1 /*
2 * Copyright (c) 2013, Red Hat Inc.
3 * Copyright (c) 2005, 2010, Oracle and/or its affiliates.
4 * All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "precompiled.hpp"
28 #include "c1/c1_FpuStackSim.hpp"
29 #include "c1/c1_FrameMap.hpp"
30 #include "utilities/array.hpp"
31 #include "utilities/ostream.hpp"
32
33 //--------------------------------------------------------
34 // FpuStackSim
35 //--------------------------------------------------------
36
37 // This class maps the FPU registers to their stack locations; it computes
38 // the offsets between individual registers and simulates the FPU stack.
39
40 const int EMPTY = -1;
41
42 int FpuStackSim::regs_at(int i) const {
43 assert(i >= 0 && i < FrameMap::nof_fpu_regs, "out of bounds");
44 return _regs[i];
45 }
46
47 void FpuStackSim::set_regs_at(int i, int val) {
48 assert(i >= 0 && i < FrameMap::nof_fpu_regs, "out of bounds");
49 _regs[i] = val;
50 }
51
52 void FpuStackSim::dec_stack_size() {
53 _stack_size--;
54 assert(_stack_size >= 0, "FPU stack underflow");
55 }
56
57 void FpuStackSim::inc_stack_size() {
58 _stack_size++;
59 assert(_stack_size <= FrameMap::nof_fpu_regs, "FPU stack overflow");
60 }
61
62 FpuStackSim::FpuStackSim(Compilation* compilation)
63 : _compilation(compilation)
64 {
65 _stack_size = 0;
66 for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
67 set_regs_at(i, EMPTY);
68 }
69 }
70
71
72 void FpuStackSim::pop() {
73 if (TraceFPUStack) { tty->print("FPU-pop "); print(); tty->cr(); }
74 set_regs_at(tos_index(), EMPTY);
75 dec_stack_size();
76 }
77
78 void FpuStackSim::pop(int rnr) {
79 if (TraceFPUStack) { tty->print("FPU-pop %d", rnr); print(); tty->cr(); }
80 assert(regs_at(tos_index()) == rnr, "rnr is not on TOS");
81 set_regs_at(tos_index(), EMPTY);
82 dec_stack_size();
83 }
84
85
86 void FpuStackSim::push(int rnr) {
87 if (TraceFPUStack) { tty->print("FPU-push %d", rnr); print(); tty->cr(); }
88 assert(regs_at(stack_size()) == EMPTY, "should be empty");
89 set_regs_at(stack_size(), rnr);
90 inc_stack_size();
91 }
92
93
94 void FpuStackSim::swap(int offset) {
95 if (TraceFPUStack) { tty->print("FPU-swap %d", offset); print(); tty->cr(); }
96 int t = regs_at(tos_index() - offset);
97 set_regs_at(tos_index() - offset, regs_at(tos_index()));
98 set_regs_at(tos_index(), t);
99 }
100
101
102 int FpuStackSim::offset_from_tos(int rnr) const {
103 for (int i = tos_index(); i >= 0; i--) {
104 if (regs_at(i) == rnr) {
105 return tos_index() - i;
106 }
107 }
108 assert(false, "FpuStackSim: register not found");
109 BAILOUT_("FpuStackSim: register not found", 0);
110 }
111
112
113 int FpuStackSim::get_slot(int tos_offset) const {
114 return regs_at(tos_index() - tos_offset);
115 }
116
117 void FpuStackSim::set_slot(int tos_offset, int rnr) {
118 set_regs_at(tos_index() - tos_offset, rnr);
119 }
120
121 void FpuStackSim::rename(int old_rnr, int new_rnr) {
122 if (TraceFPUStack) { tty->print("FPU-rename %d %d", old_rnr, new_rnr); print(); tty->cr(); }
123 if (old_rnr == new_rnr)
124 return;
125 bool found = false;
126 for (int i = 0; i < stack_size(); i++) {
127 assert(regs_at(i) != new_rnr, "should not see old occurrences of new_rnr on the stack");
128 if (regs_at(i) == old_rnr) {
129 set_regs_at(i, new_rnr);
130 found = true;
131 }
132 }
133 assert(found, "should have found at least one instance of old_rnr");
134 }
135
136
137 bool FpuStackSim::contains(int rnr) {
138 for (int i = 0; i < stack_size(); i++) {
139 if (regs_at(i) == rnr) {
140 return true;
141 }
142 }
143 return false;
144 }
145
146 bool FpuStackSim::is_empty() {
147 #ifdef ASSERT
148 if (stack_size() == 0) {
149 for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
150 assert(regs_at(i) == EMPTY, "must be empty");
151 }
152 }
153 #endif
154 return stack_size() == 0;
155 }
156
157
158 bool FpuStackSim::slot_is_empty(int tos_offset) {
159 return (regs_at(tos_index() - tos_offset) == EMPTY);
160 }
161
162
163 void FpuStackSim::clear() {
164 if (TraceFPUStack) { tty->print("FPU-clear"); print(); tty->cr(); }
165 for (int i = tos_index(); i >= 0; i--) {
166 set_regs_at(i, EMPTY);
167 }
168 _stack_size = 0;
169 }
170
171
172 intArray* FpuStackSim::write_state() {
173 intArray* res = new intArray(1 + FrameMap::nof_fpu_regs);
174 (*res)[0] = stack_size();
175 for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
176 (*res)[1 + i] = regs_at(i);
177 }
178 return res;
179 }
180
181
182 void FpuStackSim::read_state(intArray* fpu_stack_state) {
183 _stack_size = (*fpu_stack_state)[0];
184 for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
185 set_regs_at(i, (*fpu_stack_state)[1 + i]);
186 }
187 }
188
189
190 #ifndef PRODUCT
191 void FpuStackSim::print() {
192 tty->print(" N=%d[", stack_size());\
193 for (int i = 0; i < stack_size(); i++) {
194 int reg = regs_at(i);
195 if (reg != EMPTY) {
196 tty->print("%d", reg);
197 } else {
198 tty->print("_");
199 }
200 };
201 tty->print(" ]");
202 }
203 #endif