1 /* 2 * Copyright (c) 1997, 2020, 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 #if INCLUDE_ZGC 33 #include "gc/z/zBarrier.inline.hpp" 34 #endif 35 #if INCLUDE_SHENANDOAHGC 36 #include "gc/shenandoah/shenandoahBarrierSet.hpp" 37 #endif 38 39 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv) { 40 if (sv->is_location()) { 41 // Stack or register value 42 Location loc = ((LocationValue *)sv)->location(); 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 107 oop val = CompressedOops::decode(value.noop); 108 // Deoptimization must make sure all oops have passed load barriers 109 #if INCLUDE_SHENANDOAHGC 110 if (UseShenandoahGC) { 111 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val); 112 } 113 #endif 114 Handle h(Thread::current(), val); // Wrap a handle around the oop 115 return new StackValue(h); 116 } 117 #endif 118 case Location::oop: { 119 oop val = *(oop *)value_addr; 120 #ifdef _LP64 121 if (CompressedOops::is_base(val)) { 122 // Compiled code may produce decoded oop = narrow_oop_base 123 // when a narrow oop implicit null check is used. 124 // The narrow_oop_base could be NULL or be the address 125 // of the page below heap. Use NULL value for both cases. 126 val = (oop)NULL; 127 } 128 #endif 129 // Deoptimization must make sure all oops have passed load barriers 130 #if INCLUDE_SHENANDOAHGC 131 if (UseShenandoahGC) { 132 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val); 133 } 134 #endif 135 assert(oopDesc::is_oop_or_null(val, false), "bad oop found"); 136 Handle h(Thread::current(), val); // Wrap a handle around the oop 137 return new StackValue(h); 138 } 139 case Location::addr: { 140 ShouldNotReachHere(); // both C1 and C2 now inline jsrs 141 } 142 case Location::normal: { 143 // Just copy all other bits straight through 144 union { intptr_t p; jint ji;} value; 145 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 146 value.ji = *(jint*)value_addr; 147 return new StackValue(value.p); 148 } 149 case Location::invalid: { 150 return new StackValue(); 151 } 152 case Location::vector: { 153 ShouldNotReachHere(); // should be handled by Deoptimization::realloc_objects() 154 } 155 default: 156 ShouldNotReachHere(); 157 } 158 159 } else if (sv->is_constant_int()) { 160 // Constant int: treat same as register int. 161 union { intptr_t p; jint ji;} value; 162 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 163 value.ji = (jint)((ConstantIntValue*)sv)->value(); 164 return new StackValue(value.p); 165 } else if (sv->is_constant_oop()) { 166 // constant oop 167 return new StackValue(sv->as_ConstantOopReadValue()->value()); 168 #ifdef _LP64 169 } else if (sv->is_constant_double()) { 170 // Constant double in a single stack slot 171 union { intptr_t p; double d; } value; 172 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 173 value.d = ((ConstantDoubleValue *)sv)->value(); 174 return new StackValue(value.p); 175 } else if (sv->is_constant_long()) { 176 // Constant long in a single stack slot 177 union { intptr_t p; jlong jl; } value; 178 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 179 value.jl = ((ConstantLongValue *)sv)->value(); 180 return new StackValue(value.p); 181 #endif 182 } else if (sv->is_object()) { // Scalar replaced object in compiled frame 183 Handle ov = ((ObjectValue *)sv)->value(); 184 return new StackValue(ov, (ov.is_null()) ? 1 : 0); 185 } else if (sv->is_marker()) { 186 // Should never need to directly construct a marker. 187 ShouldNotReachHere(); 188 } 189 // Unknown ScopeValue type 190 ShouldNotReachHere(); 191 return new StackValue((intptr_t) 0); // dummy 192 } 193 194 195 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) { 196 assert(location.is_stack(), "for now we only look at the stack"); 197 int word_offset = location.stack_offset() / wordSize; 198 // (stack picture) 199 // high: [ ] word_offset + 1 200 // low [ ] word_offset 201 // 202 // sp-> [ ] 0 203 // the word_offset is the distance from the stack pointer to the lowest address 204 // The frame's original stack pointer, before any extension by its callee 205 // (due to Compiler1 linkage on SPARC), must be used. 206 return (BasicLock*) (fr->unextended_sp() + word_offset); 207 } 208 209 210 #ifndef PRODUCT 211 212 void StackValue::print_on(outputStream* st) const { 213 switch(_type) { 214 case T_INT: 215 st->print("%d (int) %f (float) %x (hex)", *(int *)&_integer_value, *(float *)&_integer_value, *(int *)&_integer_value); 216 break; 217 218 case T_OBJECT: 219 if (_handle_value() != NULL) { 220 _handle_value()->print_value_on(st); 221 } else { 222 st->print("NULL"); 223 } 224 st->print(" <" INTPTR_FORMAT ">", p2i(_handle_value())); 225 break; 226 227 case T_CONFLICT: 228 st->print("conflict"); 229 break; 230 231 default: 232 ShouldNotReachHere(); 233 } 234 } 235 236 #endif