/*
* Copyright (c) 1997, 2022, 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.
*
*/
#include "precompiled.hpp"
#include "asm/macroAssembler.hpp"
#include "asm/macroAssembler.inline.hpp"
#include "code/codeBlob.hpp"
#include "compiler/compilerDefinitions.inline.hpp"
#include "jvm.h"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/java.hpp"
#include "runtime/os.inline.hpp"
#include "runtime/stubCodeGenerator.hpp"
#include "runtime/vm_version.hpp"
#include "utilities/powerOfTwo.hpp"
#include "utilities/virtualizationSupport.hpp"
int VM_Version::_cpu;
int VM_Version::_model;
int VM_Version::_stepping;
bool VM_Version::_has_intel_jcc_erratum;
VM_Version::CpuidInfo VM_Version::_cpuid_info = { 0, };
#define DECLARE_CPU_FEATURE_NAME(id, name, bit) name,
const char* VM_Version::_features_names[] = { CPU_FEATURE_FLAGS(DECLARE_CPU_FEATURE_NAME)};
#undef DECLARE_CPU_FEATURE_FLAG
// Address of instruction which causes SEGV
address VM_Version::_cpuinfo_segv_addr = 0;
// Address of instruction after the one which causes SEGV
address VM_Version::_cpuinfo_cont_addr = 0;
static BufferBlob* stub_blob;
static const int stub_size = 2000;
extern "C" {
typedef void (*get_cpu_info_stub_t)(void*);
typedef void (*detect_virt_stub_t)(uint32_t, uint32_t*);
}
static get_cpu_info_stub_t get_cpu_info_stub = NULL;
static detect_virt_stub_t detect_virt_stub = NULL;
#ifdef _LP64
bool VM_Version::supports_clflush() {
// clflush should always be available on x86_64
// if not we are in real trouble because we rely on it
// to flush the code cache.
// Unfortunately, Assembler::clflush is currently called as part
// of generation of the code cache flush routine. This happens
// under Universe::init before the processor features are set
// up. Assembler::flush calls this routine to check that clflush
// is allowed. So, we give the caller a free pass if Universe init
// is still in progress.
assert ((!Universe::is_fully_initialized() || (_features & CPU_FLUSH) != 0), "clflush should be available");
return true;
}
#endif
#define CPUID_STANDARD_FN 0x0
#define CPUID_STANDARD_FN_1 0x1
#define CPUID_STANDARD_FN_4 0x4
#define CPUID_STANDARD_FN_B 0xb
#define CPUID_EXTENDED_FN 0x80000000
#define CPUID_EXTENDED_FN_1 0x80000001
#define CPUID_EXTENDED_FN_2 0x80000002
#define CPUID_EXTENDED_FN_3 0x80000003
#define CPUID_EXTENDED_FN_4 0x80000004
#define CPUID_EXTENDED_FN_7 0x80000007
#define CPUID_EXTENDED_FN_8 0x80000008
class VM_Version_StubGenerator: public StubCodeGenerator {
public:
VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
address generate_get_cpu_info() {
// Flags to test CPU type.
const uint32_t HS_EFL_AC = 0x40000;
const uint32_t HS_EFL_ID = 0x200000;
// Values for when we don't have a CPUID instruction.
const int CPU_FAMILY_SHIFT = 8;
const uint32_t CPU_FAMILY_386 = (3 << CPU_FAMILY_SHIFT);
const uint32_t CPU_FAMILY_486 = (4 << CPU_FAMILY_SHIFT);
bool use_evex = FLAG_IS_DEFAULT(UseAVX) || (UseAVX > 2);
Label detect_486, cpu486, detect_586, std_cpuid1, std_cpuid4;
Label sef_cpuid, ext_cpuid, ext_cpuid1, ext_cpuid5, ext_cpuid7, ext_cpuid8, done, wrapup;
Label legacy_setup, save_restore_except, legacy_save_restore, start_simd_check;
StubCodeMark mark(this, "VM_Version", "get_cpu_info_stub");
# define __ _masm->
address start = __ pc();
//
// void get_cpu_info(VM_Version::CpuidInfo* cpuid_info);
//
// LP64: rcx and rdx are first and second argument registers on windows
__ push(rbp);
#ifdef _LP64
__ mov(rbp, c_rarg0); // cpuid_info address
#else
__ movptr(rbp, Address(rsp, 8)); // cpuid_info address
#endif
__ push(rbx);
__ push(rsi);
__ pushf(); // preserve rbx, and flags
__ pop(rax);
__ push(rax);
__ mov(rcx, rax);
//
// if we are unable to change the AC flag, we have a 386
//
__ xorl(rax, HS_EFL_AC);
__ push(rax);
__ popf();
__ pushf();
__ pop(rax);
__ cmpptr(rax, rcx);
__ jccb(Assembler::notEqual, detect_486);
__ movl(rax, CPU_FAMILY_386);
__ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
__ jmp(done);
//
// If we are unable to change the ID flag, we have a 486 which does
// not support the "cpuid" instruction.
//
__ bind(detect_486);
__ mov(rax, rcx);
__ xorl(rax, HS_EFL_ID);
__ push(rax);
__ popf();
__ pushf();
__ pop(rax);
__ cmpptr(rcx, rax);
__ jccb(Assembler::notEqual, detect_586);
__ bind(cpu486);
__ movl(rax, CPU_FAMILY_486);
__ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
__ jmp(done);
//
// At this point, we have a chip which supports the "cpuid" instruction
//
__ bind(detect_586);
__ xorl(rax, rax);
__ cpuid();
__ orl(rax, rax);
__ jcc(Assembler::equal, cpu486); // if cpuid doesn't support an input
// value of at least 1, we give up and
// assume a 486
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
__ cmpl(rax, 0xa); // Is cpuid(0xB) supported?
__ jccb(Assembler::belowEqual, std_cpuid4);
//
// cpuid(0xB) Processor Topology
//
__ movl(rax, 0xb);
__ xorl(rcx, rcx); // Threads level
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB0_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
__ movl(rax, 0xb);
__ movl(rcx, 1); // Cores level
__ cpuid();
__ push(rax);
__ andl(rax, 0x1f); // Determine if valid topology level
__ orl(rax, rbx); // eax[4:0] | ebx[0:15] == 0 indicates invalid level
__ andl(rax, 0xffff);
__ pop(rax);
__ jccb(Assembler::equal, std_cpuid4);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB1_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
__ movl(rax, 0xb);
__ movl(rcx, 2); // Packages level
__ cpuid();
__ push(rax);
__ andl(rax, 0x1f); // Determine if valid topology level
__ orl(rax, rbx); // eax[4:0] | ebx[0:15] == 0 indicates invalid level
__ andl(rax, 0xffff);
__ pop(rax);
__ jccb(Assembler::equal, std_cpuid4);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB2_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// cpuid(0x4) Deterministic cache params
//
__ bind(std_cpuid4);
__ movl(rax, 4);
__ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x4) supported?
__ jccb(Assembler::greater, std_cpuid1);
__ xorl(rcx, rcx); // L1 cache
__ cpuid();
__ push(rax);
__ andl(rax, 0x1f); // Determine if valid cache parameters used
__ orl(rax, rax); // eax[4:0] == 0 indicates invalid cache
__ pop(rax);
__ jccb(Assembler::equal, std_cpuid1);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::dcp_cpuid4_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Standard cpuid(0x1)
//
__ bind(std_cpuid1);
__ movl(rax, 1);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Check if OS has enabled XGETBV instruction to access XCR0
// (OSXSAVE feature flag) and CPU supports AVX
//
__ andl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
__ cmpl(rcx, 0x18000000);
__ jccb(Assembler::notEqual, sef_cpuid); // jump if AVX is not supported
//
// XCR0, XFEATURE_ENABLED_MASK register
//
__ xorl(rcx, rcx); // zero for XCR0 register
__ xgetbv();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rdx);
//
// cpuid(0x7) Structured Extended Features
//
__ bind(sef_cpuid);
__ movl(rax, 7);
__ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x7) supported?
__ jccb(Assembler::greater, ext_cpuid);
__ xorl(rcx, rcx);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi, 12), rdx);
//
// Extended cpuid(0x80000000)
//
__ bind(ext_cpuid);
__ movl(rax, 0x80000000);
__ cpuid();
__ cmpl(rax, 0x80000000); // Is cpuid(0x80000001) supported?
__ jcc(Assembler::belowEqual, done);
__ cmpl(rax, 0x80000004); // Is cpuid(0x80000005) supported?
__ jcc(Assembler::belowEqual, ext_cpuid1);
__ cmpl(rax, 0x80000006); // Is cpuid(0x80000007) supported?
__ jccb(Assembler::belowEqual, ext_cpuid5);
__ cmpl(rax, 0x80000007); // Is cpuid(0x80000008) supported?
__ jccb(Assembler::belowEqual, ext_cpuid7);
__ cmpl(rax, 0x80000008); // Is cpuid(0x80000009 and above) supported?
__ jccb(Assembler::belowEqual, ext_cpuid8);
__ cmpl(rax, 0x8000001E); // Is cpuid(0x8000001E) supported?
__ jccb(Assembler::below, ext_cpuid8);
//
// Extended cpuid(0x8000001E)
//
__ movl(rax, 0x8000001E);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1E_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Extended cpuid(0x80000008)
//
__ bind(ext_cpuid8);
__ movl(rax, 0x80000008);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid8_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Extended cpuid(0x80000007)
//
__ bind(ext_cpuid7);
__ movl(rax, 0x80000007);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid7_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Extended cpuid(0x80000005)
//
__ bind(ext_cpuid5);
__ movl(rax, 0x80000005);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid5_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Extended cpuid(0x80000001)
//
__ bind(ext_cpuid1);
__ movl(rax, 0x80000001);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1_offset())));
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi,12), rdx);
//
// Check if OS has enabled XGETBV instruction to access XCR0
// (OSXSAVE feature flag) and CPU supports AVX
//
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
__ movl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
__ andl(rcx, Address(rsi, 8)); // cpuid1 bits osxsave | avx
__ cmpl(rcx, 0x18000000);
__ jccb(Assembler::notEqual, done); // jump if AVX is not supported
__ movl(rax, 0x6);
__ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
__ cmpl(rax, 0x6);
__ jccb(Assembler::equal, start_simd_check); // return if AVX is not supported
// we need to bridge farther than imm8, so we use this island as a thunk
__ bind(done);
__ jmp(wrapup);
__ bind(start_simd_check);
//
// Some OSs have a bug when upper 128/256bits of YMM/ZMM
// registers are not restored after a signal processing.
// Generate SEGV here (reference through NULL)
// and check upper YMM/ZMM bits after it.
//
int saved_useavx = UseAVX;
int saved_usesse = UseSSE;
// If UseAVX is uninitialized or is set by the user to include EVEX
if (use_evex) {
// check _cpuid_info.sef_cpuid7_ebx.bits.avx512f
__ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
__ movl(rax, 0x10000);
__ andl(rax, Address(rsi, 4)); // xcr0 bits sse | ymm
__ cmpl(rax, 0x10000);
__ jccb(Assembler::notEqual, legacy_setup); // jump if EVEX is not supported
// check _cpuid_info.xem_xcr0_eax.bits.opmask
// check _cpuid_info.xem_xcr0_eax.bits.zmm512
// check _cpuid_info.xem_xcr0_eax.bits.zmm32
__ movl(rax, 0xE0);
__ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
__ cmpl(rax, 0xE0);
__ jccb(Assembler::notEqual, legacy_setup); // jump if EVEX is not supported
if (FLAG_IS_DEFAULT(UseAVX)) {
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
__ movl(rax, Address(rsi, 0));
__ cmpl(rax, 0x50654); // If it is Skylake
__ jcc(Assembler::equal, legacy_setup);
}
// EVEX setup: run in lowest evex mode
VM_Version::set_evex_cpuFeatures(); // Enable temporary to pass asserts
UseAVX = 3;
UseSSE = 2;
#ifdef _WINDOWS
// xmm5-xmm15 are not preserved by caller on windows
// https://msdn.microsoft.com/en-us/library/9z1stfyw.aspx
__ subptr(rsp, 64);
__ evmovdqul(Address(rsp, 0), xmm7, Assembler::AVX_512bit);
#ifdef _LP64
__ subptr(rsp, 64);
__ evmovdqul(Address(rsp, 0), xmm8, Assembler::AVX_512bit);
__ subptr(rsp, 64);
__ evmovdqul(Address(rsp, 0), xmm31, Assembler::AVX_512bit);
#endif // _LP64
#endif // _WINDOWS
// load value into all 64 bytes of zmm7 register
__ movl(rcx, VM_Version::ymm_test_value());
__ movdl(xmm0, rcx);
__ vpbroadcastd(xmm0, xmm0, Assembler::AVX_512bit);
__ evmovdqul(xmm7, xmm0, Assembler::AVX_512bit);
#ifdef _LP64
__ evmovdqul(xmm8, xmm0, Assembler::AVX_512bit);
__ evmovdqul(xmm31, xmm0, Assembler::AVX_512bit);
#endif
VM_Version::clean_cpuFeatures();
__ jmp(save_restore_except);
}
__ bind(legacy_setup);
// AVX setup
VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
UseAVX = 1;
UseSSE = 2;
#ifdef _WINDOWS
__ subptr(rsp, 32);
__ vmovdqu(Address(rsp, 0), xmm7);
#ifdef _LP64
__ subptr(rsp, 32);
__ vmovdqu(Address(rsp, 0), xmm8);
__ subptr(rsp, 32);
__ vmovdqu(Address(rsp, 0), xmm15);
#endif // _LP64
#endif // _WINDOWS
// load value into all 32 bytes of ymm7 register
__ movl(rcx, VM_Version::ymm_test_value());
__ movdl(xmm0, rcx);
__ pshufd(xmm0, xmm0, 0x00);
__ vinsertf128_high(xmm0, xmm0);
__ vmovdqu(xmm7, xmm0);
#ifdef _LP64
__ vmovdqu(xmm8, xmm0);
__ vmovdqu(xmm15, xmm0);
#endif
VM_Version::clean_cpuFeatures();
__ bind(save_restore_except);
__ xorl(rsi, rsi);
VM_Version::set_cpuinfo_segv_addr(__ pc());
// Generate SEGV
__ movl(rax, Address(rsi, 0));
VM_Version::set_cpuinfo_cont_addr(__ pc());
// Returns here after signal. Save xmm0 to check it later.
// If UseAVX is uninitialized or is set by the user to include EVEX
if (use_evex) {
// check _cpuid_info.sef_cpuid7_ebx.bits.avx512f
__ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
__ movl(rax, 0x10000);
__ andl(rax, Address(rsi, 4));
__ cmpl(rax, 0x10000);
__ jcc(Assembler::notEqual, legacy_save_restore);
// check _cpuid_info.xem_xcr0_eax.bits.opmask
// check _cpuid_info.xem_xcr0_eax.bits.zmm512
// check _cpuid_info.xem_xcr0_eax.bits.zmm32
__ movl(rax, 0xE0);
__ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
__ cmpl(rax, 0xE0);
__ jcc(Assembler::notEqual, legacy_save_restore);
if (FLAG_IS_DEFAULT(UseAVX)) {
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
__ movl(rax, Address(rsi, 0));
__ cmpl(rax, 0x50654); // If it is Skylake
__ jcc(Assembler::equal, legacy_save_restore);
}
// EVEX check: run in lowest evex mode
VM_Version::set_evex_cpuFeatures(); // Enable temporary to pass asserts
UseAVX = 3;
UseSSE = 2;
__ lea(rsi, Address(rbp, in_bytes(VM_Version::zmm_save_offset())));
__ evmovdqul(Address(rsi, 0), xmm0, Assembler::AVX_512bit);
__ evmovdqul(Address(rsi, 64), xmm7, Assembler::AVX_512bit);
#ifdef _LP64
__ evmovdqul(Address(rsi, 128), xmm8, Assembler::AVX_512bit);
__ evmovdqul(Address(rsi, 192), xmm31, Assembler::AVX_512bit);
#endif
#ifdef _WINDOWS
#ifdef _LP64
__ evmovdqul(xmm31, Address(rsp, 0), Assembler::AVX_512bit);
__ addptr(rsp, 64);
__ evmovdqul(xmm8, Address(rsp, 0), Assembler::AVX_512bit);
__ addptr(rsp, 64);
#endif // _LP64
__ evmovdqul(xmm7, Address(rsp, 0), Assembler::AVX_512bit);
__ addptr(rsp, 64);
#endif // _WINDOWS
generate_vzeroupper(wrapup);
VM_Version::clean_cpuFeatures();
UseAVX = saved_useavx;
UseSSE = saved_usesse;
__ jmp(wrapup);
}
__ bind(legacy_save_restore);
// AVX check
VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
UseAVX = 1;
UseSSE = 2;
__ lea(rsi, Address(rbp, in_bytes(VM_Version::ymm_save_offset())));
__ vmovdqu(Address(rsi, 0), xmm0);
__ vmovdqu(Address(rsi, 32), xmm7);
#ifdef _LP64
__ vmovdqu(Address(rsi, 64), xmm8);
__ vmovdqu(Address(rsi, 96), xmm15);
#endif
#ifdef _WINDOWS
#ifdef _LP64
__ vmovdqu(xmm15, Address(rsp, 0));
__ addptr(rsp, 32);
__ vmovdqu(xmm8, Address(rsp, 0));
__ addptr(rsp, 32);
#endif // _LP64
__ vmovdqu(xmm7, Address(rsp, 0));
__ addptr(rsp, 32);
#endif // _WINDOWS
generate_vzeroupper(wrapup);
VM_Version::clean_cpuFeatures();
UseAVX = saved_useavx;
UseSSE = saved_usesse;
__ bind(wrapup);
__ popf();
__ pop(rsi);
__ pop(rbx);
__ pop(rbp);
__ ret(0);
# undef __
return start;
};
void generate_vzeroupper(Label& L_wrapup) {
# define __ _masm->
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
__ cmpl(Address(rsi, 4), 0x756e6547); // 'uneG'
__ jcc(Assembler::notEqual, L_wrapup);
__ movl(rcx, 0x0FFF0FF0);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
__ andl(rcx, Address(rsi, 0));
__ cmpl(rcx, 0x00050670); // If it is Xeon Phi 3200/5200/7200
__ jcc(Assembler::equal, L_wrapup);
__ cmpl(rcx, 0x00080650); // If it is Future Xeon Phi
__ jcc(Assembler::equal, L_wrapup);
// vzeroupper() will use a pre-computed instruction sequence that we
// can't compute until after we've determined CPU capabilities. Use
// uncached variant here directly to be able to bootstrap correctly
__ vzeroupper_uncached();
# undef __
}
address generate_detect_virt() {
StubCodeMark mark(this, "VM_Version", "detect_virt_stub");
# define __ _masm->
address start = __ pc();
// Evacuate callee-saved registers
__ push(rbp);
__ push(rbx);
__ push(rsi); // for Windows
#ifdef _LP64
__ mov(rax, c_rarg0); // CPUID leaf
__ mov(rsi, c_rarg1); // register array address (eax, ebx, ecx, edx)
#else
__ movptr(rax, Address(rsp, 16)); // CPUID leaf
__ movptr(rsi, Address(rsp, 20)); // register array address
#endif
__ cpuid();
// Store result to register array
__ movl(Address(rsi, 0), rax);
__ movl(Address(rsi, 4), rbx);
__ movl(Address(rsi, 8), rcx);
__ movl(Address(rsi, 12), rdx);
// Epilogue
__ pop(rsi);
__ pop(rbx);
__ pop(rbp);
__ ret(0);
# undef __
return start;
};
address generate_getCPUIDBrandString(void) {
// Flags to test CPU type.
const uint32_t HS_EFL_AC = 0x40000;
const uint32_t HS_EFL_ID = 0x200000;
// Values for when we don't have a CPUID instruction.
const int CPU_FAMILY_SHIFT = 8;
const uint32_t CPU_FAMILY_386 = (3 << CPU_FAMILY_SHIFT);
const uint32_t CPU_FAMILY_486 = (4 << CPU_FAMILY_SHIFT);
Label detect_486, cpu486, detect_586, done, ext_cpuid;
StubCodeMark mark(this, "VM_Version", "getCPUIDNameInfo_stub");
# define __ _masm->
address start = __ pc();
//
// void getCPUIDBrandString(VM_Version::CpuidInfo* cpuid_info);
//
// LP64: rcx and rdx are first and second argument registers on windows
__ push(rbp);
#ifdef _LP64
__ mov(rbp, c_rarg0); // cpuid_info address
#else
__ movptr(rbp, Address(rsp, 8)); // cpuid_info address
#endif
__ push(rbx);
__ push(rsi);
__ pushf(); // preserve rbx, and flags
__ pop(rax);
__ push(rax);
__ mov(rcx, rax);
//
// if we are unable to change the AC flag, we have a 386
//
__ xorl(rax, HS_EFL_AC);
__ push(rax);
__ popf();
__ pushf();
__ pop(rax);
__ cmpptr(rax, rcx);
__ jccb(Assembler::notEqual, detect_486);
__ movl(rax, CPU_FAMILY_386);
__ jmp(done);
//
// If we are unable to change the ID flag, we have a 486 which does
// not support the "cpuid" instruction.
//
__ bind(detect_486);
__ mov(rax, rcx);
__ xorl(rax, HS_EFL_ID);
__ push(rax);
__ popf();
__ pushf();
__ pop(rax);
__ cmpptr(rcx, rax);
__ jccb(Assembler::notEqual, detect_586);
__ bind(cpu486);
__ movl(rax, CPU_FAMILY_486);
__ jmp(done);
//
// At this point, we have a chip which supports the "cpuid" instruction
//
__ bind(detect_586);
__ xorl(rax, rax);
__ cpuid();
__ orl(rax, rax);
__ jcc(Assembler::equal, cpu486); // if cpuid doesn't support an input
// value of at least 1, we give up and
// assume a 486
//
// Extended cpuid(0x80000000) for processor brand string detection
//
__ bind(ext_cpuid);
__ movl(rax, CPUID_EXTENDED_FN);
__ cpuid();
__ cmpl(rax, CPUID_EXTENDED_FN_4);
__ jcc(Assembler::below, done);
//
// Extended cpuid(0x80000002) // first 16 bytes in brand string
//
__ movl(rax, CPUID_EXTENDED_FN_2);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_0_offset())));
__ movl(Address(rsi, 0), rax);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_1_offset())));
__ movl(Address(rsi, 0), rbx);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_2_offset())));
__ movl(Address(rsi, 0), rcx);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_3_offset())));
__ movl(Address(rsi,0), rdx);
//
// Extended cpuid(0x80000003) // next 16 bytes in brand string
//
__ movl(rax, CPUID_EXTENDED_FN_3);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_4_offset())));
__ movl(Address(rsi, 0), rax);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_5_offset())));
__ movl(Address(rsi, 0), rbx);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_6_offset())));
__ movl(Address(rsi, 0), rcx);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_7_offset())));
__ movl(Address(rsi,0), rdx);
//
// Extended cpuid(0x80000004) // last 16 bytes in brand string
//
__ movl(rax, CPUID_EXTENDED_FN_4);
__ cpuid();
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_8_offset())));
__ movl(Address(rsi, 0), rax);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_9_offset())));
__ movl(Address(rsi, 0), rbx);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_10_offset())));
__ movl(Address(rsi, 0), rcx);
__ lea(rsi, Address(rbp, in_bytes(VM_Version::proc_name_11_offset())));
__ movl(Address(rsi,0), rdx);
//
// return
//
__ bind(done);
__ popf();
__ pop(rsi);
__ pop(rbx);
__ pop(rbp);
__ ret(0);
# undef __
return start;
};
};
void VM_Version::get_processor_features() {
_cpu = 4; // 486 by default
_model = 0;
_stepping = 0;
_features = 0;
_logical_processors_per_package = 1;
// i486 internal cache is both I&D and has a 16-byte line size
_L1_data_cache_line_size = 16;
// Get raw processor info
get_cpu_info_stub(&_cpuid_info);
assert_is_initialized();
_cpu = extended_cpu_family();
_model = extended_cpu_model();
_stepping = cpu_stepping();
if (cpu_family() > 4) { // it supports CPUID
_features = feature_flags();
// Logical processors are only available on P4s and above,
// and only if hyperthreading is available.
_logical_processors_per_package = logical_processor_count();
_L1_data_cache_line_size = L1_line_size();
}
_supports_cx8 = supports_cmpxchg8();
// xchg and xadd instructions
_supports_atomic_getset4 = true;
_supports_atomic_getadd4 = true;
LP64_ONLY(_supports_atomic_getset8 = true);
LP64_ONLY(_supports_atomic_getadd8 = true);
#ifdef _LP64
// OS should support SSE for x64 and hardware should support at least SSE2.
if (!VM_Version::supports_sse2()) {
vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");
}
// in 64 bit the use of SSE2 is the minimum
if (UseSSE < 2) UseSSE = 2;
#endif
#ifdef AMD64
// flush_icache_stub have to be generated first.
// That is why Icache line size is hard coded in ICache class,
// see icache_x86.hpp. It is also the reason why we can't use
// clflush instruction in 32-bit VM since it could be running
// on CPU which does not support it.
//
// The only thing we can do is to verify that flushed
// ICache::line_size has correct value.
guarantee(_cpuid_info.std_cpuid1_edx.bits.clflush != 0, "clflush is not supported");
// clflush_size is size in quadwords (8 bytes).
guarantee(_cpuid_info.std_cpuid1_ebx.bits.clflush_size == 8, "such clflush size is not supported");
#endif
#ifdef _LP64
// assigning this field effectively enables Unsafe.writebackMemory()
// by initing UnsafeConstant.DATA_CACHE_LINE_FLUSH_SIZE to non-zero
// that is only implemented on x86_64 and only if the OS plays ball
if (os::supports_map_sync()) {
// publish data cache line flush size to generic field, otherwise
// let if default to zero thereby disabling writeback
_data_cache_line_flush_size = _cpuid_info.std_cpuid1_ebx.bits.clflush_size * 8;
}
#endif
if (UseSSE < 4) {
_features &= ~CPU_SSE4_1;
_features &= ~CPU_SSE4_2;
}
if (UseSSE < 3) {
_features &= ~CPU_SSE3;
_features &= ~CPU_SSSE3;
_features &= ~CPU_SSE4A;
}
if (UseSSE < 2)
_features &= ~CPU_SSE2;
if (UseSSE < 1)
_features &= ~CPU_SSE;
//since AVX instructions is slower than SSE in some ZX cpus, force USEAVX=0.
if (is_zx() && ((cpu_family() == 6) || (cpu_family() == 7))) {
UseAVX = 0;
}
// UseSSE is set to the smaller of what hardware supports and what
// the command line requires. I.e., you cannot set UseSSE to 2 on
// older Pentiums which do not support it.
int use_sse_limit = 0;
if (UseSSE > 0) {
if (UseSSE > 3 && supports_sse4_1()) {
use_sse_limit = 4;
} else if (UseSSE > 2 && supports_sse3()) {
use_sse_limit = 3;
} else if (UseSSE > 1 && supports_sse2()) {
use_sse_limit = 2;
} else if (UseSSE > 0 && supports_sse()) {
use_sse_limit = 1;
} else {
use_sse_limit = 0;
}
}
if (FLAG_IS_DEFAULT(UseSSE)) {
FLAG_SET_DEFAULT(UseSSE, use_sse_limit);
} else if (UseSSE > use_sse_limit) {
warning("UseSSE=%d is not supported on this CPU, setting it to UseSSE=%d", UseSSE, use_sse_limit);
FLAG_SET_DEFAULT(UseSSE, use_sse_limit);
}
// first try initial setting and detect what we can support
int use_avx_limit = 0;
if (UseAVX > 0) {
if (UseSSE < 4) {
// Don't use AVX if SSE is unavailable or has been disabled.
use_avx_limit = 0;
} else if (UseAVX > 2 && supports_evex()) {
use_avx_limit = 3;
} else if (UseAVX > 1 && supports_avx2()) {
use_avx_limit = 2;
} else if (UseAVX > 0 && supports_avx()) {
use_avx_limit = 1;
} else {
use_avx_limit = 0;
}
}
if (FLAG_IS_DEFAULT(UseAVX)) {
// Don't use AVX-512 on older Skylakes unless explicitly requested.
if (use_avx_limit > 2 && is_intel_skylake() && _stepping < 5) {
FLAG_SET_DEFAULT(UseAVX, 2);
} else {
FLAG_SET_DEFAULT(UseAVX, use_avx_limit);
}
}
if (UseAVX > use_avx_limit) {
if (UseSSE < 4) {
warning("UseAVX=%d requires UseSSE=4, setting it to UseAVX=0", UseAVX);
} else {
warning("UseAVX=%d is not supported on this CPU, setting it to UseAVX=%d", UseAVX, use_avx_limit);
}
FLAG_SET_DEFAULT(UseAVX, use_avx_limit);
}
if (UseAVX < 3) {
_features &= ~CPU_AVX512F;
_features &= ~CPU_AVX512DQ;
_features &= ~CPU_AVX512CD;
_features &= ~CPU_AVX512BW;
_features &= ~CPU_AVX512VL;
_features &= ~CPU_AVX512_VPOPCNTDQ;
_features &= ~CPU_AVX512_VPCLMULQDQ;
_features &= ~CPU_AVX512_VAES;
_features &= ~CPU_AVX512_VNNI;
_features &= ~CPU_AVX512_VBMI;
_features &= ~CPU_AVX512_VBMI2;
_features &= ~CPU_AVX512_BITALG;
_features &= ~CPU_AVX512_IFMA;
}
if (UseAVX < 2)
_features &= ~CPU_AVX2;
if (UseAVX < 1) {
_features &= ~CPU_AVX;
_features &= ~CPU_VZEROUPPER;
_features &= ~CPU_F16C;
}
if (logical_processors_per_package() == 1) {
// HT processor could be installed on a system which doesn't support HT.
_features &= ~CPU_HT;
}
if (is_intel()) { // Intel cpus specific settings
if (is_knights_family()) {
_features &= ~CPU_VZEROUPPER;
_features &= ~CPU_AVX512BW;
_features &= ~CPU_AVX512VL;
_features &= ~CPU_AVX512DQ;
_features &= ~CPU_AVX512_VNNI;
_features &= ~CPU_AVX512_VAES;
_features &= ~CPU_AVX512_VPOPCNTDQ;
_features &= ~CPU_AVX512_VPCLMULQDQ;
_features &= ~CPU_AVX512_VBMI;
_features &= ~CPU_AVX512_VBMI2;
_features &= ~CPU_CLWB;
_features &= ~CPU_FLUSHOPT;
_features &= ~CPU_GFNI;
_features &= ~CPU_AVX512_BITALG;
_features &= ~CPU_AVX512_IFMA;
}
}
if (FLAG_IS_DEFAULT(IntelJccErratumMitigation)) {
_has_intel_jcc_erratum = compute_has_intel_jcc_erratum();
} else {
_has_intel_jcc_erratum = IntelJccErratumMitigation;
}
char buf[1024];
int res = jio_snprintf(
buf, sizeof(buf),
"(%u cores per cpu, %u threads per core) family %d model %d stepping %d microcode 0x%x",
cores_per_cpu(), threads_per_core(),
cpu_family(), _model, _stepping, os::cpu_microcode_revision());
assert(res > 0, "not enough temporary space allocated");
insert_features_names(buf + res, sizeof(buf) - res, _features_names);
_features_string = os::strdup(buf);
// Use AES instructions if available.
if (supports_aes()) {
if (FLAG_IS_DEFAULT(UseAES)) {
FLAG_SET_DEFAULT(UseAES, true);
}
if (!UseAES) {
if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
warning("AES intrinsics require UseAES flag to be enabled. Intrinsics will be disabled.");
}
FLAG_SET_DEFAULT(UseAESIntrinsics, false);
} else {
if (UseSSE > 2) {
if (FLAG_IS_DEFAULT(UseAESIntrinsics)) {
FLAG_SET_DEFAULT(UseAESIntrinsics, true);
}
} else {
// The AES intrinsic stubs require AES instruction support (of course)
// but also require sse3 mode or higher for instructions it use.
if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
warning("X86 AES intrinsics require SSE3 instructions or higher. Intrinsics will be disabled.");
}
FLAG_SET_DEFAULT(UseAESIntrinsics, false);
}
// --AES-CTR begins--
if (!UseAESIntrinsics) {
if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
warning("AES-CTR intrinsics require UseAESIntrinsics flag to be enabled. Intrinsics will be disabled.");
FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
}
} else {
if (supports_sse4_1()) {
if (FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
FLAG_SET_DEFAULT(UseAESCTRIntrinsics, true);
}
} else {
// The AES-CTR intrinsic stubs require AES instruction support (of course)
// but also require sse4.1 mode or higher for instructions it use.
if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
warning("X86 AES-CTR intrinsics require SSE4.1 instructions or higher. Intrinsics will be disabled.");
}
FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
}
}
// --AES-CTR ends--
}
} else if (UseAES || UseAESIntrinsics || UseAESCTRIntrinsics) {
if (UseAES && !FLAG_IS_DEFAULT(UseAES)) {
warning("AES instructions are not available on this CPU");
FLAG_SET_DEFAULT(UseAES, false);
}
if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
warning("AES intrinsics are not available on this CPU");
FLAG_SET_DEFAULT(UseAESIntrinsics, false);
}
if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
warning("AES-CTR intrinsics are not available on this CPU");
FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
}
}
// Use CLMUL instructions if available.
if (supports_clmul()) {
if (FLAG_IS_DEFAULT(UseCLMUL)) {
UseCLMUL = true;
}
} else if (UseCLMUL) {
if (!FLAG_IS_DEFAULT(UseCLMUL))
warning("CLMUL instructions not available on this CPU (AVX may also be required)");
FLAG_SET_DEFAULT(UseCLMUL, false);
}
if (UseCLMUL && (UseSSE > 2)) {
if (FLAG_IS_DEFAULT(UseCRC32Intrinsics)) {
UseCRC32Intrinsics = true;
}
} else if (UseCRC32Intrinsics) {
if (!FLAG_IS_DEFAULT(UseCRC32Intrinsics))
warning("CRC32 Intrinsics requires CLMUL instructions (not available on this CPU)");
FLAG_SET_DEFAULT(UseCRC32Intrinsics, false);
}
#ifdef _LP64
if (supports_avx2()) {
if (FLAG_IS_DEFAULT(UseAdler32Intrinsics)) {
UseAdler32Intrinsics = true;
}
} else if (UseAdler32Intrinsics) {
if (!FLAG_IS_DEFAULT(UseAdler32Intrinsics)) {
warning("Adler32 Intrinsics requires avx2 instructions (not available on this CPU)");
}
FLAG_SET_DEFAULT(UseAdler32Intrinsics, false);
}
#else
if (UseAdler32Intrinsics) {
warning("Adler32Intrinsics not available on this CPU.");
FLAG_SET_DEFAULT(UseAdler32Intrinsics, false);
}
#endif
if (supports_sse4_2() && supports_clmul()) {
if (FLAG_IS_DEFAULT(UseCRC32CIntrinsics)) {
UseCRC32CIntrinsics = true;
}
} else if (UseCRC32CIntrinsics) {
if (!FLAG_IS_DEFAULT(UseCRC32CIntrinsics)) {
warning("CRC32C intrinsics are not available on this CPU");
}
FLAG_SET_DEFAULT(UseCRC32CIntrinsics, false);
}
// GHASH/GCM intrinsics
if (UseCLMUL && (UseSSE > 2)) {
if (FLAG_IS_DEFAULT(UseGHASHIntrinsics)) {
UseGHASHIntrinsics = true;
}
} else if (UseGHASHIntrinsics) {
if (!FLAG_IS_DEFAULT(UseGHASHIntrinsics))
warning("GHASH intrinsic requires CLMUL and SSE2 instructions on this CPU");
FLAG_SET_DEFAULT(UseGHASHIntrinsics, false);
}
// ChaCha20 Intrinsics
// As long as the system supports AVX as a baseline we can do a
// SIMD-enabled block function. StubGenerator makes the determination
// based on the VM capabilities whether to use an AVX2 or AVX512-enabled
// version.
if (UseAVX >= 1) {
if (FLAG_IS_DEFAULT(UseChaCha20Intrinsics)) {
UseChaCha20Intrinsics = true;
}
} else if (UseChaCha20Intrinsics) {
if (!FLAG_IS_DEFAULT(UseChaCha20Intrinsics)) {
warning("ChaCha20 intrinsic requires AVX instructions");
}
FLAG_SET_DEFAULT(UseChaCha20Intrinsics, false);
}
// Base64 Intrinsics (Check the condition for which the intrinsic will be active)
if ((UseAVX > 2) && supports_avx512vl() && supports_avx512bw()) {
if (FLAG_IS_DEFAULT(UseBASE64Intrinsics)) {
UseBASE64Intrinsics = true;
}
} else if (UseBASE64Intrinsics) {
if (!FLAG_IS_DEFAULT(UseBASE64Intrinsics))
warning("Base64 intrinsic requires EVEX instructions on this CPU");
FLAG_SET_DEFAULT(UseBASE64Intrinsics, false);
}
if (supports_fma() && UseSSE >= 2) { // Check UseSSE since FMA code uses SSE instructions
if (FLAG_IS_DEFAULT(UseFMA)) {
UseFMA = true;
}
} else if (UseFMA) {
warning("FMA instructions are not available on this CPU");
FLAG_SET_DEFAULT(UseFMA, false);
}
if (FLAG_IS_DEFAULT(UseMD5Intrinsics)) {
UseMD5Intrinsics = true;
}
if (supports_sha() LP64_ONLY(|| supports_avx2() && supports_bmi2())) {
if (FLAG_IS_DEFAULT(UseSHA)) {
UseSHA = true;
}
} else if (UseSHA) {
warning("SHA instructions are not available on this CPU");
FLAG_SET_DEFAULT(UseSHA, false);
}
if (supports_sha() && supports_sse4_1() && UseSHA) {
if (FLAG_IS_DEFAULT(UseSHA1Intrinsics)) {
FLAG_SET_DEFAULT(UseSHA1Intrinsics, true);
}
} else if (UseSHA1Intrinsics) {
warning("Intrinsics for SHA-1 crypto hash functions not available on this CPU.");
FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
}
if (supports_sse4_1() && UseSHA) {
if (FLAG_IS_DEFAULT(UseSHA256Intrinsics)) {
FLAG_SET_DEFAULT(UseSHA256Intrinsics, true);
}
} else if (UseSHA256Intrinsics) {
warning("Intrinsics for SHA-224 and SHA-256 crypto hash functions not available on this CPU.");
FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
}
#ifdef _LP64
// These are only supported on 64-bit
if (UseSHA && supports_avx2() && supports_bmi2()) {
if (FLAG_IS_DEFAULT(UseSHA512Intrinsics)) {
FLAG_SET_DEFAULT(UseSHA512Intrinsics, true);
}
} else
#endif
if (UseSHA512Intrinsics) {
warning("Intrinsics for SHA-384 and SHA-512 crypto hash functions not available on this CPU.");
FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
}
if (UseSHA3Intrinsics) {
warning("Intrinsics for SHA3-224, SHA3-256, SHA3-384 and SHA3-512 crypto hash functions not available on this CPU.");
FLAG_SET_DEFAULT(UseSHA3Intrinsics, false);
}
if (!(UseSHA1Intrinsics || UseSHA256Intrinsics || UseSHA512Intrinsics)) {
FLAG_SET_DEFAULT(UseSHA, false);
}
if (!supports_rtm() && UseRTMLocking) {
vm_exit_during_initialization("RTM instructions are not available on this CPU");
}
#if INCLUDE_RTM_OPT
if (UseRTMLocking) {
if (!CompilerConfig::is_c2_enabled()) {
// Only C2 does RTM locking optimization.
vm_exit_during_initialization("RTM locking optimization is not supported in this VM");
}
if (is_intel_family_core()) {
if ((_model == CPU_MODEL_HASWELL_E3) ||
(_model == CPU_MODEL_HASWELL_E7 && _stepping < 3) ||
(_model == CPU_MODEL_BROADWELL && _stepping < 4)) {
// currently a collision between SKL and HSW_E3
if (!UnlockExperimentalVMOptions && UseAVX < 3) {
vm_exit_during_initialization("UseRTMLocking is only available as experimental option on this "
"platform. It must be enabled via -XX:+UnlockExperimentalVMOptions flag.");
} else {
warning("UseRTMLocking is only available as experimental option on this platform.");
}
}
}
if (!FLAG_IS_CMDLINE(UseRTMLocking)) {
// RTM locking should be used only for applications with
// high lock contention. For now we do not use it by default.
vm_exit_during_initialization("UseRTMLocking flag should be only set on command line");
}
} else { // !UseRTMLocking
if (UseRTMForStackLocks) {
if (!FLAG_IS_DEFAULT(UseRTMForStackLocks)) {
warning("UseRTMForStackLocks flag should be off when UseRTMLocking flag is off");
}
FLAG_SET_DEFAULT(UseRTMForStackLocks, false);
}
if (UseRTMDeopt) {
FLAG_SET_DEFAULT(UseRTMDeopt, false);
}
if (PrintPreciseRTMLockingStatistics) {
FLAG_SET_DEFAULT(PrintPreciseRTMLockingStatistics, false);
}
}
#else
if (UseRTMLocking) {
// Only C2 does RTM locking optimization.
vm_exit_during_initialization("RTM locking optimization is not supported in this VM");
}
#endif
#ifdef COMPILER2
if (UseFPUForSpilling) {
if (UseSSE < 2) {
// Only supported with SSE2+
FLAG_SET_DEFAULT(UseFPUForSpilling, false);
}
}
#endif
#if COMPILER2_OR_JVMCI
int max_vector_size = 0;
if (UseSSE < 2) {
// Vectors (in XMM) are only supported with SSE2+
// SSE is always 2 on x64.
max_vector_size = 0;
} else if (UseAVX == 0 || !os_supports_avx_vectors()) {
// 16 byte vectors (in XMM) are supported with SSE2+
max_vector_size = 16;
} else if (UseAVX == 1 || UseAVX == 2) {
// 32 bytes vectors (in YMM) are only supported with AVX+
max_vector_size = 32;
} else if (UseAVX > 2) {
// 64 bytes vectors (in ZMM) are only supported with AVX 3
max_vector_size = 64;
}
#ifdef _LP64
int min_vector_size = 4; // We require MaxVectorSize to be at least 4 on 64bit
#else
int min_vector_size = 0;
#endif
if (!FLAG_IS_DEFAULT(MaxVectorSize)) {
if (MaxVectorSize < min_vector_size) {
warning("MaxVectorSize must be at least %i on this platform", min_vector_size);
FLAG_SET_DEFAULT(MaxVectorSize, min_vector_size);
}
if (MaxVectorSize > max_vector_size) {
warning("MaxVectorSize must be at most %i on this platform", max_vector_size);
FLAG_SET_DEFAULT(MaxVectorSize, max_vector_size);
}
if (!is_power_of_2(MaxVectorSize)) {
warning("MaxVectorSize must be a power of 2, setting to default: %i", max_vector_size);
FLAG_SET_DEFAULT(MaxVectorSize, max_vector_size);
}
} else {
// If default, use highest supported configuration
FLAG_SET_DEFAULT(MaxVectorSize, max_vector_size);
}
#if defined(COMPILER2)
if (FLAG_IS_DEFAULT(SuperWordMaxVectorSize)) {
if (FLAG_IS_DEFAULT(UseAVX) && UseAVX > 2 &&
is_intel_skylake() && _stepping >= 5) {
// Limit auto vectorization to 256 bit (32 byte) by default on Cascade Lake
FLAG_SET_DEFAULT(SuperWordMaxVectorSize, MIN2(MaxVectorSize, (intx)32));
} else {
FLAG_SET_DEFAULT(SuperWordMaxVectorSize, MaxVectorSize);
}
} else {
if (SuperWordMaxVectorSize > MaxVectorSize) {
warning("SuperWordMaxVectorSize cannot be greater than MaxVectorSize %i", (int) MaxVectorSize);
FLAG_SET_DEFAULT(SuperWordMaxVectorSize, MaxVectorSize);
}
if (!is_power_of_2(SuperWordMaxVectorSize)) {
warning("SuperWordMaxVectorSize must be a power of 2, setting to MaxVectorSize: %i", (int) MaxVectorSize);
FLAG_SET_DEFAULT(SuperWordMaxVectorSize, MaxVectorSize);
}
}
#endif
#if defined(COMPILER2) && defined(ASSERT)
if (MaxVectorSize > 0) {
if (supports_avx() && PrintMiscellaneous && Verbose && TraceNewVectors) {
tty->print_cr("State of YMM registers after signal handle:");
int nreg = 2 LP64_ONLY(+2);
const char* ymm_name[4] = {"0", "7", "8", "15"};
for (int i = 0; i < nreg; i++) {
tty->print("YMM%s:", ymm_name[i]);
for (int j = 7; j >=0; j--) {
tty->print(" %x", _cpuid_info.ymm_save[i*8 + j]);
}
tty->cr();
}
}
}
#endif // COMPILER2 && ASSERT
#ifdef _LP64
if (supports_avx512ifma() && supports_avx512vlbw() && MaxVectorSize >= 64) {
if (FLAG_IS_DEFAULT(UsePoly1305Intrinsics)) {
FLAG_SET_DEFAULT(UsePoly1305Intrinsics, true);
}
} else
#endif
if (UsePoly1305Intrinsics) {
warning("Intrinsics for Poly1305 crypto hash functions not available on this CPU.");
FLAG_SET_DEFAULT(UsePoly1305Intrinsics, false);
}
#ifdef _LP64
if (FLAG_IS_DEFAULT(UseMultiplyToLenIntrinsic)) {
UseMultiplyToLenIntrinsic = true;
}
if (FLAG_IS_DEFAULT(UseSquareToLenIntrinsic)) {
UseSquareToLenIntrinsic = true;
}
if (FLAG_IS_DEFAULT(UseMulAddIntrinsic)) {
UseMulAddIntrinsic = true;
}
if (FLAG_IS_DEFAULT(UseMontgomeryMultiplyIntrinsic)) {
UseMontgomeryMultiplyIntrinsic = true;
}
if (FLAG_IS_DEFAULT(UseMontgomerySquareIntrinsic)) {
UseMontgomerySquareIntrinsic = true;
}
#else
if (UseMultiplyToLenIntrinsic) {
if (!FLAG_IS_DEFAULT(UseMultiplyToLenIntrinsic)) {
warning("multiplyToLen intrinsic is not available in 32-bit VM");
}
FLAG_SET_DEFAULT(UseMultiplyToLenIntrinsic, false);
}
if (UseMontgomeryMultiplyIntrinsic) {
if (!FLAG_IS_DEFAULT(UseMontgomeryMultiplyIntrinsic)) {
warning("montgomeryMultiply intrinsic is not available in 32-bit VM");
}
FLAG_SET_DEFAULT(UseMontgomeryMultiplyIntrinsic, false);
}
if (UseMontgomerySquareIntrinsic) {
if (!FLAG_IS_DEFAULT(UseMontgomerySquareIntrinsic)) {
warning("montgomerySquare intrinsic is not available in 32-bit VM");
}
FLAG_SET_DEFAULT(UseMontgomerySquareIntrinsic, false);
}
if (UseSquareToLenIntrinsic) {
if (!FLAG_IS_DEFAULT(UseSquareToLenIntrinsic)) {
warning("squareToLen intrinsic is not available in 32-bit VM");
}
FLAG_SET_DEFAULT(UseSquareToLenIntrinsic, false);
}
if (UseMulAddIntrinsic) {
if (!FLAG_IS_DEFAULT(UseMulAddIntrinsic)) {
warning("mulAdd intrinsic is not available in 32-bit VM");
}
FLAG_SET_DEFAULT(UseMulAddIntrinsic, false);
}
#endif // _LP64
#endif // COMPILER2_OR_JVMCI
// On new cpus instructions which update whole XMM register should be used
// to prevent partial register stall due to dependencies on high half.
//
// UseXmmLoadAndClearUpper == true --> movsd(xmm, mem)
// UseXmmLoadAndClearUpper == false --> movlpd(xmm, mem)
// UseXmmRegToRegMoveAll == true --> movaps(xmm, xmm), movapd(xmm, xmm).
// UseXmmRegToRegMoveAll == false --> movss(xmm, xmm), movsd(xmm, xmm).
if (is_zx()) { // ZX cpus specific settings
if (FLAG_IS_DEFAULT(UseStoreImmI16)) {
UseStoreImmI16 = false; // don't use it on ZX cpus
}
if ((cpu_family() == 6) || (cpu_family() == 7)) {
if (FLAG_IS_DEFAULT(UseAddressNop)) {
// Use it on all ZX cpus
UseAddressNop = true;
}
}
if (FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper)) {
UseXmmLoadAndClearUpper = true; // use movsd on all ZX cpus
}
if (FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll)) {
if (supports_sse3()) {
UseXmmRegToRegMoveAll = true; // use movaps, movapd on new ZX cpus
} else {
UseXmmRegToRegMoveAll = false;
}
}
if (((cpu_family() == 6) || (cpu_family() == 7)) && supports_sse3()) { // new ZX cpus
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(MaxLoopPad)) {
// For new ZX cpus do the next optimization:
// don't align the beginning of a loop if there are enough instructions
// left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
// in current fetch line (OptoLoopAlignment) or the padding
// is big (> MaxLoopPad).
// Set MaxLoopPad to 11 for new ZX cpus to reduce number of
// generated NOP instructions. 11 is the largest size of one
// address NOP instruction '0F 1F' (see Assembler::nop(i)).
MaxLoopPad = 11;
}
#endif // COMPILER2
if (FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
UseXMMForArrayCopy = true; // use SSE2 movq on new ZX cpus
}
if (supports_sse4_2()) { // new ZX cpus
if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
UseUnalignedLoadStores = true; // use movdqu on newest ZX cpus
}
}
if (supports_sse4_2()) {
if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
FLAG_SET_DEFAULT(UseSSE42Intrinsics, true);
}
} else {
if (UseSSE42Intrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
warning("SSE4.2 intrinsics require SSE4.2 instructions or higher. Intrinsics will be disabled.");
}
FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
}
}
if (FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
}
}
if (is_amd_family()) { // AMD cpus specific settings
if (supports_sse2() && FLAG_IS_DEFAULT(UseAddressNop)) {
// Use it on new AMD cpus starting from Opteron.
UseAddressNop = true;
}
if (supports_sse2() && FLAG_IS_DEFAULT(UseNewLongLShift)) {
// Use it on new AMD cpus starting from Opteron.
UseNewLongLShift = true;
}
if (FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper)) {
if (supports_sse4a()) {
UseXmmLoadAndClearUpper = true; // use movsd only on '10h' Opteron
} else {
UseXmmLoadAndClearUpper = false;
}
}
if (FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll)) {
if (supports_sse4a()) {
UseXmmRegToRegMoveAll = true; // use movaps, movapd only on '10h'
} else {
UseXmmRegToRegMoveAll = false;
}
}
if (FLAG_IS_DEFAULT(UseXmmI2F)) {
if (supports_sse4a()) {
UseXmmI2F = true;
} else {
UseXmmI2F = false;
}
}
if (FLAG_IS_DEFAULT(UseXmmI2D)) {
if (supports_sse4a()) {
UseXmmI2D = true;
} else {
UseXmmI2D = false;
}
}
if (supports_sse4_2()) {
if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
FLAG_SET_DEFAULT(UseSSE42Intrinsics, true);
}
} else {
if (UseSSE42Intrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
warning("SSE4.2 intrinsics require SSE4.2 instructions or higher. Intrinsics will be disabled.");
}
FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
}
// some defaults for AMD family 15h
if (cpu_family() == 0x15) {
// On family 15h processors default is no sw prefetch
if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
FLAG_SET_DEFAULT(AllocatePrefetchStyle, 0);
}
// Also, if some other prefetch style is specified, default instruction type is PREFETCHW
if (FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
}
// On family 15h processors use XMM and UnalignedLoadStores for Array Copy
if (supports_sse2() && FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
FLAG_SET_DEFAULT(UseXMMForArrayCopy, true);
}
if (supports_sse2() && FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
FLAG_SET_DEFAULT(UseUnalignedLoadStores, true);
}
}
#ifdef COMPILER2
if (cpu_family() < 0x17 && MaxVectorSize > 16) {
// Limit vectors size to 16 bytes on AMD cpus < 17h.
FLAG_SET_DEFAULT(MaxVectorSize, 16);
}
#endif // COMPILER2
// Some defaults for AMD family >= 17h && Hygon family 18h
if (cpu_family() >= 0x17) {
// On family >=17h processors use XMM and UnalignedLoadStores
// for Array Copy
if (supports_sse2() && FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
FLAG_SET_DEFAULT(UseXMMForArrayCopy, true);
}
if (supports_sse2() && FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
FLAG_SET_DEFAULT(UseUnalignedLoadStores, true);
}
#ifdef COMPILER2
if (supports_sse4_2() && FLAG_IS_DEFAULT(UseFPUForSpilling)) {
FLAG_SET_DEFAULT(UseFPUForSpilling, true);
}
#endif
}
}
if (is_intel()) { // Intel cpus specific settings
if (FLAG_IS_DEFAULT(UseStoreImmI16)) {
UseStoreImmI16 = false; // don't use it on Intel cpus
}
if (cpu_family() == 6 || cpu_family() == 15) {
if (FLAG_IS_DEFAULT(UseAddressNop)) {
// Use it on all Intel cpus starting from PentiumPro
UseAddressNop = true;
}
}
if (FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper)) {
UseXmmLoadAndClearUpper = true; // use movsd on all Intel cpus
}
if (FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll)) {
if (supports_sse3()) {
UseXmmRegToRegMoveAll = true; // use movaps, movapd on new Intel cpus
} else {
UseXmmRegToRegMoveAll = false;
}
}
if (cpu_family() == 6 && supports_sse3()) { // New Intel cpus
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(MaxLoopPad)) {
// For new Intel cpus do the next optimization:
// don't align the beginning of a loop if there are enough instructions
// left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
// in current fetch line (OptoLoopAlignment) or the padding
// is big (> MaxLoopPad).
// Set MaxLoopPad to 11 for new Intel cpus to reduce number of
// generated NOP instructions. 11 is the largest size of one
// address NOP instruction '0F 1F' (see Assembler::nop(i)).
MaxLoopPad = 11;
}
#endif // COMPILER2
if (FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
UseXMMForArrayCopy = true; // use SSE2 movq on new Intel cpus
}
if ((supports_sse4_2() && supports_ht()) || supports_avx()) { // Newest Intel cpus
if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
}
}
if (supports_sse4_2()) {
if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
FLAG_SET_DEFAULT(UseSSE42Intrinsics, true);
}
} else {
if (UseSSE42Intrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
warning("SSE4.2 intrinsics require SSE4.2 instructions or higher. Intrinsics will be disabled.");
}
FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
}
}
if (is_atom_family() || is_knights_family()) {
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(OptoScheduling)) {
OptoScheduling = true;
}
#endif
if (supports_sse4_2()) { // Silvermont
if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
}
}
if (FLAG_IS_DEFAULT(UseIncDec)) {
FLAG_SET_DEFAULT(UseIncDec, false);
}
}
if (FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
}
#ifdef COMPILER2
if (UseAVX > 2) {
if (FLAG_IS_DEFAULT(ArrayOperationPartialInlineSize) ||
(!FLAG_IS_DEFAULT(ArrayOperationPartialInlineSize) &&
ArrayOperationPartialInlineSize != 0 &&
ArrayOperationPartialInlineSize != 16 &&
ArrayOperationPartialInlineSize != 32 &&
ArrayOperationPartialInlineSize != 64)) {
int inline_size = 0;
if (MaxVectorSize >= 64 && AVX3Threshold == 0) {
inline_size = 64;
} else if (MaxVectorSize >= 32) {
inline_size = 32;
} else if (MaxVectorSize >= 16) {
inline_size = 16;
}
if(!FLAG_IS_DEFAULT(ArrayOperationPartialInlineSize)) {
warning("Setting ArrayOperationPartialInlineSize as %d", inline_size);
}
ArrayOperationPartialInlineSize = inline_size;
}
if (ArrayOperationPartialInlineSize > MaxVectorSize) {
ArrayOperationPartialInlineSize = MaxVectorSize >= 16 ? MaxVectorSize : 0;
if (ArrayOperationPartialInlineSize) {
warning("Setting ArrayOperationPartialInlineSize as MaxVectorSize" INTX_FORMAT ")", MaxVectorSize);
} else {
warning("Setting ArrayOperationPartialInlineSize as " INTX_FORMAT, ArrayOperationPartialInlineSize);
}
}
}
#endif
}
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(OptimizeFill)) {
if (MaxVectorSize < 32 || !VM_Version::supports_avx512vlbw()) {
OptimizeFill = false;
}
}
#endif
#ifdef _LP64
if (UseSSE42Intrinsics) {
if (FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic)) {
UseVectorizedMismatchIntrinsic = true;
}
} else if (UseVectorizedMismatchIntrinsic) {
if (!FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic))
warning("vectorizedMismatch intrinsics are not available on this CPU");
FLAG_SET_DEFAULT(UseVectorizedMismatchIntrinsic, false);
}
#else
if (UseVectorizedMismatchIntrinsic) {
if (!FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic)) {
warning("vectorizedMismatch intrinsic is not available in 32-bit VM");
}
FLAG_SET_DEFAULT(UseVectorizedMismatchIntrinsic, false);
}
#endif // _LP64
// Use count leading zeros count instruction if available.
if (supports_lzcnt()) {
if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
UseCountLeadingZerosInstruction = true;
}
} else if (UseCountLeadingZerosInstruction) {
warning("lzcnt instruction is not available on this CPU");
FLAG_SET_DEFAULT(UseCountLeadingZerosInstruction, false);
}
// Use count trailing zeros instruction if available
if (supports_bmi1()) {
// tzcnt does not require VEX prefix
if (FLAG_IS_DEFAULT(UseCountTrailingZerosInstruction)) {
if (!UseBMI1Instructions && !FLAG_IS_DEFAULT(UseBMI1Instructions)) {
// Don't use tzcnt if BMI1 is switched off on command line.
UseCountTrailingZerosInstruction = false;
} else {
UseCountTrailingZerosInstruction = true;
}
}
} else if (UseCountTrailingZerosInstruction) {
warning("tzcnt instruction is not available on this CPU");
FLAG_SET_DEFAULT(UseCountTrailingZerosInstruction, false);
}
// BMI instructions (except tzcnt) use an encoding with VEX prefix.
// VEX prefix is generated only when AVX > 0.
if (supports_bmi1() && supports_avx()) {
if (FLAG_IS_DEFAULT(UseBMI1Instructions)) {
UseBMI1Instructions = true;
}
} else if (UseBMI1Instructions) {
warning("BMI1 instructions are not available on this CPU (AVX is also required)");
FLAG_SET_DEFAULT(UseBMI1Instructions, false);
}
if (supports_bmi2() && supports_avx()) {
if (FLAG_IS_DEFAULT(UseBMI2Instructions)) {
UseBMI2Instructions = true;
}
} else if (UseBMI2Instructions) {
warning("BMI2 instructions are not available on this CPU (AVX is also required)");
FLAG_SET_DEFAULT(UseBMI2Instructions, false);
}
// Use population count instruction if available.
if (supports_popcnt()) {
if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
UsePopCountInstruction = true;
}
} else if (UsePopCountInstruction) {
warning("POPCNT instruction is not available on this CPU");
FLAG_SET_DEFAULT(UsePopCountInstruction, false);
}
// Use fast-string operations if available.
if (supports_erms()) {
if (FLAG_IS_DEFAULT(UseFastStosb)) {
UseFastStosb = true;
}
} else if (UseFastStosb) {
warning("fast-string operations are not available on this CPU");
FLAG_SET_DEFAULT(UseFastStosb, false);
}
// For AMD Processors use XMM/YMM MOVDQU instructions
// for Object Initialization as default
if (is_amd() && cpu_family() >= 0x19) {
if (FLAG_IS_DEFAULT(UseFastStosb)) {
UseFastStosb = false;
}
}
#ifdef COMPILER2
if (is_intel() && MaxVectorSize > 16) {
if (FLAG_IS_DEFAULT(UseFastStosb)) {
UseFastStosb = false;
}
}
#endif
// Use XMM/YMM MOVDQU instruction for Object Initialization
if (!UseFastStosb && UseSSE >= 2 && UseUnalignedLoadStores) {
if (FLAG_IS_DEFAULT(UseXMMForObjInit)) {
UseXMMForObjInit = true;
}
} else if (UseXMMForObjInit) {
warning("UseXMMForObjInit requires SSE2 and unaligned load/stores. Feature is switched off.");
FLAG_SET_DEFAULT(UseXMMForObjInit, false);
}
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(AlignVector)) {
// Modern processors allow misaligned memory operations for vectors.
AlignVector = !UseUnalignedLoadStores;
}
#endif // COMPILER2
if (FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
if (AllocatePrefetchInstr == 3 && !supports_3dnow_prefetch()) {
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 0);
} else if (!supports_sse() && supports_3dnow_prefetch()) {
FLAG_SET_DEFAULT(AllocatePrefetchInstr, 3);
}
}
// Allocation prefetch settings
intx cache_line_size = prefetch_data_size();
if (FLAG_IS_DEFAULT(AllocatePrefetchStepSize) &&
(cache_line_size > AllocatePrefetchStepSize)) {
FLAG_SET_DEFAULT(AllocatePrefetchStepSize, cache_line_size);
}
if ((AllocatePrefetchDistance == 0) && (AllocatePrefetchStyle != 0)) {
assert(!FLAG_IS_DEFAULT(AllocatePrefetchDistance), "default value should not be 0");
if (!FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
warning("AllocatePrefetchDistance is set to 0 which disable prefetching. Ignoring AllocatePrefetchStyle flag.");
}
FLAG_SET_DEFAULT(AllocatePrefetchStyle, 0);
}
if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
bool use_watermark_prefetch = (AllocatePrefetchStyle == 2);
FLAG_SET_DEFAULT(AllocatePrefetchDistance, allocate_prefetch_distance(use_watermark_prefetch));
}
if (is_intel() && cpu_family() == 6 && supports_sse3()) {
if (FLAG_IS_DEFAULT(AllocatePrefetchLines) &&
supports_sse4_2() && supports_ht()) { // Nehalem based cpus
FLAG_SET_DEFAULT(AllocatePrefetchLines, 4);
}
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(UseFPUForSpilling) && supports_sse4_2()) {
FLAG_SET_DEFAULT(UseFPUForSpilling, true);
}
#endif
}
if (is_zx() && ((cpu_family() == 6) || (cpu_family() == 7)) && supports_sse4_2()) {
#ifdef COMPILER2
if (FLAG_IS_DEFAULT(UseFPUForSpilling)) {
FLAG_SET_DEFAULT(UseFPUForSpilling, true);
}
#endif
}
#ifdef _LP64
// Prefetch settings
// 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.
if (FLAG_IS_DEFAULT(PrefetchCopyIntervalInBytes)) {
FLAG_SET_DEFAULT(PrefetchCopyIntervalInBytes, 576);
}
if (FLAG_IS_DEFAULT(PrefetchScanIntervalInBytes)) {
FLAG_SET_DEFAULT(PrefetchScanIntervalInBytes, 576);
}
#endif
if (FLAG_IS_DEFAULT(ContendedPaddingWidth) &&
(cache_line_size > ContendedPaddingWidth))
ContendedPaddingWidth = cache_line_size;
// This machine allows unaligned memory accesses
if (FLAG_IS_DEFAULT(UseUnalignedAccesses)) {
FLAG_SET_DEFAULT(UseUnalignedAccesses, true);
}
#ifndef PRODUCT
if (log_is_enabled(Info, os, cpu)) {
LogStream ls(Log(os, cpu)::info());
outputStream* log = &ls;
log->print_cr("Logical CPUs per core: %u",
logical_processors_per_package());
log->print_cr("L1 data cache line size: %u", L1_data_cache_line_size());
log->print("UseSSE=%d", UseSSE);
if (UseAVX > 0) {
log->print(" UseAVX=%d", UseAVX);
}
if (UseAES) {
log->print(" UseAES=1");
}
#ifdef COMPILER2
if (MaxVectorSize > 0) {
log->print(" MaxVectorSize=%d", (int) MaxVectorSize);
}
#endif
log->cr();
log->print("Allocation");
if (AllocatePrefetchStyle <= 0 || (UseSSE == 0 && !supports_3dnow_prefetch())) {
log->print_cr(": no prefetching");
} else {
log->print(" prefetching: ");
if (UseSSE == 0 && supports_3dnow_prefetch()) {
log->print("PREFETCHW");
} else if (UseSSE >= 1) {
if (AllocatePrefetchInstr == 0) {
log->print("PREFETCHNTA");
} else if (AllocatePrefetchInstr == 1) {
log->print("PREFETCHT0");
} else if (AllocatePrefetchInstr == 2) {
log->print("PREFETCHT2");
} else if (AllocatePrefetchInstr == 3) {
log->print("PREFETCHW");
}
}
--> --------------------
--> maximum size reached
--> --------------------
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