Wed, 02 Jun 2010 09:49:32 -0700
6954029: Improve implicit null check generation with compressed oops
Summary: Hoist DecodeN instruction above null check
Reviewed-by: never, twisti
1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_vm_version_sparc.cpp.incl"
28 int VM_Version::_features = VM_Version::unknown_m;
29 const char* VM_Version::_features_str = "";
31 bool VM_Version::is_niagara1_plus() {
32 // This is a placeholder until the real test is determined.
33 return is_niagara1() &&
34 (os::processor_count() > maximum_niagara1_processor_count());
35 }
37 void VM_Version::initialize() {
38 _features = determine_features();
39 PrefetchCopyIntervalInBytes = prefetch_copy_interval_in_bytes();
40 PrefetchScanIntervalInBytes = prefetch_scan_interval_in_bytes();
41 PrefetchFieldsAhead = prefetch_fields_ahead();
43 // Allocation prefetch settings
44 intx cache_line_size = L1_data_cache_line_size();
45 if( cache_line_size > AllocatePrefetchStepSize )
46 AllocatePrefetchStepSize = cache_line_size;
47 if( FLAG_IS_DEFAULT(AllocatePrefetchLines) )
48 AllocatePrefetchLines = 3; // Optimistic value
49 assert( AllocatePrefetchLines > 0, "invalid value");
50 if( AllocatePrefetchLines < 1 ) // set valid value in product VM
51 AllocatePrefetchLines = 1; // Conservative value
53 AllocatePrefetchDistance = allocate_prefetch_distance();
54 AllocatePrefetchStyle = allocate_prefetch_style();
56 assert(AllocatePrefetchDistance % AllocatePrefetchStepSize == 0, "invalid value");
58 UseSSE = 0; // Only on x86 and x64
60 _supports_cx8 = has_v9();
62 if (is_niagara1()) {
63 // Indirect branch is the same cost as direct
64 if (FLAG_IS_DEFAULT(UseInlineCaches)) {
65 FLAG_SET_DEFAULT(UseInlineCaches, false);
66 }
67 #ifdef _LP64
68 // 32-bit oops don't make sense for the 64-bit VM on sparc
69 // since the 32-bit VM has the same registers and smaller objects.
70 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
71 #endif // _LP64
72 #ifdef COMPILER2
73 // Indirect branch is the same cost as direct
74 if (FLAG_IS_DEFAULT(UseJumpTables)) {
75 FLAG_SET_DEFAULT(UseJumpTables, true);
76 }
77 // Single-issue, so entry and loop tops are
78 // aligned on a single instruction boundary
79 if (FLAG_IS_DEFAULT(InteriorEntryAlignment)) {
80 FLAG_SET_DEFAULT(InteriorEntryAlignment, 4);
81 }
82 if (is_niagara1_plus()) {
83 if (AllocatePrefetchStyle > 0 && FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
84 // Use BIS instruction for allocation prefetch.
85 FLAG_SET_DEFAULT(AllocatePrefetchStyle, 3);
86 if (FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
87 // Use smaller prefetch distance on N2 with BIS
88 FLAG_SET_DEFAULT(AllocatePrefetchDistance, 64);
89 }
90 }
91 if (AllocatePrefetchStyle != 3 && FLAG_IS_DEFAULT(AllocatePrefetchDistance)) {
92 // Use different prefetch distance without BIS
93 FLAG_SET_DEFAULT(AllocatePrefetchDistance, 256);
94 }
95 }
96 #endif
97 if (FLAG_IS_DEFAULT(OptoLoopAlignment)) {
98 FLAG_SET_DEFAULT(OptoLoopAlignment, 4);
99 }
100 // When using CMS, we cannot use memset() in BOT updates because
101 // the sun4v/CMT version in libc_psr uses BIS which exposes
102 // "phantom zeros" to concurrent readers. See 6948537.
103 if (FLAG_IS_DEFAULT(UseMemSetInBOT) && UseConcMarkSweepGC) {
104 FLAG_SET_DEFAULT(UseMemSetInBOT, false);
105 }
106 }
108 // Use hardware population count instruction if available.
109 if (has_hardware_popc()) {
110 if (FLAG_IS_DEFAULT(UsePopCountInstruction)) {
111 FLAG_SET_DEFAULT(UsePopCountInstruction, true);
112 }
113 }
115 char buf[512];
116 jio_snprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s%s%s%s%s%s",
117 (has_v8() ? ", has_v8" : ""),
118 (has_v9() ? ", has_v9" : ""),
119 (has_hardware_popc() ? ", popc" : ""),
120 (has_vis1() ? ", has_vis1" : ""),
121 (has_vis2() ? ", has_vis2" : ""),
122 (is_ultra3() ? ", is_ultra3" : ""),
123 (is_sun4v() ? ", is_sun4v" : ""),
124 (is_niagara1() ? ", is_niagara1" : ""),
125 (is_niagara1_plus() ? ", is_niagara1_plus" : ""),
126 (!has_hardware_mul32() ? ", no-mul32" : ""),
127 (!has_hardware_div32() ? ", no-div32" : ""),
128 (!has_hardware_fsmuld() ? ", no-fsmuld" : ""));
130 // buf is started with ", " or is empty
131 _features_str = strdup(strlen(buf) > 2 ? buf + 2 : buf);
133 #ifndef PRODUCT
134 if (PrintMiscellaneous && Verbose) {
135 tty->print("Allocation: ");
136 if (AllocatePrefetchStyle <= 0) {
137 tty->print_cr("no prefetching");
138 } else {
139 if (AllocatePrefetchLines > 1) {
140 tty->print_cr("PREFETCH %d, %d lines of size %d bytes", AllocatePrefetchDistance, AllocatePrefetchLines, AllocatePrefetchStepSize);
141 } else {
142 tty->print_cr("PREFETCH %d, one line", AllocatePrefetchDistance);
143 }
144 }
145 if (PrefetchCopyIntervalInBytes > 0) {
146 tty->print_cr("PrefetchCopyIntervalInBytes %d", PrefetchCopyIntervalInBytes);
147 }
148 if (PrefetchScanIntervalInBytes > 0) {
149 tty->print_cr("PrefetchScanIntervalInBytes %d", PrefetchScanIntervalInBytes);
150 }
151 if (PrefetchFieldsAhead > 0) {
152 tty->print_cr("PrefetchFieldsAhead %d", PrefetchFieldsAhead);
153 }
154 }
155 #endif // PRODUCT
156 }
158 void VM_Version::print_features() {
159 tty->print_cr("Version:%s", cpu_features());
160 }
162 int VM_Version::determine_features() {
163 if (UseV8InstrsOnly) {
164 NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-V8");)
165 return generic_v8_m;
166 }
168 int features = platform_features(unknown_m); // platform_features() is os_arch specific
170 if (features == unknown_m) {
171 features = generic_v9_m;
172 warning("Cannot recognize SPARC version. Default to V9");
173 }
175 if (UseNiagaraInstrs) {
176 if (is_niagara1(features)) {
177 // Happy to accomodate...
178 } else {
179 NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Niagara");)
180 features = niagara1_m;
181 }
182 } else {
183 if (is_niagara1(features) && !FLAG_IS_DEFAULT(UseNiagaraInstrs)) {
184 NOT_PRODUCT(if (PrintMiscellaneous && Verbose) tty->print_cr("Version is Forced-Not-Niagara");)
185 features &= ~niagara1_unique_m;
186 } else {
187 // Happy to accomodate...
188 }
189 }
191 return features;
192 }
194 static int saved_features = 0;
196 void VM_Version::allow_all() {
197 saved_features = _features;
198 _features = all_features_m;
199 }
201 void VM_Version::revert() {
202 _features = saved_features;
203 }
205 unsigned int VM_Version::calc_parallel_worker_threads() {
206 unsigned int result;
207 if (is_niagara1_plus()) {
208 result = nof_parallel_worker_threads(5, 16, 8);
209 } else {
210 result = nof_parallel_worker_threads(5, 8, 8);
211 }
212 return result;
213 }