6708714: Optimize long LShift on 32-bits x86
Summary: For small (1-3 bits) left long shifts in 32-bits VM use sets of add+addc instructions instead of shld+shl on new AMD cpus.
Reviewed-by: never
Contributed-by: shrinivas.joshi@amd.com
/*
* Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
# include "incls/_precompiled.incl"
# include "incls/_vm_version_x86_32.cpp.incl"
int VM_Version::_cpu;
int VM_Version::_model;
int VM_Version::_stepping;
int VM_Version::_cpuFeatures;
const char* VM_Version::_features_str = "";
VM_Version::CpuidInfo VM_Version::_cpuid_info = { 0, };
static BufferBlob* stub_blob;
static const int stub_size = 300;
extern "C" {
typedef void (*getPsrInfo_stub_t)(void*);
}
static getPsrInfo_stub_t getPsrInfo_stub = NULL;
class VM_Version_StubGenerator: public StubCodeGenerator {
public:
VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
address generate_getPsrInfo() {
// Flags to test CPU type.
const uint32_t EFL_AC = 0x40000;
const uint32_t 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, std_cpuid1;
Label ext_cpuid1, ext_cpuid5, done;
StubCodeMark mark(this, "VM_Version", "getPsrInfo_stub");
# define __ _masm->
address start = __ pc();
//
// void getPsrInfo(VM_Version::CpuidInfo* cpuid_info);
//
__ pushl(rbp);
__ movl(rbp, Address(rsp, 8)); // cpuid_info address
__ pushl(rbx);
__ pushl(rsi);
__ pushfd(); // preserve rbx, and flags
__ popl(rax);
__ pushl(rax);
__ movl(rcx, rax);
//
// if we are unable to change the AC flag, we have a 386
//
__ xorl(rax, EFL_AC);
__ pushl(rax);
__ popfd();
__ pushfd();
__ popl(rax);
__ cmpl(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);
__ movl(rax, rcx);
__ xorl(rax, EFL_ID);
__ pushl(rax);
__ popfd();
__ pushfd();
__ popl(rax);
__ cmpl(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
__ leal(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, 3); // Is cpuid(0x4) supported?
__ jccb(Assembler::belowEqual, std_cpuid1);
//
// cpuid(0x4) Deterministic cache params
//
__ movl(rax, 4); // and rcx already set to 0x0
__ xorl(rcx, rcx);
__ cpuid();
__ pushl(rax);
__ andl(rax, 0x1f); // Determine if valid cache parameters used
__ orl(rax, rax); // rax,[4:0] == 0 indicates invalid cache
__ popl(rax);
__ jccb(Assembler::equal, std_cpuid1);
__ leal(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();
__ leal(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);
__ movl(rax, 0x80000000);
__ cpuid();
__ cmpl(rax, 0x80000000); // Is cpuid(0x80000001) supported?
__ jcc(Assembler::belowEqual, done);
__ cmpl(rax, 0x80000004); // Is cpuid(0x80000005) supported?
__ jccb(Assembler::belowEqual, ext_cpuid1);
__ cmpl(rax, 0x80000007); // Is cpuid(0x80000008) supported?
__ jccb(Assembler::belowEqual, ext_cpuid5);
//
// Extended cpuid(0x80000008)
//
__ movl(rax, 0x80000008);
__ cpuid();
__ leal(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(0x80000005)
//
__ bind(ext_cpuid5);
__ movl(rax, 0x80000005);
__ cpuid();
__ leal(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();
__ leal(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);
//
// return
//
__ bind(done);
__ popfd();
__ popl(rsi);
__ popl(rbx);
__ popl(rbp);
__ ret(0);
# undef __
return start;
};
};
void VM_Version::get_processor_features() {
_cpu = 4; // 486 by default
_model = 0;
_stepping = 0;
_cpuFeatures = 0;
_logical_processors_per_package = 1;
if (!Use486InstrsOnly) {
// Get raw processor info
getPsrInfo_stub(&_cpuid_info);
assert_is_initialized();
_cpu = extended_cpu_family();
_model = extended_cpu_model();
_stepping = cpu_stepping();
if (cpu_family() > 4) { // it supports CPUID
_cpuFeatures = feature_flags();
// Logical processors are only available on P4s and above,
// and only if hyperthreading is available.
_logical_processors_per_package = logical_processor_count();
}
}
_supports_cx8 = supports_cmpxchg8();
// if the OS doesn't support SSE, we can't use this feature even if the HW does
if( !os::supports_sse())
_cpuFeatures &= ~(CPU_SSE|CPU_SSE2|CPU_SSE3|CPU_SSSE3|CPU_SSE4|CPU_SSE4A);
if (UseSSE < 4)
_cpuFeatures &= ~CPU_SSE4;
if (UseSSE < 3) {
_cpuFeatures &= ~CPU_SSE3;
_cpuFeatures &= ~CPU_SSSE3;
_cpuFeatures &= ~CPU_SSE4A;
}
if (UseSSE < 2)
_cpuFeatures &= ~CPU_SSE2;
if (UseSSE < 1)
_cpuFeatures &= ~CPU_SSE;
if (logical_processors_per_package() == 1) {
// HT processor could be installed on a system which doesn't support HT.
_cpuFeatures &= ~CPU_HT;
}
char buf[256];
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",
cores_per_cpu(), threads_per_core(),
cpu_family(), _model, _stepping,
(supports_cmov() ? ", cmov" : ""),
(supports_cmpxchg8() ? ", cx8" : ""),
(supports_fxsr() ? ", fxsr" : ""),
(supports_mmx() ? ", mmx" : ""),
(supports_sse() ? ", sse" : ""),
(supports_sse2() ? ", sse2" : ""),
(supports_sse3() ? ", sse3" : ""),
(supports_ssse3()? ", ssse3": ""),
(supports_sse4() ? ", sse4" : ""),
(supports_mmx_ext() ? ", mmxext" : ""),
(supports_3dnow() ? ", 3dnow" : ""),
(supports_3dnow2() ? ", 3dnowext" : ""),
(supports_sse4a() ? ", sse4a": ""),
(supports_ht() ? ", ht": ""));
_features_str = strdup(buf);
// 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.
if( UseSSE > 4 ) UseSSE=4;
if( UseSSE < 0 ) UseSSE=0;
if( !supports_sse4() ) // Drop to 3 if no SSE4 support
UseSSE = MIN2((intx)3,UseSSE);
if( !supports_sse3() ) // Drop to 2 if no SSE3 support
UseSSE = MIN2((intx)2,UseSSE);
if( !supports_sse2() ) // Drop to 1 if no SSE2 support
UseSSE = MIN2((intx)1,UseSSE);
if( !supports_sse () ) // Drop to 0 if no SSE support
UseSSE = 0;
// 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_amd() ) { // 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( 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
}
}
assert(0 <= ReadPrefetchInstr && ReadPrefetchInstr <= 3, "invalid value");
assert(0 <= AllocatePrefetchInstr && AllocatePrefetchInstr <= 3, "invalid value");
// set valid Prefetch instruction
if( ReadPrefetchInstr < 0 ) ReadPrefetchInstr = 0;
if( ReadPrefetchInstr > 3 ) ReadPrefetchInstr = 3;
if( ReadPrefetchInstr == 3 && !supports_3dnow() ) ReadPrefetchInstr = 0;
if( !supports_sse() && supports_3dnow() ) ReadPrefetchInstr = 3;
if( AllocatePrefetchInstr < 0 ) AllocatePrefetchInstr = 0;
if( AllocatePrefetchInstr > 3 ) AllocatePrefetchInstr = 3;
if( AllocatePrefetchInstr == 3 && !supports_3dnow() ) AllocatePrefetchInstr=0;
if( !supports_sse() && supports_3dnow() ) AllocatePrefetchInstr = 3;
// Allocation prefetch settings
intx cache_line_size = L1_data_cache_line_size();
if( cache_line_size > AllocatePrefetchStepSize )
AllocatePrefetchStepSize = cache_line_size;
if( FLAG_IS_DEFAULT(AllocatePrefetchLines) )
AllocatePrefetchLines = 3; // Optimistic value
assert(AllocatePrefetchLines > 0, "invalid value");
if( AllocatePrefetchLines < 1 ) // set valid value in product VM
AllocatePrefetchLines = 1; // Conservative value
AllocatePrefetchDistance = allocate_prefetch_distance();
AllocatePrefetchStyle = allocate_prefetch_style();
if( AllocatePrefetchStyle == 2 && is_intel() &&
cpu_family() == 6 && supports_sse3() ) { // watermark prefetching on Core
AllocatePrefetchDistance = 320;
}
assert(AllocatePrefetchDistance % AllocatePrefetchStepSize == 0, "invalid value");
#ifndef PRODUCT
if (PrintMiscellaneous && Verbose) {
tty->print_cr("Logical CPUs per package: %u",
logical_processors_per_package());
tty->print_cr("UseSSE=%d",UseSSE);
tty->print("Allocation: ");
if (AllocatePrefetchStyle <= 0 || UseSSE == 0 && !supports_3dnow()) {
tty->print_cr("no prefetching");
} else {
if (UseSSE == 0 && supports_3dnow()) {
tty->print("PREFETCHW");
} else if (UseSSE >= 1) {
if (AllocatePrefetchInstr == 0) {
tty->print("PREFETCHNTA");
} else if (AllocatePrefetchInstr == 1) {
tty->print("PREFETCHT0");
} else if (AllocatePrefetchInstr == 2) {
tty->print("PREFETCHT2");
} else if (AllocatePrefetchInstr == 3) {
tty->print("PREFETCHW");
}
}
if (AllocatePrefetchLines > 1) {
tty->print_cr(" %d, %d lines with step %d bytes", AllocatePrefetchDistance, AllocatePrefetchLines, AllocatePrefetchStepSize);
} else {
tty->print_cr(" %d, one line", AllocatePrefetchDistance);
}
}
}
#endif // !PRODUCT
}
void VM_Version::initialize() {
ResourceMark rm;
// Making this stub must be FIRST use of assembler
stub_blob = BufferBlob::create("getPsrInfo_stub", stub_size);
if (stub_blob == NULL) {
vm_exit_during_initialization("Unable to allocate getPsrInfo_stub");
}
CodeBuffer c(stub_blob->instructions_begin(),
stub_blob->instructions_size());
VM_Version_StubGenerator g(&c);
getPsrInfo_stub = CAST_TO_FN_PTR(getPsrInfo_stub_t,
g.generate_getPsrInfo());
get_processor_features();
}