1 /*
2 * Copyright (c) 1997, 2017, 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 "code/debugInfo.hpp"
27 #include "oops/compressedOops.inline.hpp"
28 #include "oops/oop.hpp"
29 #include "runtime/frame.inline.hpp"
30 #include "runtime/handles.inline.hpp"
31 #include "runtime/stackValue.hpp"
32
33 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv) {
34 if (sv->is_location()) {
35 // Stack or register value
36 Location loc = ((LocationValue *)sv)->location();
37
38 #ifdef SPARC
39 // %%%%% Callee-save floats will NOT be working on a Sparc until we
40 // handle the case of a 2 floats in a single double register.
41 assert( !(loc.is_register() && loc.type() == Location::float_in_dbl), "Sparc does not handle callee-save floats yet" );
42 #endif // SPARC
43
44 // First find address of value
45
46 address value_addr = loc.is_register()
47 // Value was in a callee-save register
48 ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()))
49 // Else value was directly saved on the stack. The frame's original stack pointer,
50 // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
51 : ((address)fr->unextended_sp()) + loc.stack_offset();
52
53 // Then package it right depending on type
54 // Note: the transfer of the data is thru a union that contains
55 // an intptr_t. This is because an interpreter stack slot is
56 // really an intptr_t. The use of a union containing an intptr_t
57 // ensures that on a 64 bit platform we have proper alignment
58 // and that we store the value where the interpreter will expect
59 // to find it (i.e. proper endian). Similarly on a 32bit platform
60 // using the intptr_t ensures that when a value is larger than
61 // a stack slot (jlong/jdouble) that we capture the proper part
62 // of the value for the stack slot in question.
63 //
64 switch( loc.type() ) {
65 case Location::float_in_dbl: { // Holds a float in a double register?
66 // The callee has no clue whether the register holds a float,
67 // double or is unused. He always saves a double. Here we know
68 // a double was saved, but we only want a float back. Narrow the
69 // saved double to the float that the JVM wants.
70 assert( loc.is_register(), "floats always saved to stack in 1 word" );
71 union { intptr_t p; jfloat jf; } value;
72 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
73 value.jf = (jfloat) *(jdouble*) value_addr;
74 return new StackValue(value.p); // 64-bit high half is stack junk
75 }
76 case Location::int_in_long: { // Holds an int in a long register?
77 // The callee has no clue whether the register holds an int,
78 // long or is unused. He always saves a long. Here we know
79 // a long was saved, but we only want an int back. Narrow the
80 // saved long to the int that the JVM wants.
81 assert( loc.is_register(), "ints always saved to stack in 1 word" );
82 union { intptr_t p; jint ji;} value;
83 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
84 value.ji = (jint) *(jlong*) value_addr;
85 return new StackValue(value.p); // 64-bit high half is stack junk
86 }
87 #ifdef _LP64
88 case Location::dbl:
89 // Double value in an aligned adjacent pair
90 return new StackValue(*(intptr_t*)value_addr);
91 case Location::lng:
92 // Long value in an aligned adjacent pair
93 return new StackValue(*(intptr_t*)value_addr);
94 case Location::narrowoop: {
95 union { intptr_t p; narrowOop noop;} value;
96 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
97 if (loc.is_register()) {
98 // The callee has no clue whether the register holds an int,
99 // long or is unused. He always saves a long. Here we know
100 // a long was saved, but we only want an int back. Narrow the
101 // saved long to the int that the JVM wants.
102 value.noop = (narrowOop) *(julong*) value_addr;
103 } else {
104 value.noop = *(narrowOop*) value_addr;
105 }
106 // Decode narrowoop and wrap a handle around the oop
107 Handle h(Thread::current(), CompressedOops::decode(value.noop));
108 return new StackValue(h);
109 }
110 #endif
111 case Location::oop: {
112 oop val = *(oop *)value_addr;
113 #ifdef _LP64
114 if (Universe::is_narrow_oop_base(val)) {
115 // Compiled code may produce decoded oop = narrow_oop_base
116 // when a narrow oop implicit null check is used.
117 // The narrow_oop_base could be NULL or be the address
118 // of the page below heap. Use NULL value for both cases.
119 val = (oop)NULL;
120 }
121 #endif
122 Handle h(Thread::current(), val); // Wrap a handle around the oop
123 return new StackValue(h);
124 }
125 case Location::addr: {
126 ShouldNotReachHere(); // both C1 and C2 now inline jsrs
127 }
128 case Location::normal: {
129 // Just copy all other bits straight through
130 union { intptr_t p; jint ji;} value;
131 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
132 value.ji = *(jint*)value_addr;
133 return new StackValue(value.p);
134 }
135 case Location::invalid:
136 return new StackValue();
137 default:
138 ShouldNotReachHere();
139 }
140
141 } else if (sv->is_constant_int()) {
142 // Constant int: treat same as register int.
143 union { intptr_t p; jint ji;} value;
144 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
145 value.ji = (jint)((ConstantIntValue*)sv)->value();
146 return new StackValue(value.p);
147 } else if (sv->is_constant_oop()) {
148 // constant oop
149 return new StackValue(sv->as_ConstantOopReadValue()->value());
150 #ifdef _LP64
151 } else if (sv->is_constant_double()) {
152 // Constant double in a single stack slot
153 union { intptr_t p; double d; } value;
154 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
155 value.d = ((ConstantDoubleValue *)sv)->value();
156 return new StackValue(value.p);
157 } else if (sv->is_constant_long()) {
158 // Constant long in a single stack slot
159 union { intptr_t p; jlong jl; } value;
160 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
161 value.jl = ((ConstantLongValue *)sv)->value();
162 return new StackValue(value.p);
163 #endif
164 } else if (sv->is_object()) { // Scalar replaced object in compiled frame
165 Handle ov = ((ObjectValue *)sv)->value();
166 return new StackValue(ov, (ov.is_null()) ? 1 : 0);
167 }
168
169 // Unknown ScopeValue type
170 ShouldNotReachHere();
171 return new StackValue((intptr_t) 0); // dummy
172 }
173
174
175 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
176 assert(location.is_stack(), "for now we only look at the stack");
177 int word_offset = location.stack_offset() / wordSize;
178 // (stack picture)
179 // high: [ ] word_offset + 1
180 // low [ ] word_offset
181 //
182 // sp-> [ ] 0
183 // the word_offset is the distance from the stack pointer to the lowest address
184 // The frame's original stack pointer, before any extension by its callee
185 // (due to Compiler1 linkage on SPARC), must be used.
186 return (BasicLock*) (fr->unextended_sp() + word_offset);
187 }
188
189
190 #ifndef PRODUCT
191
192 void StackValue::print_on(outputStream* st) const {
193 switch(_type) {
194 case T_INT:
195 st->print("%d (int) %f (float) %x (hex)", *(int *)&_integer_value, *(float *)&_integer_value, *(int *)&_integer_value);
196 break;
197
198 case T_OBJECT:
199 _handle_value()->print_value_on(st);
200 st->print(" <" INTPTR_FORMAT ">", p2i((address)_handle_value()));
201 break;
202
203 case T_CONFLICT:
204 st->print("conflict");
205 break;
206
207 default:
208 ShouldNotReachHere();
209 }
210 }
211
212 #endif