1 /*
   2  * Copyright (c) 1997, 2026, 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 "asm/macroAssembler.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "classfile/vmIntrinsics.hpp"
  28 #include "code/codeBlob.hpp"
  29 #include "compiler/compilerDefinitions.inline.hpp"
  30 #include "jvm.h"
  31 #include "logging/log.hpp"
  32 #include "logging/logStream.hpp"
  33 #include "memory/resourceArea.hpp"
  34 #include "memory/universe.hpp"
  35 #include "runtime/globals_extension.hpp"
  36 #include "runtime/java.hpp"
  37 #include "runtime/os.inline.hpp"
  38 #include "runtime/stubCodeGenerator.hpp"
  39 #include "runtime/vm_version.hpp"
  40 #include "utilities/checkedCast.hpp"
  41 #include "utilities/ostream.hpp"
  42 #include "utilities/powerOfTwo.hpp"
  43 #include "utilities/virtualizationSupport.hpp"
  44 
  45 int VM_Version::_cpu;
  46 int VM_Version::_model;
  47 int VM_Version::_stepping;
  48 bool VM_Version::_has_intel_jcc_erratum;
  49 VM_Version::CpuidInfo VM_Version::_cpuid_info = { 0, };
  50 
  51 #define DECLARE_CPU_FEATURE_NAME(id, name, bit) XSTR(name),
  52 const char* VM_Version::_features_names[] = { CPU_FEATURE_FLAGS(DECLARE_CPU_FEATURE_NAME)};
  53 #undef DECLARE_CPU_FEATURE_NAME
  54 
  55 // Address of instruction which causes SEGV
  56 address VM_Version::_cpuinfo_segv_addr = nullptr;
  57 // Address of instruction after the one which causes SEGV
  58 address VM_Version::_cpuinfo_cont_addr = nullptr;
  59 // Address of instruction which causes APX specific SEGV
  60 address VM_Version::_cpuinfo_segv_addr_apx = nullptr;
  61 // Address of instruction after the one which causes APX specific SEGV
  62 address VM_Version::_cpuinfo_cont_addr_apx = nullptr;
  63 
  64 static BufferBlob* stub_blob;
  65 static const int stub_size = 2550;
  66 
  67 int VM_Version::VM_Features::_features_bitmap_size = sizeof(VM_Version::VM_Features::_features_bitmap) / BytesPerLong;
  68 
  69 VM_Version::VM_Features VM_Version::_features;
  70 VM_Version::VM_Features VM_Version::_cpu_features;
  71 
  72 extern "C" {
  73   typedef void (*get_cpu_info_stub_t)(void*);
  74   typedef void (*detect_virt_stub_t)(uint32_t, uint32_t*);
  75   typedef void (*clear_apx_test_state_t)(void);
  76   typedef void (*getCPUIDBrandString_stub_t)(void*);
  77 }
  78 static get_cpu_info_stub_t get_cpu_info_stub = nullptr;
  79 static detect_virt_stub_t detect_virt_stub = nullptr;
  80 static clear_apx_test_state_t clear_apx_test_state_stub = nullptr;
  81 static getCPUIDBrandString_stub_t getCPUIDBrandString_stub = nullptr;
  82 
  83 bool VM_Version::supports_clflush() {
  84   // clflush should always be available on x86_64
  85   // if not we are in real trouble because we rely on it
  86   // to flush the code cache.
  87   // Unfortunately, Assembler::clflush is currently called as part
  88   // of generation of the code cache flush routine. This happens
  89   // under Universe::init before the processor features are set
  90   // up. Assembler::flush calls this routine to check that clflush
  91   // is allowed. So, we give the caller a free pass if Universe init
  92   // is still in progress.
  93   assert ((!Universe::is_fully_initialized() || _features.supports_feature(CPU_FLUSH)), "clflush should be available");
  94   return true;
  95 }
  96 
  97 #define CPUID_STANDARD_FN   0x0
  98 #define CPUID_STANDARD_FN_1 0x1
  99 #define CPUID_STANDARD_FN_4 0x4
 100 #define CPUID_STANDARD_FN_B 0xb
 101 
 102 #define CPUID_EXTENDED_FN   0x80000000
 103 #define CPUID_EXTENDED_FN_1 0x80000001
 104 #define CPUID_EXTENDED_FN_2 0x80000002
 105 #define CPUID_EXTENDED_FN_3 0x80000003
 106 #define CPUID_EXTENDED_FN_4 0x80000004
 107 #define CPUID_EXTENDED_FN_7 0x80000007
 108 #define CPUID_EXTENDED_FN_8 0x80000008
 109 
 110 class VM_Version_StubGenerator: public StubCodeGenerator {
 111  public:
 112 
 113   VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
 114 
 115   address clear_apx_test_state() {
 116 #   define __ _masm->
 117     address start = __ pc();
 118     // EGPRs are call clobbered registers, Explicit clearing of r16 and r31 during signal
 119     // handling guarantees that preserved register values post signal handling were
 120     // re-instantiated by operating system and not because they were not modified externally.
 121 
 122     bool save_apx = UseAPX;
 123     VM_Version::set_apx_cpuFeatures();
 124     UseAPX = true;
 125     // EGPR state save/restoration.
 126     __ mov64(r16, 0L);
 127     __ mov64(r31, 0L);
 128     UseAPX = save_apx;
 129     VM_Version::clean_cpuFeatures();
 130     __ ret(0);
 131     return start;
 132   }
 133 
 134   address generate_get_cpu_info() {
 135     // Flags to test CPU type.
 136     const uint32_t HS_EFL_AC = 0x40000;
 137     const uint32_t HS_EFL_ID = 0x200000;
 138     // Values for when we don't have a CPUID instruction.
 139     const int      CPU_FAMILY_SHIFT = 8;
 140     const uint32_t CPU_FAMILY_386 = (3 << CPU_FAMILY_SHIFT);
 141     const uint32_t CPU_FAMILY_486 = (4 << CPU_FAMILY_SHIFT);
 142     bool use_evex = FLAG_IS_DEFAULT(UseAVX) || (UseAVX > 2);
 143 
 144     Label detect_486, cpu486, detect_586, std_cpuid1, std_cpuid4, std_cpuid24, std_cpuid29;
 145     Label sef_cpuid, sefsl1_cpuid, ext_cpuid, ext_cpuid1, ext_cpuid5, ext_cpuid7;
 146     Label ext_cpuid8, done, wrapup, vector_save_restore, apx_save_restore_warning, apx_xstate;
 147     Label legacy_setup, save_restore_except, legacy_save_restore, start_simd_check;
 148 
 149     StubCodeMark mark(this, "VM_Version", "get_cpu_info_stub");
 150 #   define __ _masm->
 151 
 152     address start = __ pc();
 153 
 154     //
 155     // void get_cpu_info(VM_Version::CpuidInfo* cpuid_info);
 156     //
 157     // rcx and rdx are first and second argument registers on windows
 158 
 159     __ push(rbp);
 160     __ mov(rbp, c_rarg0); // cpuid_info address
 161     __ push(rbx);
 162     __ push(rsi);
 163     __ pushf();          // preserve rbx, and flags
 164     __ pop(rax);
 165     __ push(rax);
 166     __ mov(rcx, rax);
 167     //
 168     // if we are unable to change the AC flag, we have a 386
 169     //
 170     __ xorl(rax, HS_EFL_AC);
 171     __ push(rax);
 172     __ popf();
 173     __ pushf();
 174     __ pop(rax);
 175     __ cmpptr(rax, rcx);
 176     __ jccb(Assembler::notEqual, detect_486);
 177 
 178     __ movl(rax, CPU_FAMILY_386);
 179     __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
 180     __ jmp(done);
 181 
 182     //
 183     // If we are unable to change the ID flag, we have a 486 which does
 184     // not support the "cpuid" instruction.
 185     //
 186     __ bind(detect_486);
 187     __ mov(rax, rcx);
 188     __ xorl(rax, HS_EFL_ID);
 189     __ push(rax);
 190     __ popf();
 191     __ pushf();
 192     __ pop(rax);
 193     __ cmpptr(rcx, rax);
 194     __ jccb(Assembler::notEqual, detect_586);
 195 
 196     __ bind(cpu486);
 197     __ movl(rax, CPU_FAMILY_486);
 198     __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
 199     __ jmp(done);
 200 
 201     //
 202     // At this point, we have a chip which supports the "cpuid" instruction
 203     //
 204     __ bind(detect_586);
 205     __ xorl(rax, rax);
 206     __ cpuid();
 207     __ orl(rax, rax);
 208     __ jcc(Assembler::equal, cpu486);   // if cpuid doesn't support an input
 209                                         // value of at least 1, we give up and
 210                                         // assume a 486
 211     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_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     __ cmpl(rax, 0xa);                  // Is cpuid(0xB) supported?
 218     __ jccb(Assembler::belowEqual, std_cpuid4);
 219 
 220     //
 221     // cpuid(0xB) Processor Topology
 222     //
 223     __ movl(rax, 0xb);
 224     __ xorl(rcx, rcx);   // Threads level
 225     __ cpuid();
 226 
 227     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB0_offset())));
 228     __ movl(Address(rsi, 0), rax);
 229     __ movl(Address(rsi, 4), rbx);
 230     __ movl(Address(rsi, 8), rcx);
 231     __ movl(Address(rsi,12), rdx);
 232 
 233     __ movl(rax, 0xb);
 234     __ movl(rcx, 1);     // Cores level
 235     __ cpuid();
 236     __ push(rax);
 237     __ andl(rax, 0x1f);  // Determine if valid topology level
 238     __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
 239     __ andl(rax, 0xffff);
 240     __ pop(rax);
 241     __ jccb(Assembler::equal, std_cpuid4);
 242 
 243     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB1_offset())));
 244     __ movl(Address(rsi, 0), rax);
 245     __ movl(Address(rsi, 4), rbx);
 246     __ movl(Address(rsi, 8), rcx);
 247     __ movl(Address(rsi,12), rdx);
 248 
 249     __ movl(rax, 0xb);
 250     __ movl(rcx, 2);     // Packages level
 251     __ cpuid();
 252     __ push(rax);
 253     __ andl(rax, 0x1f);  // Determine if valid topology level
 254     __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
 255     __ andl(rax, 0xffff);
 256     __ pop(rax);
 257     __ jccb(Assembler::equal, std_cpuid4);
 258 
 259     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB2_offset())));
 260     __ movl(Address(rsi, 0), rax);
 261     __ movl(Address(rsi, 4), rbx);
 262     __ movl(Address(rsi, 8), rcx);
 263     __ movl(Address(rsi,12), rdx);
 264 
 265     //
 266     // cpuid(0x4) Deterministic cache params
 267     //
 268     __ bind(std_cpuid4);
 269     __ movl(rax, 4);
 270     __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x4) supported?
 271     __ jccb(Assembler::greater, std_cpuid1);
 272 
 273     __ xorl(rcx, rcx);   // L1 cache
 274     __ cpuid();
 275     __ push(rax);
 276     __ andl(rax, 0x1f);  // Determine if valid cache parameters used
 277     __ orl(rax, rax);    // eax[4:0] == 0 indicates invalid cache
 278     __ pop(rax);
 279     __ jccb(Assembler::equal, std_cpuid1);
 280 
 281     __ lea(rsi, Address(rbp, in_bytes(VM_Version::dcp_cpuid4_offset())));
 282     __ movl(Address(rsi, 0), rax);
 283     __ movl(Address(rsi, 4), rbx);
 284     __ movl(Address(rsi, 8), rcx);
 285     __ movl(Address(rsi,12), rdx);
 286 
 287     //
 288     // Standard cpuid(0x1)
 289     //
 290     __ bind(std_cpuid1);
 291     __ movl(rax, 1);
 292     __ cpuid();
 293     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
 294     __ movl(Address(rsi, 0), rax);
 295     __ movl(Address(rsi, 4), rbx);
 296     __ movl(Address(rsi, 8), rcx);
 297     __ movl(Address(rsi,12), rdx);
 298 
 299     //
 300     // Check if OS has enabled XGETBV instruction to access XCR0
 301     // (OSXSAVE feature flag) and CPU supports AVX
 302     //
 303     __ andl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
 304     __ cmpl(rcx, 0x18000000);
 305     __ jccb(Assembler::notEqual, sef_cpuid); // jump if AVX is not supported
 306 
 307     //
 308     // XCR0, XFEATURE_ENABLED_MASK register
 309     //
 310     __ xorl(rcx, rcx);   // zero for XCR0 register
 311     __ xgetbv();
 312     __ lea(rsi, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset())));
 313     __ movl(Address(rsi, 0), rax);
 314     __ movl(Address(rsi, 4), rdx);
 315 
 316     //
 317     // cpuid(0x7) Structured Extended Features Enumeration Leaf.
 318     //
 319     __ bind(sef_cpuid);
 320     __ movl(rax, 7);
 321     __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x7) supported?
 322     __ jccb(Assembler::greater, ext_cpuid);
 323     // ECX = 0
 324     __ xorl(rcx, rcx);
 325     __ cpuid();
 326     __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
 327     __ movl(Address(rsi, 0), rax);
 328     __ movl(Address(rsi, 4), rbx);
 329     __ movl(Address(rsi, 8), rcx);
 330     __ movl(Address(rsi, 12), rdx);
 331 
 332     //
 333     // cpuid(0x7) Structured Extended Features Enumeration Sub-Leaf 1.
 334     //
 335     __ bind(sefsl1_cpuid);
 336     __ movl(rax, 7);
 337     __ movl(rcx, 1);
 338     __ cpuid();
 339     __ lea(rsi, Address(rbp, in_bytes(VM_Version::sefsl1_cpuid7_offset())));
 340     __ movl(Address(rsi, 0), rax);
 341     __ movl(Address(rsi, 4), rdx);
 342 
 343     //
 344     // cpuid(0x29) APX NCI NDD NF (EAX = 29H, ECX = 0).
 345     //
 346     __ bind(std_cpuid29);
 347     __ movl(rax, 0x29);
 348     __ movl(rcx, 0);
 349     __ cpuid();
 350     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid29_offset())));
 351     __ movl(Address(rsi, 0), rbx);
 352 
 353     //
 354     // cpuid(0x24) Converged Vector ISA Main Leaf (EAX = 24H, ECX = 0).
 355     //
 356     __ bind(std_cpuid24);
 357     __ movl(rax, 0x24);
 358     __ movl(rcx, 0);
 359     __ cpuid();
 360     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid24_offset())));
 361     __ movl(Address(rsi, 0), rax);
 362     __ movl(Address(rsi, 4), rbx);
 363 
 364     //
 365     // Extended cpuid(0x80000000)
 366     //
 367     __ bind(ext_cpuid);
 368     __ movl(rax, 0x80000000);
 369     __ cpuid();
 370     __ cmpl(rax, 0x80000000);     // Is cpuid(0x80000001) supported?
 371     __ jcc(Assembler::belowEqual, done);
 372     __ cmpl(rax, 0x80000004);     // Is cpuid(0x80000005) supported?
 373     __ jcc(Assembler::belowEqual, ext_cpuid1);
 374     __ cmpl(rax, 0x80000006);     // Is cpuid(0x80000007) supported?
 375     __ jccb(Assembler::belowEqual, ext_cpuid5);
 376     __ cmpl(rax, 0x80000007);     // Is cpuid(0x80000008) supported?
 377     __ jccb(Assembler::belowEqual, ext_cpuid7);
 378     __ cmpl(rax, 0x80000008);     // Is cpuid(0x80000009 and above) supported?
 379     __ jccb(Assembler::belowEqual, ext_cpuid8);
 380     __ cmpl(rax, 0x8000001E);     // Is cpuid(0x8000001E) supported?
 381     __ jccb(Assembler::below, ext_cpuid8);
 382     //
 383     // Extended cpuid(0x8000001E)
 384     //
 385     __ movl(rax, 0x8000001E);
 386     __ cpuid();
 387     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1E_offset())));
 388     __ movl(Address(rsi, 0), rax);
 389     __ movl(Address(rsi, 4), rbx);
 390     __ movl(Address(rsi, 8), rcx);
 391     __ movl(Address(rsi,12), rdx);
 392 
 393     //
 394     // Extended cpuid(0x80000008)
 395     //
 396     __ bind(ext_cpuid8);
 397     __ movl(rax, 0x80000008);
 398     __ cpuid();
 399     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid8_offset())));
 400     __ movl(Address(rsi, 0), rax);
 401     __ movl(Address(rsi, 4), rbx);
 402     __ movl(Address(rsi, 8), rcx);
 403     __ movl(Address(rsi,12), rdx);
 404 
 405     //
 406     // Extended cpuid(0x80000007)
 407     //
 408     __ bind(ext_cpuid7);
 409     __ movl(rax, 0x80000007);
 410     __ cpuid();
 411     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid7_offset())));
 412     __ movl(Address(rsi, 0), rax);
 413     __ movl(Address(rsi, 4), rbx);
 414     __ movl(Address(rsi, 8), rcx);
 415     __ movl(Address(rsi,12), rdx);
 416 
 417     //
 418     // Extended cpuid(0x80000005)
 419     //
 420     __ bind(ext_cpuid5);
 421     __ movl(rax, 0x80000005);
 422     __ cpuid();
 423     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid5_offset())));
 424     __ movl(Address(rsi, 0), rax);
 425     __ movl(Address(rsi, 4), rbx);
 426     __ movl(Address(rsi, 8), rcx);
 427     __ movl(Address(rsi,12), rdx);
 428 
 429     //
 430     // Extended cpuid(0x80000001)
 431     //
 432     __ bind(ext_cpuid1);
 433     __ movl(rax, 0x80000001);
 434     __ cpuid();
 435     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1_offset())));
 436     __ movl(Address(rsi, 0), rax);
 437     __ movl(Address(rsi, 4), rbx);
 438     __ movl(Address(rsi, 8), rcx);
 439     __ movl(Address(rsi,12), rdx);
 440 
 441     //
 442     // Check if OS has enabled XGETBV instruction to access XCR0
 443     // (OSXSAVE feature flag) and CPU supports APX
 444     //
 445     // To enable APX, check CPUID.EAX=7.ECX=1.EDX[21] bit for HW support
 446     // and XCRO[19] bit for OS support to save/restore extended GPR state.
 447     __ lea(rsi, Address(rbp, in_bytes(VM_Version::sefsl1_cpuid7_offset())));
 448     __ movl(rax, 0x200000);
 449     __ andl(rax, Address(rsi, 4));
 450     __ jcc(Assembler::equal, vector_save_restore);
 451     // check _cpuid_info.xem_xcr0_eax.bits.apx_f
 452     __ movl(rax, 0x80000);
 453     __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits apx_f
 454     __ jcc(Assembler::equal, vector_save_restore);
 455 
 456     bool save_apx = UseAPX;
 457     VM_Version::set_apx_cpuFeatures();
 458     UseAPX = true;
 459     __ mov64(r16, VM_Version::egpr_test_value());
 460     __ mov64(r31, VM_Version::egpr_test_value());
 461     __ xorl(rsi, rsi);
 462     VM_Version::set_cpuinfo_segv_addr_apx(__ pc());
 463     // Generate SEGV
 464     __ movl(rax, Address(rsi, 0));
 465 
 466     VM_Version::set_cpuinfo_cont_addr_apx(__ pc());
 467     __ lea(rsi, Address(rbp, in_bytes(VM_Version::apx_save_offset())));
 468     __ movq(Address(rsi, 0), r16);
 469     __ movq(Address(rsi, 8), r31);
 470 
 471     //
 472     // Query CPUID 0xD.19 for APX XSAVE offset
 473     // Extended State Enumeration Sub-leaf 19 (APX)
 474     // EAX = size of APX state (should be 128)
 475     // EBX = offset in standard XSAVE format
 476     //
 477     __ movl(rax, 0xD);
 478     __ movl(rcx, 19);
 479     __ cpuid();
 480     __ lea(rsi, Address(rbp, in_bytes(VM_Version::apx_xstate_size_offset())));
 481     __ movl(Address(rsi, 0), rax);
 482     __ lea(rsi, Address(rbp, in_bytes(VM_Version::apx_xstate_offset_offset())));
 483     __ movl(Address(rsi, 0), rbx);
 484 
 485     UseAPX = save_apx;
 486     __ bind(vector_save_restore);
 487     //
 488     // Check if OS has enabled XGETBV instruction to access XCR0
 489     // (OSXSAVE feature flag) and CPU supports AVX
 490     //
 491     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
 492     __ movl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
 493     __ andl(rcx, Address(rsi, 8)); // cpuid1 bits osxsave | avx
 494     __ cmpl(rcx, 0x18000000);
 495     __ jccb(Assembler::notEqual, done); // jump if AVX is not supported
 496 
 497     __ movl(rax, 0x6);
 498     __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
 499     __ cmpl(rax, 0x6);
 500     __ jccb(Assembler::equal, start_simd_check); // return if AVX is not supported
 501 
 502     // we need to bridge farther than imm8, so we use this island as a thunk
 503     __ bind(done);
 504     __ jmp(wrapup);
 505 
 506     __ bind(start_simd_check);
 507     //
 508     // Some OSs have a bug when upper 128/256bits of YMM/ZMM
 509     // registers are not restored after a signal processing.
 510     // Generate SEGV here (reference through null)
 511     // and check upper YMM/ZMM bits after it.
 512     //
 513     int saved_useavx = UseAVX;
 514     int saved_usesse = UseSSE;
 515 
 516     // If UseAVX is uninitialized or is set by the user to include EVEX
 517     if (use_evex) {
 518       // check _cpuid_info.sef_cpuid7_ebx.bits.avx512f
 519       // OR check _cpuid_info.sefsl1_cpuid7_edx.bits.avx10
 520       __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
 521       __ movl(rax, 0x10000);
 522       __ andl(rax, Address(rsi, 4));
 523       __ lea(rsi, Address(rbp, in_bytes(VM_Version::sefsl1_cpuid7_offset())));
 524       __ movl(rbx, 0x80000);
 525       __ andl(rbx, Address(rsi, 4));
 526       __ orl(rax, rbx);
 527       __ jccb(Assembler::equal, legacy_setup); // jump if EVEX is not supported
 528       // check _cpuid_info.xem_xcr0_eax.bits.opmask
 529       // check _cpuid_info.xem_xcr0_eax.bits.zmm512
 530       // check _cpuid_info.xem_xcr0_eax.bits.zmm32
 531       __ movl(rax, 0xE0);
 532       __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
 533       __ cmpl(rax, 0xE0);
 534       __ jccb(Assembler::notEqual, legacy_setup); // jump if EVEX is not supported
 535 
 536       if (FLAG_IS_DEFAULT(UseAVX)) {
 537         __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
 538         __ movl(rax, Address(rsi, 0));
 539         __ cmpl(rax, 0x50654);              // If it is Skylake
 540         __ jcc(Assembler::equal, legacy_setup);
 541       }
 542       // EVEX setup: run in lowest evex mode
 543       VM_Version::set_evex_cpuFeatures(); // Enable temporary to pass asserts
 544       UseAVX = 3;
 545       UseSSE = 2;
 546 #ifdef _WINDOWS
 547       // xmm5-xmm15 are not preserved by caller on windows
 548       // https://msdn.microsoft.com/en-us/library/9z1stfyw.aspx
 549       __ subptr(rsp, 64);
 550       __ evmovdqul(Address(rsp, 0), xmm7, Assembler::AVX_512bit);
 551       __ subptr(rsp, 64);
 552       __ evmovdqul(Address(rsp, 0), xmm8, Assembler::AVX_512bit);
 553       __ subptr(rsp, 64);
 554       __ evmovdqul(Address(rsp, 0), xmm31, Assembler::AVX_512bit);
 555 #endif // _WINDOWS
 556 
 557       // load value into all 64 bytes of zmm7 register
 558       __ movl(rcx, VM_Version::ymm_test_value());
 559       __ movdl(xmm0, rcx);
 560       __ vpbroadcastd(xmm0, xmm0, Assembler::AVX_512bit);
 561       __ evmovdqul(xmm7, xmm0, Assembler::AVX_512bit);
 562       __ evmovdqul(xmm8, xmm0, Assembler::AVX_512bit);
 563       __ evmovdqul(xmm31, xmm0, Assembler::AVX_512bit);
 564       VM_Version::clean_cpuFeatures();
 565       __ jmp(save_restore_except);
 566     }
 567 
 568     __ bind(legacy_setup);
 569     // AVX setup
 570     VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
 571     UseAVX = 1;
 572     UseSSE = 2;
 573 #ifdef _WINDOWS
 574     __ subptr(rsp, 32);
 575     __ vmovdqu(Address(rsp, 0), xmm7);
 576     __ subptr(rsp, 32);
 577     __ vmovdqu(Address(rsp, 0), xmm8);
 578     __ subptr(rsp, 32);
 579     __ vmovdqu(Address(rsp, 0), xmm15);
 580 #endif // _WINDOWS
 581 
 582     // load value into all 32 bytes of ymm7 register
 583     __ movl(rcx, VM_Version::ymm_test_value());
 584 
 585     __ movdl(xmm0, rcx);
 586     __ pshufd(xmm0, xmm0, 0x00);
 587     __ vinsertf128_high(xmm0, xmm0);
 588     __ vmovdqu(xmm7, xmm0);
 589     __ vmovdqu(xmm8, xmm0);
 590     __ vmovdqu(xmm15, xmm0);
 591     VM_Version::clean_cpuFeatures();
 592 
 593     __ bind(save_restore_except);
 594     __ xorl(rsi, rsi);
 595     VM_Version::set_cpuinfo_segv_addr(__ pc());
 596     // Generate SEGV
 597     __ movl(rax, Address(rsi, 0));
 598 
 599     VM_Version::set_cpuinfo_cont_addr(__ pc());
 600     // Returns here after signal. Save xmm0 to check it later.
 601 
 602     // If UseAVX is uninitialized or is set by the user to include EVEX
 603     if (use_evex) {
 604       // check _cpuid_info.sef_cpuid7_ebx.bits.avx512f
 605       __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
 606       __ movl(rax, 0x10000);
 607       __ andl(rax, Address(rsi, 4));
 608       __ jcc(Assembler::equal, legacy_save_restore);
 609       // check _cpuid_info.xem_xcr0_eax.bits.opmask
 610       // check _cpuid_info.xem_xcr0_eax.bits.zmm512
 611       // check _cpuid_info.xem_xcr0_eax.bits.zmm32
 612       __ movl(rax, 0xE0);
 613       __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
 614       __ cmpl(rax, 0xE0);
 615       __ jcc(Assembler::notEqual, legacy_save_restore);
 616 
 617       if (FLAG_IS_DEFAULT(UseAVX)) {
 618         __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
 619         __ movl(rax, Address(rsi, 0));
 620         __ cmpl(rax, 0x50654);              // If it is Skylake
 621         __ jcc(Assembler::equal, legacy_save_restore);
 622       }
 623       // EVEX check: run in lowest evex mode
 624       VM_Version::set_evex_cpuFeatures(); // Enable temporary to pass asserts
 625       UseAVX = 3;
 626       UseSSE = 2;
 627       __ lea(rsi, Address(rbp, in_bytes(VM_Version::zmm_save_offset())));
 628       __ evmovdqul(Address(rsi, 0), xmm0, Assembler::AVX_512bit);
 629       __ evmovdqul(Address(rsi, 64), xmm7, Assembler::AVX_512bit);
 630       __ evmovdqul(Address(rsi, 128), xmm8, Assembler::AVX_512bit);
 631       __ evmovdqul(Address(rsi, 192), xmm31, Assembler::AVX_512bit);
 632 
 633 #ifdef _WINDOWS
 634       __ evmovdqul(xmm31, Address(rsp, 0), Assembler::AVX_512bit);
 635       __ addptr(rsp, 64);
 636       __ evmovdqul(xmm8, Address(rsp, 0), Assembler::AVX_512bit);
 637       __ addptr(rsp, 64);
 638       __ evmovdqul(xmm7, Address(rsp, 0), Assembler::AVX_512bit);
 639       __ addptr(rsp, 64);
 640 #endif // _WINDOWS
 641       generate_vzeroupper(wrapup);
 642       VM_Version::clean_cpuFeatures();
 643       UseAVX = saved_useavx;
 644       UseSSE = saved_usesse;
 645       __ jmp(wrapup);
 646    }
 647 
 648     __ bind(legacy_save_restore);
 649     // AVX check
 650     VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
 651     UseAVX = 1;
 652     UseSSE = 2;
 653     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ymm_save_offset())));
 654     __ vmovdqu(Address(rsi, 0), xmm0);
 655     __ vmovdqu(Address(rsi, 32), xmm7);
 656     __ vmovdqu(Address(rsi, 64), xmm8);
 657     __ vmovdqu(Address(rsi, 96), xmm15);
 658 
 659 #ifdef _WINDOWS
 660     __ vmovdqu(xmm15, Address(rsp, 0));
 661     __ addptr(rsp, 32);
 662     __ vmovdqu(xmm8, Address(rsp, 0));
 663     __ addptr(rsp, 32);
 664     __ vmovdqu(xmm7, Address(rsp, 0));
 665     __ addptr(rsp, 32);
 666 #endif // _WINDOWS
 667 
 668     generate_vzeroupper(wrapup);
 669     VM_Version::clean_cpuFeatures();
 670     UseAVX = saved_useavx;
 671     UseSSE = saved_usesse;
 672 
 673     __ bind(wrapup);
 674     __ popf();
 675     __ pop(rsi);
 676     __ pop(rbx);
 677     __ pop(rbp);
 678     __ ret(0);
 679 
 680 #   undef __
 681 
 682     return start;
 683   };
 684   void generate_vzeroupper(Label& L_wrapup) {
 685 #   define __ _masm->
 686     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
 687     __ cmpl(Address(rsi, 4), 0x756e6547);  // 'uneG'
 688     __ jcc(Assembler::notEqual, L_wrapup);
 689     __ movl(rcx, 0x0FFF0FF0);
 690     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
 691     __ andl(rcx, Address(rsi, 0));
 692     __ cmpl(rcx, 0x00050670);              // If it is Xeon Phi 3200/5200/7200
 693     __ jcc(Assembler::equal, L_wrapup);
 694     __ cmpl(rcx, 0x00080650);              // If it is Future Xeon Phi
 695     __ jcc(Assembler::equal, L_wrapup);
 696     // vzeroupper() will use a pre-computed instruction sequence that we
 697     // can't compute until after we've determined CPU capabilities. Use
 698     // uncached variant here directly to be able to bootstrap correctly
 699     __ vzeroupper_uncached();
 700 #   undef __
 701   }
 702   address generate_detect_virt() {
 703     StubCodeMark mark(this, "VM_Version", "detect_virt_stub");
 704 #   define __ _masm->
 705 
 706     address start = __ pc();
 707 
 708     // Evacuate callee-saved registers
 709     __ push(rbp);
 710     __ push(rbx);
 711     __ push(rsi); // for Windows
 712 
 713     __ mov(rax, c_rarg0); // CPUID leaf
 714     __ mov(rsi, c_rarg1); // register array address (eax, ebx, ecx, edx)
 715 
 716     __ cpuid();
 717 
 718     // Store result to register array
 719     __ movl(Address(rsi,  0), rax);
 720     __ movl(Address(rsi,  4), rbx);
 721     __ movl(Address(rsi,  8), rcx);
 722     __ movl(Address(rsi, 12), rdx);
 723 
 724     // Epilogue
 725     __ pop(rsi);
 726     __ pop(rbx);
 727     __ pop(rbp);
 728     __ ret(0);
 729 
 730 #   undef __
 731 
 732     return start;
 733   };
 734 
 735 
 736   address generate_getCPUIDBrandString(void) {
 737     // Flags to test CPU type.
 738     const uint32_t HS_EFL_AC           = 0x40000;
 739     const uint32_t HS_EFL_ID           = 0x200000;
 740     // Values for when we don't have a CPUID instruction.
 741     const int      CPU_FAMILY_SHIFT = 8;
 742     const uint32_t CPU_FAMILY_386   = (3 << CPU_FAMILY_SHIFT);
 743     const uint32_t CPU_FAMILY_486   = (4 << CPU_FAMILY_SHIFT);
 744 
 745     Label detect_486, cpu486, detect_586, done, ext_cpuid;
 746 
 747     StubCodeMark mark(this, "VM_Version", "getCPUIDNameInfo_stub");
 748 #   define __ _masm->
 749 
 750     address start = __ pc();
 751 
 752     //
 753     // void getCPUIDBrandString(VM_Version::CpuidInfo* cpuid_info);
 754     //
 755     // rcx and rdx are first and second argument registers on windows
 756 
 757     __ push(rbp);
 758     __ mov(rbp, c_rarg0); // cpuid_info address
 759     __ push(rbx);
 760     __ push(rsi);
 761     __ pushf();          // preserve rbx, and flags
 762     __ pop(rax);
 763     __ push(rax);
 764     __ mov(rcx, rax);
 765     //
 766     // if we are unable to change the AC flag, we have a 386
 767     //
 768     __ xorl(rax, HS_EFL_AC);
 769     __ push(rax);
 770     __ popf();
 771     __ pushf();
 772     __ pop(rax);
 773     __ cmpptr(rax, rcx);
 774     __ jccb(Assembler::notEqual, detect_486);
 775 
 776     __ movl(rax, CPU_FAMILY_386);
 777     __ jmp(done);
 778 
 779     //
 780     // If we are unable to change the ID flag, we have a 486 which does
 781     // not support the "cpuid" instruction.
 782     //
 783     __ bind(detect_486);
 784     __ mov(rax, rcx);
 785     __ xorl(rax, HS_EFL_ID);
 786     __ push(rax);
 787     __ popf();
 788     __ pushf();
 789     __ pop(rax);
 790     __ cmpptr(rcx, rax);
 791     __ jccb(Assembler::notEqual, detect_586);
 792 
 793     __ bind(cpu486);
 794     __ movl(rax, CPU_FAMILY_486);
 795     __ jmp(done);
 796 
 797     //
 798     // At this point, we have a chip which supports the "cpuid" instruction
 799     //
 800     __ bind(detect_586);
 801     __ xorl(rax, rax);
 802     __ cpuid();
 803     __ orl(rax, rax);
 804     __ jcc(Assembler::equal, cpu486);   // if cpuid doesn't support an input
 805                                         // value of at least 1, we give up and
 806                                         // assume a 486
 807 
 808     //
 809     // Extended cpuid(0x80000000) for processor brand string detection
 810     //
 811     __ bind(ext_cpuid);
 812     __ movl(rax, CPUID_EXTENDED_FN);
 813     __ cpuid();
 814     __ cmpl(rax, CPUID_EXTENDED_FN_4);
 815     __ jcc(Assembler::below, done);
 816 
 817     //
 818     // Extended cpuid(0x80000002)  // first 16 bytes in brand string
 819     //
 820     __ movl(rax, CPUID_EXTENDED_FN_2);
 821     __ cpuid();
 822     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_0_offset())));
 823     __ movl(Address(rsi, 0), rax);
 824     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_1_offset())));
 825     __ movl(Address(rsi, 0), rbx);
 826     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_2_offset())));
 827     __ movl(Address(rsi, 0), rcx);
 828     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_3_offset())));
 829     __ movl(Address(rsi,0), rdx);
 830 
 831     //
 832     // Extended cpuid(0x80000003) // next 16 bytes in brand string
 833     //
 834     __ movl(rax, CPUID_EXTENDED_FN_3);
 835     __ cpuid();
 836     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_4_offset())));
 837     __ movl(Address(rsi, 0), rax);
 838     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_5_offset())));
 839     __ movl(Address(rsi, 0), rbx);
 840     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_6_offset())));
 841     __ movl(Address(rsi, 0), rcx);
 842     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_7_offset())));
 843     __ movl(Address(rsi,0), rdx);
 844 
 845     //
 846     // Extended cpuid(0x80000004) // last 16 bytes in brand string
 847     //
 848     __ movl(rax, CPUID_EXTENDED_FN_4);
 849     __ cpuid();
 850     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_8_offset())));
 851     __ movl(Address(rsi, 0), rax);
 852     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_9_offset())));
 853     __ movl(Address(rsi, 0), rbx);
 854     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_10_offset())));
 855     __ movl(Address(rsi, 0), rcx);
 856     __ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_11_offset())));
 857     __ movl(Address(rsi,0), rdx);
 858 
 859     //
 860     // return
 861     //
 862     __ bind(done);
 863     __ popf();
 864     __ pop(rsi);
 865     __ pop(rbx);
 866     __ pop(rbp);
 867     __ ret(0);
 868 
 869 #   undef __
 870 
 871     return start;
 872   };
 873 };
 874 
 875 void VM_Version::get_processor_features() {
 876 
 877   _cpu = 4; // 486 by default
 878   _model = 0;
 879   _stepping = 0;
 880   _logical_processors_per_package = 1;
 881   // i486 internal cache is both I&D and has a 16-byte line size
 882   _L1_data_cache_line_size = 16;
 883 
 884   // Get raw processor info
 885 
 886   get_cpu_info_stub(&_cpuid_info);
 887 
 888   assert_is_initialized();
 889   _cpu = extended_cpu_family();
 890   _model = extended_cpu_model();
 891   _stepping = cpu_stepping();
 892 
 893   if (cpu_family() > 4) { // it supports CPUID
 894     _features = _cpuid_info.feature_flags(); // These can be changed by VM settings
 895     _cpu_features = _features; // Preserve features
 896     // Logical processors are only available on P4s and above,
 897     // and only if hyperthreading is available.
 898     _logical_processors_per_package = logical_processor_count();
 899     _L1_data_cache_line_size = L1_line_size();
 900   }
 901 
 902   // xchg and xadd instructions
 903   _supports_atomic_getset4 = true;
 904   _supports_atomic_getadd4 = true;
 905   _supports_atomic_getset8 = true;
 906   _supports_atomic_getadd8 = true;
 907 
 908   // OS should support SSE for x64 and hardware should support at least SSE2.
 909   if (!VM_Version::supports_sse2()) {
 910     vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");
 911   }
 912   // in 64 bit the use of SSE2 is the minimum
 913   if (UseSSE < 2) UseSSE = 2;
 914 
 915   // flush_icache_stub have to be generated first.
 916   // That is why Icache line size is hard coded in ICache class,
 917   // see icache_x86.hpp. It is also the reason why we can't use
 918   // clflush instruction in 32-bit VM since it could be running
 919   // on CPU which does not support it.
 920   //
 921   // The only thing we can do is to verify that flushed
 922   // ICache::line_size has correct value.
 923   guarantee(_cpuid_info.std_cpuid1_edx.bits.clflush != 0, "clflush is not supported");
 924   // clflush_size is size in quadwords (8 bytes).
 925   guarantee(_cpuid_info.std_cpuid1_ebx.bits.clflush_size == 8, "such clflush size is not supported");
 926 
 927   // assigning this field effectively enables Unsafe.writebackMemory()
 928   // by initing UnsafeConstant.DATA_CACHE_LINE_FLUSH_SIZE to non-zero
 929   // that is only implemented on x86_64 and only if the OS plays ball
 930   if (os::supports_map_sync()) {
 931     // publish data cache line flush size to generic field, otherwise
 932     // let if default to zero thereby disabling writeback
 933     _data_cache_line_flush_size = _cpuid_info.std_cpuid1_ebx.bits.clflush_size * 8;
 934   }
 935 
 936   // Check if processor has Intel Ecore
 937   if (FLAG_IS_DEFAULT(EnableX86ECoreOpts) && is_intel() && is_intel_server_family() &&
 938     (supports_hybrid() ||
 939      _model == 0xAF /* Xeon 6 E-cores (Sierra Forest) */ ||
 940      _model == 0xDD /* Xeon 6+ E-cores (Clearwater Forest) */ )) {
 941     FLAG_SET_DEFAULT(EnableX86ECoreOpts, true);
 942   }
 943 
 944   if (UseSSE < 4) {
 945     _features.clear_feature(CPU_SSE4_1);
 946     _features.clear_feature(CPU_SSE4_2);
 947   }
 948 
 949   if (UseSSE < 3) {
 950     _features.clear_feature(CPU_SSE3);
 951     _features.clear_feature(CPU_SSSE3);
 952     _features.clear_feature(CPU_SSE4A);
 953   }
 954 
 955   if (UseSSE < 2)
 956     _features.clear_feature(CPU_SSE2);
 957 
 958   if (UseSSE < 1)
 959     _features.clear_feature(CPU_SSE);
 960 
 961   // ZX cpus specific settings
 962   if (is_zx() && FLAG_IS_DEFAULT(UseAVX)) {
 963     if (cpu_family() == 7) {
 964       if (extended_cpu_model() == 0x5B || extended_cpu_model() == 0x6B) {
 965         UseAVX = 1;
 966       } else if (extended_cpu_model() == 0x1B || extended_cpu_model() == 0x3B) {
 967         UseAVX = 0;
 968       }
 969     } else if (cpu_family() == 6) {
 970       UseAVX = 0;
 971     }
 972   }
 973 
 974   // UseSSE is set to the smaller of what hardware supports and what
 975   // the command line requires.  I.e., you cannot set UseSSE to 2 on
 976   // older Pentiums which do not support it.
 977   int use_sse_limit = 0;
 978   if (UseSSE > 0) {
 979     if (UseSSE > 3 && supports_sse4_1()) {
 980       use_sse_limit = 4;
 981     } else if (UseSSE > 2 && supports_sse3()) {
 982       use_sse_limit = 3;
 983     } else if (UseSSE > 1 && supports_sse2()) {
 984       use_sse_limit = 2;
 985     } else if (UseSSE > 0 && supports_sse()) {
 986       use_sse_limit = 1;
 987     } else {
 988       use_sse_limit = 0;
 989     }
 990   }
 991   if (FLAG_IS_DEFAULT(UseSSE)) {
 992     FLAG_SET_DEFAULT(UseSSE, use_sse_limit);
 993   } else if (UseSSE > use_sse_limit) {
 994     warning("UseSSE=%d is not supported on this CPU, setting it to UseSSE=%d", UseSSE, use_sse_limit);
 995     FLAG_SET_DEFAULT(UseSSE, use_sse_limit);
 996   }
 997 
 998   // first try initial setting and detect what we can support
 999   int use_avx_limit = 0;
1000   if (UseAVX > 0) {
1001     if (UseSSE < 4) {
1002       // Don't use AVX if SSE is unavailable or has been disabled.
1003       use_avx_limit = 0;
1004     } else if (UseAVX > 2 && supports_evex()) {
1005       use_avx_limit = 3;
1006     } else if (UseAVX > 1 && supports_avx2()) {
1007       use_avx_limit = 2;
1008     } else if (UseAVX > 0 && supports_avx()) {
1009       use_avx_limit = 1;
1010     } else {
1011       use_avx_limit = 0;
1012     }
1013   }
1014   if (FLAG_IS_DEFAULT(UseAVX)) {
1015     // Don't use AVX-512 on older Skylakes unless explicitly requested.
1016     if (use_avx_limit > 2 && is_intel_skylake() && _stepping < 5) {
1017       FLAG_SET_DEFAULT(UseAVX, 2);
1018     } else {
1019       FLAG_SET_DEFAULT(UseAVX, use_avx_limit);
1020     }
1021   }
1022 
1023   if (UseAVX > use_avx_limit) {
1024     if (UseSSE < 4) {
1025       warning("UseAVX=%d requires UseSSE=4, setting it to UseAVX=0", UseAVX);
1026     } else {
1027       warning("UseAVX=%d is not supported on this CPU, setting it to UseAVX=%d", UseAVX, use_avx_limit);
1028     }
1029     FLAG_SET_DEFAULT(UseAVX, use_avx_limit);
1030   }
1031 
1032   if (UseAVX < 3) {
1033     _features.clear_feature(CPU_AVX512F);
1034     _features.clear_feature(CPU_AVX512DQ);
1035     _features.clear_feature(CPU_AVX512CD);
1036     _features.clear_feature(CPU_AVX512BW);
1037     _features.clear_feature(CPU_AVX512ER);
1038     _features.clear_feature(CPU_AVX512PF);
1039     _features.clear_feature(CPU_AVX512VL);
1040     _features.clear_feature(CPU_AVX512_VPOPCNTDQ);
1041     _features.clear_feature(CPU_AVX512_VPCLMULQDQ);
1042     _features.clear_feature(CPU_AVX512_VAES);
1043     _features.clear_feature(CPU_AVX512_VNNI);
1044     _features.clear_feature(CPU_AVX512_VBMI);
1045     _features.clear_feature(CPU_AVX512_VBMI2);
1046     _features.clear_feature(CPU_AVX512_BITALG);
1047     _features.clear_feature(CPU_AVX512_IFMA);
1048     _features.clear_feature(CPU_APX_F);
1049     _features.clear_feature(CPU_AVX512_FP16);
1050     _features.clear_feature(CPU_AVX10_1);
1051     _features.clear_feature(CPU_AVX10_2);
1052   }
1053 
1054 
1055   if (UseAVX < 2) {
1056     _features.clear_feature(CPU_AVX2);
1057     _features.clear_feature(CPU_AVX_IFMA);
1058   }
1059 
1060   if (UseAVX < 1) {
1061     _features.clear_feature(CPU_AVX);
1062     _features.clear_feature(CPU_VZEROUPPER);
1063     _features.clear_feature(CPU_F16C);
1064     _features.clear_feature(CPU_SHA512);
1065   }
1066 
1067   if (logical_processors_per_package() == 1) {
1068     // HT processor could be installed on a system which doesn't support HT.
1069     _features.clear_feature(CPU_HT);
1070   }
1071 
1072   if (is_intel()) { // Intel cpus specific settings
1073     if (is_knights_family()) {
1074       _features.clear_feature(CPU_VZEROUPPER);
1075       _features.clear_feature(CPU_AVX512BW);
1076       _features.clear_feature(CPU_AVX512VL);
1077       _features.clear_feature(CPU_APX_F);
1078       _features.clear_feature(CPU_AVX512DQ);
1079       _features.clear_feature(CPU_AVX512_VNNI);
1080       _features.clear_feature(CPU_AVX512_VAES);
1081       _features.clear_feature(CPU_AVX512_VPOPCNTDQ);
1082       _features.clear_feature(CPU_AVX512_VPCLMULQDQ);
1083       _features.clear_feature(CPU_AVX512_VBMI);
1084       _features.clear_feature(CPU_AVX512_VBMI2);
1085       _features.clear_feature(CPU_CLWB);
1086       _features.clear_feature(CPU_FLUSHOPT);
1087       _features.clear_feature(CPU_GFNI);
1088       _features.clear_feature(CPU_AVX512_BITALG);
1089       _features.clear_feature(CPU_AVX512_IFMA);
1090       _features.clear_feature(CPU_AVX_IFMA);
1091       _features.clear_feature(CPU_AVX512_FP16);
1092       _features.clear_feature(CPU_AVX10_1);
1093       _features.clear_feature(CPU_AVX10_2);
1094     }
1095   }
1096 
1097     // Currently APX support is only enabled for targets supporting AVX512VL feature.
1098   bool apx_supported = os_supports_apx_egprs() && supports_apx_f() && supports_avx512vl();
1099   if (UseAPX && !apx_supported) {
1100     warning("UseAPX is not supported on this CPU, setting it to false");
1101     FLAG_SET_DEFAULT(UseAPX, false);
1102   }
1103 
1104   if (!UseAPX) {
1105     _features.clear_feature(CPU_APX_F);
1106   }
1107 
1108   if (FLAG_IS_DEFAULT(IntelJccErratumMitigation)) {
1109     _has_intel_jcc_erratum = compute_has_intel_jcc_erratum();
1110     FLAG_SET_ERGO(IntelJccErratumMitigation, _has_intel_jcc_erratum);
1111   } else {
1112     _has_intel_jcc_erratum = IntelJccErratumMitigation;
1113   }
1114 
1115   assert(supports_clflush(), "Always present");
1116   if (X86ICacheSync == -1) {
1117     // Auto-detect, choosing the best performant one that still flushes
1118     // the cache. We could switch to CPUID/SERIALIZE ("4"/"5") going forward.
1119     if (supports_clwb()) {
1120       FLAG_SET_ERGO(X86ICacheSync, 3);
1121     } else if (supports_clflushopt()) {
1122       FLAG_SET_ERGO(X86ICacheSync, 2);
1123     } else {
1124       FLAG_SET_ERGO(X86ICacheSync, 1);
1125     }
1126   } else {
1127     if ((X86ICacheSync == 2) && !supports_clflushopt()) {
1128       vm_exit_during_initialization("CPU does not support CLFLUSHOPT, unable to use X86ICacheSync=2");
1129     }
1130     if ((X86ICacheSync == 3) && !supports_clwb()) {
1131       vm_exit_during_initialization("CPU does not support CLWB, unable to use X86ICacheSync=3");
1132     }
1133     if ((X86ICacheSync == 5) && !supports_serialize()) {
1134       vm_exit_during_initialization("CPU does not support SERIALIZE, unable to use X86ICacheSync=5");
1135     }
1136   }
1137 
1138   stringStream ss(2048);
1139   if (supports_hybrid()) {
1140     ss.print("(hybrid)");
1141   } else {
1142     ss.print("(%u cores per cpu, %u threads per core)", cores_per_cpu(), threads_per_core());
1143   }
1144   ss.print(" family %d model %d stepping %d microcode 0x%x",
1145            cpu_family(), _model, _stepping, os::cpu_microcode_revision());
1146   ss.print(", ");
1147   int features_offset = (int)ss.size();
1148   insert_features_names(_features, ss);
1149 
1150   _cpu_info_string = ss.as_string(true);
1151   _features_string = _cpu_info_string + features_offset;
1152 
1153   // Use AES instructions if available.
1154   if (supports_aes()) {
1155     if (FLAG_IS_DEFAULT(UseAES)) {
1156       FLAG_SET_DEFAULT(UseAES, true);
1157     }
1158     if (!UseAES) {
1159       if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
1160         warning("AES intrinsics require UseAES flag to be enabled. Intrinsics will be disabled.");
1161       }
1162       FLAG_SET_DEFAULT(UseAESIntrinsics, false);
1163       if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
1164         warning("AES_CTR intrinsics require UseAES flag to be enabled. AES_CTR intrinsics will be disabled.");
1165       }
1166       FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
1167     } else {
1168       if (UseSSE > 2) {
1169         if (FLAG_IS_DEFAULT(UseAESIntrinsics)) {
1170           FLAG_SET_DEFAULT(UseAESIntrinsics, true);
1171         }
1172       } else {
1173         // The AES intrinsic stubs require AES instruction support (of course)
1174         // but also require sse3 mode or higher for instructions it use.
1175         if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
1176           warning("X86 AES intrinsics require SSE3 instructions or higher. Intrinsics will be disabled.");
1177         }
1178         FLAG_SET_DEFAULT(UseAESIntrinsics, false);
1179       }
1180 
1181       // --AES-CTR begins--
1182       if (!UseAESIntrinsics) {
1183         if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
1184           warning("AES-CTR intrinsics require UseAESIntrinsics flag to be enabled. Intrinsics will be disabled.");
1185         }
1186         FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
1187       } else {
1188         if (supports_sse4_1()) {
1189           if (FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
1190             FLAG_SET_DEFAULT(UseAESCTRIntrinsics, true);
1191           }
1192         } else {
1193            // The AES-CTR intrinsic stubs require AES instruction support (of course)
1194            // but also require sse4.1 mode or higher for instructions it use.
1195           if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
1196              warning("X86 AES-CTR intrinsics require SSE4.1 instructions or higher. Intrinsics will be disabled.");
1197            }
1198            FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
1199         }
1200       }
1201       // --AES-CTR ends--
1202     }
1203   } else if (UseAES || UseAESIntrinsics || UseAESCTRIntrinsics) {
1204     if (UseAES && !FLAG_IS_DEFAULT(UseAES)) {
1205       warning("AES instructions are not available on this CPU");
1206     }
1207     FLAG_SET_DEFAULT(UseAES, false);
1208     if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
1209       warning("AES intrinsics are not available on this CPU");
1210     }
1211     FLAG_SET_DEFAULT(UseAESIntrinsics, false);
1212     if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
1213       warning("AES-CTR intrinsics are not available on this CPU");
1214     }
1215     FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
1216   }
1217 
1218   // Use CLMUL instructions if available.
1219   if (supports_clmul()) {
1220     if (FLAG_IS_DEFAULT(UseCLMUL)) {
1221       UseCLMUL = true;
1222     }
1223   } else if (UseCLMUL) {
1224     if (!FLAG_IS_DEFAULT(UseCLMUL))
1225       warning("CLMUL instructions not available on this CPU (AVX may also be required)");
1226     FLAG_SET_DEFAULT(UseCLMUL, false);
1227   }
1228 
1229   if (UseCLMUL && (UseSSE > 2)) {
1230     if (FLAG_IS_DEFAULT(UseCRC32Intrinsics)) {
1231       UseCRC32Intrinsics = true;
1232     }
1233   } else if (UseCRC32Intrinsics) {
1234     if (!FLAG_IS_DEFAULT(UseCRC32Intrinsics))
1235       warning("CRC32 Intrinsics requires CLMUL instructions (not available on this CPU)");
1236     FLAG_SET_DEFAULT(UseCRC32Intrinsics, false);
1237   }
1238 
1239   if (supports_avx2()) {
1240     if (FLAG_IS_DEFAULT(UseAdler32Intrinsics)) {
1241       UseAdler32Intrinsics = true;
1242     }
1243   } else if (UseAdler32Intrinsics) {
1244     if (!FLAG_IS_DEFAULT(UseAdler32Intrinsics)) {
1245       warning("Adler32 Intrinsics requires avx2 instructions (not available on this CPU)");
1246     }
1247     FLAG_SET_DEFAULT(UseAdler32Intrinsics, false);
1248   }
1249 
1250   if (supports_sse4_2() && supports_clmul()) {
1251     if (FLAG_IS_DEFAULT(UseCRC32CIntrinsics)) {
1252       UseCRC32CIntrinsics = true;
1253     }
1254   } else if (UseCRC32CIntrinsics) {
1255     if (!FLAG_IS_DEFAULT(UseCRC32CIntrinsics)) {
1256       warning("CRC32C intrinsics are not available on this CPU");
1257     }
1258     FLAG_SET_DEFAULT(UseCRC32CIntrinsics, false);
1259   }
1260 
1261   // GHASH/GCM intrinsics
1262   if (UseCLMUL && (UseSSE > 2)) {
1263     if (FLAG_IS_DEFAULT(UseGHASHIntrinsics)) {
1264       UseGHASHIntrinsics = true;
1265     }
1266   } else if (UseGHASHIntrinsics) {
1267     if (!FLAG_IS_DEFAULT(UseGHASHIntrinsics))
1268       warning("GHASH intrinsic requires CLMUL and SSE2 instructions on this CPU");
1269     FLAG_SET_DEFAULT(UseGHASHIntrinsics, false);
1270   }
1271 
1272   // ChaCha20 Intrinsics
1273   // As long as the system supports AVX as a baseline we can do a
1274   // SIMD-enabled block function.  StubGenerator makes the determination
1275   // based on the VM capabilities whether to use an AVX2 or AVX512-enabled
1276   // version.
1277   if (UseAVX >= 1) {
1278       if (FLAG_IS_DEFAULT(UseChaCha20Intrinsics)) {
1279           UseChaCha20Intrinsics = true;
1280       }
1281   } else if (UseChaCha20Intrinsics) {
1282       if (!FLAG_IS_DEFAULT(UseChaCha20Intrinsics)) {
1283           warning("ChaCha20 intrinsic requires AVX instructions");
1284       }
1285       FLAG_SET_DEFAULT(UseChaCha20Intrinsics, false);
1286   }
1287 
1288   // Kyber Intrinsics
1289   // Currently we only have them for AVX512
1290   if (supports_evex() && supports_avx512bw()) {
1291       if (FLAG_IS_DEFAULT(UseKyberIntrinsics)) {
1292           UseKyberIntrinsics = true;
1293       }
1294   } else
1295   if (UseKyberIntrinsics) {
1296      warning("Intrinsics for ML-KEM are not available on this CPU.");
1297      FLAG_SET_DEFAULT(UseKyberIntrinsics, false);
1298   }
1299 
1300   // Dilithium Intrinsics
1301   if (UseAVX > 1) {
1302       if (FLAG_IS_DEFAULT(UseDilithiumIntrinsics)) {
1303           UseDilithiumIntrinsics = true;
1304       }
1305   } else if (UseDilithiumIntrinsics) {
1306       warning("Intrinsics for ML-DSA are not available on this CPU.");
1307       FLAG_SET_DEFAULT(UseDilithiumIntrinsics, false);
1308   }
1309 
1310   // Base64 Intrinsics (Check the condition for which the intrinsic will be active)
1311   if (UseAVX >= 2) {
1312     if (FLAG_IS_DEFAULT(UseBASE64Intrinsics)) {
1313       UseBASE64Intrinsics = true;
1314     }
1315   } else if (UseBASE64Intrinsics) {
1316      if (!FLAG_IS_DEFAULT(UseBASE64Intrinsics))
1317       warning("Base64 intrinsic requires EVEX instructions on this CPU");
1318     FLAG_SET_DEFAULT(UseBASE64Intrinsics, false);
1319   }
1320 
1321   if (supports_fma()) {
1322     if (FLAG_IS_DEFAULT(UseFMA)) {
1323       UseFMA = true;
1324     }
1325   } else if (UseFMA) {
1326     warning("FMA instructions are not available on this CPU");
1327     FLAG_SET_DEFAULT(UseFMA, false);
1328   }
1329 
1330   if (FLAG_IS_DEFAULT(UseMD5Intrinsics)) {
1331     UseMD5Intrinsics = true;
1332   }
1333 
1334   if (supports_sha() || (supports_avx2() && supports_bmi2())) {
1335     if (FLAG_IS_DEFAULT(UseSHA)) {
1336       UseSHA = true;
1337     }
1338   } else if (UseSHA) {
1339     warning("SHA instructions are not available on this CPU");
1340     FLAG_SET_DEFAULT(UseSHA, false);
1341   }
1342 
1343   if (supports_sha() && supports_sse4_1() && UseSHA) {
1344     if (FLAG_IS_DEFAULT(UseSHA1Intrinsics)) {
1345       FLAG_SET_DEFAULT(UseSHA1Intrinsics, true);
1346     }
1347   } else if (UseSHA1Intrinsics) {
1348     warning("Intrinsics for SHA-1 crypto hash functions not available on this CPU.");
1349     FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
1350   }
1351 
1352   if (supports_sse4_1() && UseSHA) {
1353     if (FLAG_IS_DEFAULT(UseSHA256Intrinsics)) {
1354       FLAG_SET_DEFAULT(UseSHA256Intrinsics, true);
1355     }
1356   } else if (UseSHA256Intrinsics) {
1357     warning("Intrinsics for SHA-224 and SHA-256 crypto hash functions not available on this CPU.");
1358     FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
1359   }
1360 
1361   if (UseSHA && supports_avx2() && (supports_bmi2() || supports_sha512())) {
1362     if (FLAG_IS_DEFAULT(UseSHA512Intrinsics)) {
1363       FLAG_SET_DEFAULT(UseSHA512Intrinsics, true);
1364     }
1365   } else if (UseSHA512Intrinsics) {
1366     warning("Intrinsics for SHA-384 and SHA-512 crypto hash functions not available on this CPU.");
1367     FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
1368   }
1369 
1370   if (UseSHA && supports_evex() && supports_avx512bw()) {
1371     if (FLAG_IS_DEFAULT(UseSHA3Intrinsics)) {
1372       FLAG_SET_DEFAULT(UseSHA3Intrinsics, true);
1373     }
1374   } else if (UseSHA3Intrinsics) {
1375     warning("Intrinsics for SHA3-224, SHA3-256, SHA3-384 and SHA3-512 crypto hash functions not available on this CPU.");
1376     FLAG_SET_DEFAULT(UseSHA3Intrinsics, false);
1377   }
1378 
1379   if (!(UseSHA1Intrinsics || UseSHA256Intrinsics || UseSHA512Intrinsics || UseSHA3Intrinsics)) {
1380     FLAG_SET_DEFAULT(UseSHA, false);
1381   }
1382 
1383 #if COMPILER2_OR_JVMCI
1384   int max_vector_size = 0;
1385   if (UseAVX == 0 || !os_supports_avx_vectors()) {
1386     // 16 byte vectors (in XMM) are supported with SSE2+
1387     max_vector_size = 16;
1388   } else if (UseAVX == 1 || UseAVX == 2) {
1389     // 32 bytes vectors (in YMM) are only supported with AVX+
1390     max_vector_size = 32;
1391   } else if (UseAVX > 2) {
1392     // 64 bytes vectors (in ZMM) are only supported with AVX 3
1393     max_vector_size = 64;
1394   }
1395 
1396   int min_vector_size = 4; // We require MaxVectorSize to be at least 4 on 64bit
1397 
1398   if (!FLAG_IS_DEFAULT(MaxVectorSize)) {
1399     if (MaxVectorSize < min_vector_size) {
1400       warning("MaxVectorSize must be at least %i on this platform", min_vector_size);
1401       FLAG_SET_DEFAULT(MaxVectorSize, min_vector_size);
1402     }
1403     if (MaxVectorSize > max_vector_size) {
1404       warning("MaxVectorSize must be at most %i on this platform", max_vector_size);
1405       FLAG_SET_DEFAULT(MaxVectorSize, max_vector_size);
1406     }
1407     if (!is_power_of_2(MaxVectorSize)) {
1408       warning("MaxVectorSize must be a power of 2, setting to default: %i", max_vector_size);
1409       FLAG_SET_DEFAULT(MaxVectorSize, max_vector_size);
1410     }
1411   } else {
1412     // If default, use highest supported configuration
1413     FLAG_SET_DEFAULT(MaxVectorSize, max_vector_size);
1414   }
1415 
1416 #if defined(COMPILER2) && defined(ASSERT)
1417   if (MaxVectorSize > 0) {
1418     if (supports_avx() && PrintMiscellaneous && Verbose && TraceNewVectors) {
1419       tty->print_cr("State of YMM registers after signal handle:");
1420       int nreg = 4;
1421       const char* ymm_name[4] = {"0", "7", "8", "15"};
1422       for (int i = 0; i < nreg; i++) {
1423         tty->print("YMM%s:", ymm_name[i]);
1424         for (int j = 7; j >=0; j--) {
1425           tty->print(" %x", _cpuid_info.ymm_save[i*8 + j]);
1426         }
1427         tty->cr();
1428       }
1429     }
1430   }
1431 #endif // COMPILER2 && ASSERT
1432 
1433   if ((supports_avx512ifma() && supports_avx512vlbw()) || supports_avxifma())  {
1434     if (FLAG_IS_DEFAULT(UsePoly1305Intrinsics)) {
1435       FLAG_SET_DEFAULT(UsePoly1305Intrinsics, true);
1436     }
1437   } else if (UsePoly1305Intrinsics) {
1438     warning("Intrinsics for Poly1305 crypto hash functions not available on this CPU.");
1439     FLAG_SET_DEFAULT(UsePoly1305Intrinsics, false);
1440   }
1441 
1442   if ((supports_avx512ifma() && supports_avx512vlbw()) || supports_avxifma()) {
1443     if (FLAG_IS_DEFAULT(UseIntPolyIntrinsics)) {
1444       FLAG_SET_DEFAULT(UseIntPolyIntrinsics, true);
1445     }
1446   } else if (UseIntPolyIntrinsics) {
1447     warning("Intrinsics for Polynomial crypto functions not available on this CPU.");
1448     FLAG_SET_DEFAULT(UseIntPolyIntrinsics, false);
1449   }
1450 
1451   if (FLAG_IS_DEFAULT(UseMultiplyToLenIntrinsic)) {
1452     UseMultiplyToLenIntrinsic = true;
1453   }
1454   if (FLAG_IS_DEFAULT(UseSquareToLenIntrinsic)) {
1455     UseSquareToLenIntrinsic = true;
1456   }
1457   if (FLAG_IS_DEFAULT(UseMulAddIntrinsic)) {
1458     UseMulAddIntrinsic = true;
1459   }
1460   if (FLAG_IS_DEFAULT(UseMontgomeryMultiplyIntrinsic)) {
1461     UseMontgomeryMultiplyIntrinsic = true;
1462   }
1463   if (FLAG_IS_DEFAULT(UseMontgomerySquareIntrinsic)) {
1464     UseMontgomerySquareIntrinsic = true;
1465   }
1466 #endif // COMPILER2_OR_JVMCI
1467 
1468   // On new cpus instructions which update whole XMM register should be used
1469   // to prevent partial register stall due to dependencies on high half.
1470   //
1471   // UseXmmLoadAndClearUpper == true  --> movsd(xmm, mem)
1472   // UseXmmLoadAndClearUpper == false --> movlpd(xmm, mem)
1473   // UseXmmRegToRegMoveAll == true  --> movaps(xmm, xmm), movapd(xmm, xmm).
1474   // UseXmmRegToRegMoveAll == false --> movss(xmm, xmm),  movsd(xmm, xmm).
1475 
1476 
1477   if (is_zx()) { // ZX cpus specific settings
1478     if (FLAG_IS_DEFAULT(UseStoreImmI16)) {
1479       UseStoreImmI16 = false; // don't use it on ZX cpus
1480     }
1481     if ((cpu_family() == 6) || (cpu_family() == 7)) {
1482       if (FLAG_IS_DEFAULT(UseAddressNop)) {
1483         // Use it on all ZX cpus
1484         UseAddressNop = true;
1485       }
1486     }
1487     if (FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper)) {
1488       UseXmmLoadAndClearUpper = true; // use movsd on all ZX cpus
1489     }
1490     if (FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll)) {
1491       if (supports_sse3()) {
1492         UseXmmRegToRegMoveAll = true; // use movaps, movapd on new ZX cpus
1493       } else {
1494         UseXmmRegToRegMoveAll = false;
1495       }
1496     }
1497     if (((cpu_family() == 6) || (cpu_family() == 7)) && supports_sse3()) { // new ZX cpus
1498 #ifdef COMPILER2
1499       if (FLAG_IS_DEFAULT(MaxLoopPad)) {
1500         // For new ZX cpus do the next optimization:
1501         // don't align the beginning of a loop if there are enough instructions
1502         // left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
1503         // in current fetch line (OptoLoopAlignment) or the padding
1504         // is big (> MaxLoopPad).
1505         // Set MaxLoopPad to 11 for new ZX cpus to reduce number of
1506         // generated NOP instructions. 11 is the largest size of one
1507         // address NOP instruction '0F 1F' (see Assembler::nop(i)).
1508         MaxLoopPad = 11;
1509       }
1510 #endif // COMPILER2
1511       if (FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
1512         UseXMMForArrayCopy = true; // use SSE2 movq on new ZX cpus
1513       }
1514       if (supports_sse4_2()) { // new ZX cpus
1515         if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1516           UseUnalignedLoadStores = true; // use movdqu on newest ZX cpus
1517         }
1518       }
1519     }
1520 
1521     if (FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
1522       FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
1523     }
1524   }
1525 
1526   if (is_amd_family()) { // AMD cpus specific settings
1527     if (supports_sse2() && FLAG_IS_DEFAULT(UseAddressNop)) {
1528       // Use it on new AMD cpus starting from Opteron.
1529       UseAddressNop = true;
1530     }
1531     if (supports_sse2() && FLAG_IS_DEFAULT(UseNewLongLShift)) {
1532       // Use it on new AMD cpus starting from Opteron.
1533       UseNewLongLShift = true;
1534     }
1535     if (FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper)) {
1536       if (supports_sse4a()) {
1537         UseXmmLoadAndClearUpper = true; // use movsd only on '10h' Opteron
1538       } else {
1539         UseXmmLoadAndClearUpper = false;
1540       }
1541     }
1542     if (FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll)) {
1543       if (supports_sse4a()) {
1544         UseXmmRegToRegMoveAll = true; // use movaps, movapd only on '10h'
1545       } else {
1546         UseXmmRegToRegMoveAll = false;
1547       }
1548     }
1549     if (FLAG_IS_DEFAULT(UseXmmI2F)) {
1550       if (supports_sse4a()) {
1551         UseXmmI2F = true;
1552       } else {
1553         UseXmmI2F = false;
1554       }
1555     }
1556     if (FLAG_IS_DEFAULT(UseXmmI2D)) {
1557       if (supports_sse4a()) {
1558         UseXmmI2D = true;
1559       } else {
1560         UseXmmI2D = false;
1561       }
1562     }
1563 
1564     // some defaults for AMD family 15h
1565     if (cpu_family() == 0x15) {
1566       // On family 15h processors default is no sw prefetch
1567       if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
1568         FLAG_SET_DEFAULT(AllocatePrefetchStyle, 0);
1569       }
1570       // Also, if some other prefetch style is specified, default instruction type is PREFETCHW
1571       if (FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
1572         FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
1573       }
1574       // On family 15h processors use XMM and UnalignedLoadStores for Array Copy
1575       if (supports_sse2() && FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
1576         FLAG_SET_DEFAULT(UseXMMForArrayCopy, true);
1577       }
1578       if (supports_sse2() && FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1579         FLAG_SET_DEFAULT(UseUnalignedLoadStores, true);
1580       }
1581     }
1582 
1583 #ifdef COMPILER2
1584     if (cpu_family() < 0x17 && MaxVectorSize > 16) {
1585       // Limit vectors size to 16 bytes on AMD cpus < 17h.
1586       FLAG_SET_DEFAULT(MaxVectorSize, 16);
1587     }
1588 #endif // COMPILER2
1589 
1590     // Some defaults for AMD family >= 17h && Hygon family 18h
1591     if (cpu_family() >= 0x17) {
1592       // On family >=17h processors use XMM and UnalignedLoadStores
1593       // for Array Copy
1594       if (supports_sse2() && FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
1595         FLAG_SET_DEFAULT(UseXMMForArrayCopy, true);
1596       }
1597       if (supports_sse2() && FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1598         FLAG_SET_DEFAULT(UseUnalignedLoadStores, true);
1599       }
1600 #ifdef COMPILER2
1601       if (supports_sse4_2() && FLAG_IS_DEFAULT(UseFPUForSpilling)) {
1602         FLAG_SET_DEFAULT(UseFPUForSpilling, true);
1603       }
1604 #endif
1605     }
1606   }
1607 
1608   if (is_intel()) { // Intel cpus specific settings
1609     if (FLAG_IS_DEFAULT(UseStoreImmI16)) {
1610       UseStoreImmI16 = false; // don't use it on Intel cpus
1611     }
1612     if (is_intel_server_family() || cpu_family() == 15) {
1613       if (FLAG_IS_DEFAULT(UseAddressNop)) {
1614         // Use it on all Intel cpus starting from PentiumPro
1615         UseAddressNop = true;
1616       }
1617     }
1618     if (FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper)) {
1619       UseXmmLoadAndClearUpper = true; // use movsd on all Intel cpus
1620     }
1621     if (FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll)) {
1622       if (supports_sse3()) {
1623         UseXmmRegToRegMoveAll = true; // use movaps, movapd on new Intel cpus
1624       } else {
1625         UseXmmRegToRegMoveAll = false;
1626       }
1627     }
1628     if (is_intel_server_family() && supports_sse3()) { // New Intel cpus
1629 #ifdef COMPILER2
1630       if (FLAG_IS_DEFAULT(MaxLoopPad)) {
1631         // For new Intel cpus do the next optimization:
1632         // don't align the beginning of a loop if there are enough instructions
1633         // left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
1634         // in current fetch line (OptoLoopAlignment) or the padding
1635         // is big (> MaxLoopPad).
1636         // Set MaxLoopPad to 11 for new Intel cpus to reduce number of
1637         // generated NOP instructions. 11 is the largest size of one
1638         // address NOP instruction '0F 1F' (see Assembler::nop(i)).
1639         MaxLoopPad = 11;
1640       }
1641 #endif // COMPILER2
1642 
1643       if (FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
1644         UseXMMForArrayCopy = true; // use SSE2 movq on new Intel cpus
1645       }
1646       if ((supports_sse4_2() && supports_ht()) || supports_avx()) { // Newest Intel cpus
1647         if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1648           UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
1649         }
1650       }
1651     }
1652     if (is_atom_family() || is_knights_family()) {
1653 #ifdef COMPILER2
1654       if (FLAG_IS_DEFAULT(OptoScheduling)) {
1655         OptoScheduling = true;
1656       }
1657 #endif
1658       if (supports_sse4_2()) { // Silvermont
1659         if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1660           UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
1661         }
1662       }
1663       if (FLAG_IS_DEFAULT(UseIncDec)) {
1664         FLAG_SET_DEFAULT(UseIncDec, false);
1665       }
1666     }
1667     if (FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
1668       FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
1669     }
1670   }
1671 
1672 #ifdef COMPILER2
1673   if (UseAVX > 2) {
1674     if (FLAG_IS_DEFAULT(ArrayOperationPartialInlineSize) ||
1675         (!FLAG_IS_DEFAULT(ArrayOperationPartialInlineSize) &&
1676          ArrayOperationPartialInlineSize != 0 &&
1677          ArrayOperationPartialInlineSize != 16 &&
1678          ArrayOperationPartialInlineSize != 32 &&
1679          ArrayOperationPartialInlineSize != 64)) {
1680       int inline_size = 0;
1681       if (MaxVectorSize >= 64 && AVX3Threshold == 0) {
1682         inline_size = 64;
1683       } else if (MaxVectorSize >= 32) {
1684         inline_size = 32;
1685       } else if (MaxVectorSize >= 16) {
1686         inline_size = 16;
1687       }
1688       if(!FLAG_IS_DEFAULT(ArrayOperationPartialInlineSize)) {
1689         warning("Setting ArrayOperationPartialInlineSize as %d", inline_size);
1690       }
1691       ArrayOperationPartialInlineSize = inline_size;
1692     }
1693 
1694     if (ArrayOperationPartialInlineSize > MaxVectorSize) {
1695       ArrayOperationPartialInlineSize = MaxVectorSize >= 16 ? MaxVectorSize : 0;
1696       if (ArrayOperationPartialInlineSize) {
1697         warning("Setting ArrayOperationPartialInlineSize as MaxVectorSize=%zd", MaxVectorSize);
1698       } else {
1699         warning("Setting ArrayOperationPartialInlineSize as %zd", ArrayOperationPartialInlineSize);
1700       }
1701     }
1702   }
1703 
1704   if (FLAG_IS_DEFAULT(OptimizeFill)) {
1705     if (MaxVectorSize < 32 || (!EnableX86ECoreOpts && !VM_Version::supports_avx512vlbw())) {
1706       OptimizeFill = false;
1707     }
1708   }
1709 #endif
1710   if (supports_sse4_2()) {
1711     if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
1712       FLAG_SET_DEFAULT(UseSSE42Intrinsics, true);
1713     }
1714   } else {
1715     if (UseSSE42Intrinsics && !FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
1716       warning("SSE4.2 intrinsics require SSE4.2 instructions or higher. Intrinsics will be disabled.");
1717     }
1718     FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
1719   }
1720   if (UseSSE42Intrinsics) {
1721     if (FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic)) {
1722       UseVectorizedMismatchIntrinsic = true;
1723     }
1724   } else if (UseVectorizedMismatchIntrinsic) {
1725     if (!FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic))
1726       warning("vectorizedMismatch intrinsics are not available on this CPU");
1727     FLAG_SET_DEFAULT(UseVectorizedMismatchIntrinsic, false);
1728   }
1729   if (UseAVX >= 2) {
1730     FLAG_SET_DEFAULT(UseVectorizedHashCodeIntrinsic, true);
1731   } else if (UseVectorizedHashCodeIntrinsic) {
1732     if (!FLAG_IS_DEFAULT(UseVectorizedHashCodeIntrinsic))
1733       warning("vectorizedHashCode intrinsics are not available on this CPU");
1734     FLAG_SET_DEFAULT(UseVectorizedHashCodeIntrinsic, false);
1735   }
1736 
1737   // Use count leading zeros count instruction if available.
1738   if (supports_lzcnt()) {
1739     if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
1740       UseCountLeadingZerosInstruction = true;
1741     }
1742    } else if (UseCountLeadingZerosInstruction) {
1743     warning("lzcnt instruction is not available on this CPU");
1744     FLAG_SET_DEFAULT(UseCountLeadingZerosInstruction, false);
1745   }
1746 
1747   // Use count trailing zeros instruction if available
1748   if (supports_bmi1()) {
1749     // tzcnt does not require VEX prefix
1750     if (FLAG_IS_DEFAULT(UseCountTrailingZerosInstruction)) {
1751       if (!UseBMI1Instructions && !FLAG_IS_DEFAULT(UseBMI1Instructions)) {
1752         // Don't use tzcnt if BMI1 is switched off on command line.
1753         UseCountTrailingZerosInstruction = false;
1754       } else {
1755         UseCountTrailingZerosInstruction = true;
1756       }
1757     }
1758   } else if (UseCountTrailingZerosInstruction) {
1759     warning("tzcnt instruction is not available on this CPU");
1760     FLAG_SET_DEFAULT(UseCountTrailingZerosInstruction, false);
1761   }
1762 
1763   // BMI instructions (except tzcnt) use an encoding with VEX prefix.
1764   // VEX prefix is generated only when AVX > 0.
1765   if (supports_bmi1() && supports_avx()) {
1766     if (FLAG_IS_DEFAULT(UseBMI1Instructions)) {
1767       UseBMI1Instructions = true;
1768     }
1769   } else if (UseBMI1Instructions) {
1770     warning("BMI1 instructions are not available on this CPU (AVX is also required)");
1771     FLAG_SET_DEFAULT(UseBMI1Instructions, false);
1772   }
1773 
1774   if (supports_bmi2() && supports_avx()) {
1775     if (FLAG_IS_DEFAULT(UseBMI2Instructions)) {
1776       UseBMI2Instructions = true;
1777     }
1778   } else if (UseBMI2Instructions) {
1779     warning("BMI2 instructions are not available on this CPU (AVX is also required)");
1780     FLAG_SET_DEFAULT(UseBMI2Instructions, false);
1781   }
1782 
1783   // Use population count instruction if available.
1784   if (supports_popcnt()) {
1785     if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
1786       UsePopCountInstruction = true;
1787     }
1788   } else if (UsePopCountInstruction) {
1789     warning("POPCNT instruction is not available on this CPU");
1790     FLAG_SET_DEFAULT(UsePopCountInstruction, false);
1791   }
1792 
1793   // Use fast-string operations if available.
1794   if (supports_erms()) {
1795     if (FLAG_IS_DEFAULT(UseFastStosb)) {
1796       UseFastStosb = true;
1797     }
1798   } else if (UseFastStosb) {
1799     warning("fast-string operations are not available on this CPU");
1800     FLAG_SET_DEFAULT(UseFastStosb, false);
1801   }
1802 
1803   // For AMD Processors use XMM/YMM MOVDQU instructions
1804   // for Object Initialization as default
1805   if (is_amd() && cpu_family() >= 0x19) {
1806     if (FLAG_IS_DEFAULT(UseFastStosb)) {
1807       UseFastStosb = false;
1808     }
1809   }
1810 
1811 #ifdef COMPILER2
1812   if (is_intel() && MaxVectorSize > 16) {
1813     if (FLAG_IS_DEFAULT(UseFastStosb)) {
1814       UseFastStosb = false;
1815     }
1816   }
1817 #endif
1818 
1819   // Use XMM/YMM MOVDQU instruction for Object Initialization
1820   if (!UseFastStosb && UseUnalignedLoadStores) {
1821     if (FLAG_IS_DEFAULT(UseXMMForObjInit)) {
1822       UseXMMForObjInit = true;
1823     }
1824   } else if (UseXMMForObjInit) {
1825     warning("UseXMMForObjInit requires SSE2 and unaligned load/stores. Feature is switched off.");
1826     FLAG_SET_DEFAULT(UseXMMForObjInit, false);
1827   }
1828 
1829 #ifdef COMPILER2
1830   if (FLAG_IS_DEFAULT(AlignVector)) {
1831     // Modern processors allow misaligned memory operations for vectors.
1832     AlignVector = !UseUnalignedLoadStores;
1833   }
1834 #endif // COMPILER2
1835 
1836   if (FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
1837     if (AllocatePrefetchInstr == 3 && !supports_3dnow_prefetch()) {
1838       FLAG_SET_DEFAULT(AllocatePrefetchInstr, 0);
1839     } else if (!supports_sse() && supports_3dnow_prefetch()) {
1840       FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
1841     }
1842   }
1843 
1844   // Allocation prefetch settings
1845   int cache_line_size = checked_cast<int>(prefetch_data_size());
1846   if (FLAG_IS_DEFAULT(AllocatePrefetchStepSize) &&
1847       (cache_line_size > AllocatePrefetchStepSize)) {
1848     FLAG_SET_DEFAULT(AllocatePrefetchStepSize, cache_line_size);
1849   }
1850 
1851   if ((AllocatePrefetchDistance == 0) && (AllocatePrefetchStyle != 0)) {
1852     assert(!FLAG_IS_DEFAULT(AllocatePrefetchDistance), "default value should not be 0");
1853     if (!FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
1854       warning("AllocatePrefetchDistance is set to 0 which disable prefetching. Ignoring AllocatePrefetchStyle flag.");
1855     }
1856     FLAG_SET_DEFAULT(AllocatePrefetchStyle, 0);
1857   }
1858 
1859   if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
1860     bool use_watermark_prefetch = (AllocatePrefetchStyle == 2);
1861     FLAG_SET_DEFAULT(AllocatePrefetchDistance, allocate_prefetch_distance(use_watermark_prefetch));
1862   }
1863 
1864   if (is_intel() && is_intel_server_family() && supports_sse3()) {
1865     if (FLAG_IS_DEFAULT(AllocatePrefetchLines) &&
1866         supports_sse4_2() && supports_ht()) { // Nehalem based cpus
1867       FLAG_SET_DEFAULT(AllocatePrefetchLines, 4);
1868     }
1869 #ifdef COMPILER2
1870     if (FLAG_IS_DEFAULT(UseFPUForSpilling) && supports_sse4_2()) {
1871       FLAG_SET_DEFAULT(UseFPUForSpilling, true);
1872     }
1873 #endif
1874   }
1875 
1876   if (is_zx() && ((cpu_family() == 6) || (cpu_family() == 7)) && supports_sse4_2()) {
1877 #ifdef COMPILER2
1878     if (FLAG_IS_DEFAULT(UseFPUForSpilling)) {
1879       FLAG_SET_DEFAULT(UseFPUForSpilling, true);
1880     }
1881 #endif
1882   }
1883 
1884   // Prefetch settings
1885 
1886   // Prefetch interval for gc copy/scan == 9 dcache lines.  Derived from
1887   // 50-warehouse specjbb runs on a 2-way 1.8ghz opteron using a 4gb heap.
1888   // Tested intervals from 128 to 2048 in increments of 64 == one cache line.
1889   // 256 bytes (4 dcache lines) was the nearest runner-up to 576.
1890 
1891   // gc copy/scan is disabled if prefetchw isn't supported, because
1892   // Prefetch::write emits an inlined prefetchw on Linux.
1893   // Do not use the 3dnow prefetchw instruction.  It isn't supported on em64t.
1894   // The used prefetcht0 instruction works for both amd64 and em64t.
1895 
1896   if (FLAG_IS_DEFAULT(PrefetchCopyIntervalInBytes)) {
1897     FLAG_SET_DEFAULT(PrefetchCopyIntervalInBytes, 576);
1898   }
1899   if (FLAG_IS_DEFAULT(PrefetchScanIntervalInBytes)) {
1900     FLAG_SET_DEFAULT(PrefetchScanIntervalInBytes, 576);
1901   }
1902 
1903   if (FLAG_IS_DEFAULT(ContendedPaddingWidth) &&
1904      (cache_line_size > ContendedPaddingWidth))
1905      ContendedPaddingWidth = cache_line_size;
1906 
1907   // This machine allows unaligned memory accesses
1908   if (FLAG_IS_DEFAULT(UseUnalignedAccesses)) {
1909     FLAG_SET_DEFAULT(UseUnalignedAccesses, true);
1910   }
1911 
1912 #ifndef PRODUCT
1913   if (log_is_enabled(Info, os, cpu)) {
1914     LogStream ls(Log(os, cpu)::info());
1915     outputStream* log = &ls;
1916     log->print_cr("Logical CPUs per core: %u",
1917                   logical_processors_per_package());
1918     log->print_cr("L1 data cache line size: %u", L1_data_cache_line_size());
1919     log->print("UseSSE=%d", UseSSE);
1920     if (UseAVX > 0) {
1921       log->print("  UseAVX=%d", UseAVX);
1922     }
1923     if (UseAES) {
1924       log->print("  UseAES=1");
1925     }
1926 #ifdef COMPILER2
1927     if (MaxVectorSize > 0) {
1928       log->print("  MaxVectorSize=%d", (int) MaxVectorSize);
1929     }
1930 #endif
1931     log->cr();
1932     log->print("Allocation");
1933     if (AllocatePrefetchStyle <= 0) {
1934       log->print_cr(": no prefetching");
1935     } else {
1936       log->print(" prefetching: ");
1937       if (AllocatePrefetchInstr == 0) {
1938         log->print("PREFETCHNTA");
1939       } else if (AllocatePrefetchInstr == 1) {
1940         log->print("PREFETCHT0");
1941       } else if (AllocatePrefetchInstr == 2) {
1942         log->print("PREFETCHT2");
1943       } else if (AllocatePrefetchInstr == 3) {
1944         log->print("PREFETCHW");
1945       }
1946       if (AllocatePrefetchLines > 1) {
1947         log->print_cr(" at distance %d, %d lines of %d bytes", AllocatePrefetchDistance, AllocatePrefetchLines, AllocatePrefetchStepSize);
1948       } else {
1949         log->print_cr(" at distance %d, one line of %d bytes", AllocatePrefetchDistance, AllocatePrefetchStepSize);
1950       }
1951     }
1952 
1953     if (PrefetchCopyIntervalInBytes > 0) {
1954       log->print_cr("PrefetchCopyIntervalInBytes %d", (int) PrefetchCopyIntervalInBytes);
1955     }
1956     if (PrefetchScanIntervalInBytes > 0) {
1957       log->print_cr("PrefetchScanIntervalInBytes %d", (int) PrefetchScanIntervalInBytes);
1958     }
1959     if (ContendedPaddingWidth > 0) {
1960       log->print_cr("ContendedPaddingWidth %d", (int) ContendedPaddingWidth);
1961     }
1962   }
1963 #endif // !PRODUCT
1964   if (FLAG_IS_DEFAULT(UseSignumIntrinsic)) {
1965       FLAG_SET_DEFAULT(UseSignumIntrinsic, true);
1966   }
1967   if (FLAG_IS_DEFAULT(UseCopySignIntrinsic)) {
1968       FLAG_SET_DEFAULT(UseCopySignIntrinsic, true);
1969   }
1970 }
1971 
1972 void VM_Version::print_platform_virtualization_info(outputStream* st) {
1973   VirtualizationType vrt = VM_Version::get_detected_virtualization();
1974   if (vrt == XenHVM) {
1975     st->print_cr("Xen hardware-assisted virtualization detected");
1976   } else if (vrt == KVM) {
1977     st->print_cr("KVM virtualization detected");
1978   } else if (vrt == VMWare) {
1979     st->print_cr("VMWare virtualization detected");
1980     VirtualizationSupport::print_virtualization_info(st);
1981   } else if (vrt == HyperV) {
1982     st->print_cr("Hyper-V virtualization detected");
1983   } else if (vrt == HyperVRole) {
1984     st->print_cr("Hyper-V role detected");
1985   }
1986 }
1987 
1988 bool VM_Version::compute_has_intel_jcc_erratum() {
1989   if (!is_intel_family_core()) {
1990     // Only Intel CPUs are affected.
1991     return false;
1992   }
1993   // The following table of affected CPUs is based on the following document released by Intel:
1994   // https://www.intel.com/content/dam/support/us/en/documents/processors/mitigations-jump-conditional-code-erratum.pdf
1995   switch (_model) {
1996   case 0x8E:
1997     // 06_8EH | 9 | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Amber Lake Y
1998     // 06_8EH | 9 | 7th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake U
1999     // 06_8EH | 9 | 7th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake U 23e
2000     // 06_8EH | 9 | 7th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake Y
2001     // 06_8EH | A | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Coffee Lake U43e
2002     // 06_8EH | B | 8th Generation Intel(R) Core(TM) Processors based on microarchitecture code name Whiskey Lake U
2003     // 06_8EH | C | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Amber Lake Y
2004     // 06_8EH | C | 10th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Comet Lake U42
2005     // 06_8EH | C | 8th Generation Intel(R) Core(TM) Processors based on microarchitecture code name Whiskey Lake U
2006     return _stepping == 0x9 || _stepping == 0xA || _stepping == 0xB || _stepping == 0xC;
2007   case 0x4E:
2008     // 06_4E  | 3 | 6th Generation Intel(R) Core(TM) Processors based on microarchitecture code name Skylake U
2009     // 06_4E  | 3 | 6th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Skylake U23e
2010     // 06_4E  | 3 | 6th Generation Intel(R) Core(TM) Processors based on microarchitecture code name Skylake Y
2011     return _stepping == 0x3;
2012   case 0x55:
2013     // 06_55H | 4 | Intel(R) Xeon(R) Processor D Family based on microarchitecture code name Skylake D, Bakerville
2014     // 06_55H | 4 | Intel(R) Xeon(R) Scalable Processors based on microarchitecture code name Skylake Server
2015     // 06_55H | 4 | Intel(R) Xeon(R) Processor W Family based on microarchitecture code name Skylake W
2016     // 06_55H | 4 | Intel(R) Core(TM) X-series Processors based on microarchitecture code name Skylake X
2017     // 06_55H | 4 | Intel(R) Xeon(R) Processor E3 v5 Family based on microarchitecture code name Skylake Xeon E3
2018     // 06_55  | 7 | 2nd Generation Intel(R) Xeon(R) Scalable Processors based on microarchitecture code name Cascade Lake (server)
2019     return _stepping == 0x4 || _stepping == 0x7;
2020   case 0x5E:
2021     // 06_5E  | 3 | 6th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Skylake H
2022     // 06_5E  | 3 | 6th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Skylake S
2023     return _stepping == 0x3;
2024   case 0x9E:
2025     // 06_9EH | 9 | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake G
2026     // 06_9EH | 9 | 7th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake H
2027     // 06_9EH | 9 | 7th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake S
2028     // 06_9EH | 9 | Intel(R) Core(TM) X-series Processors based on microarchitecture code name Kaby Lake X
2029     // 06_9EH | 9 | Intel(R) Xeon(R) Processor E3 v6 Family Kaby Lake Xeon E3
2030     // 06_9EH | A | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Coffee Lake H
2031     // 06_9EH | A | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Coffee Lake S
2032     // 06_9EH | A | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Coffee Lake S (6+2) x/KBP
2033     // 06_9EH | A | Intel(R) Xeon(R) Processor E Family based on microarchitecture code name Coffee Lake S (6+2)
2034     // 06_9EH | A | Intel(R) Xeon(R) Processor E Family based on microarchitecture code name Coffee Lake S (4+2)
2035     // 06_9EH | B | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Coffee Lake S (4+2)
2036     // 06_9EH | B | Intel(R) Celeron(R) Processor G Series based on microarchitecture code name Coffee Lake S (4+2)
2037     // 06_9EH | D | 9th Generation Intel(R) Core(TM) Processor Family based on microarchitecturecode name Coffee Lake H (8+2)
2038     // 06_9EH | D | 9th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Coffee Lake S (8+2)
2039     return _stepping == 0x9 || _stepping == 0xA || _stepping == 0xB || _stepping == 0xD;
2040   case 0xA5:
2041     // Not in Intel documentation.
2042     // 06_A5H |    | 10th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Comet Lake S/H
2043     return true;
2044   case 0xA6:
2045     // 06_A6H | 0  | 10th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Comet Lake U62
2046     return _stepping == 0x0;
2047   case 0xAE:
2048     // 06_AEH | A | 8th Generation Intel(R) Core(TM) Processor Family based on microarchitecture code name Kaby Lake Refresh U (4+2)
2049     return _stepping == 0xA;
2050   default:
2051     // If we are running on another intel machine not recognized in the table, we are okay.
2052     return false;
2053   }
2054 }
2055 
2056 // On Xen, the cpuid instruction returns
2057 //  eax / registers[0]: Version of Xen
2058 //  ebx / registers[1]: chars 'XenV'
2059 //  ecx / registers[2]: chars 'MMXe'
2060 //  edx / registers[3]: chars 'nVMM'
2061 //
2062 // On KVM / VMWare / MS Hyper-V, the cpuid instruction returns
2063 //  ebx / registers[1]: chars 'KVMK' / 'VMwa' / 'Micr'
2064 //  ecx / registers[2]: chars 'VMKV' / 'reVM' / 'osof'
2065 //  edx / registers[3]: chars 'M'    / 'ware' / 't Hv'
2066 //
2067 // more information :
2068 // https://kb.vmware.com/s/article/1009458
2069 //
2070 void VM_Version::check_virtualizations() {
2071   uint32_t registers[4] = {0};
2072   char signature[13] = {0};
2073 
2074   // Xen cpuid leaves can be found 0x100 aligned boundary starting
2075   // from 0x40000000 until 0x40010000.
2076   //   https://lists.linuxfoundation.org/pipermail/virtualization/2012-May/019974.html
2077   for (int leaf = 0x40000000; leaf < 0x40010000; leaf += 0x100) {
2078     detect_virt_stub(leaf, registers);
2079     memcpy(signature, &registers[1], 12);
2080 
2081     if (strncmp("VMwareVMware", signature, 12) == 0) {
2082       Abstract_VM_Version::_detected_virtualization = VMWare;
2083       // check for extended metrics from guestlib
2084       VirtualizationSupport::initialize();
2085     } else if (strncmp("Microsoft Hv", signature, 12) == 0) {
2086       Abstract_VM_Version::_detected_virtualization = HyperV;
2087 #ifdef _WINDOWS
2088       // CPUID leaf 0x40000007 is available to the root partition only.
2089       // See Hypervisor Top Level Functional Specification section 2.4.8 for more details.
2090       //   https://github.com/MicrosoftDocs/Virtualization-Documentation/raw/master/tlfs/Hypervisor%20Top%20Level%20Functional%20Specification%20v6.0b.pdf
2091       detect_virt_stub(0x40000007, registers);
2092       if ((registers[0] != 0x0) ||
2093           (registers[1] != 0x0) ||
2094           (registers[2] != 0x0) ||
2095           (registers[3] != 0x0)) {
2096         Abstract_VM_Version::_detected_virtualization = HyperVRole;
2097       }
2098 #endif
2099     } else if (strncmp("KVMKVMKVM", signature, 9) == 0) {
2100       Abstract_VM_Version::_detected_virtualization = KVM;
2101     } else if (strncmp("XenVMMXenVMM", signature, 12) == 0) {
2102       Abstract_VM_Version::_detected_virtualization = XenHVM;
2103     }
2104   }
2105 }
2106 
2107 #ifdef COMPILER2
2108 // Determine if it's running on Cascade Lake using default options.
2109 bool VM_Version::is_default_intel_cascade_lake() {
2110   return FLAG_IS_DEFAULT(UseAVX) &&
2111          FLAG_IS_DEFAULT(MaxVectorSize) &&
2112          UseAVX > 2 &&
2113          is_intel_cascade_lake();
2114 }
2115 #endif
2116 
2117 bool VM_Version::is_intel_cascade_lake() {
2118   return is_intel_skylake() && _stepping >= 5;
2119 }
2120 
2121 bool VM_Version::is_intel_darkmont() {
2122   return is_intel() && is_intel_server_family() && (_model == 0xCC || _model == 0xDD);
2123 }
2124 
2125 // avx3_threshold() sets the threshold at which 64-byte instructions are used
2126 // for implementing the array copy and clear operations.
2127 // The Intel platforms that supports the serialize instruction
2128 // has improved implementation of 64-byte load/stores and so the default
2129 // threshold is set to 0 for these platforms.
2130 int VM_Version::avx3_threshold() {
2131   return (is_intel_server_family() &&
2132           supports_serialize() &&
2133           FLAG_IS_DEFAULT(AVX3Threshold)) ? 0 : AVX3Threshold;
2134 }
2135 
2136 void VM_Version::clear_apx_test_state() {
2137   clear_apx_test_state_stub();
2138 }
2139 
2140 static bool _vm_version_initialized = false;
2141 
2142 void VM_Version::initialize() {
2143   ResourceMark rm;
2144 
2145   // Making this stub must be FIRST use of assembler
2146   stub_blob = BufferBlob::create("VM_Version stub", stub_size);
2147   if (stub_blob == nullptr) {
2148     vm_exit_during_initialization("Unable to allocate stub for VM_Version");
2149   }
2150   CodeBuffer c(stub_blob);
2151   VM_Version_StubGenerator g(&c);
2152 
2153   get_cpu_info_stub = CAST_TO_FN_PTR(get_cpu_info_stub_t,
2154                                      g.generate_get_cpu_info());
2155   detect_virt_stub = CAST_TO_FN_PTR(detect_virt_stub_t,
2156                                      g.generate_detect_virt());
2157   clear_apx_test_state_stub = CAST_TO_FN_PTR(clear_apx_test_state_t,
2158                                      g.clear_apx_test_state());
2159   getCPUIDBrandString_stub = CAST_TO_FN_PTR(getCPUIDBrandString_stub_t,
2160                                      g.generate_getCPUIDBrandString());
2161   get_processor_features();
2162 
2163   Assembler::precompute_instructions();
2164 
2165   if (VM_Version::supports_hv()) { // Supports hypervisor
2166     check_virtualizations();
2167   }
2168   _vm_version_initialized = true;
2169 }
2170 
2171 typedef enum {
2172    CPU_FAMILY_8086_8088  = 0,
2173    CPU_FAMILY_INTEL_286  = 2,
2174    CPU_FAMILY_INTEL_386  = 3,
2175    CPU_FAMILY_INTEL_486  = 4,
2176    CPU_FAMILY_PENTIUM    = 5,
2177    CPU_FAMILY_PENTIUMPRO = 6,    // Same family several models
2178    CPU_FAMILY_PENTIUM_4  = 0xF
2179 } FamilyFlag;
2180 
2181 typedef enum {
2182   RDTSCP_FLAG  = 0x08000000, // bit 27
2183   INTEL64_FLAG = 0x20000000  // bit 29
2184 } _featureExtendedEdxFlag;
2185 
2186 typedef enum {
2187    FPU_FLAG     = 0x00000001,
2188    VME_FLAG     = 0x00000002,
2189    DE_FLAG      = 0x00000004,
2190    PSE_FLAG     = 0x00000008,
2191    TSC_FLAG     = 0x00000010,
2192    MSR_FLAG     = 0x00000020,
2193    PAE_FLAG     = 0x00000040,
2194    MCE_FLAG     = 0x00000080,
2195    CX8_FLAG     = 0x00000100,
2196    APIC_FLAG    = 0x00000200,
2197    SEP_FLAG     = 0x00000800,
2198    MTRR_FLAG    = 0x00001000,
2199    PGE_FLAG     = 0x00002000,
2200    MCA_FLAG     = 0x00004000,
2201    CMOV_FLAG    = 0x00008000,
2202    PAT_FLAG     = 0x00010000,
2203    PSE36_FLAG   = 0x00020000,
2204    PSNUM_FLAG   = 0x00040000,
2205    CLFLUSH_FLAG = 0x00080000,
2206    DTS_FLAG     = 0x00200000,
2207    ACPI_FLAG    = 0x00400000,
2208    MMX_FLAG     = 0x00800000,
2209    FXSR_FLAG    = 0x01000000,
2210    SSE_FLAG     = 0x02000000,
2211    SSE2_FLAG    = 0x04000000,
2212    SS_FLAG      = 0x08000000,
2213    HTT_FLAG     = 0x10000000,
2214    TM_FLAG      = 0x20000000
2215 } FeatureEdxFlag;
2216 
2217 // VM_Version statics
2218 enum {
2219   ExtendedFamilyIdLength_INTEL = 16,
2220   ExtendedFamilyIdLength_AMD   = 24
2221 };
2222 
2223 const size_t VENDOR_LENGTH = 13;
2224 const size_t CPU_EBS_MAX_LENGTH = (3 * 4 * 4 + 1);
2225 static char* _cpu_brand_string = nullptr;
2226 static int64_t _max_qualified_cpu_frequency = 0;
2227 
2228 static int _no_of_threads = 0;
2229 static int _no_of_cores = 0;
2230 
2231 const char* const _family_id_intel[ExtendedFamilyIdLength_INTEL] = {
2232   "8086/8088",
2233   "",
2234   "286",
2235   "386",
2236   "486",
2237   "Pentium",
2238   "Pentium Pro",   //or Pentium-M/Woodcrest depending on model
2239   "",
2240   "",
2241   "",
2242   "",
2243   "",
2244   "",
2245   "",
2246   "",
2247   "Pentium 4"
2248 };
2249 
2250 const char* const _family_id_amd[ExtendedFamilyIdLength_AMD] = {
2251   "",
2252   "",
2253   "",
2254   "",
2255   "5x86",
2256   "K5/K6",
2257   "Athlon/AthlonXP",
2258   "",
2259   "",
2260   "",
2261   "",
2262   "",
2263   "",
2264   "",
2265   "",
2266   "Opteron/Athlon64",
2267   "Opteron QC/Phenom",  // Barcelona et.al.
2268   "",
2269   "",
2270   "",
2271   "",
2272   "",
2273   "",
2274   "Zen"
2275 };
2276 // Partially from Intel 64 and IA-32 Architecture Software Developer's Manual,
2277 // September 2013, Vol 3C Table 35-1
2278 const char* const _model_id_pentium_pro[] = {
2279   "",
2280   "Pentium Pro",
2281   "",
2282   "Pentium II model 3",
2283   "",
2284   "Pentium II model 5/Xeon/Celeron",
2285   "Celeron",
2286   "Pentium III/Pentium III Xeon",
2287   "Pentium III/Pentium III Xeon",
2288   "Pentium M model 9",    // Yonah
2289   "Pentium III, model A",
2290   "Pentium III, model B",
2291   "",
2292   "Pentium M model D",    // Dothan
2293   "",
2294   "Core 2",               // 0xf Woodcrest/Conroe/Merom/Kentsfield/Clovertown
2295   "",
2296   "",
2297   "",
2298   "",
2299   "",
2300   "",
2301   "Celeron",              // 0x16 Celeron 65nm
2302   "Core 2",               // 0x17 Penryn / Harpertown
2303   "",
2304   "",
2305   "Core i7",              // 0x1A CPU_MODEL_NEHALEM_EP
2306   "Atom",                 // 0x1B Z5xx series Silverthorn
2307   "",
2308   "Core 2",               // 0x1D Dunnington (6-core)
2309   "Nehalem",              // 0x1E CPU_MODEL_NEHALEM
2310   "",
2311   "",
2312   "",
2313   "",
2314   "",
2315   "",
2316   "Westmere",             // 0x25 CPU_MODEL_WESTMERE
2317   "",
2318   "",
2319   "",                     // 0x28
2320   "",
2321   "Sandy Bridge",         // 0x2a "2nd Generation Intel Core i7, i5, i3"
2322   "",
2323   "Westmere-EP",          // 0x2c CPU_MODEL_WESTMERE_EP
2324   "Sandy Bridge-EP",      // 0x2d CPU_MODEL_SANDYBRIDGE_EP
2325   "Nehalem-EX",           // 0x2e CPU_MODEL_NEHALEM_EX
2326   "Westmere-EX",          // 0x2f CPU_MODEL_WESTMERE_EX
2327   "",
2328   "",
2329   "",
2330   "",
2331   "",
2332   "",
2333   "",
2334   "",
2335   "",
2336   "",
2337   "Ivy Bridge",           // 0x3a
2338   "",
2339   "Haswell",              // 0x3c "4th Generation Intel Core Processor"
2340   "",                     // 0x3d "Next Generation Intel Core Processor"
2341   "Ivy Bridge-EP",        // 0x3e "Next Generation Intel Xeon Processor E7 Family"
2342   "",                     // 0x3f "Future Generation Intel Xeon Processor"
2343   "",
2344   "",
2345   "",
2346   "",
2347   "",
2348   "Haswell",              // 0x45 "4th Generation Intel Core Processor"
2349   "Haswell",              // 0x46 "4th Generation Intel Core Processor"
2350   nullptr
2351 };
2352 
2353 /* Brand ID is for back compatibility
2354  * Newer CPUs uses the extended brand string */
2355 const char* const _brand_id[] = {
2356   "",
2357   "Celeron processor",
2358   "Pentium III processor",
2359   "Intel Pentium III Xeon processor",
2360   "",
2361   "",
2362   "",
2363   "",
2364   "Intel Pentium 4 processor",
2365   nullptr
2366 };
2367 
2368 
2369 const char* const _feature_edx_id[] = {
2370   "On-Chip FPU",
2371   "Virtual Mode Extensions",
2372   "Debugging Extensions",
2373   "Page Size Extensions",
2374   "Time Stamp Counter",
2375   "Model Specific Registers",
2376   "Physical Address Extension",
2377   "Machine Check Exceptions",
2378   "CMPXCHG8B Instruction",
2379   "On-Chip APIC",
2380   "",
2381   "Fast System Call",
2382   "Memory Type Range Registers",
2383   "Page Global Enable",
2384   "Machine Check Architecture",
2385   "Conditional Mov Instruction",
2386   "Page Attribute Table",
2387   "36-bit Page Size Extension",
2388   "Processor Serial Number",
2389   "CLFLUSH Instruction",
2390   "",
2391   "Debug Trace Store feature",
2392   "ACPI registers in MSR space",
2393   "Intel Architecture MMX Technology",
2394   "Fast Float Point Save and Restore",
2395   "Streaming SIMD extensions",
2396   "Streaming SIMD extensions 2",
2397   "Self-Snoop",
2398   "Hyper Threading",
2399   "Thermal Monitor",
2400   "",
2401   "Pending Break Enable"
2402 };
2403 
2404 const char* const _feature_extended_edx_id[] = {
2405   "",
2406   "",
2407   "",
2408   "",
2409   "",
2410   "",
2411   "",
2412   "",
2413   "",
2414   "",
2415   "",
2416   "SYSCALL/SYSRET",
2417   "",
2418   "",
2419   "",
2420   "",
2421   "",
2422   "",
2423   "",
2424   "",
2425   "Execute Disable Bit",
2426   "",
2427   "",
2428   "",
2429   "",
2430   "",
2431   "",
2432   "RDTSCP",
2433   "",
2434   "Intel 64 Architecture",
2435   "",
2436   ""
2437 };
2438 
2439 const char* const _feature_ecx_id[] = {
2440   "Streaming SIMD Extensions 3",
2441   "PCLMULQDQ",
2442   "64-bit DS Area",
2443   "MONITOR/MWAIT instructions",
2444   "CPL Qualified Debug Store",
2445   "Virtual Machine Extensions",
2446   "Safer Mode Extensions",
2447   "Enhanced Intel SpeedStep technology",
2448   "Thermal Monitor 2",
2449   "Supplemental Streaming SIMD Extensions 3",
2450   "L1 Context ID",
2451   "",
2452   "Fused Multiply-Add",
2453   "CMPXCHG16B",
2454   "xTPR Update Control",
2455   "Perfmon and Debug Capability",
2456   "",
2457   "Process-context identifiers",
2458   "Direct Cache Access",
2459   "Streaming SIMD extensions 4.1",
2460   "Streaming SIMD extensions 4.2",
2461   "x2APIC",
2462   "MOVBE",
2463   "Popcount instruction",
2464   "TSC-Deadline",
2465   "AESNI",
2466   "XSAVE",
2467   "OSXSAVE",
2468   "AVX",
2469   "F16C",
2470   "RDRAND",
2471   ""
2472 };
2473 
2474 const char* const _feature_extended_ecx_id[] = {
2475   "LAHF/SAHF instruction support",
2476   "Core multi-processor legacy mode",
2477   "",
2478   "",
2479   "",
2480   "Advanced Bit Manipulations: LZCNT",
2481   "SSE4A: MOVNTSS, MOVNTSD, EXTRQ, INSERTQ",
2482   "Misaligned SSE mode",
2483   "",
2484   "",
2485   "",
2486   "",
2487   "",
2488   "",
2489   "",
2490   "",
2491   "",
2492   "",
2493   "",
2494   "",
2495   "",
2496   "",
2497   "",
2498   "",
2499   "",
2500   "",
2501   "",
2502   "",
2503   "",
2504   "",
2505   "",
2506   ""
2507 };
2508 
2509 const char* VM_Version::cpu_model_description(void) {
2510   uint32_t cpu_family = extended_cpu_family();
2511   uint32_t cpu_model = extended_cpu_model();
2512   const char* model = nullptr;
2513 
2514   if (cpu_family == CPU_FAMILY_PENTIUMPRO) {
2515     for (uint32_t i = 0; i <= cpu_model; i++) {
2516       model = _model_id_pentium_pro[i];
2517       if (model == nullptr) {
2518         break;
2519       }
2520     }
2521   }
2522   return model;
2523 }
2524 
2525 const char* VM_Version::cpu_brand_string(void) {
2526   if (_cpu_brand_string == nullptr) {
2527     _cpu_brand_string = NEW_C_HEAP_ARRAY_RETURN_NULL(char, CPU_EBS_MAX_LENGTH, mtInternal);
2528     if (nullptr == _cpu_brand_string) {
2529       return nullptr;
2530     }
2531     int ret_val = cpu_extended_brand_string(_cpu_brand_string, CPU_EBS_MAX_LENGTH);
2532     if (ret_val != OS_OK) {
2533       FREE_C_HEAP_ARRAY(char, _cpu_brand_string);
2534       _cpu_brand_string = nullptr;
2535     }
2536   }
2537   return _cpu_brand_string;
2538 }
2539 
2540 const char* VM_Version::cpu_brand(void) {
2541   const char*  brand  = nullptr;
2542 
2543   if ((_cpuid_info.std_cpuid1_ebx.value & 0xFF) > 0) {
2544     int brand_num = _cpuid_info.std_cpuid1_ebx.value & 0xFF;
2545     brand = _brand_id[0];
2546     for (int i = 0; brand != nullptr && i <= brand_num; i += 1) {
2547       brand = _brand_id[i];
2548     }
2549   }
2550   return brand;
2551 }
2552 
2553 bool VM_Version::cpu_is_em64t(void) {
2554   return ((_cpuid_info.ext_cpuid1_edx.value & INTEL64_FLAG) == INTEL64_FLAG);
2555 }
2556 
2557 bool VM_Version::is_netburst(void) {
2558   return (is_intel() && (extended_cpu_family() == CPU_FAMILY_PENTIUM_4));
2559 }
2560 
2561 bool VM_Version::supports_tscinv_ext(void) {
2562   if (!supports_tscinv_bit()) {
2563     return false;
2564   }
2565 
2566   if (is_intel()) {
2567     return true;
2568   }
2569 
2570   if (is_amd()) {
2571     return !is_amd_Barcelona();
2572   }
2573 
2574   if (is_hygon()) {
2575     return true;
2576   }
2577 
2578   return false;
2579 }
2580 
2581 void VM_Version::resolve_cpu_information_details(void) {
2582 
2583   // in future we want to base this information on proper cpu
2584   // and cache topology enumeration such as:
2585   // Intel 64 Architecture Processor Topology Enumeration
2586   // which supports system cpu and cache topology enumeration
2587   // either using 2xAPICIDs or initial APICIDs
2588 
2589   // currently only rough cpu information estimates
2590   // which will not necessarily reflect the exact configuration of the system
2591 
2592   // this is the number of logical hardware threads
2593   // visible to the operating system
2594   _no_of_threads = os::processor_count();
2595 
2596   // find out number of threads per cpu package
2597   int threads_per_package = _cpuid_info.tpl_cpuidB1_ebx.bits.logical_cpus;
2598   if (threads_per_package == 0) {
2599     // Fallback code to avoid div by zero in subsequent code.
2600     // CPUID 0Bh (ECX = 1) might return 0 on older AMD processor (EPYC 7763 at least)
2601     threads_per_package = threads_per_core() * cores_per_cpu();
2602   }
2603 
2604   // use amount of threads visible to the process in order to guess number of sockets
2605   _no_of_sockets = _no_of_threads / threads_per_package;
2606 
2607   // process might only see a subset of the total number of threads
2608   // from a single processor package. Virtualization/resource management for example.
2609   // If so then just write a hard 1 as num of pkgs.
2610   if (0 == _no_of_sockets) {
2611     _no_of_sockets = 1;
2612   }
2613 
2614   // estimate the number of cores
2615   _no_of_cores = cores_per_cpu() * _no_of_sockets;
2616 }
2617 
2618 
2619 const char* VM_Version::cpu_family_description(void) {
2620   int cpu_family_id = extended_cpu_family();
2621   if (is_amd()) {
2622     if (cpu_family_id < ExtendedFamilyIdLength_AMD) {
2623       return _family_id_amd[cpu_family_id];
2624     }
2625   }
2626   if (is_intel()) {
2627     if (cpu_family_id == CPU_FAMILY_PENTIUMPRO) {
2628       return cpu_model_description();
2629     }
2630     if (cpu_family_id < ExtendedFamilyIdLength_INTEL) {
2631       return _family_id_intel[cpu_family_id];
2632     }
2633   }
2634   if (is_zx()) {
2635     int cpu_model_id = extended_cpu_model();
2636     if (cpu_family_id == 7) {
2637       switch (cpu_model_id) {
2638         case 0x1B:
2639           return "wudaokou";
2640         case 0x3B:
2641           return "lujiazui";
2642         case 0x5B:
2643           return "yongfeng";
2644         case 0x6B:
2645           return "shijidadao";
2646       }
2647     } else if (cpu_family_id == 6) {
2648       return "zhangjiang";
2649     }
2650   }
2651   if (is_hygon()) {
2652     return "Dhyana";
2653   }
2654   return "Unknown x86";
2655 }
2656 
2657 int VM_Version::cpu_type_description(char* const buf, size_t buf_len) {
2658   assert(buf != nullptr, "buffer is null!");
2659   assert(buf_len >= CPU_TYPE_DESC_BUF_SIZE, "buffer len should at least be == CPU_TYPE_DESC_BUF_SIZE!");
2660 
2661   const char* cpu_type = nullptr;
2662   const char* x64 = nullptr;
2663 
2664   if (is_intel()) {
2665     cpu_type = "Intel";
2666     x64 = cpu_is_em64t() ? " Intel64" : "";
2667   } else if (is_amd()) {
2668     cpu_type = "AMD";
2669     x64 = cpu_is_em64t() ? " AMD64" : "";
2670   } else if (is_zx()) {
2671     cpu_type = "Zhaoxin";
2672     x64 = cpu_is_em64t() ? " x86_64" : "";
2673   } else if (is_hygon()) {
2674     cpu_type = "Hygon";
2675     x64 = cpu_is_em64t() ? " AMD64" : "";
2676   } else {
2677     cpu_type = "Unknown x86";
2678     x64 = cpu_is_em64t() ? " x86_64" : "";
2679   }
2680 
2681   jio_snprintf(buf, buf_len, "%s %s%s SSE SSE2%s%s%s%s%s%s%s%s",
2682     cpu_type,
2683     cpu_family_description(),
2684     supports_ht() ? " (HT)" : "",
2685     supports_sse3() ? " SSE3" : "",
2686     supports_ssse3() ? " SSSE3" : "",
2687     supports_sse4_1() ? " SSE4.1" : "",
2688     supports_sse4_2() ? " SSE4.2" : "",
2689     supports_sse4a() ? " SSE4A" : "",
2690     is_netburst() ? " Netburst" : "",
2691     is_intel_family_core() ? " Core" : "",
2692     x64);
2693 
2694   return OS_OK;
2695 }
2696 
2697 int VM_Version::cpu_extended_brand_string(char* const buf, size_t buf_len) {
2698   assert(buf != nullptr, "buffer is null!");
2699   assert(buf_len >= CPU_EBS_MAX_LENGTH, "buffer len should at least be == CPU_EBS_MAX_LENGTH!");
2700   assert(getCPUIDBrandString_stub != nullptr, "not initialized");
2701 
2702   // invoke newly generated asm code to fetch CPU Brand String
2703   getCPUIDBrandString_stub(&_cpuid_info);
2704 
2705   // fetch results into buffer
2706   *((uint32_t*) &buf[0])  = _cpuid_info.proc_name_0;
2707   *((uint32_t*) &buf[4])  = _cpuid_info.proc_name_1;
2708   *((uint32_t*) &buf[8])  = _cpuid_info.proc_name_2;
2709   *((uint32_t*) &buf[12]) = _cpuid_info.proc_name_3;
2710   *((uint32_t*) &buf[16]) = _cpuid_info.proc_name_4;
2711   *((uint32_t*) &buf[20]) = _cpuid_info.proc_name_5;
2712   *((uint32_t*) &buf[24]) = _cpuid_info.proc_name_6;
2713   *((uint32_t*) &buf[28]) = _cpuid_info.proc_name_7;
2714   *((uint32_t*) &buf[32]) = _cpuid_info.proc_name_8;
2715   *((uint32_t*) &buf[36]) = _cpuid_info.proc_name_9;
2716   *((uint32_t*) &buf[40]) = _cpuid_info.proc_name_10;
2717   *((uint32_t*) &buf[44]) = _cpuid_info.proc_name_11;
2718 
2719   return OS_OK;
2720 }
2721 
2722 size_t VM_Version::cpu_write_support_string(char* const buf, size_t buf_len) {
2723   guarantee(buf != nullptr, "buffer is null!");
2724   guarantee(buf_len > 0, "buffer len not enough!");
2725 
2726   unsigned int flag = 0;
2727   unsigned int fi = 0;
2728   size_t       written = 0;
2729   const char*  prefix = "";
2730 
2731 #define WRITE_TO_BUF(string)                                                          \
2732   {                                                                                   \
2733     int res = jio_snprintf(&buf[written], buf_len - written, "%s%s", prefix, string); \
2734     if (res < 0) {                                                                    \
2735       return buf_len - 1;                                                             \
2736     }                                                                                 \
2737     written += res;                                                                   \
2738     if (prefix[0] == '\0') {                                                          \
2739       prefix = ", ";                                                                  \
2740     }                                                                                 \
2741   }
2742 
2743   for (flag = 1, fi = 0; flag <= 0x20000000 ; flag <<= 1, fi++) {
2744     if (flag == HTT_FLAG && (((_cpuid_info.std_cpuid1_ebx.value >> 16) & 0xff) <= 1)) {
2745       continue; /* no hyperthreading */
2746     } else if (flag == SEP_FLAG && (cpu_family() == CPU_FAMILY_PENTIUMPRO && ((_cpuid_info.std_cpuid1_eax.value & 0xff) < 0x33))) {
2747       continue; /* no fast system call */
2748     }
2749     if ((_cpuid_info.std_cpuid1_edx.value & flag) && strlen(_feature_edx_id[fi]) > 0) {
2750       WRITE_TO_BUF(_feature_edx_id[fi]);
2751     }
2752   }
2753 
2754   for (flag = 1, fi = 0; flag <= 0x20000000; flag <<= 1, fi++) {
2755     if ((_cpuid_info.std_cpuid1_ecx.value & flag) && strlen(_feature_ecx_id[fi]) > 0) {
2756       WRITE_TO_BUF(_feature_ecx_id[fi]);
2757     }
2758   }
2759 
2760   for (flag = 1, fi = 0; flag <= 0x20000000 ; flag <<= 1, fi++) {
2761     if ((_cpuid_info.ext_cpuid1_ecx.value & flag) && strlen(_feature_extended_ecx_id[fi]) > 0) {
2762       WRITE_TO_BUF(_feature_extended_ecx_id[fi]);
2763     }
2764   }
2765 
2766   for (flag = 1, fi = 0; flag <= 0x20000000; flag <<= 1, fi++) {
2767     if ((_cpuid_info.ext_cpuid1_edx.value & flag) && strlen(_feature_extended_edx_id[fi]) > 0) {
2768       WRITE_TO_BUF(_feature_extended_edx_id[fi]);
2769     }
2770   }
2771 
2772   if (supports_tscinv_bit()) {
2773       WRITE_TO_BUF("Invariant TSC");
2774   }
2775 
2776   if (supports_hybrid()) {
2777       WRITE_TO_BUF("Hybrid Architecture");
2778   }
2779 
2780   return written;
2781 }
2782 
2783 /**
2784  * Write a detailed description of the cpu to a given buffer, including
2785  * feature set.
2786  */
2787 int VM_Version::cpu_detailed_description(char* const buf, size_t buf_len) {
2788   assert(buf != nullptr, "buffer is null!");
2789   assert(buf_len >= CPU_DETAILED_DESC_BUF_SIZE, "buffer len should at least be == CPU_DETAILED_DESC_BUF_SIZE!");
2790 
2791   static const char* unknown = "<unknown>";
2792   char               vendor_id[VENDOR_LENGTH];
2793   const char*        family = nullptr;
2794   const char*        model = nullptr;
2795   const char*        brand = nullptr;
2796   int                outputLen = 0;
2797 
2798   family = cpu_family_description();
2799   if (family == nullptr) {
2800     family = unknown;
2801   }
2802 
2803   model = cpu_model_description();
2804   if (model == nullptr) {
2805     model = unknown;
2806   }
2807 
2808   brand = cpu_brand_string();
2809 
2810   if (brand == nullptr) {
2811     brand = cpu_brand();
2812     if (brand == nullptr) {
2813       brand = unknown;
2814     }
2815   }
2816 
2817   *((uint32_t*) &vendor_id[0]) = _cpuid_info.std_vendor_name_0;
2818   *((uint32_t*) &vendor_id[4]) = _cpuid_info.std_vendor_name_2;
2819   *((uint32_t*) &vendor_id[8]) = _cpuid_info.std_vendor_name_1;
2820   vendor_id[VENDOR_LENGTH-1] = '\0';
2821 
2822   outputLen = jio_snprintf(buf, buf_len, "Brand: %s, Vendor: %s\n"
2823     "Family: %s (0x%x), Model: %s (0x%x), Stepping: 0x%x\n"
2824     "Ext. family: 0x%x, Ext. model: 0x%x, Type: 0x%x, Signature: 0x%8.8x\n"
2825     "Features: ebx: 0x%8.8x, ecx: 0x%8.8x, edx: 0x%8.8x\n"
2826     "Ext. features: eax: 0x%8.8x, ebx: 0x%8.8x, ecx: 0x%8.8x, edx: 0x%8.8x\n"
2827     "Supports: ",
2828     brand,
2829     vendor_id,
2830     family,
2831     extended_cpu_family(),
2832     model,
2833     extended_cpu_model(),
2834     cpu_stepping(),
2835     _cpuid_info.std_cpuid1_eax.bits.ext_family,
2836     _cpuid_info.std_cpuid1_eax.bits.ext_model,
2837     _cpuid_info.std_cpuid1_eax.bits.proc_type,
2838     _cpuid_info.std_cpuid1_eax.value,
2839     _cpuid_info.std_cpuid1_ebx.value,
2840     _cpuid_info.std_cpuid1_ecx.value,
2841     _cpuid_info.std_cpuid1_edx.value,
2842     _cpuid_info.ext_cpuid1_eax,
2843     _cpuid_info.ext_cpuid1_ebx,
2844     _cpuid_info.ext_cpuid1_ecx,
2845     _cpuid_info.ext_cpuid1_edx);
2846 
2847   if (outputLen < 0 || (size_t) outputLen >= buf_len - 1) {
2848     if (buf_len > 0) { buf[buf_len-1] = '\0'; }
2849     return OS_ERR;
2850   }
2851 
2852   cpu_write_support_string(&buf[outputLen], buf_len - outputLen);
2853 
2854   return OS_OK;
2855 }
2856 
2857 
2858 // Fill in Abstract_VM_Version statics
2859 void VM_Version::initialize_cpu_information() {
2860   assert(_vm_version_initialized, "should have initialized VM_Version long ago");
2861   assert(!_initialized, "shouldn't be initialized yet");
2862   resolve_cpu_information_details();
2863 
2864   // initialize cpu_name and cpu_desc
2865   cpu_type_description(_cpu_name, CPU_TYPE_DESC_BUF_SIZE);
2866   cpu_detailed_description(_cpu_desc, CPU_DETAILED_DESC_BUF_SIZE);
2867   _initialized = true;
2868 }
2869 
2870 /**
2871  *  For information about extracting the frequency from the cpu brand string, please see:
2872  *
2873  *    Intel Processor Identification and the CPUID Instruction
2874  *    Application Note 485
2875  *    May 2012
2876  *
2877  * The return value is the frequency in Hz.
2878  */
2879 int64_t VM_Version::max_qualified_cpu_freq_from_brand_string(void) {
2880   const char* const brand_string = cpu_brand_string();
2881   if (brand_string == nullptr) {
2882     return 0;
2883   }
2884   const int64_t MEGA = 1000000;
2885   int64_t multiplier = 0;
2886   int64_t frequency = 0;
2887   uint8_t idx = 0;
2888   // The brand string buffer is at most 48 bytes.
2889   // -2 is to prevent buffer overrun when looking for y in yHz, as z is +2 from y.
2890   for (; idx < 48-2; ++idx) {
2891     // Format is either "x.xxyHz" or "xxxxyHz", where y=M, G, T and x are digits.
2892     // Search brand string for "yHz" where y is M, G, or T.
2893     if (brand_string[idx+1] == 'H' && brand_string[idx+2] == 'z') {
2894       if (brand_string[idx] == 'M') {
2895         multiplier = MEGA;
2896       } else if (brand_string[idx] == 'G') {
2897         multiplier = MEGA * 1000;
2898       } else if (brand_string[idx] == 'T') {
2899         multiplier = MEGA * MEGA;
2900       }
2901       break;
2902     }
2903   }
2904   if (multiplier > 0) {
2905     // Compute frequency (in Hz) from brand string.
2906     if (brand_string[idx-3] == '.') { // if format is "x.xx"
2907       frequency =  (brand_string[idx-4] - '0') * multiplier;
2908       frequency += (brand_string[idx-2] - '0') * multiplier / 10;
2909       frequency += (brand_string[idx-1] - '0') * multiplier / 100;
2910     } else { // format is "xxxx"
2911       frequency =  (brand_string[idx-4] - '0') * 1000;
2912       frequency += (brand_string[idx-3] - '0') * 100;
2913       frequency += (brand_string[idx-2] - '0') * 10;
2914       frequency += (brand_string[idx-1] - '0');
2915       frequency *= multiplier;
2916     }
2917   }
2918   return frequency;
2919 }
2920 
2921 
2922 int64_t VM_Version::maximum_qualified_cpu_frequency(void) {
2923   if (_max_qualified_cpu_frequency == 0) {
2924     _max_qualified_cpu_frequency = max_qualified_cpu_freq_from_brand_string();
2925   }
2926   return _max_qualified_cpu_frequency;
2927 }
2928 
2929 VM_Version::VM_Features VM_Version::CpuidInfo::feature_flags() const {
2930   VM_Features vm_features;
2931   if (std_cpuid1_edx.bits.cmpxchg8 != 0)
2932     vm_features.set_feature(CPU_CX8);
2933   if (std_cpuid1_edx.bits.cmov != 0)
2934     vm_features.set_feature(CPU_CMOV);
2935   if (std_cpuid1_edx.bits.clflush != 0)
2936     vm_features.set_feature(CPU_FLUSH);
2937   // clflush should always be available on x86_64
2938   // if not we are in real trouble because we rely on it
2939   // to flush the code cache.
2940   assert (vm_features.supports_feature(CPU_FLUSH), "clflush should be available");
2941   if (std_cpuid1_edx.bits.fxsr != 0 || (is_amd_family() &&
2942       ext_cpuid1_edx.bits.fxsr != 0))
2943     vm_features.set_feature(CPU_FXSR);
2944   // HT flag is set for multi-core processors also.
2945   if (threads_per_core() > 1)
2946     vm_features.set_feature(CPU_HT);
2947   if (std_cpuid1_edx.bits.mmx != 0 || (is_amd_family() &&
2948       ext_cpuid1_edx.bits.mmx != 0))
2949     vm_features.set_feature(CPU_MMX);
2950   if (std_cpuid1_edx.bits.sse != 0)
2951     vm_features.set_feature(CPU_SSE);
2952   if (std_cpuid1_edx.bits.sse2 != 0)
2953     vm_features.set_feature(CPU_SSE2);
2954   if (std_cpuid1_ecx.bits.sse3 != 0)
2955     vm_features.set_feature(CPU_SSE3);
2956   if (std_cpuid1_ecx.bits.ssse3 != 0)
2957     vm_features.set_feature(CPU_SSSE3);
2958   if (std_cpuid1_ecx.bits.sse4_1 != 0)
2959     vm_features.set_feature(CPU_SSE4_1);
2960   if (std_cpuid1_ecx.bits.sse4_2 != 0)
2961     vm_features.set_feature(CPU_SSE4_2);
2962   if (std_cpuid1_ecx.bits.popcnt != 0)
2963     vm_features.set_feature(CPU_POPCNT);
2964   if (sefsl1_cpuid7_edx.bits.apx_f != 0 &&
2965       xem_xcr0_eax.bits.apx_f != 0 &&
2966       std_cpuid29_ebx.bits.apx_nci_ndd_nf != 0) {
2967     vm_features.set_feature(CPU_APX_F);
2968   }
2969   if (std_cpuid1_ecx.bits.avx != 0 &&
2970       std_cpuid1_ecx.bits.osxsave != 0 &&
2971       xem_xcr0_eax.bits.sse != 0 &&
2972       xem_xcr0_eax.bits.ymm != 0) {
2973     vm_features.set_feature(CPU_AVX);
2974     vm_features.set_feature(CPU_VZEROUPPER);
2975     if (sefsl1_cpuid7_eax.bits.sha512 != 0)
2976       vm_features.set_feature(CPU_SHA512);
2977     if (std_cpuid1_ecx.bits.f16c != 0)
2978       vm_features.set_feature(CPU_F16C);
2979     if (sef_cpuid7_ebx.bits.avx2 != 0) {
2980       vm_features.set_feature(CPU_AVX2);
2981       if (sefsl1_cpuid7_eax.bits.avx_ifma != 0)
2982         vm_features.set_feature(CPU_AVX_IFMA);
2983     }
2984     if (sef_cpuid7_ecx.bits.gfni != 0)
2985         vm_features.set_feature(CPU_GFNI);
2986     if (sef_cpuid7_ebx.bits.avx512f != 0 &&
2987         xem_xcr0_eax.bits.opmask != 0 &&
2988         xem_xcr0_eax.bits.zmm512 != 0 &&
2989         xem_xcr0_eax.bits.zmm32 != 0) {
2990       vm_features.set_feature(CPU_AVX512F);
2991       if (sef_cpuid7_ebx.bits.avx512cd != 0)
2992         vm_features.set_feature(CPU_AVX512CD);
2993       if (sef_cpuid7_ebx.bits.avx512dq != 0)
2994         vm_features.set_feature(CPU_AVX512DQ);
2995       if (sef_cpuid7_ebx.bits.avx512ifma != 0)
2996         vm_features.set_feature(CPU_AVX512_IFMA);
2997       if (sef_cpuid7_ebx.bits.avx512pf != 0)
2998         vm_features.set_feature(CPU_AVX512PF);
2999       if (sef_cpuid7_ebx.bits.avx512er != 0)
3000         vm_features.set_feature(CPU_AVX512ER);
3001       if (sef_cpuid7_ebx.bits.avx512bw != 0)
3002         vm_features.set_feature(CPU_AVX512BW);
3003       if (sef_cpuid7_ebx.bits.avx512vl != 0)
3004         vm_features.set_feature(CPU_AVX512VL);
3005       if (sef_cpuid7_ecx.bits.avx512_vpopcntdq != 0)
3006         vm_features.set_feature(CPU_AVX512_VPOPCNTDQ);
3007       if (sef_cpuid7_ecx.bits.avx512_vpclmulqdq != 0)
3008         vm_features.set_feature(CPU_AVX512_VPCLMULQDQ);
3009       if (sef_cpuid7_ecx.bits.vaes != 0)
3010         vm_features.set_feature(CPU_AVX512_VAES);
3011       if (sef_cpuid7_ecx.bits.avx512_vnni != 0)
3012         vm_features.set_feature(CPU_AVX512_VNNI);
3013       if (sef_cpuid7_ecx.bits.avx512_bitalg != 0)
3014         vm_features.set_feature(CPU_AVX512_BITALG);
3015       if (sef_cpuid7_ecx.bits.avx512_vbmi != 0)
3016         vm_features.set_feature(CPU_AVX512_VBMI);
3017       if (sef_cpuid7_ecx.bits.avx512_vbmi2 != 0)
3018         vm_features.set_feature(CPU_AVX512_VBMI2);
3019     }
3020     if (is_intel()) {
3021       if (sefsl1_cpuid7_edx.bits.avx10 != 0 &&
3022           std_cpuid24_ebx.bits.avx10_vlen_512 !=0 &&
3023           std_cpuid24_ebx.bits.avx10_converged_isa_version >= 1 &&
3024           xem_xcr0_eax.bits.opmask != 0 &&
3025           xem_xcr0_eax.bits.zmm512 != 0 &&
3026           xem_xcr0_eax.bits.zmm32 != 0) {
3027         vm_features.set_feature(CPU_AVX10_1);
3028         vm_features.set_feature(CPU_AVX512F);
3029         vm_features.set_feature(CPU_AVX512CD);
3030         vm_features.set_feature(CPU_AVX512DQ);
3031         vm_features.set_feature(CPU_AVX512PF);
3032         vm_features.set_feature(CPU_AVX512ER);
3033         vm_features.set_feature(CPU_AVX512BW);
3034         vm_features.set_feature(CPU_AVX512VL);
3035         vm_features.set_feature(CPU_AVX512_VPOPCNTDQ);
3036         vm_features.set_feature(CPU_AVX512_VPCLMULQDQ);
3037         vm_features.set_feature(CPU_AVX512_VAES);
3038         vm_features.set_feature(CPU_AVX512_VNNI);
3039         vm_features.set_feature(CPU_AVX512_BITALG);
3040         vm_features.set_feature(CPU_AVX512_VBMI);
3041         vm_features.set_feature(CPU_AVX512_VBMI2);
3042         if (std_cpuid24_ebx.bits.avx10_converged_isa_version >= 2) {
3043           vm_features.set_feature(CPU_AVX10_2);
3044         }
3045       }
3046     }
3047   }
3048 
3049   if (std_cpuid1_ecx.bits.hv != 0)
3050     vm_features.set_feature(CPU_HV);
3051   if (sef_cpuid7_ebx.bits.bmi1 != 0)
3052     vm_features.set_feature(CPU_BMI1);
3053   if (std_cpuid1_edx.bits.tsc != 0)
3054     vm_features.set_feature(CPU_TSC);
3055   if (ext_cpuid7_edx.bits.tsc_invariance != 0)
3056     vm_features.set_feature(CPU_TSCINV_BIT);
3057   if (std_cpuid1_ecx.bits.aes != 0)
3058     vm_features.set_feature(CPU_AES);
3059   if (ext_cpuid1_ecx.bits.lzcnt != 0)
3060     vm_features.set_feature(CPU_LZCNT);
3061   if (ext_cpuid1_ecx.bits.prefetchw != 0)
3062     vm_features.set_feature(CPU_3DNOW_PREFETCH);
3063   if (sef_cpuid7_ebx.bits.erms != 0)
3064     vm_features.set_feature(CPU_ERMS);
3065   if (sef_cpuid7_edx.bits.fast_short_rep_mov != 0)
3066     vm_features.set_feature(CPU_FSRM);
3067   if (std_cpuid1_ecx.bits.clmul != 0)
3068     vm_features.set_feature(CPU_CLMUL);
3069   if (sef_cpuid7_ebx.bits.rtm != 0)
3070     vm_features.set_feature(CPU_RTM);
3071   if (sef_cpuid7_ebx.bits.adx != 0)
3072      vm_features.set_feature(CPU_ADX);
3073   if (sef_cpuid7_ebx.bits.bmi2 != 0)
3074     vm_features.set_feature(CPU_BMI2);
3075   if (sef_cpuid7_ebx.bits.sha != 0)
3076     vm_features.set_feature(CPU_SHA);
3077   if (std_cpuid1_ecx.bits.fma != 0)
3078     vm_features.set_feature(CPU_FMA);
3079   if (sef_cpuid7_ebx.bits.clflushopt != 0)
3080     vm_features.set_feature(CPU_FLUSHOPT);
3081   if (sef_cpuid7_ebx.bits.clwb != 0)
3082     vm_features.set_feature(CPU_CLWB);
3083   if (ext_cpuid1_edx.bits.rdtscp != 0)
3084     vm_features.set_feature(CPU_RDTSCP);
3085   if (sef_cpuid7_ecx.bits.rdpid != 0)
3086     vm_features.set_feature(CPU_RDPID);
3087 
3088   // AMD|Hygon additional features.
3089   if (is_amd_family()) {
3090     // PREFETCHW was checked above, check TDNOW here.
3091     if ((ext_cpuid1_edx.bits.tdnow != 0))
3092       vm_features.set_feature(CPU_3DNOW_PREFETCH);
3093     if (ext_cpuid1_ecx.bits.sse4a != 0)
3094       vm_features.set_feature(CPU_SSE4A);
3095   }
3096 
3097   // Intel additional features.
3098   if (is_intel()) {
3099     if (sef_cpuid7_edx.bits.serialize != 0)
3100       vm_features.set_feature(CPU_SERIALIZE);
3101     if (sef_cpuid7_edx.bits.hybrid != 0)
3102       vm_features.set_feature(CPU_HYBRID);
3103     if (_cpuid_info.sef_cpuid7_edx.bits.avx512_fp16 != 0)
3104       vm_features.set_feature(CPU_AVX512_FP16);
3105   }
3106 
3107   // ZX additional features.
3108   if (is_zx()) {
3109     // We do not know if these are supported by ZX, so we cannot trust
3110     // common CPUID bit for them.
3111     assert(vm_features.supports_feature(CPU_CLWB), "Check if it is supported?");
3112     vm_features.clear_feature(CPU_CLWB);
3113   }
3114 
3115   // Protection key features.
3116   if (sef_cpuid7_ecx.bits.pku != 0) {
3117     vm_features.set_feature(CPU_PKU);
3118   }
3119   if (sef_cpuid7_ecx.bits.ospke != 0) {
3120     vm_features.set_feature(CPU_OSPKE);
3121   }
3122 
3123   // Control flow enforcement (CET) features.
3124   if (sef_cpuid7_ecx.bits.cet_ss != 0) {
3125     vm_features.set_feature(CPU_CET_SS);
3126   }
3127   if (sef_cpuid7_edx.bits.cet_ibt != 0) {
3128     vm_features.set_feature(CPU_CET_IBT);
3129   }
3130 
3131   // Composite features.
3132   if (supports_tscinv_bit() &&
3133       ((is_amd_family() && !is_amd_Barcelona()) ||
3134        is_intel_tsc_synched_at_init())) {
3135     vm_features.set_feature(CPU_TSCINV);
3136   }
3137   return vm_features;
3138 }
3139 
3140 bool VM_Version::os_supports_avx_vectors() {
3141   bool retVal = false;
3142   int nreg = 4;
3143   if (supports_evex()) {
3144     // Verify that OS save/restore all bits of EVEX registers
3145     // during signal processing.
3146     retVal = true;
3147     for (int i = 0; i < 16 * nreg; i++) { // 64 bytes per zmm register
3148       if (_cpuid_info.zmm_save[i] != ymm_test_value()) {
3149         retVal = false;
3150         break;
3151       }
3152     }
3153   } else if (supports_avx()) {
3154     // Verify that OS save/restore all bits of AVX registers
3155     // during signal processing.
3156     retVal = true;
3157     for (int i = 0; i < 8 * nreg; i++) { // 32 bytes per ymm register
3158       if (_cpuid_info.ymm_save[i] != ymm_test_value()) {
3159         retVal = false;
3160         break;
3161       }
3162     }
3163     // zmm_save will be set on a EVEX enabled machine even if we choose AVX code gen
3164     if (retVal == false) {
3165       // Verify that OS save/restore all bits of EVEX registers
3166       // during signal processing.
3167       retVal = true;
3168       for (int i = 0; i < 16 * nreg; i++) { // 64 bytes per zmm register
3169         if (_cpuid_info.zmm_save[i] != ymm_test_value()) {
3170           retVal = false;
3171           break;
3172         }
3173       }
3174     }
3175   }
3176   return retVal;
3177 }
3178 
3179 bool VM_Version::os_supports_apx_egprs() {
3180   if (!supports_apx_f()) {
3181     return false;
3182   }
3183   if (_cpuid_info.apx_save[0] != egpr_test_value() ||
3184       _cpuid_info.apx_save[1] != egpr_test_value()) {
3185     return false;
3186   }
3187   return true;
3188 }
3189 
3190 uint VM_Version::cores_per_cpu() {
3191   uint result = 1;
3192   if (is_intel()) {
3193     bool supports_topology = supports_processor_topology();
3194     if (supports_topology) {
3195       result = _cpuid_info.tpl_cpuidB1_ebx.bits.logical_cpus /
3196                _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
3197     }
3198     if (!supports_topology || result == 0) {
3199       result = (_cpuid_info.dcp_cpuid4_eax.bits.cores_per_cpu + 1);
3200     }
3201   } else if (is_amd_family()) {
3202     result = _cpuid_info.ext_cpuid8_ecx.bits.threads_per_cpu + 1;
3203     if (cpu_family() >= 0x17) { // Zen or later
3204       result /= _cpuid_info.ext_cpuid1E_ebx.bits.threads_per_core + 1;
3205     }
3206   } else if (is_zx()) {
3207     bool supports_topology = supports_processor_topology();
3208     if (supports_topology) {
3209       result = _cpuid_info.tpl_cpuidB1_ebx.bits.logical_cpus /
3210                _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
3211     }
3212     if (!supports_topology || result == 0) {
3213       result = (_cpuid_info.dcp_cpuid4_eax.bits.cores_per_cpu + 1);
3214     }
3215   }
3216   return result;
3217 }
3218 
3219 uint VM_Version::threads_per_core() {
3220   uint result = 1;
3221   if (is_intel() && supports_processor_topology()) {
3222     result = _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
3223   } else if (is_zx() && supports_processor_topology()) {
3224     result = _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus;
3225   } else if (_cpuid_info.std_cpuid1_edx.bits.ht != 0) {
3226     if (cpu_family() >= 0x17) {
3227       result = _cpuid_info.ext_cpuid1E_ebx.bits.threads_per_core + 1;
3228     } else {
3229       result = _cpuid_info.std_cpuid1_ebx.bits.threads_per_cpu /
3230                  cores_per_cpu();
3231     }
3232   }
3233   return (result == 0 ? 1 : result);
3234 }
3235 
3236 uint VM_Version::L1_line_size() {
3237   uint result = 0;
3238   if (is_intel()) {
3239     result = (_cpuid_info.dcp_cpuid4_ebx.bits.L1_line_size + 1);
3240   } else if (is_amd_family()) {
3241     result = _cpuid_info.ext_cpuid5_ecx.bits.L1_line_size;
3242   } else if (is_zx()) {
3243     result = (_cpuid_info.dcp_cpuid4_ebx.bits.L1_line_size + 1);
3244   }
3245   if (result < 32) // not defined ?
3246     result = 32;   // 32 bytes by default on x86 and other x64
3247   return result;
3248 }
3249 
3250 bool VM_Version::is_intel_tsc_synched_at_init() {
3251   if (is_intel_family_core()) {
3252     uint32_t ext_model = extended_cpu_model();
3253     if (ext_model == CPU_MODEL_NEHALEM_EP     ||
3254         ext_model == CPU_MODEL_WESTMERE_EP    ||
3255         ext_model == CPU_MODEL_SANDYBRIDGE_EP ||
3256         ext_model == CPU_MODEL_IVYBRIDGE_EP) {
3257       // <= 2-socket invariant tsc support. EX versions are usually used
3258       // in > 2-socket systems and likely don't synchronize tscs at
3259       // initialization.
3260       // Code that uses tsc values must be prepared for them to arbitrarily
3261       // jump forward or backward.
3262       return true;
3263     }
3264   }
3265   return false;
3266 }
3267 
3268 int VM_Version::allocate_prefetch_distance(bool use_watermark_prefetch) {
3269   // Hardware prefetching (distance/size in bytes):
3270   // Pentium 3 -  64 /  32
3271   // Pentium 4 - 256 / 128
3272   // Athlon    -  64 /  32 ????
3273   // Opteron   - 128 /  64 only when 2 sequential cache lines accessed
3274   // Core      - 128 /  64
3275   //
3276   // Software prefetching (distance in bytes / instruction with best score):
3277   // Pentium 3 - 128 / prefetchnta
3278   // Pentium 4 - 512 / prefetchnta
3279   // Athlon    - 128 / prefetchnta
3280   // Opteron   - 256 / prefetchnta
3281   // Core      - 256 / prefetchnta
3282   // It will be used only when AllocatePrefetchStyle > 0
3283 
3284   if (is_amd_family()) { // AMD | Hygon
3285     if (supports_sse2()) {
3286       return 256; // Opteron
3287     } else {
3288       return 128; // Athlon
3289     }
3290   } else if (is_zx()) {
3291     if (supports_sse2()) {
3292       return 256;
3293     } else {
3294       return 128;
3295     }
3296   } else { // Intel
3297     if (supports_sse3() && is_intel_server_family()) {
3298       if (supports_sse4_2() && supports_ht()) { // Nehalem based cpus
3299         return 192;
3300       } else if (use_watermark_prefetch) { // watermark prefetching on Core
3301         return 384;
3302       }
3303     }
3304     if (supports_sse2()) {
3305       if (is_intel_server_family()) {
3306         return 256; // Pentium M, Core, Core2
3307       } else {
3308         return 512; // Pentium 4
3309       }
3310     } else {
3311       return 128; // Pentium 3 (and all other old CPUs)
3312     }
3313   }
3314 }
3315 
3316 bool VM_Version::is_intrinsic_supported(vmIntrinsicID id) {
3317   assert(id != vmIntrinsics::_none, "must be a VM intrinsic");
3318   switch (id) {
3319   case vmIntrinsics::_floatToFloat16:
3320   case vmIntrinsics::_float16ToFloat:
3321     if (!supports_float16()) {
3322       return false;
3323     }
3324     break;
3325   default:
3326     break;
3327   }
3328   return true;
3329 }
3330 
3331 void VM_Version::insert_features_names(VM_Version::VM_Features features, stringStream& ss) {
3332   int i = 0;
3333   ss.join([&]() {
3334     const char* str = nullptr;
3335     while ((i < MAX_CPU_FEATURES) && (str == nullptr)) {
3336       if (features.supports_feature((VM_Version::Feature_Flag)i)) {
3337         str = _features_names[i];
3338       }
3339       i += 1;
3340     }
3341     return str;
3342   }, ", ");
3343 }
3344 
3345 void VM_Version::get_cpu_features_name(void* features_buffer, stringStream& ss) {
3346   VM_Features* features = (VM_Features*)features_buffer;
3347   insert_features_names(*features, ss);
3348 }
3349 
3350 void VM_Version::get_missing_features_name(void* features_set1, void* features_set2, stringStream& ss) {
3351   VM_Features* vm_features_set1 = (VM_Features*)features_set1;
3352   VM_Features* vm_features_set2 = (VM_Features*)features_set2;
3353   int i = 0;
3354   ss.join([&]() {
3355     const char* str = nullptr;
3356     while ((i < MAX_CPU_FEATURES) && (str == nullptr)) {
3357       Feature_Flag flag = (Feature_Flag)i;
3358       if (vm_features_set1->supports_feature(flag) && !vm_features_set2->supports_feature(flag)) {
3359         str = _features_names[i];
3360       }
3361       i += 1;
3362     }
3363     return str;
3364   }, ", ");
3365 }
3366 
3367 int VM_Version::cpu_features_size() {
3368   return sizeof(VM_Features);
3369 }
3370 
3371 void VM_Version::store_cpu_features(void* buf) {
3372   VM_Features copy = _features;
3373   copy.clear_feature(CPU_HT); // HT does not result in incompatibility of aot code cache
3374   memcpy(buf, &copy, sizeof(VM_Features));
3375 }
3376 
3377 bool VM_Version::supports_features(void* features_buffer) {
3378   VM_Features* features_to_test = (VM_Features*)features_buffer;
3379   return _features.supports_features(features_to_test);
3380 }