/*

 * Copyright (c) 1997, 2017, 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.

 *

 */

#include "precompiled.hpp"

#include "code/debugInfo.hpp"

#include "oops/compressedOops.inline.hpp"

#include "oops/oop.hpp"

#include "runtime/frame.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/stackValue.hpp"

#if INCLUDE_ZGC

#include "gc/z/zBarrier.inline.hpp"

#endif

#if INCLUDE_SHENANDOAHGC

#include "gc/shenandoah/shenandoahBarrierSet.hpp"

#endif

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

      oop val = CompressedOops::decode(value.noop);

      // Deoptimization must make sure all oops have passed load barriers

#if INCLUDE_SHENANDOAHGC

      if (UseShenandoahGC) {

        val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);

      }

#endif

      Handle h(Thread::current(), val); // Wrap a handle around the oop

      return new StackValue(h);

    }

#endif

    case Location::oop: {

      oop val = *(oop *)value_addr;

#ifdef _LP64

      if (CompressedOops::is_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

      // Deoptimization must make sure all oops have passed load barriers

#if INCLUDE_SHENANDOAHGC

      if (UseShenandoahGC) {

        val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);

      }

#endif

      Handle h(Thread::current(), 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 *)&_integer_value, *(float *)&_integer_value,  *(int *)&_integer_value);

      break;

    case T_OBJECT:

      if (_handle_value() != NULL) {

        _handle_value()->print_value_on(st);

      } else {

        st->print("NULL");

      }

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

     break;

    case T_CONFLICT:

     st->print("conflict");

     break;

    default:

     ShouldNotReachHere();

  }

}

#endif