src/cpu/x86/vm/vm_version_x86.cpp

Tue, 05 Aug 2014 15:02:10 -0700

author
kvn
date
Tue, 05 Aug 2014 15:02:10 -0700
changeset 7025
b1bc1af04c6e
parent 6680
78bbf4d43a14
child 7027
b20a35eae442
permissions
-rw-r--r--

8052081: Optimize generated by C2 code for Intel's Atom processor
Summary: Allow to execute vectorization and crc32 optimization on Atom. Enable UseFPUForSpilling by default on x86.
Reviewed-by: roland

     1 /*
     2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "asm/macroAssembler.hpp"
    27 #include "asm/macroAssembler.inline.hpp"
    28 #include "memory/resourceArea.hpp"
    29 #include "runtime/java.hpp"
    30 #include "runtime/stubCodeGenerator.hpp"
    31 #include "vm_version_x86.hpp"
    32 #ifdef TARGET_OS_FAMILY_linux
    33 # include "os_linux.inline.hpp"
    34 #endif
    35 #ifdef TARGET_OS_FAMILY_solaris
    36 # include "os_solaris.inline.hpp"
    37 #endif
    38 #ifdef TARGET_OS_FAMILY_windows
    39 # include "os_windows.inline.hpp"
    40 #endif
    41 #ifdef TARGET_OS_FAMILY_bsd
    42 # include "os_bsd.inline.hpp"
    43 #endif
    46 int VM_Version::_cpu;
    47 int VM_Version::_model;
    48 int VM_Version::_stepping;
    49 int VM_Version::_cpuFeatures;
    50 const char*           VM_Version::_features_str = "";
    51 VM_Version::CpuidInfo VM_Version::_cpuid_info   = { 0, };
    53 // Address of instruction which causes SEGV
    54 address VM_Version::_cpuinfo_segv_addr = 0;
    55 // Address of instruction after the one which causes SEGV
    56 address VM_Version::_cpuinfo_cont_addr = 0;
    58 static BufferBlob* stub_blob;
    59 static const int stub_size = 600;
    61 extern "C" {
    62   typedef void (*get_cpu_info_stub_t)(void*);
    63 }
    64 static get_cpu_info_stub_t get_cpu_info_stub = NULL;
    67 class VM_Version_StubGenerator: public StubCodeGenerator {
    68  public:
    70   VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
    72   address generate_get_cpu_info() {
    73     // Flags to test CPU type.
    74     const uint32_t HS_EFL_AC           = 0x40000;
    75     const uint32_t HS_EFL_ID           = 0x200000;
    76     // Values for when we don't have a CPUID instruction.
    77     const int      CPU_FAMILY_SHIFT = 8;
    78     const uint32_t CPU_FAMILY_386   = (3 << CPU_FAMILY_SHIFT);
    79     const uint32_t CPU_FAMILY_486   = (4 << CPU_FAMILY_SHIFT);
    81     Label detect_486, cpu486, detect_586, std_cpuid1, std_cpuid4;
    82     Label sef_cpuid, ext_cpuid, ext_cpuid1, ext_cpuid5, ext_cpuid7, done;
    84     StubCodeMark mark(this, "VM_Version", "get_cpu_info_stub");
    85 #   define __ _masm->
    87     address start = __ pc();
    89     //
    90     // void get_cpu_info(VM_Version::CpuidInfo* cpuid_info);
    91     //
    92     // LP64: rcx and rdx are first and second argument registers on windows
    94     __ push(rbp);
    95 #ifdef _LP64
    96     __ mov(rbp, c_rarg0); // cpuid_info address
    97 #else
    98     __ movptr(rbp, Address(rsp, 8)); // cpuid_info address
    99 #endif
   100     __ push(rbx);
   101     __ push(rsi);
   102     __ pushf();          // preserve rbx, and flags
   103     __ pop(rax);
   104     __ push(rax);
   105     __ mov(rcx, rax);
   106     //
   107     // if we are unable to change the AC flag, we have a 386
   108     //
   109     __ xorl(rax, HS_EFL_AC);
   110     __ push(rax);
   111     __ popf();
   112     __ pushf();
   113     __ pop(rax);
   114     __ cmpptr(rax, rcx);
   115     __ jccb(Assembler::notEqual, detect_486);
   117     __ movl(rax, CPU_FAMILY_386);
   118     __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
   119     __ jmp(done);
   121     //
   122     // If we are unable to change the ID flag, we have a 486 which does
   123     // not support the "cpuid" instruction.
   124     //
   125     __ bind(detect_486);
   126     __ mov(rax, rcx);
   127     __ xorl(rax, HS_EFL_ID);
   128     __ push(rax);
   129     __ popf();
   130     __ pushf();
   131     __ pop(rax);
   132     __ cmpptr(rcx, rax);
   133     __ jccb(Assembler::notEqual, detect_586);
   135     __ bind(cpu486);
   136     __ movl(rax, CPU_FAMILY_486);
   137     __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
   138     __ jmp(done);
   140     //
   141     // At this point, we have a chip which supports the "cpuid" instruction
   142     //
   143     __ bind(detect_586);
   144     __ xorl(rax, rax);
   145     __ cpuid();
   146     __ orl(rax, rax);
   147     __ jcc(Assembler::equal, cpu486);   // if cpuid doesn't support an input
   148                                         // value of at least 1, we give up and
   149                                         // assume a 486
   150     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
   151     __ movl(Address(rsi, 0), rax);
   152     __ movl(Address(rsi, 4), rbx);
   153     __ movl(Address(rsi, 8), rcx);
   154     __ movl(Address(rsi,12), rdx);
   156     __ cmpl(rax, 0xa);                  // Is cpuid(0xB) supported?
   157     __ jccb(Assembler::belowEqual, std_cpuid4);
   159     //
   160     // cpuid(0xB) Processor Topology
   161     //
   162     __ movl(rax, 0xb);
   163     __ xorl(rcx, rcx);   // Threads level
   164     __ cpuid();
   166     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB0_offset())));
   167     __ movl(Address(rsi, 0), rax);
   168     __ movl(Address(rsi, 4), rbx);
   169     __ movl(Address(rsi, 8), rcx);
   170     __ movl(Address(rsi,12), rdx);
   172     __ movl(rax, 0xb);
   173     __ movl(rcx, 1);     // Cores level
   174     __ cpuid();
   175     __ push(rax);
   176     __ andl(rax, 0x1f);  // Determine if valid topology level
   177     __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
   178     __ andl(rax, 0xffff);
   179     __ pop(rax);
   180     __ jccb(Assembler::equal, std_cpuid4);
   182     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB1_offset())));
   183     __ movl(Address(rsi, 0), rax);
   184     __ movl(Address(rsi, 4), rbx);
   185     __ movl(Address(rsi, 8), rcx);
   186     __ movl(Address(rsi,12), rdx);
   188     __ movl(rax, 0xb);
   189     __ movl(rcx, 2);     // Packages level
   190     __ cpuid();
   191     __ push(rax);
   192     __ andl(rax, 0x1f);  // Determine if valid topology level
   193     __ orl(rax, rbx);    // eax[4:0] | ebx[0:15] == 0 indicates invalid level
   194     __ andl(rax, 0xffff);
   195     __ pop(rax);
   196     __ jccb(Assembler::equal, std_cpuid4);
   198     __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB2_offset())));
   199     __ movl(Address(rsi, 0), rax);
   200     __ movl(Address(rsi, 4), rbx);
   201     __ movl(Address(rsi, 8), rcx);
   202     __ movl(Address(rsi,12), rdx);
   204     //
   205     // cpuid(0x4) Deterministic cache params
   206     //
   207     __ bind(std_cpuid4);
   208     __ movl(rax, 4);
   209     __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x4) supported?
   210     __ jccb(Assembler::greater, std_cpuid1);
   212     __ xorl(rcx, rcx);   // L1 cache
   213     __ cpuid();
   214     __ push(rax);
   215     __ andl(rax, 0x1f);  // Determine if valid cache parameters used
   216     __ orl(rax, rax);    // eax[4:0] == 0 indicates invalid cache
   217     __ pop(rax);
   218     __ jccb(Assembler::equal, std_cpuid1);
   220     __ lea(rsi, Address(rbp, in_bytes(VM_Version::dcp_cpuid4_offset())));
   221     __ movl(Address(rsi, 0), rax);
   222     __ movl(Address(rsi, 4), rbx);
   223     __ movl(Address(rsi, 8), rcx);
   224     __ movl(Address(rsi,12), rdx);
   226     //
   227     // Standard cpuid(0x1)
   228     //
   229     __ bind(std_cpuid1);
   230     __ movl(rax, 1);
   231     __ cpuid();
   232     __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
   233     __ movl(Address(rsi, 0), rax);
   234     __ movl(Address(rsi, 4), rbx);
   235     __ movl(Address(rsi, 8), rcx);
   236     __ movl(Address(rsi,12), rdx);
   238     //
   239     // Check if OS has enabled XGETBV instruction to access XCR0
   240     // (OSXSAVE feature flag) and CPU supports AVX
   241     //
   242     __ andl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
   243     __ cmpl(rcx, 0x18000000);
   244     __ jccb(Assembler::notEqual, sef_cpuid); // jump if AVX is not supported
   246     //
   247     // XCR0, XFEATURE_ENABLED_MASK register
   248     //
   249     __ xorl(rcx, rcx);   // zero for XCR0 register
   250     __ xgetbv();
   251     __ lea(rsi, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset())));
   252     __ movl(Address(rsi, 0), rax);
   253     __ movl(Address(rsi, 4), rdx);
   255     __ andl(rax, 0x6); // xcr0 bits sse | ymm
   256     __ cmpl(rax, 0x6);
   257     __ jccb(Assembler::notEqual, sef_cpuid); // jump if AVX is not supported
   259     //
   260     // Some OSs have a bug when upper 128bits of YMM
   261     // registers are not restored after a signal processing.
   262     // Generate SEGV here (reference through NULL)
   263     // and check upper YMM bits after it.
   264     //
   265     VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
   266     intx saved_useavx = UseAVX;
   267     intx saved_usesse = UseSSE;
   268     UseAVX = 1;
   269     UseSSE = 2;
   271     // load value into all 32 bytes of ymm7 register
   272     __ movl(rcx, VM_Version::ymm_test_value());
   274     __ movdl(xmm0, rcx);
   275     __ pshufd(xmm0, xmm0, 0x00);
   276     __ vinsertf128h(xmm0, xmm0, xmm0);
   277     __ vmovdqu(xmm7, xmm0);
   278 #ifdef _LP64
   279     __ vmovdqu(xmm8,  xmm0);
   280     __ vmovdqu(xmm15, xmm0);
   281 #endif
   283     __ xorl(rsi, rsi);
   284     VM_Version::set_cpuinfo_segv_addr( __ pc() );
   285     // Generate SEGV
   286     __ movl(rax, Address(rsi, 0));
   288     VM_Version::set_cpuinfo_cont_addr( __ pc() );
   289     // Returns here after signal. Save xmm0 to check it later.
   290     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ymm_save_offset())));
   291     __ vmovdqu(Address(rsi,  0), xmm0);
   292     __ vmovdqu(Address(rsi, 32), xmm7);
   293 #ifdef _LP64
   294     __ vmovdqu(Address(rsi, 64), xmm8);
   295     __ vmovdqu(Address(rsi, 96), xmm15);
   296 #endif
   298     VM_Version::clean_cpuFeatures();
   299     UseAVX = saved_useavx;
   300     UseSSE = saved_usesse;
   302     //
   303     // cpuid(0x7) Structured Extended Features
   304     //
   305     __ bind(sef_cpuid);
   306     __ movl(rax, 7);
   307     __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x7) supported?
   308     __ jccb(Assembler::greater, ext_cpuid);
   310     __ xorl(rcx, rcx);
   311     __ cpuid();
   312     __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
   313     __ movl(Address(rsi, 0), rax);
   314     __ movl(Address(rsi, 4), rbx);
   316     //
   317     // Extended cpuid(0x80000000)
   318     //
   319     __ bind(ext_cpuid);
   320     __ movl(rax, 0x80000000);
   321     __ cpuid();
   322     __ cmpl(rax, 0x80000000);     // Is cpuid(0x80000001) supported?
   323     __ jcc(Assembler::belowEqual, done);
   324     __ cmpl(rax, 0x80000004);     // Is cpuid(0x80000005) supported?
   325     __ jccb(Assembler::belowEqual, ext_cpuid1);
   326     __ cmpl(rax, 0x80000006);     // Is cpuid(0x80000007) supported?
   327     __ jccb(Assembler::belowEqual, ext_cpuid5);
   328     __ cmpl(rax, 0x80000007);     // Is cpuid(0x80000008) supported?
   329     __ jccb(Assembler::belowEqual, ext_cpuid7);
   330     //
   331     // Extended cpuid(0x80000008)
   332     //
   333     __ movl(rax, 0x80000008);
   334     __ cpuid();
   335     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid8_offset())));
   336     __ movl(Address(rsi, 0), rax);
   337     __ movl(Address(rsi, 4), rbx);
   338     __ movl(Address(rsi, 8), rcx);
   339     __ movl(Address(rsi,12), rdx);
   341     //
   342     // Extended cpuid(0x80000007)
   343     //
   344     __ bind(ext_cpuid7);
   345     __ movl(rax, 0x80000007);
   346     __ cpuid();
   347     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid7_offset())));
   348     __ movl(Address(rsi, 0), rax);
   349     __ movl(Address(rsi, 4), rbx);
   350     __ movl(Address(rsi, 8), rcx);
   351     __ movl(Address(rsi,12), rdx);
   353     //
   354     // Extended cpuid(0x80000005)
   355     //
   356     __ bind(ext_cpuid5);
   357     __ movl(rax, 0x80000005);
   358     __ cpuid();
   359     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid5_offset())));
   360     __ movl(Address(rsi, 0), rax);
   361     __ movl(Address(rsi, 4), rbx);
   362     __ movl(Address(rsi, 8), rcx);
   363     __ movl(Address(rsi,12), rdx);
   365     //
   366     // Extended cpuid(0x80000001)
   367     //
   368     __ bind(ext_cpuid1);
   369     __ movl(rax, 0x80000001);
   370     __ cpuid();
   371     __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1_offset())));
   372     __ movl(Address(rsi, 0), rax);
   373     __ movl(Address(rsi, 4), rbx);
   374     __ movl(Address(rsi, 8), rcx);
   375     __ movl(Address(rsi,12), rdx);
   377     //
   378     // return
   379     //
   380     __ bind(done);
   381     __ popf();
   382     __ pop(rsi);
   383     __ pop(rbx);
   384     __ pop(rbp);
   385     __ ret(0);
   387 #   undef __
   389     return start;
   390   };
   391 };
   394 void VM_Version::get_cpu_info_wrapper() {
   395   get_cpu_info_stub(&_cpuid_info);
   396 }
   398 #ifndef CALL_TEST_FUNC_WITH_WRAPPER_IF_NEEDED
   399   #define CALL_TEST_FUNC_WITH_WRAPPER_IF_NEEDED(f) f()
   400 #endif
   402 void VM_Version::get_processor_features() {
   404   _cpu = 4; // 486 by default
   405   _model = 0;
   406   _stepping = 0;
   407   _cpuFeatures = 0;
   408   _logical_processors_per_package = 1;
   410   if (!Use486InstrsOnly) {
   411     // Get raw processor info
   413     // Some platforms (like Win*) need a wrapper around here
   414     // in order to properly handle SEGV for YMM registers test.
   415     CALL_TEST_FUNC_WITH_WRAPPER_IF_NEEDED(get_cpu_info_wrapper);
   417     assert_is_initialized();
   418     _cpu = extended_cpu_family();
   419     _model = extended_cpu_model();
   420     _stepping = cpu_stepping();
   422     if (cpu_family() > 4) { // it supports CPUID
   423       _cpuFeatures = feature_flags();
   424       // Logical processors are only available on P4s and above,
   425       // and only if hyperthreading is available.
   426       _logical_processors_per_package = logical_processor_count();
   427     }
   428   }
   430   _supports_cx8 = supports_cmpxchg8();
   431   // xchg and xadd instructions
   432   _supports_atomic_getset4 = true;
   433   _supports_atomic_getadd4 = true;
   434   LP64_ONLY(_supports_atomic_getset8 = true);
   435   LP64_ONLY(_supports_atomic_getadd8 = true);
   437 #ifdef _LP64
   438   // OS should support SSE for x64 and hardware should support at least SSE2.
   439   if (!VM_Version::supports_sse2()) {
   440     vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");
   441   }
   442   // in 64 bit the use of SSE2 is the minimum
   443   if (UseSSE < 2) UseSSE = 2;
   444 #endif
   446 #ifdef AMD64
   447   // flush_icache_stub have to be generated first.
   448   // That is why Icache line size is hard coded in ICache class,
   449   // see icache_x86.hpp. It is also the reason why we can't use
   450   // clflush instruction in 32-bit VM since it could be running
   451   // on CPU which does not support it.
   452   //
   453   // The only thing we can do is to verify that flushed
   454   // ICache::line_size has correct value.
   455   guarantee(_cpuid_info.std_cpuid1_edx.bits.clflush != 0, "clflush is not supported");
   456   // clflush_size is size in quadwords (8 bytes).
   457   guarantee(_cpuid_info.std_cpuid1_ebx.bits.clflush_size == 8, "such clflush size is not supported");
   458 #endif
   460   // If the OS doesn't support SSE, we can't use this feature even if the HW does
   461   if (!os::supports_sse())
   462     _cpuFeatures &= ~(CPU_SSE|CPU_SSE2|CPU_SSE3|CPU_SSSE3|CPU_SSE4A|CPU_SSE4_1|CPU_SSE4_2);
   464   if (UseSSE < 4) {
   465     _cpuFeatures &= ~CPU_SSE4_1;
   466     _cpuFeatures &= ~CPU_SSE4_2;
   467   }
   469   if (UseSSE < 3) {
   470     _cpuFeatures &= ~CPU_SSE3;
   471     _cpuFeatures &= ~CPU_SSSE3;
   472     _cpuFeatures &= ~CPU_SSE4A;
   473   }
   475   if (UseSSE < 2)
   476     _cpuFeatures &= ~CPU_SSE2;
   478   if (UseSSE < 1)
   479     _cpuFeatures &= ~CPU_SSE;
   481   if (UseAVX < 2)
   482     _cpuFeatures &= ~CPU_AVX2;
   484   if (UseAVX < 1)
   485     _cpuFeatures &= ~CPU_AVX;
   487   if (!UseAES && !FLAG_IS_DEFAULT(UseAES))
   488     _cpuFeatures &= ~CPU_AES;
   490   if (logical_processors_per_package() == 1) {
   491     // HT processor could be installed on a system which doesn't support HT.
   492     _cpuFeatures &= ~CPU_HT;
   493   }
   495   char buf[256];
   496   jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
   497                cores_per_cpu(), threads_per_core(),
   498                cpu_family(), _model, _stepping,
   499                (supports_cmov() ? ", cmov" : ""),
   500                (supports_cmpxchg8() ? ", cx8" : ""),
   501                (supports_fxsr() ? ", fxsr" : ""),
   502                (supports_mmx()  ? ", mmx"  : ""),
   503                (supports_sse()  ? ", sse"  : ""),
   504                (supports_sse2() ? ", sse2" : ""),
   505                (supports_sse3() ? ", sse3" : ""),
   506                (supports_ssse3()? ", ssse3": ""),
   507                (supports_sse4_1() ? ", sse4.1" : ""),
   508                (supports_sse4_2() ? ", sse4.2" : ""),
   509                (supports_popcnt() ? ", popcnt" : ""),
   510                (supports_avx()    ? ", avx" : ""),
   511                (supports_avx2()   ? ", avx2" : ""),
   512                (supports_aes()    ? ", aes" : ""),
   513                (supports_clmul()  ? ", clmul" : ""),
   514                (supports_erms()   ? ", erms" : ""),
   515                (supports_rtm()    ? ", rtm" : ""),
   516                (supports_mmx_ext() ? ", mmxext" : ""),
   517                (supports_3dnow_prefetch() ? ", 3dnowpref" : ""),
   518                (supports_lzcnt()   ? ", lzcnt": ""),
   519                (supports_sse4a()   ? ", sse4a": ""),
   520                (supports_ht() ? ", ht": ""),
   521                (supports_tsc() ? ", tsc": ""),
   522                (supports_tscinv_bit() ? ", tscinvbit": ""),
   523                (supports_tscinv() ? ", tscinv": ""),
   524                (supports_bmi1() ? ", bmi1" : ""),
   525                (supports_bmi2() ? ", bmi2" : ""));
   526   _features_str = strdup(buf);
   528   // UseSSE is set to the smaller of what hardware supports and what
   529   // the command line requires.  I.e., you cannot set UseSSE to 2 on
   530   // older Pentiums which do not support it.
   531   if (UseSSE > 4) UseSSE=4;
   532   if (UseSSE < 0) UseSSE=0;
   533   if (!supports_sse4_1()) // Drop to 3 if no SSE4 support
   534     UseSSE = MIN2((intx)3,UseSSE);
   535   if (!supports_sse3()) // Drop to 2 if no SSE3 support
   536     UseSSE = MIN2((intx)2,UseSSE);
   537   if (!supports_sse2()) // Drop to 1 if no SSE2 support
   538     UseSSE = MIN2((intx)1,UseSSE);
   539   if (!supports_sse ()) // Drop to 0 if no SSE  support
   540     UseSSE = 0;
   542   if (UseAVX > 2) UseAVX=2;
   543   if (UseAVX < 0) UseAVX=0;
   544   if (!supports_avx2()) // Drop to 1 if no AVX2 support
   545     UseAVX = MIN2((intx)1,UseAVX);
   546   if (!supports_avx ()) // Drop to 0 if no AVX  support
   547     UseAVX = 0;
   549   // Use AES instructions if available.
   550   if (supports_aes()) {
   551     if (FLAG_IS_DEFAULT(UseAES)) {
   552       UseAES = true;
   553     }
   554   } else if (UseAES) {
   555     if (!FLAG_IS_DEFAULT(UseAES))
   556       warning("AES instructions are not available on this CPU");
   557     FLAG_SET_DEFAULT(UseAES, false);
   558   }
   560   // Use CLMUL instructions if available.
   561   if (supports_clmul()) {
   562     if (FLAG_IS_DEFAULT(UseCLMUL)) {
   563       UseCLMUL = true;
   564     }
   565   } else if (UseCLMUL) {
   566     if (!FLAG_IS_DEFAULT(UseCLMUL))
   567       warning("CLMUL instructions not available on this CPU (AVX may also be required)");
   568     FLAG_SET_DEFAULT(UseCLMUL, false);
   569   }
   571   if (UseCLMUL && (UseSSE > 2)) {
   572     if (FLAG_IS_DEFAULT(UseCRC32Intrinsics)) {
   573       UseCRC32Intrinsics = true;
   574     }
   575   } else if (UseCRC32Intrinsics) {
   576     if (!FLAG_IS_DEFAULT(UseCRC32Intrinsics))
   577       warning("CRC32 Intrinsics requires AVX and CLMUL instructions (not available on this CPU)");
   578     FLAG_SET_DEFAULT(UseCRC32Intrinsics, false);
   579   }
   581   // The AES intrinsic stubs require AES instruction support (of course)
   582   // but also require sse3 mode for instructions it use.
   583   if (UseAES && (UseSSE > 2)) {
   584     if (FLAG_IS_DEFAULT(UseAESIntrinsics)) {
   585       UseAESIntrinsics = true;
   586     }
   587   } else if (UseAESIntrinsics) {
   588     if (!FLAG_IS_DEFAULT(UseAESIntrinsics))
   589       warning("AES intrinsics are not available on this CPU");
   590     FLAG_SET_DEFAULT(UseAESIntrinsics, false);
   591   }
   593   // Adjust RTM (Restricted Transactional Memory) flags
   594   if (!supports_rtm() && UseRTMLocking) {
   595     // Can't continue because UseRTMLocking affects UseBiasedLocking flag
   596     // setting during arguments processing. See use_biased_locking().
   597     // VM_Version_init() is executed after UseBiasedLocking is used
   598     // in Thread::allocate().
   599     vm_exit_during_initialization("RTM instructions are not available on this CPU");
   600   }
   602 #if INCLUDE_RTM_OPT
   603   if (UseRTMLocking) {
   604     if (!FLAG_IS_CMDLINE(UseRTMLocking)) {
   605       // RTM locking should be used only for applications with
   606       // high lock contention. For now we do not use it by default.
   607       vm_exit_during_initialization("UseRTMLocking flag should be only set on command line");
   608     }
   609     if (!is_power_of_2(RTMTotalCountIncrRate)) {
   610       warning("RTMTotalCountIncrRate must be a power of 2, resetting it to 64");
   611       FLAG_SET_DEFAULT(RTMTotalCountIncrRate, 64);
   612     }
   613     if (RTMAbortRatio < 0 || RTMAbortRatio > 100) {
   614       warning("RTMAbortRatio must be in the range 0 to 100, resetting it to 50");
   615       FLAG_SET_DEFAULT(RTMAbortRatio, 50);
   616     }
   617   } else { // !UseRTMLocking
   618     if (UseRTMForStackLocks) {
   619       if (!FLAG_IS_DEFAULT(UseRTMForStackLocks)) {
   620         warning("UseRTMForStackLocks flag should be off when UseRTMLocking flag is off");
   621       }
   622       FLAG_SET_DEFAULT(UseRTMForStackLocks, false);
   623     }
   624     if (UseRTMDeopt) {
   625       FLAG_SET_DEFAULT(UseRTMDeopt, false);
   626     }
   627     if (PrintPreciseRTMLockingStatistics) {
   628       FLAG_SET_DEFAULT(PrintPreciseRTMLockingStatistics, false);
   629     }
   630   }
   631 #else
   632   if (UseRTMLocking) {
   633     // Only C2 does RTM locking optimization.
   634     // Can't continue because UseRTMLocking affects UseBiasedLocking flag
   635     // setting during arguments processing. See use_biased_locking().
   636     vm_exit_during_initialization("RTM locking optimization is not supported in this VM");
   637   }
   638 #endif
   640 #ifdef COMPILER2
   641   if (UseFPUForSpilling) {
   642     if (UseSSE < 2) {
   643       // Only supported with SSE2+
   644       FLAG_SET_DEFAULT(UseFPUForSpilling, false);
   645     }
   646   }
   647   if (MaxVectorSize > 0) {
   648     if (!is_power_of_2(MaxVectorSize)) {
   649       warning("MaxVectorSize must be a power of 2");
   650       FLAG_SET_DEFAULT(MaxVectorSize, 32);
   651     }
   652     if (MaxVectorSize > 32) {
   653       FLAG_SET_DEFAULT(MaxVectorSize, 32);
   654     }
   655     if (MaxVectorSize > 16 && (UseAVX == 0 || !os_supports_avx_vectors())) {
   656       // 32 bytes vectors (in YMM) are only supported with AVX+
   657       FLAG_SET_DEFAULT(MaxVectorSize, 16);
   658     }
   659     if (UseSSE < 2) {
   660       // Vectors (in XMM) are only supported with SSE2+
   661       FLAG_SET_DEFAULT(MaxVectorSize, 0);
   662     }
   663 #ifdef ASSERT
   664     if (supports_avx() && PrintMiscellaneous && Verbose && TraceNewVectors) {
   665       tty->print_cr("State of YMM registers after signal handle:");
   666       int nreg = 2 LP64_ONLY(+2);
   667       const char* ymm_name[4] = {"0", "7", "8", "15"};
   668       for (int i = 0; i < nreg; i++) {
   669         tty->print("YMM%s:", ymm_name[i]);
   670         for (int j = 7; j >=0; j--) {
   671           tty->print(" %x", _cpuid_info.ymm_save[i*8 + j]);
   672         }
   673         tty->cr();
   674       }
   675     }
   676 #endif
   677   }
   678 #endif
   680   // On new cpus instructions which update whole XMM register should be used
   681   // to prevent partial register stall due to dependencies on high half.
   682   //
   683   // UseXmmLoadAndClearUpper == true  --> movsd(xmm, mem)
   684   // UseXmmLoadAndClearUpper == false --> movlpd(xmm, mem)
   685   // UseXmmRegToRegMoveAll == true  --> movaps(xmm, xmm), movapd(xmm, xmm).
   686   // UseXmmRegToRegMoveAll == false --> movss(xmm, xmm),  movsd(xmm, xmm).
   688   if( is_amd() ) { // AMD cpus specific settings
   689     if( supports_sse2() && FLAG_IS_DEFAULT(UseAddressNop) ) {
   690       // Use it on new AMD cpus starting from Opteron.
   691       UseAddressNop = true;
   692     }
   693     if( supports_sse2() && FLAG_IS_DEFAULT(UseNewLongLShift) ) {
   694       // Use it on new AMD cpus starting from Opteron.
   695       UseNewLongLShift = true;
   696     }
   697     if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
   698       if( supports_sse4a() ) {
   699         UseXmmLoadAndClearUpper = true; // use movsd only on '10h' Opteron
   700       } else {
   701         UseXmmLoadAndClearUpper = false;
   702       }
   703     }
   704     if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
   705       if( supports_sse4a() ) {
   706         UseXmmRegToRegMoveAll = true; // use movaps, movapd only on '10h'
   707       } else {
   708         UseXmmRegToRegMoveAll = false;
   709       }
   710     }
   711     if( FLAG_IS_DEFAULT(UseXmmI2F) ) {
   712       if( supports_sse4a() ) {
   713         UseXmmI2F = true;
   714       } else {
   715         UseXmmI2F = false;
   716       }
   717     }
   718     if( FLAG_IS_DEFAULT(UseXmmI2D) ) {
   719       if( supports_sse4a() ) {
   720         UseXmmI2D = true;
   721       } else {
   722         UseXmmI2D = false;
   723       }
   724     }
   725     if( FLAG_IS_DEFAULT(UseSSE42Intrinsics) ) {
   726       if( supports_sse4_2() && UseSSE >= 4 ) {
   727         UseSSE42Intrinsics = true;
   728       }
   729     }
   731     // some defaults for AMD family 15h
   732     if ( cpu_family() == 0x15 ) {
   733       // On family 15h processors default is no sw prefetch
   734       if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
   735         AllocatePrefetchStyle = 0;
   736       }
   737       // Also, if some other prefetch style is specified, default instruction type is PREFETCHW
   738       if (FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
   739         AllocatePrefetchInstr = 3;
   740       }
   741       // On family 15h processors use XMM and UnalignedLoadStores for Array Copy
   742       if (supports_sse2() && FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
   743         UseXMMForArrayCopy = true;
   744       }
   745       if (supports_sse2() && FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
   746         UseUnalignedLoadStores = true;
   747       }
   748     }
   750 #ifdef COMPILER2
   751     if (MaxVectorSize > 16) {
   752       // Limit vectors size to 16 bytes on current AMD cpus.
   753       FLAG_SET_DEFAULT(MaxVectorSize, 16);
   754     }
   755 #endif // COMPILER2
   756   }
   758   if( is_intel() ) { // Intel cpus specific settings
   759     if( FLAG_IS_DEFAULT(UseStoreImmI16) ) {
   760       UseStoreImmI16 = false; // don't use it on Intel cpus
   761     }
   762     if( cpu_family() == 6 || cpu_family() == 15 ) {
   763       if( FLAG_IS_DEFAULT(UseAddressNop) ) {
   764         // Use it on all Intel cpus starting from PentiumPro
   765         UseAddressNop = true;
   766       }
   767     }
   768     if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
   769       UseXmmLoadAndClearUpper = true; // use movsd on all Intel cpus
   770     }
   771     if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
   772       if( supports_sse3() ) {
   773         UseXmmRegToRegMoveAll = true; // use movaps, movapd on new Intel cpus
   774       } else {
   775         UseXmmRegToRegMoveAll = false;
   776       }
   777     }
   778     if( cpu_family() == 6 && supports_sse3() ) { // New Intel cpus
   779 #ifdef COMPILER2
   780       if( FLAG_IS_DEFAULT(MaxLoopPad) ) {
   781         // For new Intel cpus do the next optimization:
   782         // don't align the beginning of a loop if there are enough instructions
   783         // left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
   784         // in current fetch line (OptoLoopAlignment) or the padding
   785         // is big (> MaxLoopPad).
   786         // Set MaxLoopPad to 11 for new Intel cpus to reduce number of
   787         // generated NOP instructions. 11 is the largest size of one
   788         // address NOP instruction '0F 1F' (see Assembler::nop(i)).
   789         MaxLoopPad = 11;
   790       }
   791 #endif // COMPILER2
   792       if (FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
   793         UseXMMForArrayCopy = true; // use SSE2 movq on new Intel cpus
   794       }
   795       if (supports_sse4_2() && supports_ht()) { // Newest Intel cpus
   796         if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
   797           UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
   798         }
   799       }
   800       if (supports_sse4_2() && UseSSE >= 4) {
   801         if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
   802           UseSSE42Intrinsics = true;
   803         }
   804       }
   805     }
   806     if ((cpu_family() == 0x06) &&
   807         ((extended_cpu_model() == 0x36) || // Centerton
   808          (extended_cpu_model() == 0x37) || // Silvermont
   809          (extended_cpu_model() == 0x4D))) {
   810 #ifdef COMPILER2
   811       if (FLAG_IS_DEFAULT(OptoScheduling)) {
   812         OptoScheduling = true;
   813       }
   814 #endif
   815       if (supports_sse4_2()) { // Silvermont
   816         if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
   817           UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
   818         }
   819       }
   820     }
   821   }
   823   // Use count leading zeros count instruction if available.
   824   if (supports_lzcnt()) {
   825     if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
   826       UseCountLeadingZerosInstruction = true;
   827     }
   828    } else if (UseCountLeadingZerosInstruction) {
   829     warning("lzcnt instruction is not available on this CPU");
   830     FLAG_SET_DEFAULT(UseCountLeadingZerosInstruction, false);
   831   }
   833   if (supports_bmi1()) {
   834     if (FLAG_IS_DEFAULT(UseBMI1Instructions)) {
   835       UseBMI1Instructions = true;
   836     }
   837   } else if (UseBMI1Instructions) {
   838     warning("BMI1 instructions are not available on this CPU");
   839     FLAG_SET_DEFAULT(UseBMI1Instructions, false);
   840   }
   842   // Use count trailing zeros instruction if available
   843   if (supports_bmi1()) {
   844     if (FLAG_IS_DEFAULT(UseCountTrailingZerosInstruction)) {
   845       UseCountTrailingZerosInstruction = UseBMI1Instructions;
   846     }
   847   } else if (UseCountTrailingZerosInstruction) {
   848     warning("tzcnt instruction is not available on this CPU");
   849     FLAG_SET_DEFAULT(UseCountTrailingZerosInstruction, false);
   850   }
   852   // Use population count instruction if available.
   853   if (supports_popcnt()) {
   854     if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
   855       UsePopCountInstruction = true;
   856     }
   857   } else if (UsePopCountInstruction) {
   858     warning("POPCNT instruction is not available on this CPU");
   859     FLAG_SET_DEFAULT(UsePopCountInstruction, false);
   860   }
   862   // Use fast-string operations if available.
   863   if (supports_erms()) {
   864     if (FLAG_IS_DEFAULT(UseFastStosb)) {
   865       UseFastStosb = true;
   866     }
   867   } else if (UseFastStosb) {
   868     warning("fast-string operations are not available on this CPU");
   869     FLAG_SET_DEFAULT(UseFastStosb, false);
   870   }
   872 #ifdef COMPILER2
   873   if (FLAG_IS_DEFAULT(AlignVector)) {
   874     // Modern processors allow misaligned memory operations for vectors.
   875     AlignVector = !UseUnalignedLoadStores;
   876   }
   877 #endif // COMPILER2
   879   assert(0 <= ReadPrefetchInstr && ReadPrefetchInstr <= 3, "invalid value");
   880   assert(0 <= AllocatePrefetchInstr && AllocatePrefetchInstr <= 3, "invalid value");
   882   // set valid Prefetch instruction
   883   if( ReadPrefetchInstr < 0 ) ReadPrefetchInstr = 0;
   884   if( ReadPrefetchInstr > 3 ) ReadPrefetchInstr = 3;
   885   if( ReadPrefetchInstr == 3 && !supports_3dnow_prefetch() ) ReadPrefetchInstr = 0;
   886   if( !supports_sse() && supports_3dnow_prefetch() ) ReadPrefetchInstr = 3;
   888   if( AllocatePrefetchInstr < 0 ) AllocatePrefetchInstr = 0;
   889   if( AllocatePrefetchInstr > 3 ) AllocatePrefetchInstr = 3;
   890   if( AllocatePrefetchInstr == 3 && !supports_3dnow_prefetch() ) AllocatePrefetchInstr=0;
   891   if( !supports_sse() && supports_3dnow_prefetch() ) AllocatePrefetchInstr = 3;
   893   // Allocation prefetch settings
   894   intx cache_line_size = prefetch_data_size();
   895   if( cache_line_size > AllocatePrefetchStepSize )
   896     AllocatePrefetchStepSize = cache_line_size;
   898   assert(AllocatePrefetchLines > 0, "invalid value");
   899   if( AllocatePrefetchLines < 1 )     // set valid value in product VM
   900     AllocatePrefetchLines = 3;
   901   assert(AllocateInstancePrefetchLines > 0, "invalid value");
   902   if( AllocateInstancePrefetchLines < 1 ) // set valid value in product VM
   903     AllocateInstancePrefetchLines = 1;
   905   AllocatePrefetchDistance = allocate_prefetch_distance();
   906   AllocatePrefetchStyle    = allocate_prefetch_style();
   908   if (is_intel() && cpu_family() == 6 && supports_sse3()) {
   909     if (AllocatePrefetchStyle == 2) { // watermark prefetching on Core
   910 #ifdef _LP64
   911       AllocatePrefetchDistance = 384;
   912 #else
   913       AllocatePrefetchDistance = 320;
   914 #endif
   915     }
   916     if (supports_sse4_2() && supports_ht()) { // Nehalem based cpus
   917       AllocatePrefetchDistance = 192;
   918       AllocatePrefetchLines = 4;
   919     }
   920 #ifdef COMPILER2
   921     if (supports_sse4_2()) {
   922       if (FLAG_IS_DEFAULT(UseFPUForSpilling)) {
   923         FLAG_SET_DEFAULT(UseFPUForSpilling, true);
   924       }
   925     }
   926 #endif
   927   }
   928   assert(AllocatePrefetchDistance % AllocatePrefetchStepSize == 0, "invalid value");
   930 #ifdef _LP64
   931   // Prefetch settings
   932   PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
   933   PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
   934   PrefetchFieldsAhead         = prefetch_fields_ahead();
   935 #endif
   937   if (FLAG_IS_DEFAULT(ContendedPaddingWidth) &&
   938      (cache_line_size > ContendedPaddingWidth))
   939      ContendedPaddingWidth = cache_line_size;
   941 #ifndef PRODUCT
   942   if (PrintMiscellaneous && Verbose) {
   943     tty->print_cr("Logical CPUs per core: %u",
   944                   logical_processors_per_package());
   945     tty->print("UseSSE=%d", (int) UseSSE);
   946     if (UseAVX > 0) {
   947       tty->print("  UseAVX=%d", (int) UseAVX);
   948     }
   949     if (UseAES) {
   950       tty->print("  UseAES=1");
   951     }
   952 #ifdef COMPILER2
   953     if (MaxVectorSize > 0) {
   954       tty->print("  MaxVectorSize=%d", (int) MaxVectorSize);
   955     }
   956 #endif
   957     tty->cr();
   958     tty->print("Allocation");
   959     if (AllocatePrefetchStyle <= 0 || UseSSE == 0 && !supports_3dnow_prefetch()) {
   960       tty->print_cr(": no prefetching");
   961     } else {
   962       tty->print(" prefetching: ");
   963       if (UseSSE == 0 && supports_3dnow_prefetch()) {
   964         tty->print("PREFETCHW");
   965       } else if (UseSSE >= 1) {
   966         if (AllocatePrefetchInstr == 0) {
   967           tty->print("PREFETCHNTA");
   968         } else if (AllocatePrefetchInstr == 1) {
   969           tty->print("PREFETCHT0");
   970         } else if (AllocatePrefetchInstr == 2) {
   971           tty->print("PREFETCHT2");
   972         } else if (AllocatePrefetchInstr == 3) {
   973           tty->print("PREFETCHW");
   974         }
   975       }
   976       if (AllocatePrefetchLines > 1) {
   977         tty->print_cr(" at distance %d, %d lines of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchLines, (int) AllocatePrefetchStepSize);
   978       } else {
   979         tty->print_cr(" at distance %d, one line of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchStepSize);
   980       }
   981     }
   983     if (PrefetchCopyIntervalInBytes > 0) {
   984       tty->print_cr("PrefetchCopyIntervalInBytes %d", (int) PrefetchCopyIntervalInBytes);
   985     }
   986     if (PrefetchScanIntervalInBytes > 0) {
   987       tty->print_cr("PrefetchScanIntervalInBytes %d", (int) PrefetchScanIntervalInBytes);
   988     }
   989     if (PrefetchFieldsAhead > 0) {
   990       tty->print_cr("PrefetchFieldsAhead %d", (int) PrefetchFieldsAhead);
   991     }
   992     if (ContendedPaddingWidth > 0) {
   993       tty->print_cr("ContendedPaddingWidth %d", (int) ContendedPaddingWidth);
   994     }
   995   }
   996 #endif // !PRODUCT
   997 }
   999 bool VM_Version::use_biased_locking() {
  1000 #if INCLUDE_RTM_OPT
  1001   // RTM locking is most useful when there is high lock contention and
  1002   // low data contention.  With high lock contention the lock is usually
  1003   // inflated and biased locking is not suitable for that case.
  1004   // RTM locking code requires that biased locking is off.
  1005   // Note: we can't switch off UseBiasedLocking in get_processor_features()
  1006   // because it is used by Thread::allocate() which is called before
  1007   // VM_Version::initialize().
  1008   if (UseRTMLocking && UseBiasedLocking) {
  1009     if (FLAG_IS_DEFAULT(UseBiasedLocking)) {
  1010       FLAG_SET_DEFAULT(UseBiasedLocking, false);
  1011     } else {
  1012       warning("Biased locking is not supported with RTM locking; ignoring UseBiasedLocking flag." );
  1013       UseBiasedLocking = false;
  1016 #endif
  1017   return UseBiasedLocking;
  1020 void VM_Version::initialize() {
  1021   ResourceMark rm;
  1022   // Making this stub must be FIRST use of assembler
  1024   stub_blob = BufferBlob::create("get_cpu_info_stub", stub_size);
  1025   if (stub_blob == NULL) {
  1026     vm_exit_during_initialization("Unable to allocate get_cpu_info_stub");
  1028   CodeBuffer c(stub_blob);
  1029   VM_Version_StubGenerator g(&c);
  1030   get_cpu_info_stub = CAST_TO_FN_PTR(get_cpu_info_stub_t,
  1031                                      g.generate_get_cpu_info());
  1033   get_processor_features();

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