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