
	}
	} else if (UseAES \|\| UseAESIntrinsics) {
	warning("AES instructions are not available on this CPU");
	if (UseAES) {
	FLAG_SET_DEFAULT(UseAES, false);
	}
	if (UseAESIntrinsics) {
	FLAG_SET_DEFAULT(UseAESIntrinsics, false);
	}
	}

	// SHA1, SHA256, and SHA512 instructions were added to SPARC T-series at different times
	if (has_sha1() \|\| has_sha256() \|\| has_sha512()) {
	if (UseVIS > 0) { // SHA intrinsics use VIS1 instructions
	if (FLAG_IS_DEFAULT(UseSHA)) {
	FLAG_SET_DEFAULT(UseSHA, true);
	}
	} else {
	if (UseSHA) {
	warning("SPARC SHA intrinsics require VIS1 instruction support. Intrinsics will be disabled.");
	FLAG_SET_DEFAULT(UseSHA, false);
	}
	}
	} else if (UseSHA) {
	warning("SHA instructions are not available on this CPU");
	FLAG_SET_DEFAULT(UseSHA, false);
	}

	if (!UseSHA) {
	FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
	FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
	FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
	} else {
	if (has_sha1()) {
	if (FLAG_IS_DEFAULT(UseSHA1Intrinsics)) {
	FLAG_SET_DEFAULT(UseSHA1Intrinsics, true);
	}
	} else if (UseSHA1Intrinsics) {
	warning("SHA1 instruction is not available on this CPU.");
	FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
	}
	if (has_sha256()) {
	if (FLAG_IS_DEFAULT(UseSHA256Intrinsics)) {
	FLAG_SET_DEFAULT(UseSHA256Intrinsics, true);
	}
	} else if (UseSHA256Intrinsics) {
	warning("SHA256 instruction (for SHA-224 and SHA-256) is not available on this CPU.");
	FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
	}

	if (has_sha512()) {
	if (FLAG_IS_DEFAULT(UseSHA512Intrinsics)) {
	FLAG_SET_DEFAULT(UseSHA512Intrinsics, true);
	}
	} else if (UseSHA512Intrinsics) {
	warning("SHA512 instruction (for SHA-384 and SHA-512) is not available on this CPU.");
	FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
	}
	if (!(UseSHA1Intrinsics \|\| UseSHA256Intrinsics \|\| UseSHA512Intrinsics)) {
	FLAG_SET_DEFAULT(UseSHA, false);
	}
	}

	if (FLAG_IS_DEFAULT(ContendedPaddingWidth) &&
	(cache_line_size > ContendedPaddingWidth))
	ContendedPaddingWidth = cache_line_size;

	#ifndef PRODUCT
	if (PrintMiscellaneous && Verbose) {
	tty->print_cr("L2 data cache line size: %u", L2_data_cache_line_size());
	tty->print("Allocation");
	if (AllocatePrefetchStyle <= 0) {
	tty->print_cr(": no prefetching");
	} else {
	tty->print(" prefetching: ");
	if (AllocatePrefetchInstr == 0) {
	tty->print("PREFETCH");
	} else if (AllocatePrefetchInstr == 1) {
	tty->print("BIS");
	}
	if (AllocatePrefetchLines > 1) {
	tty->print_cr(" at distance %d, %d lines of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchLines, (int) AllocatePrefetchStepSize);
	} else {
	tty->print_cr(" at distance %d, one line of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchStepSize);
	}
	}
	if (PrefetchCopyIntervalInBytes > 0) {
	tty->print_cr("PrefetchCopyIntervalInBytes %d", (int) PrefetchCopyIntervalInBytes);
	}
	if (PrefetchScanIntervalInBytes > 0) {
	tty->print_cr("PrefetchScanIntervalInBytes %d", (int) PrefetchScanIntervalInBytes);
	}
	if (PrefetchFieldsAhead > 0) {
	tty->print_cr("PrefetchFieldsAhead %d", (int) PrefetchFieldsAhead);
	}
	if (ContendedPaddingWidth > 0) {
	tty->print_cr("ContendedPaddingWidth %d", (int) ContendedPaddingWidth);
	}
	}
	#endif // PRODUCT
	}

	void VM_Version::print_features() {
	tty->print_cr("Version:%s", cpu_features());
	}

	int VM_Version::determine_features() {
	if (UseV8InstrsOnly) {
	NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-V8");)
	return generic_v8_m;
	}

	int features = platform_features(unknown_m); // platform_features() is os_arch specific

	if (features == unknown_m) {
	features = generic_v9_m;
	warning("Cannot recognize SPARC version. Default to V9");
	}

	assert(is_T_family(features) == is_niagara(features), "Niagara should be T series");
	if (UseNiagaraInstrs) { // Force code generation for Niagara
	if (is_T_family(features)) {
	// Happy to accomodate...
	} else {
	NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Niagara");)
	features \|= T_family_m;
	}
	} else {
	if (is_T_family(features) && !FLAG_IS_DEFAULT(UseNiagaraInstrs)) {
	NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Not-Niagara");)
	features &= ~(T_family_m \| T1_model_m);
	} else {
	// Happy to accomodate...
	}
	}

	return features;
	}

	static int saved_features = 0;

	void VM_Version::allow_all() {
	saved_features = _features;
	_features = all_features_m;
	}

	void VM_Version::revert() {
	_features = saved_features;
	}

	unsigned int VM_Version::calc_parallel_worker_threads() {
	unsigned int result;
	if (is_M_series()) {
	// for now, use same gc thread calculation for M-series as for niagara-plus
	// in future, we may want to tweak parameters for nof_parallel_worker_thread
	result = nof_parallel_worker_threads(5, 16, 8);
	} else if (is_niagara_plus()) {
	result = nof_parallel_worker_threads(5, 16, 8);
	} else {
	result = nof_parallel_worker_threads(5, 8, 8);
	}
	return result;
	}