1 /*
   2  * Copyright (c) 1997, 2014, 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/oop.inline.hpp"
  28 #include "runtime/frame.inline.hpp"
  29 #include "runtime/handles.inline.hpp"
  30 #include "runtime/stackValue.hpp"
  31 
  32 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv) {
  33   if (sv->is_location()) {
  34     // Stack or register value
  35     Location loc = ((LocationValue *)sv)->location();
  36 
  37 #ifdef SPARC
  38     // %%%%% Callee-save floats will NOT be working on a Sparc until we
  39     // handle the case of a 2 floats in a single double register.
  40     assert( !(loc.is_register() && loc.type() == Location::float_in_dbl), "Sparc does not handle callee-save floats yet" );
  41 #endif // SPARC
  42 
  43     // First find address of value
  44 
  45     address value_addr = loc.is_register()
  46       // Value was in a callee-save register
  47       ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()))
  48       // Else value was directly saved on the stack. The frame's original stack pointer,
  49       // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
  50       : ((address)fr->unextended_sp()) + loc.stack_offset();
  51 
  52     // Then package it right depending on type
  53     // Note: the transfer of the data is thru a union that contains
  54     // an intptr_t. This is because an interpreter stack slot is
  55     // really an intptr_t. The use of a union containing an intptr_t
  56     // ensures that on a 64 bit platform we have proper alignment
  57     // and that we store the value where the interpreter will expect
  58     // to find it (i.e. proper endian). Similarly on a 32bit platform
  59     // using the intptr_t ensures that when a value is larger than
  60     // a stack slot (jlong/jdouble) that we capture the proper part
  61     // of the value for the stack slot in question.
  62     //
  63     switch( loc.type() ) {
  64     case Location::float_in_dbl: { // Holds a float in a double register?
  65       // The callee has no clue whether the register holds a float,
  66       // double or is unused.  He always saves a double.  Here we know
  67       // a double was saved, but we only want a float back.  Narrow the
  68       // saved double to the float that the JVM wants.
  69       assert( loc.is_register(), "floats always saved to stack in 1 word" );
  70       union { intptr_t p; jfloat jf; } value;
  71       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
  72       value.jf = (jfloat) *(jdouble*) value_addr;
  73       return new StackValue(value.p); // 64-bit high half is stack junk
  74     }
  75     case Location::int_in_long: { // Holds an int in a long register?
  76       // The callee has no clue whether the register holds an int,
  77       // long or is unused.  He always saves a long.  Here we know
  78       // a long was saved, but we only want an int back.  Narrow the
  79       // saved long to the int that the JVM wants.
  80       assert( loc.is_register(), "ints always saved to stack in 1 word" );
  81       union { intptr_t p; jint ji;} value;
  82       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
  83       value.ji = (jint) *(jlong*) value_addr;
  84       return new StackValue(value.p); // 64-bit high half is stack junk
  85     }
  86 #ifdef _LP64
  87     case Location::dbl:
  88       // Double value in an aligned adjacent pair
  89       return new StackValue(*(intptr_t*)value_addr);
  90     case Location::lng:
  91       // Long   value in an aligned adjacent pair
  92       return new StackValue(*(intptr_t*)value_addr);
  93     case Location::narrowoop: {
  94       union { intptr_t p; narrowOop noop;} value;
  95       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
  96       if (loc.is_register()) {
  97         // The callee has no clue whether the register holds an int,
  98         // long or is unused.  He always saves a long.  Here we know
  99         // a long was saved, but we only want an int back.  Narrow the
 100         // saved long to the int that the JVM wants.
 101         value.noop =  (narrowOop) *(julong*) value_addr;
 102       } else {
 103         value.noop = *(narrowOop*) value_addr;
 104       }
 105       // Decode narrowoop
 106       oop val = oopDesc::decode_heap_oop(value.noop);
 107       // Deoptimization must make sure all oops have passed load barriers
 108 #if INCLUDE_ALL_GCS
 109       if (UseShenandoahGC) {
 110         val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
 111       }
 112 #endif
 113       Handle h(val); // Wrap a handle around the oop
 114       return new StackValue(h);
 115     }
 116 #endif
 117     case Location::oop: {
 118       oop val = *(oop *)value_addr;
 119 #ifdef _LP64
 120       if (Universe::is_narrow_oop_base(val)) {
 121          // Compiled code may produce decoded oop = narrow_oop_base
 122          // when a narrow oop implicit null check is used.
 123          // The narrow_oop_base could be NULL or be the address
 124          // of the page below heap. Use NULL value for both cases.
 125          val = (oop)NULL;
 126       }
 127 #endif
 128       // Deoptimization must make sure all oops have passed load barriers
 129 #if INCLUDE_ALL_GCS
 130       if (UseShenandoahGC) {
 131         val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
 132       }
 133 #endif
 134       Handle h(val); // Wrap a handle around the oop
 135       return new StackValue(h);
 136     }
 137     case Location::addr: {
 138       ShouldNotReachHere(); // both C1 and C2 now inline jsrs
 139     }
 140     case Location::normal: {
 141       // Just copy all other bits straight through
 142       union { intptr_t p; jint ji;} value;
 143       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
 144       value.ji = *(jint*)value_addr;
 145       return new StackValue(value.p);
 146     }
 147     case Location::invalid:
 148       return new StackValue();
 149     default:
 150       ShouldNotReachHere();
 151     }
 152 
 153   } else if (sv->is_constant_int()) {
 154     // Constant int: treat same as register int.
 155     union { intptr_t p; jint ji;} value;
 156     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
 157     value.ji = (jint)((ConstantIntValue*)sv)->value();
 158     return new StackValue(value.p);
 159   } else if (sv->is_constant_oop()) {
 160     // constant oop
 161     return new StackValue(sv->as_ConstantOopReadValue()->value());
 162 #ifdef _LP64
 163   } else if (sv->is_constant_double()) {
 164     // Constant double in a single stack slot
 165     union { intptr_t p; double d; } value;
 166     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
 167     value.d = ((ConstantDoubleValue *)sv)->value();
 168     return new StackValue(value.p);
 169   } else if (sv->is_constant_long()) {
 170     // Constant long in a single stack slot
 171     union { intptr_t p; jlong jl; } value;
 172     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
 173     value.jl = ((ConstantLongValue *)sv)->value();
 174     return new StackValue(value.p);
 175 #endif
 176   } else if (sv->is_object()) { // Scalar replaced object in compiled frame
 177     Handle ov = ((ObjectValue *)sv)->value();
 178     return new StackValue(ov, (ov.is_null()) ? 1 : 0);
 179   }
 180 
 181   // Unknown ScopeValue type
 182   ShouldNotReachHere();
 183   return new StackValue((intptr_t) 0);   // dummy
 184 }
 185 
 186 
 187 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
 188   assert(location.is_stack(), "for now we only look at the stack");
 189   int word_offset = location.stack_offset() / wordSize;
 190   // (stack picture)
 191   // high: [     ]  word_offset + 1
 192   // low   [     ]  word_offset
 193   //
 194   // sp->  [     ]  0
 195   // the word_offset is the distance from the stack pointer to the lowest address
 196   // The frame's original stack pointer, before any extension by its callee
 197   // (due to Compiler1 linkage on SPARC), must be used.
 198   return (BasicLock*) (fr->unextended_sp() + word_offset);
 199 }
 200 
 201 
 202 #ifndef PRODUCT
 203 
 204 void StackValue::print_on(outputStream* st) const {
 205   switch(_type) {
 206     case T_INT:
 207       st->print("%d (int) %f (float) %x (hex)",  *(int *)&_i, *(float *)&_i,  *(int *)&_i);
 208       break;
 209 
 210     case T_OBJECT:
 211      _o()->print_value_on(st);
 212       st->print(" <" INTPTR_FORMAT ">", p2i((address)_o()));
 213      break;
 214 
 215     case T_CONFLICT:
 216      st->print("conflict");
 217      break;
 218 
 219     default:
 220      ShouldNotReachHere();
 221   }
 222 }
 223 
 224 #endif
--- EOF ---