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 */
24
25 # include "incls/_precompiled.incl"
26 # include "incls/_stackValue.cpp.incl"
27
28 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv) {
29 if (sv->is_location()) {
30 // Stack or register value
31 Location loc = ((LocationValue *)sv)->location();
32
33 #ifdef SPARC
34 // %%%%% Callee-save floats will NOT be working on a Sparc until we
35 // handle the case of a 2 floats in a single double register.
36 assert( !(loc.is_register() && loc.type() == Location::float_in_dbl), "Sparc does not handle callee-save floats yet" );
37 #endif // SPARC
38
39 // First find address of value
40
41 address value_addr = loc.is_register()
42 // Value was in a callee-save register
43 ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()))
44 // Else value was directly saved on the stack. The frame's original stack pointer,
45 // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
46 : ((address)fr->unextended_sp()) + loc.stack_offset();
47
48 // Then package it right depending on type
49 // Note: the transfer of the data is thru a union that contains
50 // an intptr_t. This is because an interpreter stack slot is
51 // really an intptr_t. The use of a union containing an intptr_t
52 // ensures that on a 64 bit platform we have proper alignment
53 // and that we store the value where the interpreter will expect
54 // to find it (i.e. proper endian). Similarly on a 32bit platform
55 // using the intptr_t ensures that when a value is larger than
56 // a stack slot (jlong/jdouble) that we capture the proper part
57 // of the value for the stack slot in question.
58 //
59 switch( loc.type() ) {
60 case Location::float_in_dbl: { // Holds a float in a double register?
61 assert( loc.is_register(), "floats always saved to stack in 1 word" );
62 // Call platform specific function defined in sharedRuntime_<arch>.cpp.
63 return create_float_stack_value(value_addr);
64 }
65 case Location::int_in_long: { // Holds an int in a long register?
66 // The callee has no clue whether the register holds an int,
67 // long or is unused. He always saves a long. Here we know
68 // a long was saved, but we only want an int back. Narrow the
69 // saved long to the int that the JVM wants.
70 assert( loc.is_register(), "ints always saved to stack in 1 word" );
71 union { intptr_t p; jint ji;} value;
72 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
73 value.ji = (jint) *(jlong*) value_addr;
74 return new StackValue(value.p); // 64-bit high half is stack junk
75 }
76 #ifdef _LP64
77 case Location::dbl:
78 // Double value in an aligned adjacent pair
79 return new StackValue(*(intptr_t*)value_addr);
80 case Location::lng:
81 // Long value in an aligned adjacent pair
82 return new StackValue(*(intptr_t*)value_addr);
83 case Location::narrowoop: {
84 union { intptr_t p; narrowOop noop;} value;
85 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
86 if (loc.is_register()) {
87 // The callee has no clue whether the register holds an int,
88 // long or is unused. He always saves a long. Here we know
89 // a long was saved, but we only want an int back. Narrow the
90 // saved long to the int that the JVM wants.
91 value.noop = (narrowOop) *(julong*) value_addr;
92 } else {
93 value.noop = *(narrowOop*) value_addr;
94 }
95 // Decode narrowoop and wrap a handle around the oop
96 Handle h(oopDesc::decode_heap_oop(value.noop));
97 return new StackValue(h);
98 }
99 #endif
100 case Location::oop: {
101 oop val = *(oop *)value_addr;
102 #ifdef _LP64
103 if (Universe::is_narrow_oop_base(val)) {
104 // Compiled code may produce decoded oop = narrow_oop_base
105 // when a narrow oop implicit null check is used.
106 // The narrow_oop_base could be NULL or be the address
107 // of the page below heap. Use NULL value for both cases.
108 val = (oop)NULL;
109 }
110 #endif
111 Handle h(val); // Wrap a handle around the oop
112 return new StackValue(h);
113 }
114 case Location::addr: {
115 ShouldNotReachHere(); // both C1 and C2 now inline jsrs
116 }
117 case Location::normal: {
118 // Just copy all other bits straight through
119 union { intptr_t p; jint ji;} value;
120 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
121 value.ji = *(jint*)value_addr;
122 return new StackValue(value.p);
123 }
124 case Location::invalid:
125 return new StackValue();
126 default:
127 ShouldNotReachHere();
128 }
129
130 } else if (sv->is_constant_int()) {
131 // Constant int: treat same as register int.
132 union { intptr_t p; jint ji;} value;
133 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
134 value.ji = (jint)((ConstantIntValue*)sv)->value();
135 return new StackValue(value.p);
136 } else if (sv->is_constant_oop()) {
137 // constant oop
138 return new StackValue(((ConstantOopReadValue *)sv)->value());
139 #ifdef _LP64
140 } else if (sv->is_constant_double()) {
141 // Constant double in a single stack slot
142 union { intptr_t p; double d; } value;
143 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
144 value.d = ((ConstantDoubleValue *)sv)->value();
145 return new StackValue(value.p);
146 } else if (sv->is_constant_long()) {
147 // Constant long in a single stack slot
148 union { intptr_t p; jlong jl; } value;
149 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
150 value.jl = ((ConstantLongValue *)sv)->value();
151 return new StackValue(value.p);
152 #endif
153 } else if (sv->is_object()) { // Scalar replaced object in compiled frame
154 Handle ov = ((ObjectValue *)sv)->value();
155 return new StackValue(ov, (ov.is_null()) ? 1 : 0);
156 }
157
158 // Unknown ScopeValue type
159 ShouldNotReachHere();
160 return new StackValue((intptr_t) 0); // dummy
161 }
162
163
164 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
165 assert(location.is_stack(), "for now we only look at the stack");
166 int word_offset = location.stack_offset() / wordSize;
167 // (stack picture)
168 // high: [ ] word_offset + 1
169 // low [ ] word_offset
170 //
171 // sp-> [ ] 0
172 // the word_offset is the distance from the stack pointer to the lowest address
173 // The frame's original stack pointer, before any extension by its callee
174 // (due to Compiler1 linkage on SPARC), must be used.
175 return (BasicLock*) (fr->unextended_sp() + word_offset);
176 }
177
178
179 #ifndef PRODUCT
180
181 void StackValue::print_on(outputStream* st) const {
182 switch(_type) {
183 case T_INT:
184 st->print("%d (int) %f (float) %x (hex)", *(int *)&_i, *(float *)&_i, *(int *)&_i);
185 break;
186
187 case T_OBJECT:
188 _o()->print_value_on(st);
189 st->print(" <" INTPTR_FORMAT ">", (address)_o());
190 break;
191
192 case T_CONFLICT:
193 st->print("conflict");
194 break;
195
196 default:
197 ShouldNotReachHere();
198 }
199 }
200
201 #endif