1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "runtime/java.hpp"
30 #include "runtime/os.hpp"
31 #include "runtime/stubCodeGenerator.hpp"
32 #include "vm_version_x86.hpp"
33
34
35 int VM_Version::_cpu;
36 int VM_Version::_model;
37 int VM_Version::_stepping;
38 VM_Version::CpuidInfo VM_Version::_cpuid_info = { 0, };
39
40 // Address of instruction which causes SEGV
41 address VM_Version::_cpuinfo_segv_addr = 0;
42 // Address of instruction after the one which causes SEGV
43 address VM_Version::_cpuinfo_cont_addr = 0;
44
45 static BufferBlob* stub_blob;
46 static const int stub_size = 1000;
47
48 extern "C" {
49 typedef void (*get_cpu_info_stub_t)(void*);
50 }
51 static get_cpu_info_stub_t get_cpu_info_stub = NULL;
52
53
54 class VM_Version_StubGenerator: public StubCodeGenerator {
55 public:
56
57 VM_Version_StubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
58
59 address generate_get_cpu_info() {
60 // Flags to test CPU type.
61 const uint32_t HS_EFL_AC = 0x40000;
62 const uint32_t HS_EFL_ID = 0x200000;
63 // Values for when we don't have a CPUID instruction.
64 const int CPU_FAMILY_SHIFT = 8;
65 const uint32_t CPU_FAMILY_386 = (3 << CPU_FAMILY_SHIFT);
66 const uint32_t CPU_FAMILY_486 = (4 << CPU_FAMILY_SHIFT);
67
68 Label detect_486, cpu486, detect_586, std_cpuid1, std_cpuid4;
69 Label sef_cpuid, ext_cpuid, ext_cpuid1, ext_cpuid5, ext_cpuid7, done, wrapup;
70 Label legacy_setup, save_restore_except, legacy_save_restore, start_simd_check;
71
72 StubCodeMark mark(this, "VM_Version", "get_cpu_info_stub");
73 # define __ _masm->
74
75 address start = __ pc();
76
77 //
78 // void get_cpu_info(VM_Version::CpuidInfo* cpuid_info);
79 //
80 // LP64: rcx and rdx are first and second argument registers on windows
81
82 __ push(rbp);
83 #ifdef _LP64
84 __ mov(rbp, c_rarg0); // cpuid_info address
85 #else
86 __ movptr(rbp, Address(rsp, 8)); // cpuid_info address
87 #endif
88 __ push(rbx);
89 __ push(rsi);
90 __ pushf(); // preserve rbx, and flags
91 __ pop(rax);
92 __ push(rax);
93 __ mov(rcx, rax);
94 //
95 // if we are unable to change the AC flag, we have a 386
96 //
97 __ xorl(rax, HS_EFL_AC);
98 __ push(rax);
99 __ popf();
100 __ pushf();
101 __ pop(rax);
102 __ cmpptr(rax, rcx);
103 __ jccb(Assembler::notEqual, detect_486);
104
105 __ movl(rax, CPU_FAMILY_386);
106 __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
107 __ jmp(done);
108
109 //
110 // If we are unable to change the ID flag, we have a 486 which does
111 // not support the "cpuid" instruction.
112 //
113 __ bind(detect_486);
114 __ mov(rax, rcx);
115 __ xorl(rax, HS_EFL_ID);
116 __ push(rax);
117 __ popf();
118 __ pushf();
119 __ pop(rax);
120 __ cmpptr(rcx, rax);
121 __ jccb(Assembler::notEqual, detect_586);
122
123 __ bind(cpu486);
124 __ movl(rax, CPU_FAMILY_486);
125 __ movl(Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())), rax);
126 __ jmp(done);
127
128 //
129 // At this point, we have a chip which supports the "cpuid" instruction
130 //
131 __ bind(detect_586);
132 __ xorl(rax, rax);
133 __ cpuid();
134 __ orl(rax, rax);
135 __ jcc(Assembler::equal, cpu486); // if cpuid doesn't support an input
136 // value of at least 1, we give up and
137 // assume a 486
138 __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset())));
139 __ movl(Address(rsi, 0), rax);
140 __ movl(Address(rsi, 4), rbx);
141 __ movl(Address(rsi, 8), rcx);
142 __ movl(Address(rsi,12), rdx);
143
144 __ cmpl(rax, 0xa); // Is cpuid(0xB) supported?
145 __ jccb(Assembler::belowEqual, std_cpuid4);
146
147 //
148 // cpuid(0xB) Processor Topology
149 //
150 __ movl(rax, 0xb);
151 __ xorl(rcx, rcx); // Threads level
152 __ cpuid();
153
154 __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB0_offset())));
155 __ movl(Address(rsi, 0), rax);
156 __ movl(Address(rsi, 4), rbx);
157 __ movl(Address(rsi, 8), rcx);
158 __ movl(Address(rsi,12), rdx);
159
160 __ movl(rax, 0xb);
161 __ movl(rcx, 1); // Cores level
162 __ cpuid();
163 __ push(rax);
164 __ andl(rax, 0x1f); // Determine if valid topology level
165 __ orl(rax, rbx); // eax[4:0] | ebx[0:15] == 0 indicates invalid level
166 __ andl(rax, 0xffff);
167 __ pop(rax);
168 __ jccb(Assembler::equal, std_cpuid4);
169
170 __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB1_offset())));
171 __ movl(Address(rsi, 0), rax);
172 __ movl(Address(rsi, 4), rbx);
173 __ movl(Address(rsi, 8), rcx);
174 __ movl(Address(rsi,12), rdx);
175
176 __ movl(rax, 0xb);
177 __ movl(rcx, 2); // Packages level
178 __ cpuid();
179 __ push(rax);
180 __ andl(rax, 0x1f); // Determine if valid topology level
181 __ orl(rax, rbx); // eax[4:0] | ebx[0:15] == 0 indicates invalid level
182 __ andl(rax, 0xffff);
183 __ pop(rax);
184 __ jccb(Assembler::equal, std_cpuid4);
185
186 __ lea(rsi, Address(rbp, in_bytes(VM_Version::tpl_cpuidB2_offset())));
187 __ movl(Address(rsi, 0), rax);
188 __ movl(Address(rsi, 4), rbx);
189 __ movl(Address(rsi, 8), rcx);
190 __ movl(Address(rsi,12), rdx);
191
192 //
193 // cpuid(0x4) Deterministic cache params
194 //
195 __ bind(std_cpuid4);
196 __ movl(rax, 4);
197 __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x4) supported?
198 __ jccb(Assembler::greater, std_cpuid1);
199
200 __ xorl(rcx, rcx); // L1 cache
201 __ cpuid();
202 __ push(rax);
203 __ andl(rax, 0x1f); // Determine if valid cache parameters used
204 __ orl(rax, rax); // eax[4:0] == 0 indicates invalid cache
205 __ pop(rax);
206 __ jccb(Assembler::equal, std_cpuid1);
207
208 __ lea(rsi, Address(rbp, in_bytes(VM_Version::dcp_cpuid4_offset())));
209 __ movl(Address(rsi, 0), rax);
210 __ movl(Address(rsi, 4), rbx);
211 __ movl(Address(rsi, 8), rcx);
212 __ movl(Address(rsi,12), rdx);
213
214 //
215 // Standard cpuid(0x1)
216 //
217 __ bind(std_cpuid1);
218 __ movl(rax, 1);
219 __ cpuid();
220 __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
221 __ movl(Address(rsi, 0), rax);
222 __ movl(Address(rsi, 4), rbx);
223 __ movl(Address(rsi, 8), rcx);
224 __ movl(Address(rsi,12), rdx);
225
226 //
227 // Check if OS has enabled XGETBV instruction to access XCR0
228 // (OSXSAVE feature flag) and CPU supports AVX
229 //
230 __ andl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
231 __ cmpl(rcx, 0x18000000);
232 __ jccb(Assembler::notEqual, sef_cpuid); // jump if AVX is not supported
233
234 //
235 // XCR0, XFEATURE_ENABLED_MASK register
236 //
237 __ xorl(rcx, rcx); // zero for XCR0 register
238 __ xgetbv();
239 __ lea(rsi, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset())));
240 __ movl(Address(rsi, 0), rax);
241 __ movl(Address(rsi, 4), rdx);
242
243 //
244 // cpuid(0x7) Structured Extended Features
245 //
246 __ bind(sef_cpuid);
247 __ movl(rax, 7);
248 __ cmpl(rax, Address(rbp, in_bytes(VM_Version::std_cpuid0_offset()))); // Is cpuid(0x7) supported?
249 __ jccb(Assembler::greater, ext_cpuid);
250
251 __ xorl(rcx, rcx);
252 __ cpuid();
253 __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
254 __ movl(Address(rsi, 0), rax);
255 __ movl(Address(rsi, 4), rbx);
256
257 //
258 // Extended cpuid(0x80000000)
259 //
260 __ bind(ext_cpuid);
261 __ movl(rax, 0x80000000);
262 __ cpuid();
263 __ cmpl(rax, 0x80000000); // Is cpuid(0x80000001) supported?
264 __ jcc(Assembler::belowEqual, done);
265 __ cmpl(rax, 0x80000004); // Is cpuid(0x80000005) supported?
266 __ jccb(Assembler::belowEqual, ext_cpuid1);
267 __ cmpl(rax, 0x80000006); // Is cpuid(0x80000007) supported?
268 __ jccb(Assembler::belowEqual, ext_cpuid5);
269 __ cmpl(rax, 0x80000007); // Is cpuid(0x80000008) supported?
270 __ jccb(Assembler::belowEqual, ext_cpuid7);
271 //
272 // Extended cpuid(0x80000008)
273 //
274 __ movl(rax, 0x80000008);
275 __ cpuid();
276 __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid8_offset())));
277 __ movl(Address(rsi, 0), rax);
278 __ movl(Address(rsi, 4), rbx);
279 __ movl(Address(rsi, 8), rcx);
280 __ movl(Address(rsi,12), rdx);
281
282 //
283 // Extended cpuid(0x80000007)
284 //
285 __ bind(ext_cpuid7);
286 __ movl(rax, 0x80000007);
287 __ cpuid();
288 __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid7_offset())));
289 __ movl(Address(rsi, 0), rax);
290 __ movl(Address(rsi, 4), rbx);
291 __ movl(Address(rsi, 8), rcx);
292 __ movl(Address(rsi,12), rdx);
293
294 //
295 // Extended cpuid(0x80000005)
296 //
297 __ bind(ext_cpuid5);
298 __ movl(rax, 0x80000005);
299 __ cpuid();
300 __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid5_offset())));
301 __ movl(Address(rsi, 0), rax);
302 __ movl(Address(rsi, 4), rbx);
303 __ movl(Address(rsi, 8), rcx);
304 __ movl(Address(rsi,12), rdx);
305
306 //
307 // Extended cpuid(0x80000001)
308 //
309 __ bind(ext_cpuid1);
310 __ movl(rax, 0x80000001);
311 __ cpuid();
312 __ lea(rsi, Address(rbp, in_bytes(VM_Version::ext_cpuid1_offset())));
313 __ movl(Address(rsi, 0), rax);
314 __ movl(Address(rsi, 4), rbx);
315 __ movl(Address(rsi, 8), rcx);
316 __ movl(Address(rsi,12), rdx);
317
318 //
319 // Check if OS has enabled XGETBV instruction to access XCR0
320 // (OSXSAVE feature flag) and CPU supports AVX
321 //
322 __ lea(rsi, Address(rbp, in_bytes(VM_Version::std_cpuid1_offset())));
323 __ movl(rcx, 0x18000000); // cpuid1 bits osxsave | avx
324 __ andl(rcx, Address(rsi, 8)); // cpuid1 bits osxsave | avx
325 __ cmpl(rcx, 0x18000000);
326 __ jccb(Assembler::notEqual, done); // jump if AVX is not supported
327
328 __ movl(rax, 0x6);
329 __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
330 __ cmpl(rax, 0x6);
331 __ jccb(Assembler::equal, start_simd_check); // return if AVX is not supported
332
333 // we need to bridge farther than imm8, so we use this island as a thunk
334 __ bind(done);
335 __ jmp(wrapup);
336
337 __ bind(start_simd_check);
338 //
339 // Some OSs have a bug when upper 128/256bits of YMM/ZMM
340 // registers are not restored after a signal processing.
341 // Generate SEGV here (reference through NULL)
342 // and check upper YMM/ZMM bits after it.
343 //
344 intx saved_useavx = UseAVX;
345 intx saved_usesse = UseSSE;
346 // check _cpuid_info.sef_cpuid7_ebx.bits.avx512f
347 __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
348 __ movl(rax, 0x10000);
349 __ andl(rax, Address(rsi, 4)); // xcr0 bits sse | ymm
350 __ cmpl(rax, 0x10000);
351 __ jccb(Assembler::notEqual, legacy_setup); // jump if EVEX is not supported
352 // check _cpuid_info.xem_xcr0_eax.bits.opmask
353 // check _cpuid_info.xem_xcr0_eax.bits.zmm512
354 // check _cpuid_info.xem_xcr0_eax.bits.zmm32
355 __ movl(rax, 0xE0);
356 __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
357 __ cmpl(rax, 0xE0);
358 __ jccb(Assembler::notEqual, legacy_setup); // jump if EVEX is not supported
359
360 // EVEX setup: run in lowest evex mode
361 VM_Version::set_evex_cpuFeatures(); // Enable temporary to pass asserts
362 UseAVX = 3;
363 UseSSE = 2;
364 // load value into all 64 bytes of zmm7 register
365 __ movl(rcx, VM_Version::ymm_test_value());
366 __ movdl(xmm0, rcx);
367 __ movl(rcx, 0xffff);
368 __ kmovwl(k1, rcx);
369 __ evpbroadcastd(xmm0, xmm0, Assembler::AVX_512bit);
370 __ evmovdqul(xmm7, xmm0, Assembler::AVX_512bit);
371 #ifdef _LP64
372 __ evmovdqul(xmm8, xmm0, Assembler::AVX_512bit);
373 __ evmovdqul(xmm31, xmm0, Assembler::AVX_512bit);
374 #endif
375 VM_Version::clean_cpuFeatures();
376 __ jmp(save_restore_except);
377
378 __ bind(legacy_setup);
379 // AVX setup
380 VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
381 UseAVX = 1;
382 UseSSE = 2;
383 // load value into all 32 bytes of ymm7 register
384 __ movl(rcx, VM_Version::ymm_test_value());
385
386 __ movdl(xmm0, rcx);
387 __ pshufd(xmm0, xmm0, 0x00);
388 __ vinsertf128h(xmm0, xmm0, xmm0);
389 __ vmovdqu(xmm7, xmm0);
390 #ifdef _LP64
391 __ vmovdqu(xmm8, xmm0);
392 __ vmovdqu(xmm15, xmm0);
393 #endif
394 VM_Version::clean_cpuFeatures();
395
396 __ bind(save_restore_except);
397 __ xorl(rsi, rsi);
398 VM_Version::set_cpuinfo_segv_addr(__ pc());
399 // Generate SEGV
400 __ movl(rax, Address(rsi, 0));
401
402 VM_Version::set_cpuinfo_cont_addr(__ pc());
403 // Returns here after signal. Save xmm0 to check it later.
404
405 // check _cpuid_info.sef_cpuid7_ebx.bits.avx512f
406 __ lea(rsi, Address(rbp, in_bytes(VM_Version::sef_cpuid7_offset())));
407 __ movl(rax, 0x10000);
408 __ andl(rax, Address(rsi, 4));
409 __ cmpl(rax, 0x10000);
410 __ jccb(Assembler::notEqual, legacy_save_restore);
411 // check _cpuid_info.xem_xcr0_eax.bits.opmask
412 // check _cpuid_info.xem_xcr0_eax.bits.zmm512
413 // check _cpuid_info.xem_xcr0_eax.bits.zmm32
414 __ movl(rax, 0xE0);
415 __ andl(rax, Address(rbp, in_bytes(VM_Version::xem_xcr0_offset()))); // xcr0 bits sse | ymm
416 __ cmpl(rax, 0xE0);
417 __ jccb(Assembler::notEqual, legacy_save_restore);
418
419 // EVEX check: run in lowest evex mode
420 VM_Version::set_evex_cpuFeatures(); // Enable temporary to pass asserts
421 UseAVX = 3;
422 UseSSE = 2;
423 __ lea(rsi, Address(rbp, in_bytes(VM_Version::zmm_save_offset())));
424 __ evmovdqul(Address(rsi, 0), xmm0, Assembler::AVX_512bit);
425 __ evmovdqul(Address(rsi, 64), xmm7, Assembler::AVX_512bit);
426 #ifdef _LP64
427 __ evmovdqul(Address(rsi, 128), xmm8, Assembler::AVX_512bit);
428 __ evmovdqul(Address(rsi, 192), xmm31, Assembler::AVX_512bit);
429 #endif
430 VM_Version::clean_cpuFeatures();
431 UseAVX = saved_useavx;
432 UseSSE = saved_usesse;
433 __ jmp(wrapup);
434
435 __ bind(legacy_save_restore);
436 // AVX check
437 VM_Version::set_avx_cpuFeatures(); // Enable temporary to pass asserts
438 UseAVX = 1;
439 UseSSE = 2;
440 __ lea(rsi, Address(rbp, in_bytes(VM_Version::ymm_save_offset())));
441 __ vmovdqu(Address(rsi, 0), xmm0);
442 __ vmovdqu(Address(rsi, 32), xmm7);
443 #ifdef _LP64
444 __ vmovdqu(Address(rsi, 64), xmm8);
445 __ vmovdqu(Address(rsi, 96), xmm15);
446 #endif
447 VM_Version::clean_cpuFeatures();
448 UseAVX = saved_useavx;
449 UseSSE = saved_usesse;
450
451 __ bind(wrapup);
452 __ popf();
453 __ pop(rsi);
454 __ pop(rbx);
455 __ pop(rbp);
456 __ ret(0);
457
458 # undef __
459
460 return start;
461 };
462 };
463
464 void VM_Version::get_processor_features() {
465
466 _cpu = 4; // 486 by default
467 _model = 0;
468 _stepping = 0;
469 _features = 0;
470 _logical_processors_per_package = 1;
471 // i486 internal cache is both I&D and has a 16-byte line size
472 _L1_data_cache_line_size = 16;
473
474 // Get raw processor info
475
476 get_cpu_info_stub(&_cpuid_info);
477
478 assert_is_initialized();
479 _cpu = extended_cpu_family();
480 _model = extended_cpu_model();
481 _stepping = cpu_stepping();
482
483 if (cpu_family() > 4) { // it supports CPUID
484 _features = feature_flags();
485 // Logical processors are only available on P4s and above,
486 // and only if hyperthreading is available.
487 _logical_processors_per_package = logical_processor_count();
488 _L1_data_cache_line_size = L1_line_size();
489 }
490
491 _supports_cx8 = supports_cmpxchg8();
492 // xchg and xadd instructions
493 _supports_atomic_getset4 = true;
494 _supports_atomic_getadd4 = true;
495 LP64_ONLY(_supports_atomic_getset8 = true);
496 LP64_ONLY(_supports_atomic_getadd8 = true);
497
498 #ifdef _LP64
499 // OS should support SSE for x64 and hardware should support at least SSE2.
500 if (!VM_Version::supports_sse2()) {
501 vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");
502 }
503 // in 64 bit the use of SSE2 is the minimum
504 if (UseSSE < 2) UseSSE = 2;
505 #endif
506
507 #ifdef AMD64
508 // flush_icache_stub have to be generated first.
509 // That is why Icache line size is hard coded in ICache class,
510 // see icache_x86.hpp. It is also the reason why we can't use
511 // clflush instruction in 32-bit VM since it could be running
512 // on CPU which does not support it.
513 //
514 // The only thing we can do is to verify that flushed
515 // ICache::line_size has correct value.
516 guarantee(_cpuid_info.std_cpuid1_edx.bits.clflush != 0, "clflush is not supported");
517 // clflush_size is size in quadwords (8 bytes).
518 guarantee(_cpuid_info.std_cpuid1_ebx.bits.clflush_size == 8, "such clflush size is not supported");
519 #endif
520
521 // If the OS doesn't support SSE, we can't use this feature even if the HW does
522 if (!os::supports_sse())
523 _features &= ~(CPU_SSE|CPU_SSE2|CPU_SSE3|CPU_SSSE3|CPU_SSE4A|CPU_SSE4_1|CPU_SSE4_2);
524
525 if (UseSSE < 4) {
526 _features &= ~CPU_SSE4_1;
527 _features &= ~CPU_SSE4_2;
528 }
529
530 if (UseSSE < 3) {
531 _features &= ~CPU_SSE3;
532 _features &= ~CPU_SSSE3;
533 _features &= ~CPU_SSE4A;
534 }
535
536 if (UseSSE < 2)
537 _features &= ~CPU_SSE2;
538
539 if (UseSSE < 1)
540 _features &= ~CPU_SSE;
541
542 // first try initial setting and detect what we can support
543 if (UseAVX > 0) {
544 if (UseAVX > 2 && supports_evex()) {
545 UseAVX = 3;
546 } else if (UseAVX > 1 && supports_avx2()) {
547 UseAVX = 2;
548 } else if (UseAVX > 0 && supports_avx()) {
549 UseAVX = 1;
550 } else {
551 UseAVX = 0;
552 }
553 } else if (UseAVX < 0) {
554 UseAVX = 0;
555 }
556
557 if (UseAVX < 3) {
558 _features &= ~CPU_AVX512F;
559 _features &= ~CPU_AVX512DQ;
560 _features &= ~CPU_AVX512CD;
561 _features &= ~CPU_AVX512BW;
562 _features &= ~CPU_AVX512VL;
563 }
564
565 if (UseAVX < 2)
566 _features &= ~CPU_AVX2;
567
568 if (UseAVX < 1)
569 _features &= ~CPU_AVX;
570
571 if (!UseAES && !FLAG_IS_DEFAULT(UseAES))
572 _features &= ~CPU_AES;
573
574 if (logical_processors_per_package() == 1) {
575 // HT processor could be installed on a system which doesn't support HT.
576 _features &= ~CPU_HT;
577 }
578
579 char buf[256];
580 jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
581 cores_per_cpu(), threads_per_core(),
582 cpu_family(), _model, _stepping,
583 (supports_cmov() ? ", cmov" : ""),
584 (supports_cmpxchg8() ? ", cx8" : ""),
585 (supports_fxsr() ? ", fxsr" : ""),
586 (supports_mmx() ? ", mmx" : ""),
587 (supports_sse() ? ", sse" : ""),
588 (supports_sse2() ? ", sse2" : ""),
589 (supports_sse3() ? ", sse3" : ""),
590 (supports_ssse3()? ", ssse3": ""),
591 (supports_sse4_1() ? ", sse4.1" : ""),
592 (supports_sse4_2() ? ", sse4.2" : ""),
593 (supports_popcnt() ? ", popcnt" : ""),
594 (supports_avx() ? ", avx" : ""),
595 (supports_avx2() ? ", avx2" : ""),
596 (supports_aes() ? ", aes" : ""),
597 (supports_clmul() ? ", clmul" : ""),
598 (supports_erms() ? ", erms" : ""),
599 (supports_rtm() ? ", rtm" : ""),
600 (supports_mmx_ext() ? ", mmxext" : ""),
601 (supports_3dnow_prefetch() ? ", 3dnowpref" : ""),
602 (supports_lzcnt() ? ", lzcnt": ""),
603 (supports_sse4a() ? ", sse4a": ""),
604 (supports_ht() ? ", ht": ""),
605 (supports_tsc() ? ", tsc": ""),
606 (supports_tscinv_bit() ? ", tscinvbit": ""),
607 (supports_tscinv() ? ", tscinv": ""),
608 (supports_bmi1() ? ", bmi1" : ""),
609 (supports_bmi2() ? ", bmi2" : ""),
610 (supports_adx() ? ", adx" : ""),
611 (supports_evex() ? ", evex" : ""),
612 (supports_sha() ? ", sha" : ""));
613 _features_string = os::strdup(buf);
614
615 // UseSSE is set to the smaller of what hardware supports and what
616 // the command line requires. I.e., you cannot set UseSSE to 2 on
617 // older Pentiums which do not support it.
618 if (UseSSE > 4) UseSSE=4;
619 if (UseSSE < 0) UseSSE=0;
620 if (!supports_sse4_1()) // Drop to 3 if no SSE4 support
621 UseSSE = MIN2((intx)3,UseSSE);
622 if (!supports_sse3()) // Drop to 2 if no SSE3 support
623 UseSSE = MIN2((intx)2,UseSSE);
624 if (!supports_sse2()) // Drop to 1 if no SSE2 support
625 UseSSE = MIN2((intx)1,UseSSE);
626 if (!supports_sse ()) // Drop to 0 if no SSE support
627 UseSSE = 0;
628
629 // Use AES instructions if available.
630 if (supports_aes()) {
631 if (FLAG_IS_DEFAULT(UseAES)) {
632 FLAG_SET_DEFAULT(UseAES, true);
633 }
634 if (!UseAES) {
635 if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
636 warning("AES intrinsics require UseAES flag to be enabled. Intrinsics will be disabled.");
637 }
638 FLAG_SET_DEFAULT(UseAESIntrinsics, false);
639 } else {
640 if (UseSSE > 2) {
641 if (FLAG_IS_DEFAULT(UseAESIntrinsics)) {
642 FLAG_SET_DEFAULT(UseAESIntrinsics, true);
643 }
644 } else {
645 // The AES intrinsic stubs require AES instruction support (of course)
646 // but also require sse3 mode or higher for instructions it use.
647 if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
648 warning("X86 AES intrinsics require SSE3 instructions or higher. Intrinsics will be disabled.");
649 }
650 FLAG_SET_DEFAULT(UseAESIntrinsics, false);
651 }
652
653 // --AES-CTR begins--
654 if (!UseAESIntrinsics) {
655 if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
656 warning("AES-CTR intrinsics require UseAESIntrinsics flag to be enabled. Intrinsics will be disabled.");
657 FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
658 }
659 } else {
660 if(supports_sse4_1() && UseSSE >= 4) {
661 if (FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
662 FLAG_SET_DEFAULT(UseAESCTRIntrinsics, true);
663 }
664 } else {
665 // The AES-CTR intrinsic stubs require AES instruction support (of course)
666 // but also require sse4.1 mode or higher for instructions it use.
667 if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
668 warning("X86 AES-CTR intrinsics require SSE4.1 instructions or higher. Intrinsics will be disabled.");
669 }
670 FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
671 }
672 }
673 // --AES-CTR ends--
674 }
675 } else if (UseAES || UseAESIntrinsics || UseAESCTRIntrinsics) {
676 if (UseAES && !FLAG_IS_DEFAULT(UseAES)) {
677 warning("AES instructions are not available on this CPU");
678 FLAG_SET_DEFAULT(UseAES, false);
679 }
680 if (UseAESIntrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
681 warning("AES intrinsics are not available on this CPU");
682 FLAG_SET_DEFAULT(UseAESIntrinsics, false);
683 }
684 if (UseAESCTRIntrinsics && !FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
685 warning("AES-CTR intrinsics are not available on this CPU");
686 FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
687 }
688 }
689
690 // Use CLMUL instructions if available.
691 if (supports_clmul()) {
692 if (FLAG_IS_DEFAULT(UseCLMUL)) {
693 UseCLMUL = true;
694 }
695 } else if (UseCLMUL) {
696 if (!FLAG_IS_DEFAULT(UseCLMUL))
697 warning("CLMUL instructions not available on this CPU (AVX may also be required)");
698 FLAG_SET_DEFAULT(UseCLMUL, false);
699 }
700
701 if (UseCLMUL && (UseSSE > 2)) {
702 if (FLAG_IS_DEFAULT(UseCRC32Intrinsics)) {
703 UseCRC32Intrinsics = true;
704 }
705 } else if (UseCRC32Intrinsics) {
706 if (!FLAG_IS_DEFAULT(UseCRC32Intrinsics))
707 warning("CRC32 Intrinsics requires CLMUL instructions (not available on this CPU)");
708 FLAG_SET_DEFAULT(UseCRC32Intrinsics, false);
709 }
710
711 if (supports_sse4_2()) {
712 if (FLAG_IS_DEFAULT(UseCRC32CIntrinsics)) {
713 UseCRC32CIntrinsics = true;
714 }
715 }
716 else if (UseCRC32CIntrinsics) {
717 if (!FLAG_IS_DEFAULT(UseCRC32CIntrinsics)) {
718 warning("CRC32C intrinsics are not available on this CPU");
719 }
720 FLAG_SET_DEFAULT(UseCRC32CIntrinsics, false);
721 }
722
723 // GHASH/GCM intrinsics
724 if (UseCLMUL && (UseSSE > 2)) {
725 if (FLAG_IS_DEFAULT(UseGHASHIntrinsics)) {
726 UseGHASHIntrinsics = true;
727 }
728 } else if (UseGHASHIntrinsics) {
729 if (!FLAG_IS_DEFAULT(UseGHASHIntrinsics))
730 warning("GHASH intrinsic requires CLMUL and SSE2 instructions on this CPU");
731 FLAG_SET_DEFAULT(UseGHASHIntrinsics, false);
732 }
733
734 if (supports_sha()) {
735 if (FLAG_IS_DEFAULT(UseSHA)) {
736 UseSHA = true;
737 }
738 }
739 else if (UseSHA) {
740 if (!FLAG_IS_DEFAULT(UseSHA))
741 warning("SHA instructions are not available on this CPU");
742 FLAG_SET_DEFAULT(UseSHA, false);
743 }
744
745 if (UseSHA && supports_sha()) {
746 if (FLAG_IS_DEFAULT(UseSHA1Intrinsics)) {
747 FLAG_SET_DEFAULT(UseSHA1Intrinsics, true);
748 }
749 } else if (UseSHA1Intrinsics) {
750 warning("Intrinsics for SHA-1 crypto hash functions not available on this CPU.");
751 FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
752 }
753
754 if (UseSHA && supports_sha()) {
755 if (FLAG_IS_DEFAULT(UseSHA256Intrinsics)) {
756 FLAG_SET_DEFAULT(UseSHA256Intrinsics, true);
757 }
758 } else if (UseSHA256Intrinsics) {
759 warning("Intrinsics for SHA-224 and SHA-256 crypto hash functions not available on this CPU.");
760 FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
761 }
762
763 if (UseSHA512Intrinsics) {
764 warning("Intrinsics for SHA-384 and SHA-512 crypto hash functions not available on this CPU.");
765 FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
766 }
767
768 if (UseAdler32Intrinsics) {
769 warning("Adler32Intrinsics not available on this CPU.");
770 FLAG_SET_DEFAULT(UseAdler32Intrinsics, false);
771 }
772
773 // Adjust RTM (Restricted Transactional Memory) flags
774 if (!supports_rtm() && UseRTMLocking) {
775 // Can't continue because UseRTMLocking affects UseBiasedLocking flag
776 // setting during arguments processing. See use_biased_locking().
777 // VM_Version_init() is executed after UseBiasedLocking is used
778 // in Thread::allocate().
779 vm_exit_during_initialization("RTM instructions are not available on this CPU");
780 }
781
782 #if INCLUDE_RTM_OPT
783 if (UseRTMLocking) {
784 if (is_intel_family_core()) {
785 if ((_model == CPU_MODEL_HASWELL_E3) ||
786 (_model == CPU_MODEL_HASWELL_E7 && _stepping < 3) ||
787 (_model == CPU_MODEL_BROADWELL && _stepping < 4)) {
788 // currently a collision between SKL and HSW_E3
789 if (!UnlockExperimentalVMOptions && UseAVX < 3) {
790 vm_exit_during_initialization("UseRTMLocking is only available as experimental option on this platform. It must be enabled via -XX:+UnlockExperimentalVMOptions flag.");
791 } else {
792 warning("UseRTMLocking is only available as experimental option on this platform.");
793 }
794 }
795 }
796 if (!FLAG_IS_CMDLINE(UseRTMLocking)) {
797 // RTM locking should be used only for applications with
798 // high lock contention. For now we do not use it by default.
799 vm_exit_during_initialization("UseRTMLocking flag should be only set on command line");
800 }
801 if (!is_power_of_2(RTMTotalCountIncrRate)) {
802 warning("RTMTotalCountIncrRate must be a power of 2, resetting it to 64");
803 FLAG_SET_DEFAULT(RTMTotalCountIncrRate, 64);
804 }
805 if (RTMAbortRatio < 0 || RTMAbortRatio > 100) {
806 warning("RTMAbortRatio must be in the range 0 to 100, resetting it to 50");
807 FLAG_SET_DEFAULT(RTMAbortRatio, 50);
808 }
809 } else { // !UseRTMLocking
810 if (UseRTMForStackLocks) {
811 if (!FLAG_IS_DEFAULT(UseRTMForStackLocks)) {
812 warning("UseRTMForStackLocks flag should be off when UseRTMLocking flag is off");
813 }
814 FLAG_SET_DEFAULT(UseRTMForStackLocks, false);
815 }
816 if (UseRTMDeopt) {
817 FLAG_SET_DEFAULT(UseRTMDeopt, false);
818 }
819 if (PrintPreciseRTMLockingStatistics) {
820 FLAG_SET_DEFAULT(PrintPreciseRTMLockingStatistics, false);
821 }
822 }
823 #else
824 if (UseRTMLocking) {
825 // Only C2 does RTM locking optimization.
826 // Can't continue because UseRTMLocking affects UseBiasedLocking flag
827 // setting during arguments processing. See use_biased_locking().
828 vm_exit_during_initialization("RTM locking optimization is not supported in this VM");
829 }
830 #endif
831
832 #ifdef COMPILER2
833 if (UseFPUForSpilling) {
834 if (UseSSE < 2) {
835 // Only supported with SSE2+
836 FLAG_SET_DEFAULT(UseFPUForSpilling, false);
837 }
838 }
839 #endif
840 #if defined(COMPILER2) || INCLUDE_JVMCI
841 if (MaxVectorSize > 0) {
842 if (!is_power_of_2(MaxVectorSize)) {
843 warning("MaxVectorSize must be a power of 2");
844 FLAG_SET_DEFAULT(MaxVectorSize, 64);
845 }
846 if (MaxVectorSize > 64) {
847 FLAG_SET_DEFAULT(MaxVectorSize, 64);
848 }
849 if (MaxVectorSize > 16 && (UseAVX == 0 || !os_supports_avx_vectors())) {
850 // 32 bytes vectors (in YMM) are only supported with AVX+
851 FLAG_SET_DEFAULT(MaxVectorSize, 16);
852 }
853 if (UseSSE < 2) {
854 // Vectors (in XMM) are only supported with SSE2+
855 FLAG_SET_DEFAULT(MaxVectorSize, 0);
856 }
857 #if defined(COMPILER2) && defined(ASSERT)
858 if (supports_avx() && PrintMiscellaneous && Verbose && TraceNewVectors) {
859 tty->print_cr("State of YMM registers after signal handle:");
860 int nreg = 2 LP64_ONLY(+2);
861 const char* ymm_name[4] = {"0", "7", "8", "15"};
862 for (int i = 0; i < nreg; i++) {
863 tty->print("YMM%s:", ymm_name[i]);
864 for (int j = 7; j >=0; j--) {
865 tty->print(" %x", _cpuid_info.ymm_save[i*8 + j]);
866 }
867 tty->cr();
868 }
869 }
870 #endif // COMPILER2 && ASSERT
871 }
872 #endif // COMPILER2 || INCLUDE_JVMCI
873
874 #ifdef COMPILER2
875 #ifdef _LP64
876 if (FLAG_IS_DEFAULT(UseMultiplyToLenIntrinsic)) {
877 UseMultiplyToLenIntrinsic = true;
878 }
879 if (FLAG_IS_DEFAULT(UseSquareToLenIntrinsic)) {
880 UseSquareToLenIntrinsic = true;
881 }
882 if (FLAG_IS_DEFAULT(UseMulAddIntrinsic)) {
883 UseMulAddIntrinsic = true;
884 }
885 if (FLAG_IS_DEFAULT(UseMontgomeryMultiplyIntrinsic)) {
886 UseMontgomeryMultiplyIntrinsic = true;
887 }
888 if (FLAG_IS_DEFAULT(UseMontgomerySquareIntrinsic)) {
889 UseMontgomerySquareIntrinsic = true;
890 }
891 #else
892 if (UseMultiplyToLenIntrinsic) {
893 if (!FLAG_IS_DEFAULT(UseMultiplyToLenIntrinsic)) {
894 warning("multiplyToLen intrinsic is not available in 32-bit VM");
895 }
896 FLAG_SET_DEFAULT(UseMultiplyToLenIntrinsic, false);
897 }
898 if (UseMontgomeryMultiplyIntrinsic) {
899 if (!FLAG_IS_DEFAULT(UseMontgomeryMultiplyIntrinsic)) {
900 warning("montgomeryMultiply intrinsic is not available in 32-bit VM");
901 }
902 FLAG_SET_DEFAULT(UseMontgomeryMultiplyIntrinsic, false);
903 }
904 if (UseMontgomerySquareIntrinsic) {
905 if (!FLAG_IS_DEFAULT(UseMontgomerySquareIntrinsic)) {
906 warning("montgomerySquare intrinsic is not available in 32-bit VM");
907 }
908 FLAG_SET_DEFAULT(UseMontgomerySquareIntrinsic, false);
909 }
910 if (UseSquareToLenIntrinsic) {
911 if (!FLAG_IS_DEFAULT(UseSquareToLenIntrinsic)) {
912 warning("squareToLen intrinsic is not available in 32-bit VM");
913 }
914 FLAG_SET_DEFAULT(UseSquareToLenIntrinsic, false);
915 }
916 if (UseMulAddIntrinsic) {
917 if (!FLAG_IS_DEFAULT(UseMulAddIntrinsic)) {
918 warning("mulAdd intrinsic is not available in 32-bit VM");
919 }
920 FLAG_SET_DEFAULT(UseMulAddIntrinsic, false);
921 }
922 #endif
923 #endif // COMPILER2
924
925 // On new cpus instructions which update whole XMM register should be used
926 // to prevent partial register stall due to dependencies on high half.
927 //
928 // UseXmmLoadAndClearUpper == true --> movsd(xmm, mem)
929 // UseXmmLoadAndClearUpper == false --> movlpd(xmm, mem)
930 // UseXmmRegToRegMoveAll == true --> movaps(xmm, xmm), movapd(xmm, xmm).
931 // UseXmmRegToRegMoveAll == false --> movss(xmm, xmm), movsd(xmm, xmm).
932
933 if( is_amd() ) { // AMD cpus specific settings
934 if( supports_sse2() && FLAG_IS_DEFAULT(UseAddressNop) ) {
935 // Use it on new AMD cpus starting from Opteron.
936 UseAddressNop = true;
937 }
938 if( supports_sse2() && FLAG_IS_DEFAULT(UseNewLongLShift) ) {
939 // Use it on new AMD cpus starting from Opteron.
940 UseNewLongLShift = true;
941 }
942 if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
943 if (supports_sse4a()) {
944 UseXmmLoadAndClearUpper = true; // use movsd only on '10h' Opteron
945 } else {
946 UseXmmLoadAndClearUpper = false;
947 }
948 }
949 if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
950 if( supports_sse4a() ) {
951 UseXmmRegToRegMoveAll = true; // use movaps, movapd only on '10h'
952 } else {
953 UseXmmRegToRegMoveAll = false;
954 }
955 }
956 if( FLAG_IS_DEFAULT(UseXmmI2F) ) {
957 if( supports_sse4a() ) {
958 UseXmmI2F = true;
959 } else {
960 UseXmmI2F = false;
961 }
962 }
963 if( FLAG_IS_DEFAULT(UseXmmI2D) ) {
964 if( supports_sse4a() ) {
965 UseXmmI2D = true;
966 } else {
967 UseXmmI2D = false;
968 }
969 }
970 if (supports_sse4_2() && UseSSE >= 4) {
971 if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
972 FLAG_SET_DEFAULT(UseSSE42Intrinsics, true);
973 }
974 } else {
975 if (UseSSE42Intrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
976 warning("SSE4.2 intrinsics require SSE4.2 instructions or higher. Intrinsics will be disabled.");
977 }
978 FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
979 }
980
981 // some defaults for AMD family 15h
982 if ( cpu_family() == 0x15 ) {
983 // On family 15h processors default is no sw prefetch
984 if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
985 AllocatePrefetchStyle = 0;
986 }
987 // Also, if some other prefetch style is specified, default instruction type is PREFETCHW
988 if (FLAG_IS_DEFAULT(AllocatePrefetchInstr)) {
989 AllocatePrefetchInstr = 3;
990 }
991 // On family 15h processors use XMM and UnalignedLoadStores for Array Copy
992 if (supports_sse2() && FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
993 UseXMMForArrayCopy = true;
994 }
995 if (supports_sse2() && FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
996 UseUnalignedLoadStores = true;
997 }
998 }
999
1000 #ifdef COMPILER2
1001 if (MaxVectorSize > 16) {
1002 // Limit vectors size to 16 bytes on current AMD cpus.
1003 FLAG_SET_DEFAULT(MaxVectorSize, 16);
1004 }
1005 #endif // COMPILER2
1006 }
1007
1008 if( is_intel() ) { // Intel cpus specific settings
1009 if( FLAG_IS_DEFAULT(UseStoreImmI16) ) {
1010 UseStoreImmI16 = false; // don't use it on Intel cpus
1011 }
1012 if( cpu_family() == 6 || cpu_family() == 15 ) {
1013 if( FLAG_IS_DEFAULT(UseAddressNop) ) {
1014 // Use it on all Intel cpus starting from PentiumPro
1015 UseAddressNop = true;
1016 }
1017 }
1018 if( FLAG_IS_DEFAULT(UseXmmLoadAndClearUpper) ) {
1019 UseXmmLoadAndClearUpper = true; // use movsd on all Intel cpus
1020 }
1021 if( FLAG_IS_DEFAULT(UseXmmRegToRegMoveAll) ) {
1022 if( supports_sse3() ) {
1023 UseXmmRegToRegMoveAll = true; // use movaps, movapd on new Intel cpus
1024 } else {
1025 UseXmmRegToRegMoveAll = false;
1026 }
1027 }
1028 if( cpu_family() == 6 && supports_sse3() ) { // New Intel cpus
1029 #ifdef COMPILER2
1030 if( FLAG_IS_DEFAULT(MaxLoopPad) ) {
1031 // For new Intel cpus do the next optimization:
1032 // don't align the beginning of a loop if there are enough instructions
1033 // left (NumberOfLoopInstrToAlign defined in c2_globals.hpp)
1034 // in current fetch line (OptoLoopAlignment) or the padding
1035 // is big (> MaxLoopPad).
1036 // Set MaxLoopPad to 11 for new Intel cpus to reduce number of
1037 // generated NOP instructions. 11 is the largest size of one
1038 // address NOP instruction '0F 1F' (see Assembler::nop(i)).
1039 MaxLoopPad = 11;
1040 }
1041 #endif // COMPILER2
1042 if (FLAG_IS_DEFAULT(UseXMMForArrayCopy)) {
1043 UseXMMForArrayCopy = true; // use SSE2 movq on new Intel cpus
1044 }
1045 if (supports_sse4_2() && supports_ht()) { // Newest Intel cpus
1046 if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1047 UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
1048 }
1049 }
1050 if (supports_sse4_2() && UseSSE >= 4) {
1051 if (FLAG_IS_DEFAULT(UseSSE42Intrinsics)) {
1052 FLAG_SET_DEFAULT(UseSSE42Intrinsics, true);
1053 }
1054 } else {
1055 if (UseSSE42Intrinsics && !FLAG_IS_DEFAULT(UseAESIntrinsics)) {
1056 warning("SSE4.2 intrinsics require SSE4.2 instructions or higher. Intrinsics will be disabled.");
1057 }
1058 FLAG_SET_DEFAULT(UseSSE42Intrinsics, false);
1059 }
1060 }
1061 if ((cpu_family() == 0x06) &&
1062 ((extended_cpu_model() == 0x36) || // Centerton
1063 (extended_cpu_model() == 0x37) || // Silvermont
1064 (extended_cpu_model() == 0x4D))) {
1065 #ifdef COMPILER2
1066 if (FLAG_IS_DEFAULT(OptoScheduling)) {
1067 OptoScheduling = true;
1068 }
1069 #endif
1070 if (supports_sse4_2()) { // Silvermont
1071 if (FLAG_IS_DEFAULT(UseUnalignedLoadStores)) {
1072 UseUnalignedLoadStores = true; // use movdqu on newest Intel cpus
1073 }
1074 }
1075 }
1076 if(FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
1077 AllocatePrefetchInstr = 3;
1078 }
1079 }
1080
1081 #ifdef _LP64
1082 if (UseSSE42Intrinsics) {
1083 if (FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic)) {
1084 UseVectorizedMismatchIntrinsic = true;
1085 }
1086 } else if (UseVectorizedMismatchIntrinsic) {
1087 if (!FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic))
1088 warning("vectorizedMismatch intrinsics are not available on this CPU");
1089 FLAG_SET_DEFAULT(UseVectorizedMismatchIntrinsic, false);
1090 }
1091 #else
1092 if (UseVectorizedMismatchIntrinsic) {
1093 if (!FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic)) {
1094 warning("vectorizedMismatch intrinsic is not available in 32-bit VM");
1095 }
1096 FLAG_SET_DEFAULT(UseVectorizedMismatchIntrinsic, false);
1097 }
1098 #endif // _LP64
1099
1100 // Use count leading zeros count instruction if available.
1101 if (supports_lzcnt()) {
1102 if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
1103 UseCountLeadingZerosInstruction = true;
1104 }
1105 } else if (UseCountLeadingZerosInstruction) {
1106 warning("lzcnt instruction is not available on this CPU");
1107 FLAG_SET_DEFAULT(UseCountLeadingZerosInstruction, false);
1108 }
1109
1110 // Use count trailing zeros instruction if available
1111 if (supports_bmi1()) {
1112 // tzcnt does not require VEX prefix
1113 if (FLAG_IS_DEFAULT(UseCountTrailingZerosInstruction)) {
1114 if (!UseBMI1Instructions && !FLAG_IS_DEFAULT(UseBMI1Instructions)) {
1115 // Don't use tzcnt if BMI1 is switched off on command line.
1116 UseCountTrailingZerosInstruction = false;
1117 } else {
1118 UseCountTrailingZerosInstruction = true;
1119 }
1120 }
1121 } else if (UseCountTrailingZerosInstruction) {
1122 warning("tzcnt instruction is not available on this CPU");
1123 FLAG_SET_DEFAULT(UseCountTrailingZerosInstruction, false);
1124 }
1125
1126 // BMI instructions (except tzcnt) use an encoding with VEX prefix.
1127 // VEX prefix is generated only when AVX > 0.
1128 if (supports_bmi1() && supports_avx()) {
1129 if (FLAG_IS_DEFAULT(UseBMI1Instructions)) {
1130 UseBMI1Instructions = true;
1131 }
1132 } else if (UseBMI1Instructions) {
1133 warning("BMI1 instructions are not available on this CPU (AVX is also required)");
1134 FLAG_SET_DEFAULT(UseBMI1Instructions, false);
1135 }
1136
1137 if (supports_bmi2() && supports_avx()) {
1138 if (FLAG_IS_DEFAULT(UseBMI2Instructions)) {
1139 UseBMI2Instructions = true;
1140 }
1141 } else if (UseBMI2Instructions) {
1142 warning("BMI2 instructions are not available on this CPU (AVX is also required)");
1143 FLAG_SET_DEFAULT(UseBMI2Instructions, false);
1144 }
1145
1146 // Use population count instruction if available.
1147 if (supports_popcnt()) {
1148 if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
1149 UsePopCountInstruction = true;
1150 }
1151 } else if (UsePopCountInstruction) {
1152 warning("POPCNT instruction is not available on this CPU");
1153 FLAG_SET_DEFAULT(UsePopCountInstruction, false);
1154 }
1155
1156 // Use fast-string operations if available.
1157 if (supports_erms()) {
1158 if (FLAG_IS_DEFAULT(UseFastStosb)) {
1159 UseFastStosb = true;
1160 }
1161 } else if (UseFastStosb) {
1162 warning("fast-string operations are not available on this CPU");
1163 FLAG_SET_DEFAULT(UseFastStosb, false);
1164 }
1165
1166 #ifdef COMPILER2
1167 if (FLAG_IS_DEFAULT(AlignVector)) {
1168 // Modern processors allow misaligned memory operations for vectors.
1169 AlignVector = !UseUnalignedLoadStores;
1170 }
1171 #endif // COMPILER2
1172
1173 if( AllocatePrefetchInstr == 3 && !supports_3dnow_prefetch() ) AllocatePrefetchInstr=0;
1174 if( !supports_sse() && supports_3dnow_prefetch() ) AllocatePrefetchInstr = 3;
1175
1176 // Allocation prefetch settings
1177 intx cache_line_size = prefetch_data_size();
1178 if( cache_line_size > AllocatePrefetchStepSize )
1179 AllocatePrefetchStepSize = cache_line_size;
1180
1181 AllocatePrefetchDistance = allocate_prefetch_distance();
1182 AllocatePrefetchStyle = allocate_prefetch_style();
1183
1184 if (is_intel() && cpu_family() == 6 && supports_sse3()) {
1185 if (AllocatePrefetchStyle == 2) { // watermark prefetching on Core
1186 #ifdef _LP64
1187 AllocatePrefetchDistance = 384;
1188 #else
1189 AllocatePrefetchDistance = 320;
1190 #endif
1191 }
1192 if (supports_sse4_2() && supports_ht()) { // Nehalem based cpus
1193 AllocatePrefetchDistance = 192;
1194 if (FLAG_IS_DEFAULT(AllocatePrefetchLines)) {
1195 FLAG_SET_DEFAULT(AllocatePrefetchLines, 4);
1196 }
1197 }
1198 #ifdef COMPILER2
1199 if (supports_sse4_2()) {
1200 if (FLAG_IS_DEFAULT(UseFPUForSpilling)) {
1201 FLAG_SET_DEFAULT(UseFPUForSpilling, true);
1202 }
1203 }
1204 #endif
1205 }
1206
1207 #ifdef _LP64
1208 // Prefetch settings
1209 PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
1210 PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
1211 PrefetchFieldsAhead = prefetch_fields_ahead();
1212 #endif
1213
1214 if (FLAG_IS_DEFAULT(ContendedPaddingWidth) &&
1215 (cache_line_size > ContendedPaddingWidth))
1216 ContendedPaddingWidth = cache_line_size;
1217
1218 // This machine allows unaligned memory accesses
1219 if (FLAG_IS_DEFAULT(UseUnalignedAccesses)) {
1220 FLAG_SET_DEFAULT(UseUnalignedAccesses, true);
1221 }
1222
1223 #ifndef PRODUCT
1224 if (PrintMiscellaneous && Verbose) {
1225 tty->print_cr("Logical CPUs per core: %u",
1226 logical_processors_per_package());
1227 tty->print_cr("L1 data cache line size: %u", L1_data_cache_line_size());
1228 tty->print("UseSSE=%d", (int) UseSSE);
1229 if (UseAVX > 0) {
1230 tty->print(" UseAVX=%d", (int) UseAVX);
1231 }
1232 if (UseAES) {
1233 tty->print(" UseAES=1");
1234 }
1235 #ifdef COMPILER2
1236 if (MaxVectorSize > 0) {
1237 tty->print(" MaxVectorSize=%d", (int) MaxVectorSize);
1238 }
1239 #endif
1240 tty->cr();
1241 tty->print("Allocation");
1242 if (AllocatePrefetchStyle <= 0 || UseSSE == 0 && !supports_3dnow_prefetch()) {
1243 tty->print_cr(": no prefetching");
1244 } else {
1245 tty->print(" prefetching: ");
1246 if (UseSSE == 0 && supports_3dnow_prefetch()) {
1247 tty->print("PREFETCHW");
1248 } else if (UseSSE >= 1) {
1249 if (AllocatePrefetchInstr == 0) {
1250 tty->print("PREFETCHNTA");
1251 } else if (AllocatePrefetchInstr == 1) {
1252 tty->print("PREFETCHT0");
1253 } else if (AllocatePrefetchInstr == 2) {
1254 tty->print("PREFETCHT2");
1255 } else if (AllocatePrefetchInstr == 3) {
1256 tty->print("PREFETCHW");
1257 }
1258 }
1259 if (AllocatePrefetchLines > 1) {
1260 tty->print_cr(" at distance %d, %d lines of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchLines, (int) AllocatePrefetchStepSize);
1261 } else {
1262 tty->print_cr(" at distance %d, one line of %d bytes", (int) AllocatePrefetchDistance, (int) AllocatePrefetchStepSize);
1263 }
1264 }
1265
1266 if (PrefetchCopyIntervalInBytes > 0) {
1267 tty->print_cr("PrefetchCopyIntervalInBytes %d", (int) PrefetchCopyIntervalInBytes);
1268 }
1269 if (PrefetchScanIntervalInBytes > 0) {
1270 tty->print_cr("PrefetchScanIntervalInBytes %d", (int) PrefetchScanIntervalInBytes);
1271 }
1272 if (PrefetchFieldsAhead > 0) {
1273 tty->print_cr("PrefetchFieldsAhead %d", (int) PrefetchFieldsAhead);
1274 }
1275 if (ContendedPaddingWidth > 0) {
1276 tty->print_cr("ContendedPaddingWidth %d", (int) ContendedPaddingWidth);
1277 }
1278 }
1279 #endif // !PRODUCT
1280 }
1281
1282 bool VM_Version::use_biased_locking() {
1283 #if INCLUDE_RTM_OPT
1284 // RTM locking is most useful when there is high lock contention and
1285 // low data contention. With high lock contention the lock is usually
1286 // inflated and biased locking is not suitable for that case.
1287 // RTM locking code requires that biased locking is off.
1288 // Note: we can't switch off UseBiasedLocking in get_processor_features()
1289 // because it is used by Thread::allocate() which is called before
1290 // VM_Version::initialize().
1291 if (UseRTMLocking && UseBiasedLocking) {
1292 if (FLAG_IS_DEFAULT(UseBiasedLocking)) {
1293 FLAG_SET_DEFAULT(UseBiasedLocking, false);
1294 } else {
1295 warning("Biased locking is not supported with RTM locking; ignoring UseBiasedLocking flag." );
1296 UseBiasedLocking = false;
1297 }
1298 }
1299 #endif
1300 return UseBiasedLocking;
1301 }
1302
1303 void VM_Version::initialize() {
1304 ResourceMark rm;
1305 // Making this stub must be FIRST use of assembler
1306
1307 stub_blob = BufferBlob::create("get_cpu_info_stub", stub_size);
1308 if (stub_blob == NULL) {
1309 vm_exit_during_initialization("Unable to allocate get_cpu_info_stub");
1310 }
1311 CodeBuffer c(stub_blob);
1312 VM_Version_StubGenerator g(&c);
1313 get_cpu_info_stub = CAST_TO_FN_PTR(get_cpu_info_stub_t,
1314 g.generate_get_cpu_info());
1315
1316 get_processor_features();
1317 }