1 /*
   2  * Copyright (c) 1997, 2014, 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     CPU_MODEL_HASWELL_E3     = 0x3c,
 281     CPU_MODEL_HASWELL_E7     = 0x3f,
 282     CPU_MODEL_BROADWELL      = 0x3d
 283   } cpuExtendedFamily;
 284 
 285   // cpuid information block.  All info derived from executing cpuid with
 286   // various function numbers is stored here.  Intel and AMD info is
 287   // merged in this block: accessor methods disentangle it.
 288   //
 289   // The info block is laid out in subblocks of 4 dwords corresponding to
 290   // eax, ebx, ecx and edx, whether or not they contain anything useful.
 291   struct CpuidInfo {
 292     // cpuid function 0
 293     uint32_t std_max_function;
 294     uint32_t std_vendor_name_0;
 295     uint32_t std_vendor_name_1;
 296     uint32_t std_vendor_name_2;
 297 
 298     // cpuid function 1
 299     StdCpuid1Eax std_cpuid1_eax;
 300     StdCpuid1Ebx std_cpuid1_ebx;
 301     StdCpuid1Ecx std_cpuid1_ecx;
 302     StdCpuid1Edx std_cpuid1_edx;
 303 
 304     // cpuid function 4 (deterministic cache parameters)
 305     DcpCpuid4Eax dcp_cpuid4_eax;
 306     DcpCpuid4Ebx dcp_cpuid4_ebx;
 307     uint32_t     dcp_cpuid4_ecx; // unused currently
 308     uint32_t     dcp_cpuid4_edx; // unused currently
 309 
 310     // cpuid function 7 (structured extended features)
 311     SefCpuid7Eax sef_cpuid7_eax;
 312     SefCpuid7Ebx sef_cpuid7_ebx;
 313     uint32_t     sef_cpuid7_ecx; // unused currently
 314     uint32_t     sef_cpuid7_edx; // unused currently
 315 
 316     // cpuid function 0xB (processor topology)
 317     // ecx = 0
 318     uint32_t     tpl_cpuidB0_eax;
 319     TplCpuidBEbx tpl_cpuidB0_ebx;
 320     uint32_t     tpl_cpuidB0_ecx; // unused currently
 321     uint32_t     tpl_cpuidB0_edx; // unused currently
 322 
 323     // ecx = 1
 324     uint32_t     tpl_cpuidB1_eax;
 325     TplCpuidBEbx tpl_cpuidB1_ebx;
 326     uint32_t     tpl_cpuidB1_ecx; // unused currently
 327     uint32_t     tpl_cpuidB1_edx; // unused currently
 328 
 329     // ecx = 2
 330     uint32_t     tpl_cpuidB2_eax;
 331     TplCpuidBEbx tpl_cpuidB2_ebx;
 332     uint32_t     tpl_cpuidB2_ecx; // unused currently
 333     uint32_t     tpl_cpuidB2_edx; // unused currently
 334 
 335     // cpuid function 0x80000000 // example, unused
 336     uint32_t ext_max_function;
 337     uint32_t ext_vendor_name_0;
 338     uint32_t ext_vendor_name_1;
 339     uint32_t ext_vendor_name_2;
 340 
 341     // cpuid function 0x80000001
 342     uint32_t     ext_cpuid1_eax; // reserved
 343     uint32_t     ext_cpuid1_ebx; // reserved
 344     ExtCpuid1Ecx ext_cpuid1_ecx;
 345     ExtCpuid1Edx ext_cpuid1_edx;
 346 
 347     // cpuid functions 0x80000002 thru 0x80000004: example, unused
 348     uint32_t proc_name_0, proc_name_1, proc_name_2, proc_name_3;
 349     uint32_t proc_name_4, proc_name_5, proc_name_6, proc_name_7;
 350     uint32_t proc_name_8, proc_name_9, proc_name_10,proc_name_11;
 351 
 352     // cpuid function 0x80000005 // AMD L1, Intel reserved
 353     uint32_t     ext_cpuid5_eax; // unused currently
 354     uint32_t     ext_cpuid5_ebx; // reserved
 355     ExtCpuid5Ex  ext_cpuid5_ecx; // L1 data cache info (AMD)
 356     ExtCpuid5Ex  ext_cpuid5_edx; // L1 instruction cache info (AMD)
 357 
 358     // cpuid function 0x80000007
 359     uint32_t     ext_cpuid7_eax; // reserved
 360     uint32_t     ext_cpuid7_ebx; // reserved
 361     uint32_t     ext_cpuid7_ecx; // reserved
 362     ExtCpuid7Edx ext_cpuid7_edx; // tscinv
 363 
 364     // cpuid function 0x80000008
 365     uint32_t     ext_cpuid8_eax; // unused currently
 366     uint32_t     ext_cpuid8_ebx; // reserved
 367     ExtCpuid8Ecx ext_cpuid8_ecx;
 368     uint32_t     ext_cpuid8_edx; // reserved
 369 
 370     // extended control register XCR0 (the XFEATURE_ENABLED_MASK register)
 371     XemXcr0Eax   xem_xcr0_eax;
 372     uint32_t     xem_xcr0_edx; // reserved
 373 
 374     // Space to save ymm registers after signal handle
 375     int          ymm_save[8*4]; // Save ymm0, ymm7, ymm8, ymm15
 376   };
 377 
 378   // The actual cpuid info block
 379   static CpuidInfo _cpuid_info;
 380 
 381   // Extractors and predicates
 382   static uint32_t extended_cpu_family() {
 383     uint32_t result = _cpuid_info.std_cpuid1_eax.bits.family;
 384     result += _cpuid_info.std_cpuid1_eax.bits.ext_family;
 385     return result;
 386   }
 387 
 388   static uint32_t extended_cpu_model() {
 389     uint32_t result = _cpuid_info.std_cpuid1_eax.bits.model;
 390     result |= _cpuid_info.std_cpuid1_eax.bits.ext_model << 4;
 391     return result;
 392   }
 393 
 394   static uint32_t cpu_stepping() {
 395     uint32_t result = _cpuid_info.std_cpuid1_eax.bits.stepping;
 396     return result;
 397   }
 398 
 399   static uint logical_processor_count() {
 400     uint result = threads_per_core();
 401     return result;
 402   }
 403 
 404   static uint32_t feature_flags() {
 405     uint32_t result = 0;
 406     if (_cpuid_info.std_cpuid1_edx.bits.cmpxchg8 != 0)
 407       result |= CPU_CX8;
 408     if (_cpuid_info.std_cpuid1_edx.bits.cmov != 0)
 409       result |= CPU_CMOV;
 410     if (_cpuid_info.std_cpuid1_edx.bits.fxsr != 0 || (is_amd() &&
 411         _cpuid_info.ext_cpuid1_edx.bits.fxsr != 0))
 412       result |= CPU_FXSR;
 413     // HT flag is set for multi-core processors also.
 414     if (threads_per_core() > 1)
 415       result |= CPU_HT;
 416     if (_cpuid_info.std_cpuid1_edx.bits.mmx != 0 || (is_amd() &&
 417         _cpuid_info.ext_cpuid1_edx.bits.mmx != 0))
 418       result |= CPU_MMX;
 419     if (_cpuid_info.std_cpuid1_edx.bits.sse != 0)
 420       result |= CPU_SSE;
 421     if (_cpuid_info.std_cpuid1_edx.bits.sse2 != 0)
 422       result |= CPU_SSE2;
 423     if (_cpuid_info.std_cpuid1_ecx.bits.sse3 != 0)
 424       result |= CPU_SSE3;
 425     if (_cpuid_info.std_cpuid1_ecx.bits.ssse3 != 0)
 426       result |= CPU_SSSE3;
 427     if (_cpuid_info.std_cpuid1_ecx.bits.sse4_1 != 0)
 428       result |= CPU_SSE4_1;
 429     if (_cpuid_info.std_cpuid1_ecx.bits.sse4_2 != 0)
 430       result |= CPU_SSE4_2;
 431     if (_cpuid_info.std_cpuid1_ecx.bits.popcnt != 0)
 432       result |= CPU_POPCNT;
 433     if (_cpuid_info.std_cpuid1_ecx.bits.avx != 0 &&
 434         _cpuid_info.std_cpuid1_ecx.bits.osxsave != 0 &&
 435         _cpuid_info.xem_xcr0_eax.bits.sse != 0 &&
 436         _cpuid_info.xem_xcr0_eax.bits.ymm != 0) {
 437       result |= CPU_AVX;
 438       if (_cpuid_info.sef_cpuid7_ebx.bits.avx2 != 0)
 439         result |= CPU_AVX2;
 440     }
 441     if(_cpuid_info.sef_cpuid7_ebx.bits.bmi1 != 0)
 442       result |= CPU_BMI1;
 443     if (_cpuid_info.std_cpuid1_edx.bits.tsc != 0)
 444       result |= CPU_TSC;
 445     if (_cpuid_info.ext_cpuid7_edx.bits.tsc_invariance != 0)
 446       result |= CPU_TSCINV;
 447     if (_cpuid_info.std_cpuid1_ecx.bits.aes != 0)
 448       result |= CPU_AES;
 449     if (_cpuid_info.sef_cpuid7_ebx.bits.erms != 0)
 450       result |= CPU_ERMS;
 451     if (_cpuid_info.std_cpuid1_ecx.bits.clmul != 0)
 452       result |= CPU_CLMUL;
 453     if (_cpuid_info.sef_cpuid7_ebx.bits.rtm != 0)
 454       result |= CPU_RTM;
 455 
 456     // AMD features.
 457     if (is_amd()) {
 458       if ((_cpuid_info.ext_cpuid1_edx.bits.tdnow != 0) ||
 459           (_cpuid_info.ext_cpuid1_ecx.bits.prefetchw != 0))
 460         result |= CPU_3DNOW_PREFETCH;
 461       if (_cpuid_info.ext_cpuid1_ecx.bits.lzcnt != 0)
 462         result |= CPU_LZCNT;
 463       if (_cpuid_info.ext_cpuid1_ecx.bits.sse4a != 0)
 464         result |= CPU_SSE4A;
 465     }
 466     // Intel features.
 467     if(is_intel()) {
 468       if(_cpuid_info.sef_cpuid7_ebx.bits.bmi2 != 0)
 469         result |= CPU_BMI2;
 470       if(_cpuid_info.ext_cpuid1_ecx.bits.lzcnt_intel != 0)
 471         result |= CPU_LZCNT;
 472     }
 473 
 474     return result;
 475   }
 476 
 477   static bool os_supports_avx_vectors() {
 478     if (!supports_avx()) {
 479       return false;
 480     }
 481     // Verify that OS save/restore all bits of AVX registers
 482     // during signal processing.
 483     int nreg = 2 LP64_ONLY(+2);
 484     for (int i = 0; i < 8 * nreg; i++) { // 32 bytes per ymm register
 485       if (_cpuid_info.ymm_save[i] != ymm_test_value()) {
 486         return false;
 487       }
 488     }
 489     return true;
 490   }
 491 
 492   static void get_processor_features();
 493 
 494 public:
 495   // Offsets for cpuid asm stub
 496   static ByteSize std_cpuid0_offset() { return byte_offset_of(CpuidInfo, std_max_function); }
 497   static ByteSize std_cpuid1_offset() { return byte_offset_of(CpuidInfo, std_cpuid1_eax); }
 498   static ByteSize dcp_cpuid4_offset() { return byte_offset_of(CpuidInfo, dcp_cpuid4_eax); }
 499   static ByteSize sef_cpuid7_offset() { return byte_offset_of(CpuidInfo, sef_cpuid7_eax); }
 500   static ByteSize ext_cpuid1_offset() { return byte_offset_of(CpuidInfo, ext_cpuid1_eax); }
 501   static ByteSize ext_cpuid5_offset() { return byte_offset_of(CpuidInfo, ext_cpuid5_eax); }
 502   static ByteSize ext_cpuid7_offset() { return byte_offset_of(CpuidInfo, ext_cpuid7_eax); }
 503   static ByteSize ext_cpuid8_offset() { return byte_offset_of(CpuidInfo, ext_cpuid8_eax); }
 504   static ByteSize tpl_cpuidB0_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB0_eax); }
 505   static ByteSize tpl_cpuidB1_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB1_eax); }
 506   static ByteSize tpl_cpuidB2_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB2_eax); }
 507   static ByteSize xem_xcr0_offset() { return byte_offset_of(CpuidInfo, xem_xcr0_eax); }
 508   static ByteSize ymm_save_offset() { return byte_offset_of(CpuidInfo, ymm_save); }
 509 
 510   // The value used to check ymm register after signal handle
 511   static int ymm_test_value()    { return 0xCAFEBABE; }
 512 
 513   static void get_cpu_info_wrapper();
 514   static void set_cpuinfo_segv_addr(address pc) { _cpuinfo_segv_addr = pc; }
 515   static bool  is_cpuinfo_segv_addr(address pc) { return _cpuinfo_segv_addr == pc; }
 516   static void set_cpuinfo_cont_addr(address pc) { _cpuinfo_cont_addr = pc; }
 517   static address  cpuinfo_cont_addr()           { return _cpuinfo_cont_addr; }
 518 
 519   static void clean_cpuFeatures()   { _cpuFeatures = 0; }
 520   static void set_avx_cpuFeatures() { _cpuFeatures = (CPU_SSE | CPU_SSE2 | CPU_AVX); }
 521 
 522 
 523   // Initialization
 524   static void initialize();
 525 
 526   // Override Abstract_VM_Version implementation
 527   static bool use_biased_locking();
 528 
 529   // Asserts
 530   static void assert_is_initialized() {
 531     assert(_cpuid_info.std_cpuid1_eax.bits.family != 0, "VM_Version not initialized");
 532   }
 533 
 534   //
 535   // Processor family:
 536   //       3   -  386
 537   //       4   -  486
 538   //       5   -  Pentium
 539   //       6   -  PentiumPro, Pentium II, Celeron, Xeon, Pentium III, Athlon,
 540   //              Pentium M, Core Solo, Core Duo, Core2 Duo
 541   //    family 6 model:   9,        13,       14,        15
 542   //    0x0f   -  Pentium 4, Opteron
 543   //
 544   // Note: The cpu family should be used to select between
 545   //       instruction sequences which are valid on all Intel
 546   //       processors.  Use the feature test functions below to
 547   //       determine whether a particular instruction is supported.
 548   //
 549   static int  cpu_family()        { return _cpu;}
 550   static bool is_P6()             { return cpu_family() >= 6; }
 551   static bool is_amd()            { assert_is_initialized(); return _cpuid_info.std_vendor_name_0 == 0x68747541; } // 'htuA'
 552   static bool is_intel()          { assert_is_initialized(); return _cpuid_info.std_vendor_name_0 == 0x756e6547; } // 'uneG'
 553 
 554   static bool supports_processor_topology() {
 555     return (_cpuid_info.std_max_function >= 0xB) &&
 556            // eax[4:0] | ebx[0:15] == 0 indicates invalid topology level.
 557            // Some cpus have max cpuid >= 0xB but do not support processor topology.
 558            (((_cpuid_info.tpl_cpuidB0_eax & 0x1f) | _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus) != 0);
 559   }
 560 
 561   static uint cores_per_cpu()  {
 562     uint result = 1;
 563     if (is_intel()) {
 564       if (supports_processor_topology()) {
 565         result = _cpuid_info.tpl_cpuidB1_ebx.bits.logical_cpus /
 566                  _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
 567       } else {
 568         result = (_cpuid_info.dcp_cpuid4_eax.bits.cores_per_cpu + 1);
 569       }
 570     } else if (is_amd()) {
 571       result = (_cpuid_info.ext_cpuid8_ecx.bits.cores_per_cpu + 1);
 572     }
 573     return result;
 574   }
 575 
 576   static uint threads_per_core()  {
 577     uint result = 1;
 578     if (is_intel() && supports_processor_topology()) {
 579       result = _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
 580     } else if (_cpuid_info.std_cpuid1_edx.bits.ht != 0) {
 581       result = _cpuid_info.std_cpuid1_ebx.bits.threads_per_cpu /
 582                cores_per_cpu();
 583     }
 584     return result;
 585   }
 586 
 587   static intx L1_line_size()  {
 588     intx result = 0;
 589     if (is_intel()) {
 590       result = (_cpuid_info.dcp_cpuid4_ebx.bits.L1_line_size + 1);
 591     } else if (is_amd()) {
 592       result = _cpuid_info.ext_cpuid5_ecx.bits.L1_line_size;
 593     }
 594     if (result < 32) // not defined ?
 595       result = 32;   // 32 bytes by default on x86 and other x64
 596     return result;
 597   }
 598 
 599   static intx prefetch_data_size()  {
 600     return L1_line_size();
 601   }
 602 
 603   //
 604   // Feature identification
 605   //
 606   static bool supports_cpuid()    { return _cpuFeatures  != 0; }
 607   static bool supports_cmpxchg8() { return (_cpuFeatures & CPU_CX8) != 0; }
 608   static bool supports_cmov()     { return (_cpuFeatures & CPU_CMOV) != 0; }
 609   static bool supports_fxsr()     { return (_cpuFeatures & CPU_FXSR) != 0; }
 610   static bool supports_ht()       { return (_cpuFeatures & CPU_HT) != 0; }
 611   static bool supports_mmx()      { return (_cpuFeatures & CPU_MMX) != 0; }
 612   static bool supports_sse()      { return (_cpuFeatures & CPU_SSE) != 0; }
 613   static bool supports_sse2()     { return (_cpuFeatures & CPU_SSE2) != 0; }
 614   static bool supports_sse3()     { return (_cpuFeatures & CPU_SSE3) != 0; }
 615   static bool supports_ssse3()    { return (_cpuFeatures & CPU_SSSE3)!= 0; }
 616   static bool supports_sse4_1()   { return (_cpuFeatures & CPU_SSE4_1) != 0; }
 617   static bool supports_sse4_2()   { return (_cpuFeatures & CPU_SSE4_2) != 0; }
 618   static bool supports_popcnt()   { return (_cpuFeatures & CPU_POPCNT) != 0; }
 619   static bool supports_avx()      { return (_cpuFeatures & CPU_AVX) != 0; }
 620   static bool supports_avx2()     { return (_cpuFeatures & CPU_AVX2) != 0; }
 621   static bool supports_tsc()      { return (_cpuFeatures & CPU_TSC)    != 0; }
 622   static bool supports_aes()      { return (_cpuFeatures & CPU_AES) != 0; }
 623   static bool supports_erms()     { return (_cpuFeatures & CPU_ERMS) != 0; }
 624   static bool supports_clmul()    { return (_cpuFeatures & CPU_CLMUL) != 0; }
 625   static bool supports_rtm()      { return (_cpuFeatures & CPU_RTM) != 0; }
 626   static bool supports_bmi1()     { return (_cpuFeatures & CPU_BMI1) != 0; }
 627   static bool supports_bmi2()     { return (_cpuFeatures & CPU_BMI2) != 0; }
 628   // Intel features
 629   static bool is_intel_family_core() { return is_intel() &&
 630                                        extended_cpu_family() == CPU_FAMILY_INTEL_CORE; }
 631 
 632   static bool is_intel_tsc_synched_at_init()  {
 633     if (is_intel_family_core()) {
 634       uint32_t ext_model = extended_cpu_model();
 635       if (ext_model == CPU_MODEL_NEHALEM_EP     ||
 636           ext_model == CPU_MODEL_WESTMERE_EP    ||
 637           ext_model == CPU_MODEL_SANDYBRIDGE_EP ||
 638           ext_model == CPU_MODEL_IVYBRIDGE_EP) {
 639         // <= 2-socket invariant tsc support. EX versions are usually used
 640         // in > 2-socket systems and likely don't synchronize tscs at
 641         // initialization.
 642         // Code that uses tsc values must be prepared for them to arbitrarily
 643         // jump forward or backward.
 644         return true;
 645       }
 646     }
 647     return false;
 648   }
 649 
 650   // AMD features
 651   static bool supports_3dnow_prefetch()    { return (_cpuFeatures & CPU_3DNOW_PREFETCH) != 0; }
 652   static bool supports_mmx_ext()  { return is_amd() && _cpuid_info.ext_cpuid1_edx.bits.mmx_amd != 0; }
 653   static bool supports_lzcnt()    { return (_cpuFeatures & CPU_LZCNT) != 0; }
 654   static bool supports_sse4a()    { return (_cpuFeatures & CPU_SSE4A) != 0; }
 655 
 656   static bool is_amd_Barcelona()  { return is_amd() &&
 657                                            extended_cpu_family() == CPU_FAMILY_AMD_11H; }
 658 
 659   // Intel and AMD newer cores support fast timestamps well
 660   static bool supports_tscinv_bit() {
 661     return (_cpuFeatures & CPU_TSCINV) != 0;
 662   }
 663   static bool supports_tscinv() {
 664     return supports_tscinv_bit() &&
 665            ( (is_amd() && !is_amd_Barcelona()) ||
 666              is_intel_tsc_synched_at_init() );
 667   }
 668 
 669   // Intel Core and newer cpus have fast IDIV instruction (excluding Atom).
 670   static bool has_fast_idiv()     { return is_intel() && cpu_family() == 6 &&
 671                                            supports_sse3() && _model != 0x1C; }
 672 
 673   static bool supports_compare_and_exchange() { return true; }
 674 
 675   static const char* cpu_features()           { return _features_str; }
 676 
 677   static intx allocate_prefetch_distance() {
 678     // This method should be called before allocate_prefetch_style().
 679     //
 680     // Hardware prefetching (distance/size in bytes):
 681     // Pentium 3 -  64 /  32
 682     // Pentium 4 - 256 / 128
 683     // Athlon    -  64 /  32 ????
 684     // Opteron   - 128 /  64 only when 2 sequential cache lines accessed
 685     // Core      - 128 /  64
 686     //
 687     // Software prefetching (distance in bytes / instruction with best score):
 688     // Pentium 3 - 128 / prefetchnta
 689     // Pentium 4 - 512 / prefetchnta
 690     // Athlon    - 128 / prefetchnta
 691     // Opteron   - 256 / prefetchnta
 692     // Core      - 256 / prefetchnta
 693     // It will be used only when AllocatePrefetchStyle > 0
 694 
 695     intx count = AllocatePrefetchDistance;
 696     if (count < 0) {   // default ?
 697       if (is_amd()) {  // AMD
 698         if (supports_sse2())
 699           count = 256; // Opteron
 700         else
 701           count = 128; // Athlon
 702       } else {         // Intel
 703         if (supports_sse2())
 704           if (cpu_family() == 6) {
 705             count = 256; // Pentium M, Core, Core2
 706           } else {
 707             count = 512; // Pentium 4
 708           }
 709         else
 710           count = 128; // Pentium 3 (and all other old CPUs)
 711       }
 712     }
 713     return count;
 714   }
 715   static intx allocate_prefetch_style() {
 716     assert(AllocatePrefetchStyle >= 0, "AllocatePrefetchStyle should be positive");
 717     // Return 0 if AllocatePrefetchDistance was not defined.
 718     return AllocatePrefetchDistance > 0 ? AllocatePrefetchStyle : 0;
 719   }
 720 
 721   // Prefetch interval for gc copy/scan == 9 dcache lines.  Derived from
 722   // 50-warehouse specjbb runs on a 2-way 1.8ghz opteron using a 4gb heap.
 723   // Tested intervals from 128 to 2048 in increments of 64 == one cache line.
 724   // 256 bytes (4 dcache lines) was the nearest runner-up to 576.
 725 
 726   // gc copy/scan is disabled if prefetchw isn't supported, because
 727   // Prefetch::write emits an inlined prefetchw on Linux.
 728   // Do not use the 3dnow prefetchw instruction.  It isn't supported on em64t.
 729   // The used prefetcht0 instruction works for both amd64 and em64t.
 730   static intx prefetch_copy_interval_in_bytes() {
 731     intx interval = PrefetchCopyIntervalInBytes;
 732     return interval >= 0 ? interval : 576;
 733   }
 734   static intx prefetch_scan_interval_in_bytes() {
 735     intx interval = PrefetchScanIntervalInBytes;
 736     return interval >= 0 ? interval : 576;
 737   }
 738   static intx prefetch_fields_ahead() {
 739     intx count = PrefetchFieldsAhead;
 740     return count >= 0 ? count : 1;
 741   }
 742 };
 743 
 744 #endif // CPU_X86_VM_VM_VERSION_X86_HPP