/* * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef CPU_X86_VM_VM_VERSION_X86_HPP #define CPU_X86_VM_VM_VERSION_X86_HPP #include "runtime/globals_extension.hpp" #include "runtime/vm_version.hpp" class VM_Version : public Abstract_VM_Version { public: // cpuid result register layouts. These are all unions of a uint32_t // (in case anyone wants access to the register as a whole) and a bitfield. union StdCpuid1Eax { uint32_t value; struct { uint32_t stepping : 4, model : 4, family : 4, proc_type : 2, : 2, ext_model : 4, ext_family : 8, : 4; } bits; }; union StdCpuid1Ebx { // example, unused uint32_t value; struct { uint32_t brand_id : 8, clflush_size : 8, threads_per_cpu : 8, apic_id : 8; } bits; }; union StdCpuid1Ecx { uint32_t value; struct { uint32_t sse3 : 1, clmul : 1, : 1, monitor : 1, : 1, vmx : 1, : 1, est : 1, : 1, ssse3 : 1, cid : 1, : 2, cmpxchg16: 1, : 4, dca : 1, sse4_1 : 1, sse4_2 : 1, : 2, popcnt : 1, : 1, aes : 1, : 1, osxsave : 1, avx : 1, : 3; } bits; }; union StdCpuid1Edx { uint32_t value; struct { uint32_t : 4, tsc : 1, : 3, cmpxchg8 : 1, : 6, cmov : 1, : 3, clflush : 1, : 3, mmx : 1, fxsr : 1, sse : 1, sse2 : 1, : 1, ht : 1, : 3; } bits; }; union DcpCpuid4Eax { uint32_t value; struct { uint32_t cache_type : 5, : 21, cores_per_cpu : 6; } bits; }; union DcpCpuid4Ebx { uint32_t value; struct { uint32_t L1_line_size : 12, partitions : 10, associativity : 10; } bits; }; union TplCpuidBEbx { uint32_t value; struct { uint32_t logical_cpus : 16, : 16; } bits; }; union ExtCpuid1Ecx { uint32_t value; struct { uint32_t LahfSahf : 1, CmpLegacy : 1, : 3, lzcnt_intel : 1, lzcnt : 1, sse4a : 1, misalignsse : 1, prefetchw : 1, : 22; } bits; }; union ExtCpuid1Edx { uint32_t value; struct { uint32_t : 22, mmx_amd : 1, mmx : 1, fxsr : 1, : 4, long_mode : 1, tdnow2 : 1, tdnow : 1; } bits; }; union ExtCpuid5Ex { uint32_t value; struct { uint32_t L1_line_size : 8, L1_tag_lines : 8, L1_assoc : 8, L1_size : 8; } bits; }; union ExtCpuid7Edx { uint32_t value; struct { uint32_t : 8, tsc_invariance : 1, : 23; } bits; }; union ExtCpuid8Ecx { uint32_t value; struct { uint32_t cores_per_cpu : 8, : 24; } bits; }; union SefCpuid7Eax { uint32_t value; }; union SefCpuid7Ebx { uint32_t value; struct { uint32_t fsgsbase : 1, : 2, bmi1 : 1, : 1, avx2 : 1, : 2, bmi2 : 1, erms : 1, : 1, rtm : 1, : 7, adx : 1, : 12; } bits; }; union XemXcr0Eax { uint32_t value; struct { uint32_t x87 : 1, sse : 1, ymm : 1, : 29; } bits; }; protected: static int _cpu; static int _model; static int _stepping; static int _cpuFeatures; // features returned by the "cpuid" instruction // 0 if this instruction is not available static const char* _features_str; static address _cpuinfo_segv_addr; // address of instruction which causes SEGV static address _cpuinfo_cont_addr; // address of instruction after the one which causes SEGV enum { CPU_CX8 = (1 << 0), // next bits are from cpuid 1 (EDX) CPU_CMOV = (1 << 1), CPU_FXSR = (1 << 2), CPU_HT = (1 << 3), CPU_MMX = (1 << 4), CPU_3DNOW_PREFETCH = (1 << 5), // Processor supports 3dnow prefetch and prefetchw instructions // may not necessarily support other 3dnow instructions CPU_SSE = (1 << 6), CPU_SSE2 = (1 << 7), CPU_SSE3 = (1 << 8), // SSE3 comes from cpuid 1 (ECX) CPU_SSSE3 = (1 << 9), CPU_SSE4A = (1 << 10), CPU_SSE4_1 = (1 << 11), CPU_SSE4_2 = (1 << 12), CPU_POPCNT = (1 << 13), CPU_LZCNT = (1 << 14), CPU_TSC = (1 << 15), CPU_TSCINV = (1 << 16), CPU_AVX = (1 << 17), CPU_AVX2 = (1 << 18), CPU_AES = (1 << 19), CPU_ERMS = (1 << 20), // enhanced 'rep movsb/stosb' instructions CPU_CLMUL = (1 << 21), // carryless multiply for CRC CPU_BMI1 = (1 << 22), CPU_BMI2 = (1 << 23), CPU_RTM = (1 << 24), // Restricted Transactional Memory instructions CPU_ADX = (1 << 25) } cpuFeatureFlags; enum { // AMD CPU_FAMILY_AMD_11H = 0x11, // Intel CPU_FAMILY_INTEL_CORE = 6, CPU_MODEL_NEHALEM = 0x1e, CPU_MODEL_NEHALEM_EP = 0x1a, CPU_MODEL_NEHALEM_EX = 0x2e, CPU_MODEL_WESTMERE = 0x25, CPU_MODEL_WESTMERE_EP = 0x2c, CPU_MODEL_WESTMERE_EX = 0x2f, CPU_MODEL_SANDYBRIDGE = 0x2a, CPU_MODEL_SANDYBRIDGE_EP = 0x2d, CPU_MODEL_IVYBRIDGE_EP = 0x3a, CPU_MODEL_HASWELL_E3 = 0x3c, CPU_MODEL_HASWELL_E7 = 0x3f, CPU_MODEL_BROADWELL = 0x3d } cpuExtendedFamily; // cpuid information block. All info derived from executing cpuid with // various function numbers is stored here. Intel and AMD info is // merged in this block: accessor methods disentangle it. // // The info block is laid out in subblocks of 4 dwords corresponding to // eax, ebx, ecx and edx, whether or not they contain anything useful. struct CpuidInfo { // cpuid function 0 uint32_t std_max_function; uint32_t std_vendor_name_0; uint32_t std_vendor_name_1; uint32_t std_vendor_name_2; // cpuid function 1 StdCpuid1Eax std_cpuid1_eax; StdCpuid1Ebx std_cpuid1_ebx; StdCpuid1Ecx std_cpuid1_ecx; StdCpuid1Edx std_cpuid1_edx; // cpuid function 4 (deterministic cache parameters) DcpCpuid4Eax dcp_cpuid4_eax; DcpCpuid4Ebx dcp_cpuid4_ebx; uint32_t dcp_cpuid4_ecx; // unused currently uint32_t dcp_cpuid4_edx; // unused currently // cpuid function 7 (structured extended features) SefCpuid7Eax sef_cpuid7_eax; SefCpuid7Ebx sef_cpuid7_ebx; uint32_t sef_cpuid7_ecx; // unused currently uint32_t sef_cpuid7_edx; // unused currently // cpuid function 0xB (processor topology) // ecx = 0 uint32_t tpl_cpuidB0_eax; TplCpuidBEbx tpl_cpuidB0_ebx; uint32_t tpl_cpuidB0_ecx; // unused currently uint32_t tpl_cpuidB0_edx; // unused currently // ecx = 1 uint32_t tpl_cpuidB1_eax; TplCpuidBEbx tpl_cpuidB1_ebx; uint32_t tpl_cpuidB1_ecx; // unused currently uint32_t tpl_cpuidB1_edx; // unused currently // ecx = 2 uint32_t tpl_cpuidB2_eax; TplCpuidBEbx tpl_cpuidB2_ebx; uint32_t tpl_cpuidB2_ecx; // unused currently uint32_t tpl_cpuidB2_edx; // unused currently // cpuid function 0x80000000 // example, unused uint32_t ext_max_function; uint32_t ext_vendor_name_0; uint32_t ext_vendor_name_1; uint32_t ext_vendor_name_2; // cpuid function 0x80000001 uint32_t ext_cpuid1_eax; // reserved uint32_t ext_cpuid1_ebx; // reserved ExtCpuid1Ecx ext_cpuid1_ecx; ExtCpuid1Edx ext_cpuid1_edx; // cpuid functions 0x80000002 thru 0x80000004: example, unused uint32_t proc_name_0, proc_name_1, proc_name_2, proc_name_3; uint32_t proc_name_4, proc_name_5, proc_name_6, proc_name_7; uint32_t proc_name_8, proc_name_9, proc_name_10,proc_name_11; // cpuid function 0x80000005 // AMD L1, Intel reserved uint32_t ext_cpuid5_eax; // unused currently uint32_t ext_cpuid5_ebx; // reserved ExtCpuid5Ex ext_cpuid5_ecx; // L1 data cache info (AMD) ExtCpuid5Ex ext_cpuid5_edx; // L1 instruction cache info (AMD) // cpuid function 0x80000007 uint32_t ext_cpuid7_eax; // reserved uint32_t ext_cpuid7_ebx; // reserved uint32_t ext_cpuid7_ecx; // reserved ExtCpuid7Edx ext_cpuid7_edx; // tscinv // cpuid function 0x80000008 uint32_t ext_cpuid8_eax; // unused currently uint32_t ext_cpuid8_ebx; // reserved ExtCpuid8Ecx ext_cpuid8_ecx; uint32_t ext_cpuid8_edx; // reserved // extended control register XCR0 (the XFEATURE_ENABLED_MASK register) XemXcr0Eax xem_xcr0_eax; uint32_t xem_xcr0_edx; // reserved // Space to save ymm registers after signal handle int ymm_save[8*4]; // Save ymm0, ymm7, ymm8, ymm15 }; // The actual cpuid info block static CpuidInfo _cpuid_info; // Extractors and predicates static uint32_t extended_cpu_family() { uint32_t result = _cpuid_info.std_cpuid1_eax.bits.family; result += _cpuid_info.std_cpuid1_eax.bits.ext_family; return result; } static uint32_t extended_cpu_model() { uint32_t result = _cpuid_info.std_cpuid1_eax.bits.model; result |= _cpuid_info.std_cpuid1_eax.bits.ext_model << 4; return result; } static uint32_t cpu_stepping() { uint32_t result = _cpuid_info.std_cpuid1_eax.bits.stepping; return result; } static uint logical_processor_count() { uint result = threads_per_core(); return result; } static uint32_t feature_flags() { uint32_t result = 0; if (_cpuid_info.std_cpuid1_edx.bits.cmpxchg8 != 0) result |= CPU_CX8; if (_cpuid_info.std_cpuid1_edx.bits.cmov != 0) result |= CPU_CMOV; if (_cpuid_info.std_cpuid1_edx.bits.fxsr != 0 || (is_amd() && _cpuid_info.ext_cpuid1_edx.bits.fxsr != 0)) result |= CPU_FXSR; // HT flag is set for multi-core processors also. if (threads_per_core() > 1) result |= CPU_HT; if (_cpuid_info.std_cpuid1_edx.bits.mmx != 0 || (is_amd() && _cpuid_info.ext_cpuid1_edx.bits.mmx != 0)) result |= CPU_MMX; if (_cpuid_info.std_cpuid1_edx.bits.sse != 0) result |= CPU_SSE; if (_cpuid_info.std_cpuid1_edx.bits.sse2 != 0) result |= CPU_SSE2; if (_cpuid_info.std_cpuid1_ecx.bits.sse3 != 0) result |= CPU_SSE3; if (_cpuid_info.std_cpuid1_ecx.bits.ssse3 != 0) result |= CPU_SSSE3; if (_cpuid_info.std_cpuid1_ecx.bits.sse4_1 != 0) result |= CPU_SSE4_1; if (_cpuid_info.std_cpuid1_ecx.bits.sse4_2 != 0) result |= CPU_SSE4_2; if (_cpuid_info.std_cpuid1_ecx.bits.popcnt != 0) result |= CPU_POPCNT; if (_cpuid_info.std_cpuid1_ecx.bits.avx != 0 && _cpuid_info.std_cpuid1_ecx.bits.osxsave != 0 && _cpuid_info.xem_xcr0_eax.bits.sse != 0 && _cpuid_info.xem_xcr0_eax.bits.ymm != 0) { result |= CPU_AVX; if (_cpuid_info.sef_cpuid7_ebx.bits.avx2 != 0) result |= CPU_AVX2; } if(_cpuid_info.sef_cpuid7_ebx.bits.bmi1 != 0) result |= CPU_BMI1; if (_cpuid_info.std_cpuid1_edx.bits.tsc != 0) result |= CPU_TSC; if (_cpuid_info.ext_cpuid7_edx.bits.tsc_invariance != 0) result |= CPU_TSCINV; if (_cpuid_info.std_cpuid1_ecx.bits.aes != 0) result |= CPU_AES; if (_cpuid_info.sef_cpuid7_ebx.bits.erms != 0) result |= CPU_ERMS; if (_cpuid_info.std_cpuid1_ecx.bits.clmul != 0) result |= CPU_CLMUL; if (_cpuid_info.sef_cpuid7_ebx.bits.rtm != 0) result |= CPU_RTM; // AMD features. if (is_amd()) { if ((_cpuid_info.ext_cpuid1_edx.bits.tdnow != 0) || (_cpuid_info.ext_cpuid1_ecx.bits.prefetchw != 0)) result |= CPU_3DNOW_PREFETCH; if (_cpuid_info.ext_cpuid1_ecx.bits.lzcnt != 0) result |= CPU_LZCNT; if (_cpuid_info.ext_cpuid1_ecx.bits.sse4a != 0) result |= CPU_SSE4A; } // Intel features. if(is_intel()) { if(_cpuid_info.sef_cpuid7_ebx.bits.adx != 0) result |= CPU_ADX; if(_cpuid_info.sef_cpuid7_ebx.bits.bmi2 != 0) result |= CPU_BMI2; if(_cpuid_info.ext_cpuid1_ecx.bits.lzcnt_intel != 0) result |= CPU_LZCNT; // for Intel, ecx.bits.misalignsse bit (bit 8) indicates support for prefetchw if (_cpuid_info.ext_cpuid1_ecx.bits.misalignsse != 0) { result |= CPU_3DNOW_PREFETCH; } } return result; } static bool os_supports_avx_vectors() { if (!supports_avx()) { return false; } // Verify that OS save/restore all bits of AVX registers // during signal processing. int nreg = 2 LP64_ONLY(+2); for (int i = 0; i < 8 * nreg; i++) { // 32 bytes per ymm register if (_cpuid_info.ymm_save[i] != ymm_test_value()) { return false; } } return true; } static void get_processor_features(); public: // Offsets for cpuid asm stub static ByteSize std_cpuid0_offset() { return byte_offset_of(CpuidInfo, std_max_function); } static ByteSize std_cpuid1_offset() { return byte_offset_of(CpuidInfo, std_cpuid1_eax); } static ByteSize dcp_cpuid4_offset() { return byte_offset_of(CpuidInfo, dcp_cpuid4_eax); } static ByteSize sef_cpuid7_offset() { return byte_offset_of(CpuidInfo, sef_cpuid7_eax); } static ByteSize ext_cpuid1_offset() { return byte_offset_of(CpuidInfo, ext_cpuid1_eax); } static ByteSize ext_cpuid5_offset() { return byte_offset_of(CpuidInfo, ext_cpuid5_eax); } static ByteSize ext_cpuid7_offset() { return byte_offset_of(CpuidInfo, ext_cpuid7_eax); } static ByteSize ext_cpuid8_offset() { return byte_offset_of(CpuidInfo, ext_cpuid8_eax); } static ByteSize tpl_cpuidB0_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB0_eax); } static ByteSize tpl_cpuidB1_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB1_eax); } static ByteSize tpl_cpuidB2_offset() { return byte_offset_of(CpuidInfo, tpl_cpuidB2_eax); } static ByteSize xem_xcr0_offset() { return byte_offset_of(CpuidInfo, xem_xcr0_eax); } static ByteSize ymm_save_offset() { return byte_offset_of(CpuidInfo, ymm_save); } // The value used to check ymm register after signal handle static int ymm_test_value() { return 0xCAFEBABE; } static void get_cpu_info_wrapper(); static void set_cpuinfo_segv_addr(address pc) { _cpuinfo_segv_addr = pc; } static bool is_cpuinfo_segv_addr(address pc) { return _cpuinfo_segv_addr == pc; } static void set_cpuinfo_cont_addr(address pc) { _cpuinfo_cont_addr = pc; } static address cpuinfo_cont_addr() { return _cpuinfo_cont_addr; } static void clean_cpuFeatures() { _cpuFeatures = 0; } static void set_avx_cpuFeatures() { _cpuFeatures = (CPU_SSE | CPU_SSE2 | CPU_AVX); } // Initialization static void initialize(); // Override Abstract_VM_Version implementation static bool use_biased_locking(); // Asserts static void assert_is_initialized() { assert(_cpuid_info.std_cpuid1_eax.bits.family != 0, "VM_Version not initialized"); } // // Processor family: // 3 - 386 // 4 - 486 // 5 - Pentium // 6 - PentiumPro, Pentium II, Celeron, Xeon, Pentium III, Athlon, // Pentium M, Core Solo, Core Duo, Core2 Duo // family 6 model: 9, 13, 14, 15 // 0x0f - Pentium 4, Opteron // // Note: The cpu family should be used to select between // instruction sequences which are valid on all Intel // processors. Use the feature test functions below to // determine whether a particular instruction is supported. // static int cpu_family() { return _cpu;} static bool is_P6() { return cpu_family() >= 6; } static bool is_amd() { assert_is_initialized(); return _cpuid_info.std_vendor_name_0 == 0x68747541; } // 'htuA' static bool is_intel() { assert_is_initialized(); return _cpuid_info.std_vendor_name_0 == 0x756e6547; } // 'uneG' static bool supports_processor_topology() { return (_cpuid_info.std_max_function >= 0xB) && // eax[4:0] | ebx[0:15] == 0 indicates invalid topology level. // Some cpus have max cpuid >= 0xB but do not support processor topology. (((_cpuid_info.tpl_cpuidB0_eax & 0x1f) | _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus) != 0); } static uint cores_per_cpu() { uint result = 1; if (is_intel()) { bool supports_topology = supports_processor_topology(); if (supports_topology) { result = _cpuid_info.tpl_cpuidB1_ebx.bits.logical_cpus / _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus; } if (!supports_topology || result == 0) { result = (_cpuid_info.dcp_cpuid4_eax.bits.cores_per_cpu + 1); } } else if (is_amd()) { result = (_cpuid_info.ext_cpuid8_ecx.bits.cores_per_cpu + 1); } return result; } static uint threads_per_core() { uint result = 1; if (is_intel() && supports_processor_topology()) { result = _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus; } else if (_cpuid_info.std_cpuid1_edx.bits.ht != 0) { result = _cpuid_info.std_cpuid1_ebx.bits.threads_per_cpu / cores_per_cpu(); } return (result == 0 ? 1 : result); } static intx L1_line_size() { intx result = 0; if (is_intel()) { result = (_cpuid_info.dcp_cpuid4_ebx.bits.L1_line_size + 1); } else if (is_amd()) { result = _cpuid_info.ext_cpuid5_ecx.bits.L1_line_size; } if (result < 32) // not defined ? result = 32; // 32 bytes by default on x86 and other x64 return result; } static intx prefetch_data_size() { return L1_line_size(); } // // Feature identification // static bool supports_cpuid() { return _cpuFeatures != 0; } static bool supports_cmpxchg8() { return (_cpuFeatures & CPU_CX8) != 0; } static bool supports_cmov() { return (_cpuFeatures & CPU_CMOV) != 0; } static bool supports_fxsr() { return (_cpuFeatures & CPU_FXSR) != 0; } static bool supports_ht() { return (_cpuFeatures & CPU_HT) != 0; } static bool supports_mmx() { return (_cpuFeatures & CPU_MMX) != 0; } static bool supports_sse() { return (_cpuFeatures & CPU_SSE) != 0; } static bool supports_sse2() { return (_cpuFeatures & CPU_SSE2) != 0; } static bool supports_sse3() { return (_cpuFeatures & CPU_SSE3) != 0; } static bool supports_ssse3() { return (_cpuFeatures & CPU_SSSE3)!= 0; } static bool supports_sse4_1() { return (_cpuFeatures & CPU_SSE4_1) != 0; } static bool supports_sse4_2() { return (_cpuFeatures & CPU_SSE4_2) != 0; } static bool supports_popcnt() { return (_cpuFeatures & CPU_POPCNT) != 0; } static bool supports_avx() { return (_cpuFeatures & CPU_AVX) != 0; } static bool supports_avx2() { return (_cpuFeatures & CPU_AVX2) != 0; } static bool supports_tsc() { return (_cpuFeatures & CPU_TSC) != 0; } static bool supports_aes() { return (_cpuFeatures & CPU_AES) != 0; } static bool supports_erms() { return (_cpuFeatures & CPU_ERMS) != 0; } static bool supports_clmul() { return (_cpuFeatures & CPU_CLMUL) != 0; } static bool supports_rtm() { return (_cpuFeatures & CPU_RTM) != 0; } static bool supports_bmi1() { return (_cpuFeatures & CPU_BMI1) != 0; } static bool supports_bmi2() { return (_cpuFeatures & CPU_BMI2) != 0; } static bool supports_adx() { return (_cpuFeatures & CPU_ADX) != 0; } // Intel features static bool is_intel_family_core() { return is_intel() && extended_cpu_family() == CPU_FAMILY_INTEL_CORE; } static bool is_intel_tsc_synched_at_init() { if (is_intel_family_core()) { uint32_t ext_model = extended_cpu_model(); if (ext_model == CPU_MODEL_NEHALEM_EP || ext_model == CPU_MODEL_WESTMERE_EP || ext_model == CPU_MODEL_SANDYBRIDGE_EP || ext_model == CPU_MODEL_IVYBRIDGE_EP) { // <= 2-socket invariant tsc support. EX versions are usually used // in > 2-socket systems and likely don't synchronize tscs at // initialization. // Code that uses tsc values must be prepared for them to arbitrarily // jump forward or backward. return true; } } return false; } // AMD features static bool supports_3dnow_prefetch() { return (_cpuFeatures & CPU_3DNOW_PREFETCH) != 0; } static bool supports_mmx_ext() { return is_amd() && _cpuid_info.ext_cpuid1_edx.bits.mmx_amd != 0; } static bool supports_lzcnt() { return (_cpuFeatures & CPU_LZCNT) != 0; } static bool supports_sse4a() { return (_cpuFeatures & CPU_SSE4A) != 0; } static bool is_amd_Barcelona() { return is_amd() && extended_cpu_family() == CPU_FAMILY_AMD_11H; } // Intel and AMD newer cores support fast timestamps well static bool supports_tscinv_bit() { return (_cpuFeatures & CPU_TSCINV) != 0; } static bool supports_tscinv() { return supports_tscinv_bit() && ( (is_amd() && !is_amd_Barcelona()) || is_intel_tsc_synched_at_init() ); } // Intel Core and newer cpus have fast IDIV instruction (excluding Atom). static bool has_fast_idiv() { return is_intel() && cpu_family() == 6 && supports_sse3() && _model != 0x1C; } static bool supports_compare_and_exchange() { return true; } static const char* cpu_features() { return _features_str; } static intx allocate_prefetch_distance() { // This method should be called before allocate_prefetch_style(). // // Hardware prefetching (distance/size in bytes): // Pentium 3 - 64 / 32 // Pentium 4 - 256 / 128 // Athlon - 64 / 32 ???? // Opteron - 128 / 64 only when 2 sequential cache lines accessed // Core - 128 / 64 // // Software prefetching (distance in bytes / instruction with best score): // Pentium 3 - 128 / prefetchnta // Pentium 4 - 512 / prefetchnta // Athlon - 128 / prefetchnta // Opteron - 256 / prefetchnta // Core - 256 / prefetchnta // It will be used only when AllocatePrefetchStyle > 0 intx count = AllocatePrefetchDistance; if (count < 0) { // default ? if (is_amd()) { // AMD if (supports_sse2()) count = 256; // Opteron else count = 128; // Athlon } else { // Intel if (supports_sse2()) if (cpu_family() == 6) { count = 256; // Pentium M, Core, Core2 } else { count = 512; // Pentium 4 } else count = 128; // Pentium 3 (and all other old CPUs) } } return count; } static intx allocate_prefetch_style() { assert(AllocatePrefetchStyle >= 0, "AllocatePrefetchStyle should be positive"); // Return 0 if AllocatePrefetchDistance was not defined. return AllocatePrefetchDistance > 0 ? AllocatePrefetchStyle : 0; } // Prefetch interval for gc copy/scan == 9 dcache lines. Derived from // 50-warehouse specjbb runs on a 2-way 1.8ghz opteron using a 4gb heap. // Tested intervals from 128 to 2048 in increments of 64 == one cache line. // 256 bytes (4 dcache lines) was the nearest runner-up to 576. // gc copy/scan is disabled if prefetchw isn't supported, because // Prefetch::write emits an inlined prefetchw on Linux. // Do not use the 3dnow prefetchw instruction. It isn't supported on em64t. // The used prefetcht0 instruction works for both amd64 and em64t. static intx prefetch_copy_interval_in_bytes() { intx interval = PrefetchCopyIntervalInBytes; return interval >= 0 ? interval : 576; } static intx prefetch_scan_interval_in_bytes() { intx interval = PrefetchScanIntervalInBytes; return interval >= 0 ? interval : 576; } static intx prefetch_fields_ahead() { intx count = PrefetchFieldsAhead; return count >= 0 ? count : 1; } }; #endif // CPU_X86_VM_VM_VERSION_X86_HPP