stackValue.cpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 1997, 2009, 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 "incls/_precompiled.incl" 26# include "incls/_stackValue.cpp.incl" 27 28StackValue* 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 170BasicLock* 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 187void 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 208