1 /*
   2  * Copyright (c) 1997, 2010, Oracle and/or its affiliates.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "assembler_x86.inline.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "runtime/java.hpp"
  29 #include "runtime/stubCodeGenerator.hpp"
  30 #include "vm_version_x86.hpp"
  31 #ifdef TARGET_OS_FAMILY_linux
  32 # include "os_linux.inline.hpp"
  33 #endif
  34 #ifdef TARGET_OS_FAMILY_solaris
  35 # include "os_solaris.inline.hpp"
  36 #endif
  37 #ifdef TARGET_OS_FAMILY_windows
  38 # include "os_windows.inline.hpp"
  39 #endif
  40 
  41 
  42 int VM_Version::_cpu;
  43 int VM_Version::_model;
  44 int VM_Version::_stepping;
  45 int VM_Version::_cpuFeatures;
  46 const char*           VM_Version::_features_str = "";
  47 VM_Version::CpuidInfo VM_Version::_cpuid_info   = { 0, };
  48 
  49 static BufferBlob* stub_blob;
  50 static const int stub_size = 400;
  51 
  52 extern "C" {
  53   typedef void (*getPsrInfo_stub_t)(void*);
  54 }
  55 static getPsrInfo_stub_t getPsrInfo_stub = NULL;
  56 
  57 
  58 class VM_Version_StubGenerator: public StubCodeGenerator {
  59  public:
  60 
  61   VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
  62 
  63   address generate_getPsrInfo() {
  64     // Flags to test CPU type.
  65     const uint32_t EFL_AC           = 0x40000;
  66     const uint32_t EFL_ID           = 0x200000;
  67     // Values for when we don't have a CPUID instruction.
  68     const int      CPU_FAMILY_SHIFT = 8;
  69     const uint32_t CPU_FAMILY_386   = (3 << CPU_FAMILY_SHIFT);
  70     const uint32_t CPU_FAMILY_486   = (4 << CPU_FAMILY_SHIFT);
  71 
  72     Label detect_486, cpu486, detect_586, std_cpuid1, std_cpuid4;
  73     Label ext_cpuid1, ext_cpuid5, done;
  74 
  75     StubCodeMark mark(this, "VM_Version", "getPsrInfo_stub");
  76 #   define __ _masm->
  77 
  78     address start = __ pc();
  79 
  80     //
  81     // void getPsrInfo(VM_Version::CpuidInfo* cpuid_info);
  82     //
  83     // LP64: rcx and rdx are first and second argument registers on windows
  84 
  85     __ push(rbp);
  86 #ifdef _LP64
  87     __ mov(rbp, c_rarg0); // cpuid_info address
  88 #else
  89     __ movptr(rbp, Address(rsp, 8)); // cpuid_info address
  90 #endif
  91     __ push(rbx);
  92     __ push(rsi);
  93     __ pushf();          // preserve rbx, and flags
  94     __ pop(rax);
  95     __ push(rax);
  96     __ mov(rcx, rax);
  97     //
  98     // if we are unable to change the AC flag, we have a 386
  99     //
 100     __ xorl(rax, EFL_AC);
 101     __ push(rax);
 102     __ popf();
 103     __ pushf();
 104     __ pop(rax);
 105     __ cmpptr(rax, rcx);
 106     __ jccb(Assembler::notEqual, detect_486);
 107 
 108     __ movl(rax, CPU_FAMILY_386);
 109     __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
 110     __ jmp(done);
 111 
 112     //
 113     // If we are unable to change the ID flag, we have a 486 which does
 114     // not support the "cpuid" instruction.
 115     //
 116     __ bind(detect_486);
 117     __ mov(rax, rcx);
 118     __ xorl(rax, EFL_ID);
 119     __ push(rax);
 120     __ popf();
 121     __ pushf();
 122     __ pop(rax);
 123     __ cmpptr(rcx, rax);
 124     __ jccb(Assembler::notEqual, detect_586);
 125 
 126     __ bind(cpu486);
 127     __ movl(rax, CPU_FAMILY_486);
 128     __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
 129     __ jmp(done);
 130 
 131     //
 132     // At this point, we have a chip which supports the "cpuid" instruction
 133     //
 134     __ bind(detect_586);
 135     __ xorl(rax, rax);
 136     __ cpuid();
 137     __ orl(rax, rax);
 138     __ jcc(Assembler::equal, cpu486);   // if cpuid doesn't support an input
 139                                         // value of at least 1, we give up and
 140                                         // assume a 486
 141     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
 142     __ movl(Address(rsi, 0), rax);
 143     __ movl(Address(rsi, 4), rbx);
 144     __ movl(Address(rsi, 8), rcx);
 145     __ movl(Address(rsi,12), rdx);
 146 
 147     __ cmpl(rax, 0xa);                  // Is cpuid(0xB) supported?
 148     __ jccb(Assembler::belowEqual, std_cpuid4);
 149 
 150     //
 151     // cpuid(0xB) Processor Topology
 152     //
 153     __ movl(rax, 0xb);
 154     __ xorl(rcx, rcx);   // Threads level
 155     __ cpuid();
 156 
 157     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB0_offset())));
 158     __ movl(Address(rsi, 0), rax);
 159     __ movl(Address(rsi, 4), rbx);
 160     __ movl(Address(rsi, 8), rcx);
 161     __ movl(Address(rsi,12), rdx);
 162 
 163     __ movl(rax, 0xb);
 164     __ movl(rcx, 1);     // Cores level
 165     __ cpuid();
 166     __ push(rax);
 167     __ andl(rax, 0x1f);  // Determine if valid topology level
 168     __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
 169     __ andl(rax, 0xffff);
 170     __ pop(rax);
 171     __ jccb(Assembler::equal, std_cpuid4);
 172 
 173     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB1_offset())));
 174     __ movl(Address(rsi, 0), rax);
 175     __ movl(Address(rsi, 4), rbx);
 176     __ movl(Address(rsi, 8), rcx);
 177     __ movl(Address(rsi,12), rdx);
 178 
 179     __ movl(rax, 0xb);
 180     __ movl(rcx, 2);     // Packages level
 181     __ cpuid();
 182     __ push(rax);
 183     __ andl(rax, 0x1f);  // Determine if valid topology level
 184     __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
 185     __ andl(rax, 0xffff);
 186     __ pop(rax);
 187     __ jccb(Assembler::equal, std_cpuid4);
 188 
 189     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB2_offset())));
 190     __ movl(Address(rsi, 0), rax);
 191     __ movl(Address(rsi, 4), rbx);
 192     __ movl(Address(rsi, 8), rcx);
 193     __ movl(Address(rsi,12), rdx);
 194 
 195     //
 196     // cpuid(0x4) Deterministic cache params
 197     //
 198     __ bind(std_cpuid4);
 199     __ movl(rax, 4);
 200     __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x4) supported?
 201     __ jccb(Assembler::greater, std_cpuid1);
 202 
 203     __ xorl(rcx, rcx);   // L1 cache
 204     __ cpuid();
 205     __ push(rax);
 206     __ andl(rax, 0x1f);  // Determine if valid cache parameters used
 207     __ orl(rax, rax);    // eax[4:0] == 0 indicates invalid cache
 208     __ pop(rax);
 209     __ jccb(Assembler::equal, std_cpuid1);
 210 
 211     __ lea(rsi, Address(rbp, in_bytes(VM_Version::dcp_cpuid4_offset())));
 212     __ movl(Address(rsi, 0), rax);
 213     __ movl(Address(rsi, 4), rbx);
 214     __ movl(Address(rsi, 8), rcx);
 215     __ movl(Address(rsi,12), rdx);
 216 
 217     //
 218     // Standard cpuid(0x1)
 219     //
 220     __ bind(std_cpuid1);
 221     __ movl(rax, 1);
 222     __ cpuid();
 223     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
 224     __ movl(Address(rsi, 0), rax);
 225     __ movl(Address(rsi, 4), rbx);
 226     __ movl(Address(rsi, 8), rcx);
 227     __ movl(Address(rsi,12), rdx);
 228 
 229     __ movl(rax, 0x80000000);
 230     __ cpuid();
 231     __ cmpl(rax, 0x80000000);     // Is cpuid(0x80000001) supported?
 232     __ jcc(Assembler::belowEqual, done);
 233     __ cmpl(rax, 0x80000004);     // Is cpuid(0x80000005) supported?
 234     __ jccb(Assembler::belowEqual, ext_cpuid1);
 235     __ cmpl(rax, 0x80000007);     // Is cpuid(0x80000008) supported?
 236     __ jccb(Assembler::belowEqual, ext_cpuid5);
 237     //
 238     // Extended cpuid(0x80000008)
 239     //
 240     __ movl(rax, 0x80000008);
 241     __ cpuid();
 242     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid8_offset())));
 243     __ movl(Address(rsi, 0), rax);
 244     __ movl(Address(rsi, 4), rbx);
 245     __ movl(Address(rsi, 8), rcx);
 246     __ movl(Address(rsi,12), rdx);
 247 
 248     //
 249     // Extended cpuid(0x80000005)
 250     //
 251     __ bind(ext_cpuid5);
 252     __ movl(rax, 0x80000005);
 253     __ cpuid();
 254     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid5_offset())));
 255     __ movl(Address(rsi, 0), rax);
 256     __ movl(Address(rsi, 4), rbx);
 257     __ movl(Address(rsi, 8), rcx);
 258     __ movl(Address(rsi,12), rdx);
 259 
 260     //
 261     // Extended cpuid(0x80000001)
 262     //
 263     __ bind(ext_cpuid1);
 264     __ movl(rax, 0x80000001);
 265     __ cpuid();
 266     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1_offset())));
 267     __ movl(Address(rsi, 0), rax);
 268     __ movl(Address(rsi, 4), rbx);
 269     __ movl(Address(rsi, 8), rcx);
 270     __ movl(Address(rsi,12), rdx);
 271 
 272     //
 273     // return
 274     //
 275     __ bind(done);
 276     __ popf();
 277     __ pop(rsi);
 278     __ pop(rbx);
 279     __ pop(rbp);
 280     __ ret(0);
 281 
 282 #   undef __
 283 
 284     return start;
 285   };
 286 };
 287 
 288 
 289 void VM_Version::get_processor_features() {
 290 
 291   _cpu = 4; // 486 by default
 292   _model = 0;
 293   _stepping = 0;
 294   _cpuFeatures = 0;
 295   _logical_processors_per_package = 1;
 296 
 297   if (!Use486InstrsOnly) {
 298     // Get raw processor info
 299     getPsrInfo_stub(&_cpuid_info);
 300     assert_is_initialized();
 301     _cpu = extended_cpu_family();
 302     _model = extended_cpu_model();
 303     _stepping = cpu_stepping();
 304 
 305     if (cpu_family() > 4) { // it supports CPUID
 306       _cpuFeatures = feature_flags();
 307       // Logical processors are only available on P4s and above,
 308       // and only if hyperthreading is available.
 309       _logical_processors_per_package = logical_processor_count();
 310     }
 311   }
 312 
 313   _supports_cx8 = supports_cmpxchg8();
 314 
 315 #ifdef _LP64
 316   // OS should support SSE for x64 and hardware should support at least SSE2.
 317   if (!VM_Version::supports_sse2()) {
 318     vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");
 319   }
 320   // in 64 bit the use of SSE2 is the minimum
 321   if (UseSSE < 2) UseSSE = 2;
 322 #endif
 323 
 324   // If the OS doesn't support SSE, we can't use this feature even if the HW does
 325   if (!os::supports_sse())
 326     _cpuFeatures &= ~(CPU_SSE|CPU_SSE2|CPU_SSE3|CPU_SSSE3|CPU_SSE4A|CPU_SSE4_1|CPU_SSE4_2);
 327 
 328   if (UseSSE < 4) {
 329     _cpuFeatures &= ~CPU_SSE4_1;
 330     _cpuFeatures &= ~CPU_SSE4_2;
 331   }
 332 
 333   if (UseSSE < 3) {
 334     _cpuFeatures &= ~CPU_SSE3;
 335     _cpuFeatures &= ~CPU_SSSE3;
 336     _cpuFeatures &= ~CPU_SSE4A;
 337   }
 338 
 339   if (UseSSE < 2)
 340     _cpuFeatures &= ~CPU_SSE2;
 341 
 342   if (UseSSE < 1)
 343     _cpuFeatures &= ~CPU_SSE;
 344 
 345   if (logical_processors_per_package() == 1) {
 346     // HT processor could be installed on a system which doesn't support HT.
 347     _cpuFeatures &= ~CPU_HT;
 348   }
 349 
 350   char buf[256];
 351   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",
 352                cores_per_cpu(), threads_per_core(),
 353                cpu_family(), _model, _stepping,
 354                (supports_cmov() ? ", cmov" : ""),
 355                (supports_cmpxchg8() ? ", cx8" : ""),
 356                (supports_fxsr() ? ", fxsr" : ""),
 357                (supports_mmx()  ? ", mmx"  : ""),
 358                (supports_sse()  ? ", sse"  : ""),
 359                (supports_sse2() ? ", sse2" : ""),
 360                (supports_sse3() ? ", sse3" : ""),
 361                (supports_ssse3()? ", ssse3": ""),
 362                (supports_sse4_1() ? ", sse4.1" : ""),
 363                (supports_sse4_2() ? ", sse4.2" : ""),
 364                (supports_popcnt() ? ", popcnt" : ""),
 365                (supports_mmx_ext() ? ", mmxext" : ""),
 366                (supports_3dnow()   ? ", 3dnow"  : ""),
 367                (supports_3dnow2()  ? ", 3dnowext" : ""),
 368                (supports_lzcnt()   ? ", lzcnt": ""),
 369                (supports_sse4a()   ? ", sse4a": ""),
 370                (supports_ht() ? ", ht": ""));
 371   _features_str = strdup(buf);
 372 
 373   // UseSSE is set to the smaller of what hardware supports and what
 374   // the command line requires.  I.e., you cannot set UseSSE to 2 on
 375   // older Pentiums which do not support it.
 376   if( UseSSE > 4 ) UseSSE=4;
 377   if( UseSSE < 0 ) UseSSE=0;
 378   if( !supports_sse4_1() ) // Drop to 3 if no SSE4 support
 379     UseSSE = MIN2((intx)3,UseSSE);
 380   if( !supports_sse3() ) // Drop to 2 if no SSE3 support
 381     UseSSE = MIN2((intx)2,UseSSE);
 382   if( !supports_sse2() ) // Drop to 1 if no SSE2 support
 383     UseSSE = MIN2((intx)1,UseSSE);
 384   if( !supports_sse () ) // Drop to 0 if no SSE  support
 385     UseSSE = 0;
 386 
 387   // On new cpus instructions which update whole XMM register should be used
 388   // to prevent partial register stall due to dependencies on high half.
 389   //
 390   // UseXmmLoadAndClearUpper == true  --> movsd(xmm, mem)
 391   // UseXmmLoadAndClearUpper == false --> movlpd(xmm, mem)
 392   // UseXmmRegToRegMoveAll == true  --> movaps(xmm, xmm), movapd(xmm, xmm).
 393   // UseXmmRegToRegMoveAll == false --> movss(xmm, xmm),  movsd(xmm, xmm).
 394 
 395   if( is_amd() ) { // AMD cpus specific settings
 396     if( supports_sse2() && FLAG_IS_DEFAULT(UseAddressNop) ) {
 397       // Use it on new AMD cpus starting from Opteron.
 398       UseAddressNop = true;
 399     }
 400     if( supports_sse2() && FLAG_IS_DEFAULT(UseNewLongLShift) ) {
 401       // Use it on new AMD cpus starting from Opteron.
 402       UseNewLongLShift = true;
 403     }
 404     if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
 405       if( supports_sse4a() ) {
 406         UseXmmLoadAndClearUpper = true; // use movsd only on '10h' Opteron
 407       } else {
 408         UseXmmLoadAndClearUpper = false;
 409       }
 410     }
 411     if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
 412       if( supports_sse4a() ) {
 413         UseXmmRegToRegMoveAll = true; // use movaps, movapd only on '10h'
 414       } else {
 415         UseXmmRegToRegMoveAll = false;
 416       }
 417     }
 418     if( FLAG_IS_DEFAULT(UseXmmI2F) ) {
 419       if( supports_sse4a() ) {
 420         UseXmmI2F = true;
 421       } else {
 422         UseXmmI2F = false;
 423       }
 424     }
 425     if( FLAG_IS_DEFAULT(UseXmmI2D) ) {
 426       if( supports_sse4a() ) {
 427         UseXmmI2D = true;
 428       } else {
 429         UseXmmI2D = false;
 430       }
 431     }
 432 
 433     // Use count leading zeros count instruction if available.
 434     if (supports_lzcnt()) {
 435       if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
 436         UseCountLeadingZerosInstruction = true;
 437       }
 438     }
 439 
 440     // On family 21 processors default is no sw prefetch
 441     if ( cpu_family() == 21 ) {
 442       if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
 443         AllocatePrefetchStyle = 0;
 444       }
 445     }
 446   }
 447 
 448   if( is_intel() ) { // Intel cpus specific settings
 449     if( FLAG_IS_DEFAULT(UseStoreImmI16) ) {
 450       UseStoreImmI16 = false; // don't use it on Intel cpus
 451     }
 452     if( cpu_family() == 6 || cpu_family() == 15 ) {
 453       if( FLAG_IS_DEFAULT(UseAddressNop) ) {
 454         // Use it on all Intel cpus starting from PentiumPro
 455         UseAddressNop = true;
 456       }
 457     }
 458     if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
 459       UseXmmLoadAndClearUpper = true; // use movsd on all Intel cpus
 460     }
 461     if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
 462       if( supports_sse3() ) {
 463         UseXmmRegToRegMoveAll = true; // use movaps, movapd on new Intel cpus
 464       } else {
 465         UseXmmRegToRegMoveAll = false;
 466       }
 467     }
 468     if( cpu_family() == 6 && supports_sse3() ) { // New Intel cpus
 469 #ifdef COMPILER2
 470       if( FLAG_IS_DEFAULT(MaxLoopPad) ) {
 471         // For new Intel cpus do the next optimization:
 472         // don't align the beginning of a loop if there are enough instructions
 473         // left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
 474         // in current fetch line (OptoLoopAlignment) or the padding
 475         // is big (> MaxLoopPad).
 476         // Set MaxLoopPad to 11 for new Intel cpus to reduce number of
 477         // generated NOP instructions. 11 is the largest size of one
 478         // address NOP instruction '0F 1F' (see Assembler::nop(i)).
 479         MaxLoopPad = 11;
 480       }
 481 #endif // COMPILER2
 482       if( FLAG_IS_DEFAULT(UseXMMForArrayCopy) ) {
 483         UseXMMForArrayCopy = true; // use SSE2 movq on new Intel cpus
 484       }
 485       if( supports_sse4_2() && supports_ht() ) { // Newest Intel cpus
 486         if( FLAG_IS_DEFAULT(UseUnalignedLoadStores) && UseXMMForArrayCopy ) {
 487           UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
 488         }
 489       }
 490       if( supports_sse4_2() && UseSSE >= 4 ) {
 491         if( FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
 492           UseSSE42Intrinsics = true;
 493         }
 494       }
 495     }
 496   }
 497 
 498   // Use population count instruction if available.
 499   if (supports_popcnt()) {
 500     if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
 501       UsePopCountInstruction = true;
 502     }
 503   }
 504 
 505 #ifdef COMPILER2
 506   if (UseFPUForSpilling) {
 507     if (UseSSE < 2) {
 508       // Only supported with SSE2+
 509       FLAG_SET_DEFAULT(UseFPUForSpilling, false);
 510     }
 511   }
 512 #endif
 513 
 514   assert(0 <= ReadPrefetchInstr && ReadPrefetchInstr <= 3, "invalid value");
 515   assert(0 <= AllocatePrefetchInstr && AllocatePrefetchInstr <= 3, "invalid value");
 516 
 517   // set valid Prefetch instruction
 518   if( ReadPrefetchInstr < 0 ) ReadPrefetchInstr = 0;
 519   if( ReadPrefetchInstr > 3 ) ReadPrefetchInstr = 3;
 520   if( ReadPrefetchInstr == 3 && !supports_3dnow() ) ReadPrefetchInstr = 0;
 521   if( !supports_sse() && supports_3dnow() ) ReadPrefetchInstr = 3;
 522 
 523   if( AllocatePrefetchInstr < 0 ) AllocatePrefetchInstr = 0;
 524   if( AllocatePrefetchInstr > 3 ) AllocatePrefetchInstr = 3;
 525   if( AllocatePrefetchInstr == 3 && !supports_3dnow() ) AllocatePrefetchInstr=0;
 526   if( !supports_sse() && supports_3dnow() ) AllocatePrefetchInstr = 3;
 527 
 528   // Allocation prefetch settings
 529   intx cache_line_size = L1_data_cache_line_size();
 530   if( cache_line_size > AllocatePrefetchStepSize )
 531     AllocatePrefetchStepSize = cache_line_size;
 532   if( FLAG_IS_DEFAULT(AllocatePrefetchLines) )
 533     AllocatePrefetchLines = 3; // Optimistic value
 534   assert(AllocatePrefetchLines > 0, "invalid value");
 535   if( AllocatePrefetchLines < 1 ) // set valid value in product VM
 536     AllocatePrefetchLines = 1; // Conservative value
 537 
 538   AllocatePrefetchDistance = allocate_prefetch_distance();
 539   AllocatePrefetchStyle    = allocate_prefetch_style();
 540 
 541   if( is_intel() && cpu_family() == 6 && supports_sse3() ) {
 542     if( AllocatePrefetchStyle == 2 ) { // watermark prefetching on Core
 543 #ifdef _LP64
 544       AllocatePrefetchDistance = 384;
 545 #else
 546       AllocatePrefetchDistance = 320;
 547 #endif
 548     }
 549     if( supports_sse4_2() && supports_ht() ) { // Nehalem based cpus
 550       AllocatePrefetchDistance = 192;
 551       AllocatePrefetchLines = 4;
 552 #ifdef COMPILER2
 553       if (AggressiveOpts && FLAG_IS_DEFAULT(UseFPUForSpilling)) {
 554         FLAG_SET_DEFAULT(UseFPUForSpilling, true);
 555       }
 556 #endif
 557     }
 558   }
 559   assert(AllocatePrefetchDistance % AllocatePrefetchStepSize == 0, "invalid value");
 560 
 561 #ifdef _LP64
 562   // Prefetch settings
 563   PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
 564   PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
 565   PrefetchFieldsAhead         = prefetch_fields_ahead();
 566 #endif
 567 
 568 #ifndef PRODUCT
 569   if (PrintMiscellaneous && Verbose) {
 570     tty->print_cr("Logical CPUs per core: %u",
 571                   logical_processors_per_package());
 572     tty->print_cr("UseSSE=%d",UseSSE);
 573     tty->print("Allocation: ");
 574     if (AllocatePrefetchStyle <= 0 || UseSSE == 0 && !supports_3dnow()) {
 575       tty->print_cr("no prefetching");
 576     } else {
 577       if (UseSSE == 0 && supports_3dnow()) {
 578         tty->print("PREFETCHW");
 579       } else if (UseSSE >= 1) {
 580         if (AllocatePrefetchInstr == 0) {
 581           tty->print("PREFETCHNTA");
 582         } else if (AllocatePrefetchInstr == 1) {
 583           tty->print("PREFETCHT0");
 584         } else if (AllocatePrefetchInstr == 2) {
 585           tty->print("PREFETCHT2");
 586         } else if (AllocatePrefetchInstr == 3) {
 587           tty->print("PREFETCHW");
 588         }
 589       }
 590       if (AllocatePrefetchLines > 1) {
 591         tty->print_cr(" %d, %d lines with step %d bytes", AllocatePrefetchDistance, AllocatePrefetchLines, AllocatePrefetchStepSize);
 592       } else {
 593         tty->print_cr(" %d, one line", AllocatePrefetchDistance);
 594       }
 595     }
 596 
 597     if (PrefetchCopyIntervalInBytes > 0) {
 598       tty->print_cr("PrefetchCopyIntervalInBytes %d", PrefetchCopyIntervalInBytes);
 599     }
 600     if (PrefetchScanIntervalInBytes > 0) {
 601       tty->print_cr("PrefetchScanIntervalInBytes %d", PrefetchScanIntervalInBytes);
 602     }
 603     if (PrefetchFieldsAhead > 0) {
 604       tty->print_cr("PrefetchFieldsAhead %d", PrefetchFieldsAhead);
 605     }
 606   }
 607 #endif // !PRODUCT
 608 }
 609 
 610 void VM_Version::initialize() {
 611   ResourceMark rm;
 612   // Making this stub must be FIRST use of assembler
 613 
 614   stub_blob = BufferBlob::create("getPsrInfo_stub", stub_size);
 615   if (stub_blob == NULL) {
 616     vm_exit_during_initialization("Unable to allocate getPsrInfo_stub");
 617   }
 618   CodeBuffer c(stub_blob);
 619   VM_Version_StubGenerator g(&c);
 620   getPsrInfo_stub = CAST_TO_FN_PTR(getPsrInfo_stub_t,
 621                                    g.generate_getPsrInfo());
 622 
 623   get_processor_features();
 624 }