1 /*
   2  * Copyright (c) 1997, 2013, 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 #ifndef CPU_X86_VM_VM_VERSION_X86_HPP
  26 #define CPU_X86_VM_VM_VERSION_X86_HPP
  27 
  28 #include "runtime/globals_extension.hpp"
  29 #include "runtime/vm_version.hpp"
  30 
  31 class VM_Version : public Abstract_VM_Version {
  32 public:
  33   // cpuid result register layouts.  These are all unions of a uint32_t
  34   // (in case anyone wants access to the register as a whole) and a bitfield.
  35 
  36   union StdCpuid1Eax {
  37     uint32_t value;
  38     struct {
  39       uint32_t stepping   : 4,
  40                model      : 4,
  41                family     : 4,
  42                proc_type  : 2,
  43                           : 2,
  44                ext_model  : 4,
  45                ext_family : 8,
  46                           : 4;
  47     } bits;
  48   };
  49 
  50   union StdCpuid1Ebx { // example, unused
  51     uint32_t value;
  52     struct {
  53       uint32_t brand_id         : 8,
  54                clflush_size     : 8,
  55                threads_per_cpu  : 8,
  56                apic_id          : 8;
  57     } bits;
  58   };
  59 
  60   union StdCpuid1Ecx {
  61     uint32_t value;
  62     struct {
  63       uint32_t sse3     : 1,
  64                clmul    : 1,
  65                         : 1,
  66                monitor  : 1,
  67                         : 1,
  68                vmx      : 1,
  69                         : 1,
  70                est      : 1,
  71                         : 1,
  72                ssse3    : 1,
  73                cid      : 1,
  74                         : 2,
  75                cmpxchg16: 1,
  76                         : 4,
  77                dca      : 1,
  78                sse4_1   : 1,
  79                sse4_2   : 1,
  80                         : 2,
  81                popcnt   : 1,
  82                         : 1,
  83                aes      : 1,
  84                         : 1,
  85                osxsave  : 1,
  86                avx      : 1,
  87                         : 3;
  88     } bits;
  89   };
  90 
  91   union StdCpuid1Edx {
  92     uint32_t value;
  93     struct {
  94       uint32_t          : 4,
  95                tsc      : 1,
  96                         : 3,
  97                cmpxchg8 : 1,
  98                         : 6,
  99                cmov     : 1,
 100                         : 3,
 101                clflush  : 1,
 102                         : 3,
 103                mmx      : 1,
 104                fxsr     : 1,
 105                sse      : 1,
 106                sse2     : 1,
 107                         : 1,
 108                ht       : 1,
 109                         : 3;
 110     } bits;
 111   };
 112 
 113   union DcpCpuid4Eax {
 114     uint32_t value;
 115     struct {
 116       uint32_t cache_type    : 5,
 117                              : 21,
 118                cores_per_cpu : 6;
 119     } bits;
 120   };
 121 
 122   union DcpCpuid4Ebx {
 123     uint32_t value;
 124     struct {
 125       uint32_t L1_line_size  : 12,
 126                partitions    : 10,
 127                associativity : 10;
 128     } bits;
 129   };
 130 
 131   union TplCpuidBEbx {
 132     uint32_t value;
 133     struct {
 134       uint32_t logical_cpus : 16,
 135                             : 16;
 136     } bits;
 137   };
 138 
 139   union ExtCpuid1Ecx {
 140     uint32_t value;
 141     struct {
 142       uint32_t LahfSahf     : 1,
 143                CmpLegacy    : 1,
 144                             : 3,
 145                lzcnt_intel  : 1,
 146                lzcnt        : 1,
 147                sse4a        : 1,
 148                misalignsse  : 1,
 149                prefetchw    : 1,
 150                             : 22;
 151     } bits;
 152   };
 153 
 154   union ExtCpuid1Edx {
 155     uint32_t value;
 156     struct {
 157       uint32_t           : 22,
 158                mmx_amd   : 1,
 159                mmx       : 1,
 160                fxsr      : 1,
 161                          : 4,
 162                long_mode : 1,
 163                tdnow2    : 1,
 164                tdnow     : 1;
 165     } bits;
 166   };
 167 
 168   union ExtCpuid5Ex {
 169     uint32_t value;
 170     struct {
 171       uint32_t L1_line_size : 8,
 172                L1_tag_lines : 8,
 173                L1_assoc     : 8,
 174                L1_size      : 8;
 175     } bits;
 176   };
 177 
 178   union ExtCpuid7Edx {
 179     uint32_t value;
 180     struct {
 181       uint32_t               : 8,
 182               tsc_invariance : 1,
 183                              : 23;
 184     } bits;
 185   };
 186 
 187   union ExtCpuid8Ecx {
 188     uint32_t value;
 189     struct {
 190       uint32_t cores_per_cpu : 8,
 191                              : 24;
 192     } bits;
 193   };
 194 
 195   union SefCpuid7Eax {
 196     uint32_t value;
 197   };
 198 
 199   union SefCpuid7Ebx {
 200     uint32_t value;
 201     struct {
 202       uint32_t fsgsbase : 1,
 203                         : 2,
 204                    bmi1 : 1,
 205                         : 1,
 206                    avx2 : 1,
 207                         : 2,
 208                    bmi2 : 1,
 209                    erms : 1,
 210                         : 1,
 211                    rtm  : 1,
 212                         : 20;
 213     } bits;
 214   };
 215 
 216   union XemXcr0Eax {
 217     uint32_t value;
 218     struct {
 219       uint32_t x87 : 1,
 220                sse : 1,
 221                ymm : 1,
 222                    : 29;
 223     } bits;
 224   };
 225 
 226 protected:
 227   static int _cpu;
 228   static int _model;
 229   static int _stepping;
 230   static int _cpuFeatures;     // features returned by the "cpuid" instruction
 231                                // 0 if this instruction is not available
 232   static const char* _features_str;
 233 
 234   static address   _cpuinfo_segv_addr; // address of instruction which causes SEGV
 235   static address   _cpuinfo_cont_addr; // address of instruction after the one which causes SEGV
 236 
 237   enum {
 238     CPU_CX8    = (1 << 0), // next bits are from cpuid 1 (EDX)
 239     CPU_CMOV   = (1 << 1),
 240     CPU_FXSR   = (1 << 2),
 241     CPU_HT     = (1 << 3),
 242     CPU_MMX    = (1 << 4),
 243     CPU_3DNOW_PREFETCH  = (1 << 5), // Processor supports 3dnow prefetch and prefetchw instructions
 244                                     // may not necessarily support other 3dnow instructions
 245     CPU_SSE    = (1 << 6),
 246     CPU_SSE2   = (1 << 7),
 247     CPU_SSE3   = (1 << 8), // SSE3 comes from cpuid 1 (ECX)
 248     CPU_SSSE3  = (1 << 9),
 249     CPU_SSE4A  = (1 << 10),
 250     CPU_SSE4_1 = (1 << 11),
 251     CPU_SSE4_2 = (1 << 12),
 252     CPU_POPCNT = (1 << 13),
 253     CPU_LZCNT  = (1 << 14),
 254     CPU_TSC    = (1 << 15),
 255     CPU_TSCINV = (1 << 16),
 256     CPU_AVX    = (1 << 17),
 257     CPU_AVX2   = (1 << 18),
 258     CPU_AES    = (1 << 19),
 259     CPU_ERMS   = (1 << 20), // enhanced 'rep movsb/stosb' instructions
 260     CPU_CLMUL  = (1 << 21), // carryless multiply for CRC
 261     CPU_BMI1   = (1 << 22),
 262     CPU_BMI2   = (1 << 23),
 263     CPU_RTM    = (1 << 24)  // Restricted Transactional Memory instructions
 264   } cpuFeatureFlags;
 265 
 266   enum {
 267     // AMD
 268     CPU_FAMILY_AMD_11H       = 0x11,
 269     // Intel
 270     CPU_FAMILY_INTEL_CORE    = 6,
 271     CPU_MODEL_NEHALEM        = 0x1e,
 272     CPU_MODEL_NEHALEM_EP     = 0x1a,
 273     CPU_MODEL_NEHALEM_EX     = 0x2e,
 274     CPU_MODEL_WESTMERE       = 0x25,
 275     CPU_MODEL_WESTMERE_EP    = 0x2c,
 276     CPU_MODEL_WESTMERE_EX    = 0x2f,
 277     CPU_MODEL_SANDYBRIDGE    = 0x2a,
 278     CPU_MODEL_SANDYBRIDGE_EP = 0x2d,
 279     CPU_MODEL_IVYBRIDGE_EP   = 0x3a
 280   } cpuExtendedFamily;
 281 
 282   // cpuid information block.  All info derived from executing cpuid with
 283   // various function numbers is stored here.  Intel and AMD info is
 284   // merged in this block: accessor methods disentangle it.
 285   //
 286   // The info block is laid out in subblocks of 4 dwords corresponding to
 287   // eax, ebx, ecx and edx, whether or not they contain anything useful.
 288   struct CpuidInfo {
 289     // cpuid function 0
 290     uint32_t std_max_function;
 291     uint32_t std_vendor_name_0;
 292     uint32_t std_vendor_name_1;
 293     uint32_t std_vendor_name_2;
 294 
 295     // cpuid function 1
 296     StdCpuid1Eax std_cpuid1_eax;
 297     StdCpuid1Ebx std_cpuid1_ebx;
 298     StdCpuid1Ecx std_cpuid1_ecx;
 299     StdCpuid1Edx std_cpuid1_edx;
 300 
 301     // cpuid function 4 (deterministic cache parameters)
 302     DcpCpuid4Eax dcp_cpuid4_eax;
 303     DcpCpuid4Ebx dcp_cpuid4_ebx;
 304     uint32_t     dcp_cpuid4_ecx; // unused currently
 305     uint32_t     dcp_cpuid4_edx; // unused currently
 306 
 307     // cpuid function 7 (structured extended features)
 308     SefCpuid7Eax sef_cpuid7_eax;
 309     SefCpuid7Ebx sef_cpuid7_ebx;
 310     uint32_t     sef_cpuid7_ecx; // unused currently
 311     uint32_t     sef_cpuid7_edx; // unused currently
 312 
 313     // cpuid function 0xB (processor topology)
 314     // ecx = 0
 315     uint32_t     tpl_cpuidB0_eax;
 316     TplCpuidBEbx tpl_cpuidB0_ebx;
 317     uint32_t     tpl_cpuidB0_ecx; // unused currently
 318     uint32_t     tpl_cpuidB0_edx; // unused currently
 319 
 320     // ecx = 1
 321     uint32_t     tpl_cpuidB1_eax;
 322     TplCpuidBEbx tpl_cpuidB1_ebx;
 323     uint32_t     tpl_cpuidB1_ecx; // unused currently
 324     uint32_t     tpl_cpuidB1_edx; // unused currently
 325 
 326     // ecx = 2
 327     uint32_t     tpl_cpuidB2_eax;
 328     TplCpuidBEbx tpl_cpuidB2_ebx;
 329     uint32_t     tpl_cpuidB2_ecx; // unused currently
 330     uint32_t     tpl_cpuidB2_edx; // unused currently
 331 
 332     // cpuid function 0x80000000 // example, unused
 333     uint32_t ext_max_function;
 334     uint32_t ext_vendor_name_0;
 335     uint32_t ext_vendor_name_1;
 336     uint32_t ext_vendor_name_2;
 337 
 338     // cpuid function 0x80000001
 339     uint32_t     ext_cpuid1_eax; // reserved
 340     uint32_t     ext_cpuid1_ebx; // reserved
 341     ExtCpuid1Ecx ext_cpuid1_ecx;
 342     ExtCpuid1Edx ext_cpuid1_edx;
 343 
 344     // cpuid functions 0x80000002 thru 0x80000004: example, unused
 345     uint32_t proc_name_0, proc_name_1, proc_name_2, proc_name_3;
 346     uint32_t proc_name_4, proc_name_5, proc_name_6, proc_name_7;
 347     uint32_t proc_name_8, proc_name_9, proc_name_10,proc_name_11;
 348 
 349     // cpuid function 0x80000005 // AMD L1, Intel reserved
 350     uint32_t     ext_cpuid5_eax; // unused currently
 351     uint32_t     ext_cpuid5_ebx; // reserved
 352     ExtCpuid5Ex  ext_cpuid5_ecx; // L1 data cache info (AMD)
 353     ExtCpuid5Ex  ext_cpuid5_edx; // L1 instruction cache info (AMD)
 354 
 355     // cpuid function 0x80000007
 356     uint32_t     ext_cpuid7_eax; // reserved
 357     uint32_t     ext_cpuid7_ebx; // reserved
 358     uint32_t     ext_cpuid7_ecx; // reserved
 359     ExtCpuid7Edx ext_cpuid7_edx; // tscinv
 360 
 361     // cpuid function 0x80000008
 362     uint32_t     ext_cpuid8_eax; // unused currently
 363     uint32_t     ext_cpuid8_ebx; // reserved
 364     ExtCpuid8Ecx ext_cpuid8_ecx;
 365     uint32_t     ext_cpuid8_edx; // reserved
 366 
 367     // extended control register XCR0 (the XFEATURE_ENABLED_MASK register)
 368     XemXcr0Eax   xem_xcr0_eax;
 369     uint32_t     xem_xcr0_edx; // reserved
 370 
 371     // Space to save ymm registers after signal handle
 372     int          ymm_save[8*4]; // Save ymm0, ymm7, ymm8, ymm15
 373   };
 374 
 375   // The actual cpuid info block
 376   static CpuidInfo _cpuid_info;
 377 
 378   // Extractors and predicates
 379   static uint32_t extended_cpu_family() {
 380     uint32_t result = _cpuid_info.std_cpuid1_eax.bits.family;
 381     result += _cpuid_info.std_cpuid1_eax.bits.ext_family;
 382     return result;
 383   }
 384 
 385   static uint32_t extended_cpu_model() {
 386     uint32_t result = _cpuid_info.std_cpuid1_eax.bits.model;
 387     result |= _cpuid_info.std_cpuid1_eax.bits.ext_model << 4;
 388     return result;
 389   }
 390 
 391   static uint32_t cpu_stepping() {
 392     uint32_t result = _cpuid_info.std_cpuid1_eax.bits.stepping;
 393     return result;
 394   }
 395 
 396   static uint logical_processor_count() {
 397     uint result = threads_per_core();
 398     return result;
 399   }
 400 
 401   static uint32_t feature_flags() {
 402     uint32_t result = 0;
 403     if (_cpuid_info.std_cpuid1_edx.bits.cmpxchg8 != 0)
 404       result |= CPU_CX8;
 405     if (_cpuid_info.std_cpuid1_edx.bits.cmov != 0)
 406       result |= CPU_CMOV;
 407     if (_cpuid_info.std_cpuid1_edx.bits.fxsr != 0 || (is_amd() &&
 408         _cpuid_info.ext_cpuid1_edx.bits.fxsr != 0))
 409       result |= CPU_FXSR;
 410     // HT flag is set for multi-core processors also.
 411     if (threads_per_core() > 1)
 412       result |= CPU_HT;
 413     if (_cpuid_info.std_cpuid1_edx.bits.mmx != 0 || (is_amd() &&
 414         _cpuid_info.ext_cpuid1_edx.bits.mmx != 0))
 415       result |= CPU_MMX;
 416     if (_cpuid_info.std_cpuid1_edx.bits.sse != 0)
 417       result |= CPU_SSE;
 418     if (_cpuid_info.std_cpuid1_edx.bits.sse2 != 0)
 419       result |= CPU_SSE2;
 420     if (_cpuid_info.std_cpuid1_ecx.bits.sse3 != 0)
 421       result |= CPU_SSE3;
 422     if (_cpuid_info.std_cpuid1_ecx.bits.ssse3 != 0)
 423       result |= CPU_SSSE3;
 424     if (_cpuid_info.std_cpuid1_ecx.bits.sse4_1 != 0)
 425       result |= CPU_SSE4_1;
 426     if (_cpuid_info.std_cpuid1_ecx.bits.sse4_2 != 0)
 427       result |= CPU_SSE4_2;
 428     if (_cpuid_info.std_cpuid1_ecx.bits.popcnt != 0)
 429       result |= CPU_POPCNT;
 430     if (_cpuid_info.std_cpuid1_ecx.bits.avx != 0 &&
 431         _cpuid_info.std_cpuid1_ecx.bits.osxsave != 0 &&
 432         _cpuid_info.xem_xcr0_eax.bits.sse != 0 &&
 433         _cpuid_info.xem_xcr0_eax.bits.ymm != 0) {
 434       result |= CPU_AVX;
 435       if (_cpuid_info.sef_cpuid7_ebx.bits.avx2 != 0)
 436         result |= CPU_AVX2;
 437     }
 438     if(_cpuid_info.sef_cpuid7_ebx.bits.bmi1 != 0)
 439       result |= CPU_BMI1;
 440     if (_cpuid_info.std_cpuid1_edx.bits.tsc != 0)
 441       result |= CPU_TSC;
 442     if (_cpuid_info.ext_cpuid7_edx.bits.tsc_invariance != 0)
 443       result |= CPU_TSCINV;
 444     if (_cpuid_info.std_cpuid1_ecx.bits.aes != 0)
 445       result |= CPU_AES;
 446     if (_cpuid_info.sef_cpuid7_ebx.bits.erms != 0)
 447       result |= CPU_ERMS;
 448     if (_cpuid_info.std_cpuid1_ecx.bits.clmul != 0)
 449       result |= CPU_CLMUL;
 450     if (_cpuid_info.sef_cpuid7_ebx.bits.rtm != 0)
 451       result |= CPU_RTM;
 452 
 453     // AMD features.
 454     if (is_amd()) {
 455       if ((_cpuid_info.ext_cpuid1_edx.bits.tdnow != 0) ||
 456           (_cpuid_info.ext_cpuid1_ecx.bits.prefetchw != 0))
 457         result |= CPU_3DNOW_PREFETCH;
 458       if (_cpuid_info.ext_cpuid1_ecx.bits.lzcnt != 0)
 459         result |= CPU_LZCNT;
 460       if (_cpuid_info.ext_cpuid1_ecx.bits.sse4a != 0)
 461         result |= CPU_SSE4A;
 462     }
 463     // Intel features.
 464     if(is_intel()) {
 465       if(_cpuid_info.sef_cpuid7_ebx.bits.bmi2 != 0)
 466         result |= CPU_BMI2;
 467       if(_cpuid_info.ext_cpuid1_ecx.bits.lzcnt_intel != 0)
 468         result |= CPU_LZCNT;
 469     }
 470 
 471     return result;
 472   }
 473 
 474   static bool os_supports_avx_vectors() {
 475     if (!supports_avx()) {
 476       return false;
 477     }
 478     // Verify that OS save/restore all bits of AVX registers
 479     // during signal processing.
 480     int nreg = 2 LP64_ONLY(+2);
 481     for (int i = 0; i < 8 * nreg; i++) { // 32 bytes per ymm register
 482       if (_cpuid_info.ymm_save[i] != ymm_test_value()) {
 483         return false;
 484       }
 485     }
 486     return true;
 487   }
 488 
 489   static void get_processor_features();
 490 
 491 public:
 492   // Offsets for cpuid asm stub
 493   static ByteSize std_cpuid0_offset() { return byte_offset_of(CpuidInfo, std_max_function); }
 494   static ByteSize std_cpuid1_offset() { return byte_offset_of(CpuidInfo, std_cpuid1_eax); }
 495   static ByteSize dcp_cpuid4_offset() { return byte_offset_of(CpuidInfo, dcp_cpuid4_eax); }
 496   static ByteSize sef_cpuid7_offset() { return byte_offset_of(CpuidInfo, sef_cpuid7_eax); }
 497   static ByteSize ext_cpuid1_offset() { return byte_offset_of(CpuidInfo, ext_cpuid1_eax); }
 498   static ByteSize ext_cpuid5_offset() { return byte_offset_of(CpuidInfo, ext_cpuid5_eax); }
 499   static ByteSize ext_cpuid7_offset() { return byte_offset_of(CpuidInfo, ext_cpuid7_eax); }
 500   static ByteSize ext_cpuid8_offset() { return byte_offset_of(CpuidInfo, ext_cpuid8_eax); }
 501   static ByteSize tpl_cpuidB0_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB0_eax); }
 502   static ByteSize tpl_cpuidB1_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB1_eax); }
 503   static ByteSize tpl_cpuidB2_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB2_eax); }
 504   static ByteSize xem_xcr0_offset() { return byte_offset_of(CpuidInfo, xem_xcr0_eax); }
 505   static ByteSize ymm_save_offset() { return byte_offset_of(CpuidInfo, ymm_save); }
 506 
 507   // The value used to check ymm register after signal handle
 508   static int ymm_test_value()    { return 0xCAFEBABE; }
 509 
 510   static void set_cpuinfo_segv_addr(address pc) { _cpuinfo_segv_addr = pc; }
 511   static bool  is_cpuinfo_segv_addr(address pc) { return _cpuinfo_segv_addr == pc; }
 512   static void set_cpuinfo_cont_addr(address pc) { _cpuinfo_cont_addr = pc; }
 513   static address  cpuinfo_cont_addr()           { return _cpuinfo_cont_addr; }
 514 
 515   static void clean_cpuFeatures()   { _cpuFeatures = 0; }
 516   static void set_avx_cpuFeatures() { _cpuFeatures = (CPU_SSE | CPU_SSE2 | CPU_AVX); }
 517 
 518 
 519   // Initialization
 520   static void initialize();
 521 
 522   // Override Abstract_VM_Version implementation
 523   static bool use_biased_locking();
 524 
 525   // Asserts
 526   static void assert_is_initialized() {
 527     assert(_cpuid_info.std_cpuid1_eax.bits.family != 0, "VM_Version not initialized");
 528   }
 529 
 530   //
 531   // Processor family:
 532   //       3   -  386
 533   //       4   -  486
 534   //       5   -  Pentium
 535   //       6   -  PentiumPro, Pentium II, Celeron, Xeon, Pentium III, Athlon,
 536   //              Pentium M, Core Solo, Core Duo, Core2 Duo
 537   //    family 6 model:   9,        13,       14,        15
 538   //    0x0f   -  Pentium 4, Opteron
 539   //
 540   // Note: The cpu family should be used to select between
 541   //       instruction sequences which are valid on all Intel
 542   //       processors.  Use the feature test functions below to
 543   //       determine whether a particular instruction is supported.
 544   //
 545   static int  cpu_family()        { return _cpu;}
 546   static bool is_P6()             { return cpu_family() >= 6; }
 547   static bool is_amd()            { assert_is_initialized(); return _cpuid_info.std_vendor_name_0 == 0x68747541; } // 'htuA'
 548   static bool is_intel()          { assert_is_initialized(); return _cpuid_info.std_vendor_name_0 == 0x756e6547; } // 'uneG'
 549 
 550   static bool supports_processor_topology() {
 551     return (_cpuid_info.std_max_function >= 0xB) &&
 552            // eax[4:0] | ebx[0:15] == 0 indicates invalid topology level.
 553            // Some cpus have max cpuid >= 0xB but do not support processor topology.
 554            (((_cpuid_info.tpl_cpuidB0_eax & 0x1f) | _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus) != 0);
 555   }
 556 
 557   static uint cores_per_cpu()  {
 558     uint result = 1;
 559     if (is_intel()) {
 560       if (supports_processor_topology()) {
 561         result = _cpuid_info.tpl_cpuidB1_ebx.bits.logical_cpus /
 562                  _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
 563       } else {
 564         result = (_cpuid_info.dcp_cpuid4_eax.bits.cores_per_cpu + 1);
 565       }
 566     } else if (is_amd()) {
 567       result = (_cpuid_info.ext_cpuid8_ecx.bits.cores_per_cpu + 1);
 568     }
 569     return result;
 570   }
 571 
 572   static uint threads_per_core()  {
 573     uint result = 1;
 574     if (is_intel() && supports_processor_topology()) {
 575       result = _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
 576     } else if (_cpuid_info.std_cpuid1_edx.bits.ht != 0) {
 577       result = _cpuid_info.std_cpuid1_ebx.bits.threads_per_cpu /
 578                cores_per_cpu();
 579     }
 580     return result;
 581   }
 582 
 583   static intx prefetch_data_size()  {
 584     intx result = 0;
 585     if (is_intel()) {
 586       result = (_cpuid_info.dcp_cpuid4_ebx.bits.L1_line_size + 1);
 587     } else if (is_amd()) {
 588       result = _cpuid_info.ext_cpuid5_ecx.bits.L1_line_size;
 589     }
 590     if (result < 32) // not defined ?
 591       result = 32;   // 32 bytes by default on x86 and other x64
 592     return result;
 593   }
 594 
 595   //
 596   // Feature identification
 597   //
 598   static bool supports_cpuid()    { return _cpuFeatures  != 0; }
 599   static bool supports_cmpxchg8() { return (_cpuFeatures & CPU_CX8) != 0; }
 600   static bool supports_cmov()     { return (_cpuFeatures & CPU_CMOV) != 0; }
 601   static bool supports_fxsr()     { return (_cpuFeatures & CPU_FXSR) != 0; }
 602   static bool supports_ht()       { return (_cpuFeatures & CPU_HT) != 0; }
 603   static bool supports_mmx()      { return (_cpuFeatures & CPU_MMX) != 0; }
 604   static bool supports_sse()      { return (_cpuFeatures & CPU_SSE) != 0; }
 605   static bool supports_sse2()     { return (_cpuFeatures & CPU_SSE2) != 0; }
 606   static bool supports_sse3()     { return (_cpuFeatures & CPU_SSE3) != 0; }
 607   static bool supports_ssse3()    { return (_cpuFeatures & CPU_SSSE3)!= 0; }
 608   static bool supports_sse4_1()   { return (_cpuFeatures & CPU_SSE4_1) != 0; }
 609   static bool supports_sse4_2()   { return (_cpuFeatures & CPU_SSE4_2) != 0; }
 610   static bool supports_popcnt()   { return (_cpuFeatures & CPU_POPCNT) != 0; }
 611   static bool supports_avx()      { return (_cpuFeatures & CPU_AVX) != 0; }
 612   static bool supports_avx2()     { return (_cpuFeatures & CPU_AVX2) != 0; }
 613   static bool supports_tsc()      { return (_cpuFeatures & CPU_TSC)    != 0; }
 614   static bool supports_aes()      { return (_cpuFeatures & CPU_AES) != 0; }
 615   static bool supports_erms()     { return (_cpuFeatures & CPU_ERMS) != 0; }
 616   static bool supports_clmul()    { return (_cpuFeatures & CPU_CLMUL) != 0; }
 617   static bool supports_rtm()      { return (_cpuFeatures & CPU_RTM) != 0; }
 618   static bool supports_bmi1()     { return (_cpuFeatures & CPU_BMI1) != 0; }
 619   static bool supports_bmi2()     { return (_cpuFeatures & CPU_BMI2) != 0; }
 620   // Intel features
 621   static bool is_intel_family_core() { return is_intel() &&
 622                                        extended_cpu_family() == CPU_FAMILY_INTEL_CORE; }
 623 
 624   static bool is_intel_tsc_synched_at_init()  {
 625     if (is_intel_family_core()) {
 626       uint32_t ext_model = extended_cpu_model();
 627       if (ext_model == CPU_MODEL_NEHALEM_EP     ||
 628           ext_model == CPU_MODEL_WESTMERE_EP    ||
 629           ext_model == CPU_MODEL_SANDYBRIDGE_EP ||
 630           ext_model == CPU_MODEL_IVYBRIDGE_EP) {
 631         // <= 2-socket invariant tsc support. EX versions are usually used
 632         // in > 2-socket systems and likely don't synchronize tscs at
 633         // initialization.
 634         // Code that uses tsc values must be prepared for them to arbitrarily
 635         // jump forward or backward.
 636         return true;
 637       }
 638     }
 639     return false;
 640   }
 641 
 642   // AMD features
 643   static bool supports_3dnow_prefetch()    { return (_cpuFeatures & CPU_3DNOW_PREFETCH) != 0; }
 644   static bool supports_mmx_ext()  { return is_amd() && _cpuid_info.ext_cpuid1_edx.bits.mmx_amd != 0; }
 645   static bool supports_lzcnt()    { return (_cpuFeatures & CPU_LZCNT) != 0; }
 646   static bool supports_sse4a()    { return (_cpuFeatures & CPU_SSE4A) != 0; }
 647 
 648   static bool is_amd_Barcelona()  { return is_amd() &&
 649                                            extended_cpu_family() == CPU_FAMILY_AMD_11H; }
 650 
 651   // Intel and AMD newer cores support fast timestamps well
 652   static bool supports_tscinv_bit() {
 653     return (_cpuFeatures & CPU_TSCINV) != 0;
 654   }
 655   static bool supports_tscinv() {
 656     return supports_tscinv_bit() &&
 657            ( (is_amd() && !is_amd_Barcelona()) ||
 658              is_intel_tsc_synched_at_init() );
 659   }
 660 
 661   // Intel Core and newer cpus have fast IDIV instruction (excluding Atom).
 662   static bool has_fast_idiv()     { return is_intel() && cpu_family() == 6 &&
 663                                            supports_sse3() && _model != 0x1C; }
 664 
 665   static bool supports_compare_and_exchange() { return true; }
 666 
 667   static const char* cpu_features()           { return _features_str; }
 668 
 669   static intx allocate_prefetch_distance() {
 670     // This method should be called before allocate_prefetch_style().
 671     //
 672     // Hardware prefetching (distance/size in bytes):
 673     // Pentium 3 -  64 /  32
 674     // Pentium 4 - 256 / 128
 675     // Athlon    -  64 /  32 ????
 676     // Opteron   - 128 /  64 only when 2 sequential cache lines accessed
 677     // Core      - 128 /  64
 678     //
 679     // Software prefetching (distance in bytes / instruction with best score):
 680     // Pentium 3 - 128 / prefetchnta
 681     // Pentium 4 - 512 / prefetchnta
 682     // Athlon    - 128 / prefetchnta
 683     // Opteron   - 256 / prefetchnta
 684     // Core      - 256 / prefetchnta
 685     // It will be used only when AllocatePrefetchStyle > 0
 686 
 687     intx count = AllocatePrefetchDistance;
 688     if (count < 0) {   // default ?
 689       if (is_amd()) {  // AMD
 690         if (supports_sse2())
 691           count = 256; // Opteron
 692         else
 693           count = 128; // Athlon
 694       } else {         // Intel
 695         if (supports_sse2())
 696           if (cpu_family() == 6) {
 697             count = 256; // Pentium M, Core, Core2
 698           } else {
 699             count = 512; // Pentium 4
 700           }
 701         else
 702           count = 128; // Pentium 3 (and all other old CPUs)
 703       }
 704     }
 705     return count;
 706   }
 707   static intx allocate_prefetch_style() {
 708     assert(AllocatePrefetchStyle >= 0, "AllocatePrefetchStyle should be positive");
 709     // Return 0 if AllocatePrefetchDistance was not defined.
 710     return AllocatePrefetchDistance > 0 ? AllocatePrefetchStyle : 0;
 711   }
 712 
 713   // Prefetch interval for gc copy/scan == 9 dcache lines.  Derived from
 714   // 50-warehouse specjbb runs on a 2-way 1.8ghz opteron using a 4gb heap.
 715   // Tested intervals from 128 to 2048 in increments of 64 == one cache line.
 716   // 256 bytes (4 dcache lines) was the nearest runner-up to 576.
 717 
 718   // gc copy/scan is disabled if prefetchw isn't supported, because
 719   // Prefetch::write emits an inlined prefetchw on Linux.
 720   // Do not use the 3dnow prefetchw instruction.  It isn't supported on em64t.
 721   // The used prefetcht0 instruction works for both amd64 and em64t.
 722   static intx prefetch_copy_interval_in_bytes() {
 723     intx interval = PrefetchCopyIntervalInBytes;
 724     return interval >= 0 ? interval : 576;
 725   }
 726   static intx prefetch_scan_interval_in_bytes() {
 727     intx interval = PrefetchScanIntervalInBytes;
 728     return interval >= 0 ? interval : 576;
 729   }
 730   static intx prefetch_fields_ahead() {
 731     intx count = PrefetchFieldsAhead;
 732     return count >= 0 ? count : 1;
 733   }
 734 };
 735 
 736 #endif // CPU_X86_VM_VM_VERSION_X86_HPP