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 class VM_Version : public Abstract_VM_Version {
26 public:
27 // cpuid result register layouts. These are all unions of a uint32_t
28 // (in case anyone wants access to the register as a whole) and a bitfield.
29
30 union StdCpuid1Eax {
31 uint32_t value;
32 struct {
33 uint32_t stepping : 4,
34 model : 4,
35 family : 4,
36 proc_type : 2,
37 : 2,
38 ext_model : 4,
39 ext_family : 8,
40 : 4;
41 } bits;
42 };
43
44 union StdCpuid1Ebx { // example, unused
499 // Tested intervals from 128 to 2048 in increments of 64 == one cache line.
500 // 256 bytes (4 dcache lines) was the nearest runner-up to 576.
501
502 // gc copy/scan is disabled if prefetchw isn't supported, because
503 // Prefetch::write emits an inlined prefetchw on Linux.
504 // Do not use the 3dnow prefetchw instruction. It isn't supported on em64t.
505 // The used prefetcht0 instruction works for both amd64 and em64t.
506 static intx prefetch_copy_interval_in_bytes() {
507 intx interval = PrefetchCopyIntervalInBytes;
508 return interval >= 0 ? interval : 576;
509 }
510 static intx prefetch_scan_interval_in_bytes() {
511 intx interval = PrefetchScanIntervalInBytes;
512 return interval >= 0 ? interval : 576;
513 }
514 static intx prefetch_fields_ahead() {
515 intx count = PrefetchFieldsAhead;
516 return count >= 0 ? count : 1;
517 }
518 };
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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 #ifndef CPU_X86_VM_VM_VERSION_X86_HPP
26 #define CPU_X86_VM_VM_VERSION_X86_HPP
27
28 #include "runtime/globals_extension.hpp"
29 #include "runtime/vm_version.hpp"
30
31 class VM_Version : public Abstract_VM_Version {
32 public:
33 // cpuid result register layouts. These are all unions of a uint32_t
34 // (in case anyone wants access to the register as a whole) and a bitfield.
35
36 union StdCpuid1Eax {
37 uint32_t value;
38 struct {
39 uint32_t stepping : 4,
40 model : 4,
41 family : 4,
42 proc_type : 2,
43 : 2,
44 ext_model : 4,
45 ext_family : 8,
46 : 4;
47 } bits;
48 };
49
50 union StdCpuid1Ebx { // example, unused
505 // Tested intervals from 128 to 2048 in increments of 64 == one cache line.
506 // 256 bytes (4 dcache lines) was the nearest runner-up to 576.
507
508 // gc copy/scan is disabled if prefetchw isn't supported, because
509 // Prefetch::write emits an inlined prefetchw on Linux.
510 // Do not use the 3dnow prefetchw instruction. It isn't supported on em64t.
511 // The used prefetcht0 instruction works for both amd64 and em64t.
512 static intx prefetch_copy_interval_in_bytes() {
513 intx interval = PrefetchCopyIntervalInBytes;
514 return interval >= 0 ? interval : 576;
515 }
516 static intx prefetch_scan_interval_in_bytes() {
517 intx interval = PrefetchScanIntervalInBytes;
518 return interval >= 0 ? interval : 576;
519 }
520 static intx prefetch_fields_ahead() {
521 intx count = PrefetchFieldsAhead;
522 return count >= 0 ? count : 1;
523 }
524 };
525
526 #endif // CPU_X86_VM_VM_VERSION_X86_HPP
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