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 /*

  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

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  */

 #include "precompiled.hpp"

 #include "code/debugInfo.hpp"

 #include "oops/oop.inline.hpp"

 #include "runtime/frame.inline.hpp"

 #include "runtime/handles.inline.hpp"

 #include "runtime/stackValue.hpp"

 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv) {

   if (sv->is_location()) {

     // Stack or register value

     Location loc = ((LocationValue *)sv)->location();

 #ifdef SPARC

     // %%%%% Callee-save floats will NOT be working on a Sparc until we

     // handle the case of a 2 floats in a single double register.

     assert( !(loc.is_register() && loc.type() == Location::float_in_dbl), "Sparc does not handle callee-save floats yet" );

 #endif // SPARC

     // First find address of value

     address value_addr = loc.is_register()

       // Value was in a callee-save register

       ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()))

       // Else value was directly saved on the stack. The frame's original stack pointer,

       // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.

       : ((address)fr->unextended_sp()) + loc.stack_offset();

     // Then package it right depending on type

     // Note: the transfer of the data is thru a union that contains

     // an intptr_t. This is because an interpreter stack slot is

     // really an intptr_t. The use of a union containing an intptr_t

     // ensures that on a 64 bit platform we have proper alignment

     // and that we store the value where the interpreter will expect

     // to find it (i.e. proper endian). Similarly on a 32bit platform

     // using the intptr_t ensures that when a value is larger than

     // a stack slot (jlong/jdouble) that we capture the proper part

     // of the value for the stack slot in question.

     //

     switch( loc.type() ) {

     case Location::float_in_dbl: { // Holds a float in a double register?

       // The callee has no clue whether the register holds a float,

       // double or is unused.  He always saves a double.  Here we know

       // a double was saved, but we only want a float back.  Narrow the

       // saved double to the float that the JVM wants.

       assert( loc.is_register(), "floats always saved to stack in 1 word" );

       union { intptr_t p; jfloat jf; } value;

       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

       value.jf = (jfloat) *(jdouble*) value_addr;

       return new StackValue(value.p); // 64-bit high half is stack junk

     }

     case Location::int_in_long: { // Holds an int in a long register?

       // The callee has no clue whether the register holds an int,

       // long or is unused.  He always saves a long.  Here we know

       // a long was saved, but we only want an int back.  Narrow the

       // saved long to the int that the JVM wants.

       assert( loc.is_register(), "ints always saved to stack in 1 word" );

       union { intptr_t p; jint ji;} value;

       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

       value.ji = (jint) *(jlong*) value_addr;

       return new StackValue(value.p); // 64-bit high half is stack junk

     }

 #ifdef _LP64

     case Location::dbl:

       // Double value in an aligned adjacent pair

       return new StackValue(*(intptr_t*)value_addr);

     case Location::lng:

       // Long   value in an aligned adjacent pair

       return new StackValue(*(intptr_t*)value_addr);

     case Location::narrowoop: {

       union { intptr_t p; narrowOop noop;} value;

       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

       if (loc.is_register()) {

         // The callee has no clue whether the register holds an int,

         // long or is unused.  He always saves a long.  Here we know

         // a long was saved, but we only want an int back.  Narrow the

         // saved long to the int that the JVM wants.

         value.noop =  (narrowOop) *(julong*) value_addr;

       } else {

         value.noop = *(narrowOop*) value_addr;

       }

       // Decode narrowoop and wrap a handle around the oop

       Handle h(oopDesc::decode_heap_oop(value.noop));

       return new StackValue(h);

     }

 #endif

     case Location::oop: {

       oop val = *(oop *)value_addr;

 #ifdef _LP64

       if (Universe::is_narrow_oop_base(val)) {

          // Compiled code may produce decoded oop = narrow_oop_base

          // when a narrow oop implicit null check is used.

          // The narrow_oop_base could be NULL or be the address

          // of the page below heap. Use NULL value for both cases.

          val = (oop)NULL;

       }

 #endif

       Handle h(val); // Wrap a handle around the oop

       return new StackValue(h);

     }

     case Location::addr: {

       ShouldNotReachHere(); // both C1 and C2 now inline jsrs

     }

     case Location::normal: {

       // Just copy all other bits straight through

       union { intptr_t p; jint ji;} value;

       value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

       value.ji = *(jint*)value_addr;

       return new StackValue(value.p);

     }

     case Location::invalid:

       return new StackValue();

     default:

       ShouldNotReachHere();

     }

   } else if (sv->is_constant_int()) {

     // Constant int: treat same as register int.

     union { intptr_t p; jint ji;} value;

     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

     value.ji = (jint)((ConstantIntValue*)sv)->value();

     return new StackValue(value.p);

   } else if (sv->is_constant_oop()) {

     // constant oop

     return new StackValue(sv->as_ConstantOopReadValue()->value());

 #ifdef _LP64

   } else if (sv->is_constant_double()) {

     // Constant double in a single stack slot

     union { intptr_t p; double d; } value;

     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

     value.d = ((ConstantDoubleValue *)sv)->value();

     return new StackValue(value.p);

   } else if (sv->is_constant_long()) {

     // Constant long in a single stack slot

     union { intptr_t p; jlong jl; } value;

     value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);

     value.jl = ((ConstantLongValue *)sv)->value();

     return new StackValue(value.p);

 #endif

   } else if (sv->is_object()) { // Scalar replaced object in compiled frame

     Handle ov = ((ObjectValue *)sv)->value();

     return new StackValue(ov, (ov.is_null()) ? 1 : 0);

   }

   // Unknown ScopeValue type

   ShouldNotReachHere();

   return new StackValue((intptr_t) 0);   // dummy

 }

 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {

   assert(location.is_stack(), "for now we only look at the stack");

   int word_offset = location.stack_offset() / wordSize;

   // (stack picture)

   // high: [     ]  word_offset + 1

   // low   [     ]  word_offset

   //

   // sp->  [     ]  0

   // the word_offset is the distance from the stack pointer to the lowest address

   // The frame's original stack pointer, before any extension by its callee

   // (due to Compiler1 linkage on SPARC), must be used.

   return (BasicLock*) (fr->unextended_sp() + word_offset);

 }

 #ifndef PRODUCT

 void StackValue::print_on(outputStream* st) const {

   switch(_type) {

     case T_INT:

       st->print("%d (int) %f (float) %x (hex)",  *(int *)&_i, *(float *)&_i,  *(int *)&_i);

       break;

     case T_OBJECT:

      _o()->print_value_on(st);

       st->print(" <" INTPTR_FORMAT ">", p2i((address)_o()));

      break;

     case T_CONFLICT:

      st->print("conflict");

      break;

     default:

      ShouldNotReachHere();

   }

 }

 #endif