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 // The callee has no clue whether the register holds a float,
62 // double or is unused. He always saves a double. Here we know
63 // a double was saved, but we only want a float back. Narrow the
64 // saved double to the float that the JVM wants.
65 assert( loc.is_register(), "floats always saved to stack in 1 word" );
66 union { intptr_t p; jfloat jf; } value;
67 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
68 value.jf = (jfloat) *(jdouble*) value_addr;
69 return new StackValue(value.p); // 64-bit high half is stack junk
70 }
71 case Location::int_in_long: { // Holds an int in a long register?
72 // The callee has no clue whether the register holds an int,
73 // long or is unused. He always saves a long. Here we know
74 // a long was saved, but we only want an int back. Narrow the
75 // saved long to the int that the JVM wants.
76 assert( loc.is_register(), "ints always saved to stack in 1 word" );
77 union { intptr_t p; jint ji;} value;
78 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
79 value.ji = (jint) *(jlong*) value_addr;
80 return new StackValue(value.p); // 64-bit high half is stack junk
81 }
82 #ifdef _LP64
83 case Location::dbl:
84 // Double value in an aligned adjacent pair
85 return new StackValue(*(intptr_t*)value_addr);
86 case Location::lng:
87 // Long value in an aligned adjacent pair
88 return new StackValue(*(intptr_t*)value_addr);
89 case Location::narrowoop: {
90 union { intptr_t p; narrowOop noop;} value;
91 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
92 if (loc.is_register()) {
93 // The callee has no clue whether the register holds an int,
94 // long or is unused. He always saves a long. Here we know
95 // a long was saved, but we only want an int back. Narrow the
96 // saved long to the int that the JVM wants.
97 value.noop = (narrowOop) *(julong*) value_addr;
98 } else {
99 value.noop = *(narrowOop*) value_addr;
100 }
101 // Decode narrowoop and wrap a handle around the oop
102 Handle h(oopDesc::decode_heap_oop(value.noop));
103 return new StackValue(h);
104 }
105 #endif
106 case Location::oop: {
107 oop val = *(oop *)value_addr;
108 #ifdef _LP64
109 if (Universe::is_narrow_oop_base(val)) {
110 // Compiled code may produce decoded oop = narrow_oop_base
111 // when a narrow oop implicit null check is used.
112 // The narrow_oop_base could be NULL or be the address
113 // of the page below heap. Use NULL value for both cases.
114 val = (oop)NULL;
115 }
116 #endif
117 Handle h(val); // Wrap a handle around the oop
118 return new StackValue(h);
119 }
120 case Location::addr: {
121 ShouldNotReachHere(); // both C1 and C2 now inline jsrs
122 }
123 case Location::normal: {
124 // Just copy all other bits straight through
125 union { intptr_t p; jint ji;} value;
126 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
127 value.ji = *(jint*)value_addr;
128 return new StackValue(value.p);
129 }
130 case Location::invalid:
131 return new StackValue();
132 default:
133 ShouldNotReachHere();
134 }
135
136 } else if (sv->is_constant_int()) {
137 // Constant int: treat same as register int.
138 union { intptr_t p; jint ji;} value;
139 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
140 value.ji = (jint)((ConstantIntValue*)sv)->value();
141 return new StackValue(value.p);
142 } else if (sv->is_constant_oop()) {
143 // constant oop
144 return new StackValue(((ConstantOopReadValue *)sv)->value());
145 #ifdef _LP64
146 } else if (sv->is_constant_double()) {
147 // Constant double in a single stack slot
148 union { intptr_t p; double d; } value;
149 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
150 value.d = ((ConstantDoubleValue *)sv)->value();
151 return new StackValue(value.p);
152 } else if (sv->is_constant_long()) {
153 // Constant long in a single stack slot
154 union { intptr_t p; jlong jl; } value;
155 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
156 value.jl = ((ConstantLongValue *)sv)->value();
157 return new StackValue(value.p);
158 #endif
159 } else if (sv->is_object()) { // Scalar replaced object in compiled frame
160 Handle ov = ((ObjectValue *)sv)->value();
161 return new StackValue(ov, (ov.is_null()) ? 1 : 0);
162 }
163
164 // Unknown ScopeValue type
165 ShouldNotReachHere();
166 return new StackValue((intptr_t) 0); // dummy
167 }
168
169
170 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
171 assert(location.is_stack(), "for now we only look at the stack");
172 int word_offset = location.stack_offset() / wordSize;
173 // (stack picture)
174 // high: [ ] word_offset + 1
175 // low [ ] word_offset
176 //
177 // sp-> [ ] 0
178 // the word_offset is the distance from the stack pointer to the lowest address
179 // The frame's original stack pointer, before any extension by its callee
180 // (due to Compiler1 linkage on SPARC), must be used.
181 return (BasicLock*) (fr->unextended_sp() + word_offset);
182 }
183
184
185 #ifndef PRODUCT
186
187 void StackValue::print_on(outputStream* st) const {
188 switch(_type) {
189 case T_INT:
190 st->print("%d (int) %f (float) %x (hex)", *(int *)&_i, *(float *)&_i, *(int *)&_i);
191 break;
192
193 case T_OBJECT:
194 _o()->print_value_on(st);
195 st->print(" <" INTPTR_FORMAT ">", (address)_o());
196 break;
197
198 case T_CONFLICT:
199 st->print("conflict");
200 break;
201
202 default:
203 ShouldNotReachHere();
204 }
205 }
206
207 #endif