1 /*
2 * Copyright (c) 1997, 2014, 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
106 oop val = oopDesc::decode_heap_oop(value.noop);
107 // Deoptimization must make sure all oops have passed load barriers
108 #if INCLUDE_ALL_GCS
109 if (UseShenandoahGC) {
110 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
111 }
112 #endif
113 Handle h(val); // Wrap a handle around the oop
114 return new StackValue(h);
115 }
116 #endif
117 case Location::oop: {
118 oop val = *(oop *)value_addr;
119 #ifdef _LP64
120 if (Universe::is_narrow_oop_base(val)) {
121 // Compiled code may produce decoded oop = narrow_oop_base
122 // when a narrow oop implicit null check is used.
123 // The narrow_oop_base could be NULL or be the address
124 // of the page below heap. Use NULL value for both cases.
125 val = (oop)NULL;
126 }
127 #endif
128 // Deoptimization must make sure all oops have passed load barriers
129 #if INCLUDE_ALL_GCS
130 if (UseShenandoahGC) {
131 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
132 }
133 #endif
134 Handle h(val); // Wrap a handle around the oop
135 return new StackValue(h);
136 }
137 case Location::addr: {
138 ShouldNotReachHere(); // both C1 and C2 now inline jsrs
139 }
140 case Location::normal: {
141 // Just copy all other bits straight through
142 union { intptr_t p; jint ji;} value;
143 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
144 value.ji = *(jint*)value_addr;
145 return new StackValue(value.p);
146 }
147 case Location::invalid:
148 return new StackValue();
149 default:
150 ShouldNotReachHere();
151 }
152
153 } else if (sv->is_constant_int()) {
154 // Constant int: treat same as register int.
155 union { intptr_t p; jint ji;} value;
156 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
157 value.ji = (jint)((ConstantIntValue*)sv)->value();
158 return new StackValue(value.p);
159 } else if (sv->is_constant_oop()) {
160 // constant oop
161 return new StackValue(sv->as_ConstantOopReadValue()->value());
162 #ifdef _LP64
163 } else if (sv->is_constant_double()) {
164 // Constant double in a single stack slot
165 union { intptr_t p; double d; } value;
166 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
167 value.d = ((ConstantDoubleValue *)sv)->value();
168 return new StackValue(value.p);
169 } else if (sv->is_constant_long()) {
170 // Constant long in a single stack slot
171 union { intptr_t p; jlong jl; } value;
172 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
173 value.jl = ((ConstantLongValue *)sv)->value();
174 return new StackValue(value.p);
175 #endif
176 } else if (sv->is_object()) { // Scalar replaced object in compiled frame
177 Handle ov = ((ObjectValue *)sv)->value();
178 return new StackValue(ov, (ov.is_null()) ? 1 : 0);
179 }
180
181 // Unknown ScopeValue type
182 ShouldNotReachHere();
183 return new StackValue((intptr_t) 0); // dummy
184 }
185
186
187 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
188 assert(location.is_stack(), "for now we only look at the stack");
189 int word_offset = location.stack_offset() / wordSize;
190 // (stack picture)
191 // high: [ ] word_offset + 1
192 // low [ ] word_offset
193 //
194 // sp-> [ ] 0
195 // the word_offset is the distance from the stack pointer to the lowest address
196 // The frame's original stack pointer, before any extension by its callee
197 // (due to Compiler1 linkage on SPARC), must be used.
198 return (BasicLock*) (fr->unextended_sp() + word_offset);
199 }
200
201
202 #ifndef PRODUCT
203
204 void StackValue::print_on(outputStream* st) const {
205 switch(_type) {
206 case T_INT:
207 st->print("%d (int) %f (float) %x (hex)", *(int *)&_i, *(float *)&_i, *(int *)&_i);
208 break;
209
210 case T_OBJECT:
211 _o()->print_value_on(st);
212 st->print(" <" INTPTR_FORMAT ">", p2i((address)_o()));
213 break;
214
215 case T_CONFLICT:
216 st->print("conflict");
217 break;
218
219 default:
220 ShouldNotReachHere();
221 }
222 }
223
224 #endif