hotspot/src/share/vm/opto/multnode.cpp

/*
 * Copyright 1997-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

#include "incls/_precompiled.incl"
#include "incls/_multnode.cpp.incl"

//=============================================================================
//------------------------------MultiNode--------------------------------------
const RegMask &MultiNode::out_RegMask() const {
  return RegMask::Empty;
}

Node *MultiNode::match( const ProjNode *proj, const Matcher *m ) { return proj->clone(); }

//------------------------------proj_out---------------------------------------
// Get a named projection
ProjNode* MultiNode::proj_out(uint which_proj) const {
  assert(Opcode() != Op_If || which_proj == (uint)true || which_proj == (uint)false, "must be 1 or 0");
  assert(Opcode() != Op_If || outcnt() == 2, "bad if #1");
  for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
    Node *p = fast_out(i);
    if( !p->is_Proj() ) {
      assert(p == this && this->is_Start(), "else must be proj");
      continue;
    }
    ProjNode *proj = p->as_Proj();
    if( proj->_con == which_proj ) {
      assert(Opcode() != Op_If || proj->Opcode() == (which_proj?Op_IfTrue:Op_IfFalse), "bad if #2");
      return proj;
    }
  }
  return NULL;
}

//=============================================================================
//------------------------------ProjNode---------------------------------------
uint ProjNode::hash() const {
  // only one input
  return (uintptr_t)in(TypeFunc::Control) + (_con << 1) + (_is_io_use ? 1 : 0);
}
uint ProjNode::cmp( const Node &n ) const { return _con == ((ProjNode&)n)._con && ((ProjNode&)n)._is_io_use == _is_io_use; }
uint ProjNode::size_of() const { return sizeof(ProjNode); }

// Test if we propagate interesting control along this projection
bool ProjNode::is_CFG() const {
  Node *def = in(0);
  return (_con == TypeFunc::Control && def->is_CFG());
}

const Type *ProjNode::bottom_type() const {
  if (in(0) == NULL)  return Type::TOP;
  const Type *tb = in(0)->bottom_type();
  if( tb == Type::TOP ) return Type::TOP;
  if( tb == Type::BOTTOM ) return Type::BOTTOM;
  const TypeTuple *t = tb->is_tuple();
  return t->field_at(_con);
}

const TypePtr *ProjNode::adr_type() const {
  if (bottom_type() == Type::MEMORY) {
    // in(0) might be a narrow MemBar; otherwise we will report TypePtr::BOTTOM
    const TypePtr* adr_type = in(0)->adr_type();
    #ifdef ASSERT
    if (!is_error_reported() && !Node::in_dump())
      assert(adr_type != NULL, "source must have adr_type");
    #endif
    return adr_type;
  }
  assert(bottom_type()->base() != Type::Memory, "no other memories?");
  return NULL;
}

bool ProjNode::pinned() const { return in(0)->pinned(); }
#ifndef PRODUCT
void ProjNode::dump_spec(outputStream *st) const { st->print("#%d",_con); if(_is_io_use) st->print(" (i_o_use)");}
#endif

//----------------------------check_con----------------------------------------
void ProjNode::check_con() const {
  Node* n = in(0);
  if (n == NULL)       return;  // should be assert, but NodeHash makes bogons
  if (n->is_Mach())    return;  // mach. projs. are not type-safe
  if (n->is_Start())   return;  // alas, starts can have mach. projs. also
  if (_con == SCMemProjNode::SCMEMPROJCON ) return;
  const Type* t = n->bottom_type();
  if (t == Type::TOP)  return;  // multi is dead
  assert(_con < t->is_tuple()->cnt(), "ProjNode::_con must be in range");
}

//------------------------------Value------------------------------------------
const Type *ProjNode::Value( PhaseTransform *phase ) const {
  if( !in(0) ) return Type::TOP;
  const Type *t = phase->type(in(0));
  if( t == Type::TOP ) return t;
  if( t == Type::BOTTOM ) return t;
  return t->is_tuple()->field_at(_con);
}

//------------------------------out_RegMask------------------------------------
// Pass the buck uphill
const RegMask &ProjNode::out_RegMask() const {
  return RegMask::Empty;
}

//------------------------------ideal_reg--------------------------------------
uint ProjNode::ideal_reg() const {
  return Matcher::base2reg[bottom_type()->base()];
}