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