view src/cpu/x86/vm/vm_version_x86.cpp @ 1842:6e0aac35bfa9

6980838: G1: guarantee(false) failed: thread has an unexpected active value in its SATB queue Summary: Under certain circumstances a safepoint could happen between a JavaThread object being created and that object being added to the Java threads list. This could cause the active field of that thread's SATB queue to get out-of-sync with respect to the other Java threads. The solution is to activate the SATB queue, when necessary, before adding the thread to the Java threads list, not when the JavaThread object is created. The changeset also includes a small fix to rename the surrogate locker thread from "Surrogate Locker Thread (CMS)" to "Surrogate Locker Thread (Concurrent GC)" since it's also used in G1. Reviewed-by: iveresov, ysr, johnc, jcoomes
author tonyp
date Fri, 01 Oct 2010 16:43:05 -0400
parents 3e8fbc61cee8
children f95d63e2154a
line wrap: on
line source

/*
 * Copyright (c) 1997, 2010, 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 "incls/_precompiled.incl"
# include "incls/_vm_version_x86.cpp.incl"


int VM_Version::_cpu;
int VM_Version::_model;
int VM_Version::_stepping;
int VM_Version::_cpuFeatures;
const char*           VM_Version::_features_str = "";
VM_Version::CpuidInfo VM_Version::_cpuid_info   = { 0, };

static BufferBlob* stub_blob;
static const int stub_size = 400;

extern "C" {
  typedef void (*getPsrInfo_stub_t)(void*);
}
static getPsrInfo_stub_t getPsrInfo_stub = NULL;


class VM_Version_StubGenerator: public StubCodeGenerator {
 public:

  VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}

  address generate_getPsrInfo() {
    // Flags to test CPU type.
    const uint32_t EFL_AC           = 0x40000;
    const uint32_t EFL_ID           = 0x200000;
    // Values for when we don't have a CPUID instruction.
    const int      CPU_FAMILY_SHIFT = 8;
    const uint32_t CPU_FAMILY_386   = (3 << CPU_FAMILY_SHIFT);
    const uint32_t CPU_FAMILY_486   = (4 << CPU_FAMILY_SHIFT);

    Label detect_486, cpu486, detect_586, std_cpuid1, std_cpuid4;
    Label ext_cpuid1, ext_cpuid5, done;

    StubCodeMark mark(this, "VM_Version", "getPsrInfo_stub");
#   define __ _masm->

    address start = __ pc();

    //
    // void getPsrInfo(VM_Version::CpuidInfo* cpuid_info);
    //
    // LP64: rcx and rdx are first and second argument registers on windows

    __ push(rbp);
#ifdef _LP64
    __ mov(rbp, c_rarg0); // cpuid_info address
#else
    __ movptr(rbp, Address(rsp, 8)); // cpuid_info address
#endif
    __ push(rbx);
    __ push(rsi);
    __ pushf();          // preserve rbx, and flags
    __ pop(rax);
    __ push(rax);
    __ mov(rcx, rax);
    //
    // if we are unable to change the AC flag, we have a 386
    //
    __ xorl(rax, EFL_AC);
    __ push(rax);
    __ popf();
    __ pushf();
    __ pop(rax);
    __ cmpptr(rax, rcx);
    __ jccb(Assembler::notEqual, detect_486);

    __ movl(rax, CPU_FAMILY_386);
    __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
    __ jmp(done);

    //
    // If we are unable to change the ID flag, we have a 486 which does
    // not support the "cpuid" instruction.
    //
    __ bind(detect_486);
    __ mov(rax, rcx);
    __ xorl(rax, EFL_ID);
    __ push(rax);
    __ popf();
    __ pushf();
    __ pop(rax);
    __ cmpptr(rcx, rax);
    __ jccb(Assembler::notEqual, detect_586);

    __ bind(cpu486);
    __ movl(rax, CPU_FAMILY_486);
    __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
    __ jmp(done);

    //
    // At this point, we have a chip which supports the "cpuid" instruction
    //
    __ bind(detect_586);
    __ xorl(rax, rax);
    __ cpuid();
    __ orl(rax, rax);
    __ jcc(Assembler::equal, cpu486);   // if cpuid doesn't support an input
                                        // value of at least 1, we give up and
                                        // assume a 486
    __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    __ cmpl(rax, 0xa);                  // Is cpuid(0xB) supported?
    __ jccb(Assembler::belowEqual, std_cpuid4);

    //
    // cpuid(0xB) Processor Topology
    //
    __ movl(rax, 0xb);
    __ xorl(rcx, rcx);   // Threads level
    __ cpuid();

    __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB0_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    __ movl(rax, 0xb);
    __ movl(rcx, 1);     // Cores level
    __ cpuid();
    __ push(rax);
    __ andl(rax, 0x1f);  // Determine if valid topology level
    __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
    __ andl(rax, 0xffff);
    __ pop(rax);
    __ jccb(Assembler::equal, std_cpuid4);

    __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB1_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    __ movl(rax, 0xb);
    __ movl(rcx, 2);     // Packages level
    __ cpuid();
    __ push(rax);
    __ andl(rax, 0x1f);  // Determine if valid topology level
    __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
    __ andl(rax, 0xffff);
    __ pop(rax);
    __ jccb(Assembler::equal, std_cpuid4);

    __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB2_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    //
    // cpuid(0x4) Deterministic cache params
    //
    __ bind(std_cpuid4);
    __ movl(rax, 4);
    __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x4) supported?
    __ jccb(Assembler::greater, std_cpuid1);

    __ xorl(rcx, rcx);   // L1 cache
    __ cpuid();
    __ push(rax);
    __ andl(rax, 0x1f);  // Determine if valid cache parameters used
    __ orl(rax, rax);    // eax[4:0] == 0 indicates invalid cache
    __ pop(rax);
    __ jccb(Assembler::equal, std_cpuid1);

    __ lea(rsi, Address(rbp, in_bytes(VM_Version::dcp_cpuid4_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    //
    // Standard cpuid(0x1)
    //
    __ bind(std_cpuid1);
    __ movl(rax, 1);
    __ cpuid();
    __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    __ movl(rax, 0x80000000);
    __ cpuid();
    __ cmpl(rax, 0x80000000);     // Is cpuid(0x80000001) supported?
    __ jcc(Assembler::belowEqual, done);
    __ cmpl(rax, 0x80000004);     // Is cpuid(0x80000005) supported?
    __ jccb(Assembler::belowEqual, ext_cpuid1);
    __ cmpl(rax, 0x80000007);     // Is cpuid(0x80000008) supported?
    __ jccb(Assembler::belowEqual, ext_cpuid5);
    //
    // Extended cpuid(0x80000008)
    //
    __ movl(rax, 0x80000008);
    __ cpuid();
    __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid8_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    //
    // Extended cpuid(0x80000005)
    //
    __ bind(ext_cpuid5);
    __ movl(rax, 0x80000005);
    __ cpuid();
    __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid5_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    //
    // Extended cpuid(0x80000001)
    //
    __ bind(ext_cpuid1);
    __ movl(rax, 0x80000001);
    __ cpuid();
    __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1_offset())));
    __ movl(Address(rsi, 0), rax);
    __ movl(Address(rsi, 4), rbx);
    __ movl(Address(rsi, 8), rcx);
    __ movl(Address(rsi,12), rdx);

    //
    // return
    //
    __ bind(done);
    __ popf();
    __ pop(rsi);
    __ pop(rbx);
    __ pop(rbp);
    __ ret(0);

#   undef __

    return start;
  };
};


void VM_Version::get_processor_features() {

  _cpu = 4; // 486 by default
  _model = 0;
  _stepping = 0;
  _cpuFeatures = 0;
  _logical_processors_per_package = 1;

  if (!Use486InstrsOnly) {
    // Get raw processor info
    getPsrInfo_stub(&_cpuid_info);
    assert_is_initialized();
    _cpu = extended_cpu_family();
    _model = extended_cpu_model();
    _stepping = cpu_stepping();

    if (cpu_family() > 4) { // it supports CPUID
      _cpuFeatures = feature_flags();
      // Logical processors are only available on P4s and above,
      // and only if hyperthreading is available.
      _logical_processors_per_package = logical_processor_count();
    }
  }

  _supports_cx8 = supports_cmpxchg8();

#ifdef _LP64
  // OS should support SSE for x64 and hardware should support at least SSE2.
  if (!VM_Version::supports_sse2()) {
    vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");
  }
  // in 64 bit the use of SSE2 is the minimum
  if (UseSSE < 2) UseSSE = 2;
#endif

  // If the OS doesn't support SSE, we can't use this feature even if the HW does
  if (!os::supports_sse())
    _cpuFeatures &= ~(CPU_SSE|CPU_SSE2|CPU_SSE3|CPU_SSSE3|CPU_SSE4A|CPU_SSE4_1|CPU_SSE4_2);

  if (UseSSE < 4) {
    _cpuFeatures &= ~CPU_SSE4_1;
    _cpuFeatures &= ~CPU_SSE4_2;
  }

  if (UseSSE < 3) {
    _cpuFeatures &= ~CPU_SSE3;
    _cpuFeatures &= ~CPU_SSSE3;
    _cpuFeatures &= ~CPU_SSE4A;
  }

  if (UseSSE < 2)
    _cpuFeatures &= ~CPU_SSE2;

  if (UseSSE < 1)
    _cpuFeatures &= ~CPU_SSE;

  if (logical_processors_per_package() == 1) {
    // HT processor could be installed on a system which doesn't support HT.
    _cpuFeatures &= ~CPU_HT;
  }

  char buf[256];
  jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
               cores_per_cpu(), threads_per_core(),
               cpu_family(), _model, _stepping,
               (supports_cmov() ? ", cmov" : ""),
               (supports_cmpxchg8() ? ", cx8" : ""),
               (supports_fxsr() ? ", fxsr" : ""),
               (supports_mmx()  ? ", mmx"  : ""),
               (supports_sse()  ? ", sse"  : ""),
               (supports_sse2() ? ", sse2" : ""),
               (supports_sse3() ? ", sse3" : ""),
               (supports_ssse3()? ", ssse3": ""),
               (supports_sse4_1() ? ", sse4.1" : ""),
               (supports_sse4_2() ? ", sse4.2" : ""),
               (supports_popcnt() ? ", popcnt" : ""),
               (supports_mmx_ext() ? ", mmxext" : ""),
               (supports_3dnow()   ? ", 3dnow"  : ""),
               (supports_3dnow2()  ? ", 3dnowext" : ""),
               (supports_lzcnt()   ? ", lzcnt": ""),
               (supports_sse4a()   ? ", sse4a": ""),
               (supports_ht() ? ", ht": ""));
  _features_str = strdup(buf);

  // UseSSE is set to the smaller of what hardware supports and what
  // the command line requires.  I.e., you cannot set UseSSE to 2 on
  // older Pentiums which do not support it.
  if( UseSSE > 4 ) UseSSE=4;
  if( UseSSE < 0 ) UseSSE=0;
  if( !supports_sse4_1() ) // Drop to 3 if no SSE4 support
    UseSSE = MIN2((intx)3,UseSSE);
  if( !supports_sse3() ) // Drop to 2 if no SSE3 support
    UseSSE = MIN2((intx)2,UseSSE);
  if( !supports_sse2() ) // Drop to 1 if no SSE2 support
    UseSSE = MIN2((intx)1,UseSSE);
  if( !supports_sse () ) // Drop to 0 if no SSE  support
    UseSSE = 0;

  // On new cpus instructions which update whole XMM register should be used
  // to prevent partial register stall due to dependencies on high half.
  //
  // UseXmmLoadAndClearUpper == true  --> movsd(xmm, mem)
  // UseXmmLoadAndClearUpper == false --> movlpd(xmm, mem)
  // UseXmmRegToRegMoveAll == true  --> movaps(xmm, xmm), movapd(xmm, xmm).
  // UseXmmRegToRegMoveAll == false --> movss(xmm, xmm),  movsd(xmm, xmm).

  if( is_amd() ) { // AMD cpus specific settings
    if( supports_sse2() && FLAG_IS_DEFAULT(UseAddressNop) ) {
      // Use it on new AMD cpus starting from Opteron.
      UseAddressNop = true;
    }
    if( supports_sse2() && FLAG_IS_DEFAULT(UseNewLongLShift) ) {
      // Use it on new AMD cpus starting from Opteron.
      UseNewLongLShift = true;
    }
    if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
      if( supports_sse4a() ) {
        UseXmmLoadAndClearUpper = true; // use movsd only on '10h' Opteron
      } else {
        UseXmmLoadAndClearUpper = false;
      }
    }
    if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
      if( supports_sse4a() ) {
        UseXmmRegToRegMoveAll = true; // use movaps, movapd only on '10h'
      } else {
        UseXmmRegToRegMoveAll = false;
      }
    }
    if( FLAG_IS_DEFAULT(UseXmmI2F) ) {
      if( supports_sse4a() ) {
        UseXmmI2F = true;
      } else {
        UseXmmI2F = false;
      }
    }
    if( FLAG_IS_DEFAULT(UseXmmI2D) ) {
      if( supports_sse4a() ) {
        UseXmmI2D = true;
      } else {
        UseXmmI2D = false;
      }
    }

    // Use count leading zeros count instruction if available.
    if (supports_lzcnt()) {
      if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
        UseCountLeadingZerosInstruction = true;
      }
    }
  }

  if( is_intel() ) { // Intel cpus specific settings
    if( FLAG_IS_DEFAULT(UseStoreImmI16) ) {
      UseStoreImmI16 = false; // don't use it on Intel cpus
    }
    if( cpu_family() == 6 || cpu_family() == 15 ) {
      if( FLAG_IS_DEFAULT(UseAddressNop) ) {
        // Use it on all Intel cpus starting from PentiumPro
        UseAddressNop = true;
      }
    }
    if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
      UseXmmLoadAndClearUpper = true; // use movsd on all Intel cpus
    }
    if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
      if( supports_sse3() ) {
        UseXmmRegToRegMoveAll = true; // use movaps, movapd on new Intel cpus
      } else {
        UseXmmRegToRegMoveAll = false;
      }
    }
    if( cpu_family() == 6 && supports_sse3() ) { // New Intel cpus
#ifdef COMPILER2
      if( FLAG_IS_DEFAULT(MaxLoopPad) ) {
        // For new Intel cpus do the next optimization:
        // don't align the beginning of a loop if there are enough instructions
        // left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
        // in current fetch line (OptoLoopAlignment) or the padding
        // is big (> MaxLoopPad).
        // Set MaxLoopPad to 11 for new Intel cpus to reduce number of
        // generated NOP instructions. 11 is the largest size of one
        // address NOP instruction '0F 1F' (see Assembler::nop(i)).
        MaxLoopPad = 11;
      }
#endif // COMPILER2
      if( FLAG_IS_DEFAULT(UseXMMForArrayCopy) ) {
        UseXMMForArrayCopy = true; // use SSE2 movq on new Intel cpus
      }
      if( supports_sse4_2() && supports_ht() ) { // Newest Intel cpus
        if( FLAG_IS_DEFAULT(UseUnalignedLoadStores) && UseXMMForArrayCopy ) {
          UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
        }
      }
      if( supports_sse4_2() && UseSSE >= 4 ) {
        if( FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
          UseSSE42Intrinsics = true;
        }
      }
    }
  }

  // Use population count instruction if available.
  if (supports_popcnt()) {
    if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
      UsePopCountInstruction = true;
    }
  }

#ifdef COMPILER2
  if (UseFPUForSpilling) {
    if (UseSSE < 2) {
      // Only supported with SSE2+
      FLAG_SET_DEFAULT(UseFPUForSpilling, false);
    }
  }
#endif

  assert(0 <= ReadPrefetchInstr && ReadPrefetchInstr <= 3, "invalid value");
  assert(0 <= AllocatePrefetchInstr && AllocatePrefetchInstr <= 3, "invalid value");

  // set valid Prefetch instruction
  if( ReadPrefetchInstr < 0 ) ReadPrefetchInstr = 0;
  if( ReadPrefetchInstr > 3 ) ReadPrefetchInstr = 3;
  if( ReadPrefetchInstr == 3 && !supports_3dnow() ) ReadPrefetchInstr = 0;
  if( !supports_sse() && supports_3dnow() ) ReadPrefetchInstr = 3;

  if( AllocatePrefetchInstr < 0 ) AllocatePrefetchInstr = 0;
  if( AllocatePrefetchInstr > 3 ) AllocatePrefetchInstr = 3;
  if( AllocatePrefetchInstr == 3 && !supports_3dnow() ) AllocatePrefetchInstr=0;
  if( !supports_sse() && supports_3dnow() ) AllocatePrefetchInstr = 3;

  // Allocation prefetch settings
  intx cache_line_size = L1_data_cache_line_size();
  if( cache_line_size > AllocatePrefetchStepSize )
    AllocatePrefetchStepSize = cache_line_size;
  if( FLAG_IS_DEFAULT(AllocatePrefetchLines) )
    AllocatePrefetchLines = 3; // Optimistic value
  assert(AllocatePrefetchLines > 0, "invalid value");
  if( AllocatePrefetchLines < 1 ) // set valid value in product VM
    AllocatePrefetchLines = 1; // Conservative value

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

  if( is_intel() && cpu_family() == 6 && supports_sse3() ) {
    if( AllocatePrefetchStyle == 2 ) { // watermark prefetching on Core
#ifdef _LP64
      AllocatePrefetchDistance = 384;
#else
      AllocatePrefetchDistance = 320;
#endif
    }
    if( supports_sse4_2() && supports_ht() ) { // Nehalem based cpus
      AllocatePrefetchDistance = 192;
      AllocatePrefetchLines = 4;
#ifdef COMPILER2
      if (AggressiveOpts && FLAG_IS_DEFAULT(UseFPUForSpilling)) {
        FLAG_SET_DEFAULT(UseFPUForSpilling, true);
      }
#endif
    }
  }
  assert(AllocatePrefetchDistance % AllocatePrefetchStepSize == 0, "invalid value");

#ifdef _LP64
  // Prefetch settings
  PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
  PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
  PrefetchFieldsAhead         = prefetch_fields_ahead();
#endif

#ifndef PRODUCT
  if (PrintMiscellaneous && Verbose) {
    tty->print_cr("Logical CPUs per core: %u",
                  logical_processors_per_package());
    tty->print_cr("UseSSE=%d",UseSSE);
    tty->print("Allocation: ");
    if (AllocatePrefetchStyle <= 0 || UseSSE == 0 && !supports_3dnow()) {
      tty->print_cr("no prefetching");
    } else {
      if (UseSSE == 0 && supports_3dnow()) {
        tty->print("PREFETCHW");
      } else if (UseSSE >= 1) {
        if (AllocatePrefetchInstr == 0) {
          tty->print("PREFETCHNTA");
        } else if (AllocatePrefetchInstr == 1) {
          tty->print("PREFETCHT0");
        } else if (AllocatePrefetchInstr == 2) {
          tty->print("PREFETCHT2");
        } else if (AllocatePrefetchInstr == 3) {
          tty->print("PREFETCHW");
        }
      }
      if (AllocatePrefetchLines > 1) {
        tty->print_cr(" %d, %d lines with step %d bytes", AllocatePrefetchDistance, AllocatePrefetchLines, AllocatePrefetchStepSize);
      } else {
        tty->print_cr(" %d, one line", AllocatePrefetchDistance);
      }
    }

    if (PrefetchCopyIntervalInBytes > 0) {
      tty->print_cr("PrefetchCopyIntervalInBytes %d", PrefetchCopyIntervalInBytes);
    }
    if (PrefetchScanIntervalInBytes > 0) {
      tty->print_cr("PrefetchScanIntervalInBytes %d", PrefetchScanIntervalInBytes);
    }
    if (PrefetchFieldsAhead > 0) {
      tty->print_cr("PrefetchFieldsAhead %d", PrefetchFieldsAhead);
    }
  }
#endif // !PRODUCT
}

void VM_Version::initialize() {
  ResourceMark rm;
  // Making this stub must be FIRST use of assembler

  stub_blob = BufferBlob::create("getPsrInfo_stub", stub_size);
  if (stub_blob == NULL) {
    vm_exit_during_initialization("Unable to allocate getPsrInfo_stub");
  }
  CodeBuffer c(stub_blob);
  VM_Version_StubGenerator g(&c);
  getPsrInfo_stub = CAST_TO_FN_PTR(getPsrInfo_stub_t,
                                   g.generate_getPsrInfo());

  get_processor_features();
}