/*

 * Copyright (c) 1997, 2010, 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 "opto/compile.hpp"

#include "opto/regmask.hpp"

#ifdef TARGET_ARCH_MODEL_x86_32

# include "adfiles/ad_x86_32.hpp"

#endif

#ifdef TARGET_ARCH_MODEL_x86_64

# include "adfiles/ad_x86_64.hpp"

#endif

#ifdef TARGET_ARCH_MODEL_sparc

# include "adfiles/ad_sparc.hpp"

#endif

#ifdef TARGET_ARCH_MODEL_zero

# include "adfiles/ad_zero.hpp"

#endif

#define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */

//-------------Non-zero bit search methods used by RegMask---------------------

// Find lowest 1, or return 32 if empty

int find_lowest_bit( uint32 mask ) {

  int n = 0;

  if( (mask & 0xffff) == 0 ) {

    mask >>= 16;

    n += 16;

  }

  if( (mask & 0xff) == 0 ) {

    mask >>= 8;

    n += 8;

  }

  if( (mask & 0xf) == 0 ) {

    mask >>= 4;

    n += 4;

  }

  if( (mask & 0x3) == 0 ) {

    mask >>= 2;

    n += 2;

  }

  if( (mask & 0x1) == 0 ) {

    mask >>= 1;

     n += 1;

  }

  if( mask == 0 ) {

    n = 32;

  }

  return n;

}

// Find highest 1, or return 32 if empty

int find_hihghest_bit( uint32 mask ) {

  int n = 0;

  if( mask > 0xffff ) {

    mask >>= 16;

    n += 16;

  }

  if( mask > 0xff ) {

    mask >>= 8;

    n += 8;

  }

  if( mask > 0xf ) {

    mask >>= 4;

    n += 4;

  }

  if( mask > 0x3 ) {

    mask >>= 2;

    n += 2;

  }

  if( mask > 0x1 ) {

    mask >>= 1;

    n += 1;

  }

  if( mask == 0 ) {

    n = 32;

  }

  return n;

}

//------------------------------dump-------------------------------------------

#ifndef PRODUCT

void OptoReg::dump( int r ) {

  switch( r ) {

  case Special: tty->print("r---");   break;

  case Bad:     tty->print("rBAD");   break;

  default:

    if( r < _last_Mach_Reg ) tty->print(Matcher::regName[r]);

    else tty->print("rS%d",r);

    break;

  }

}

#endif

//=============================================================================

const RegMask RegMask::Empty(

# define BODY(I) 0,

  FORALL_BODY

# undef BODY

  0

);

//------------------------------find_first_pair--------------------------------

// Find the lowest-numbered register pair in the mask.  Return the

// HIGHEST register number in the pair, or BAD if no pairs.

OptoReg::Name RegMask::find_first_pair() const {

  VerifyPairs();

  for( int i = 0; i < RM_SIZE; i++ ) {

    if( _A[i] ) {               // Found some bits

      int bit = _A[i] & -_A[i]; // Extract low bit

      // Convert to bit number, return hi bit in pair

      return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);

    }

  }

  return OptoReg::Bad;

}

//------------------------------ClearToPairs-----------------------------------

// Clear out partial bits; leave only bit pairs

void RegMask::ClearToPairs() {

  for( int i = 0; i < RM_SIZE; i++ ) {

    int bits = _A[i];

    bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair

    bits |= (bits>>1);          // Smear 1 hi-bit into a pair

    _A[i] = bits;

  }

  VerifyPairs();

}

//------------------------------SmearToPairs-----------------------------------

// Smear out partial bits; leave only bit pairs

void RegMask::SmearToPairs() {

  for( int i = 0; i < RM_SIZE; i++ ) {

    int bits = _A[i];

    bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair

    bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair

    _A[i] = bits;

  }

  VerifyPairs();

}

//------------------------------is_aligned_pairs-------------------------------

bool RegMask::is_aligned_Pairs() const {

  // Assert that the register mask contains only bit pairs.

  for( int i = 0; i < RM_SIZE; i++ ) {

    int bits = _A[i];

    while( bits ) {             // Check bits for pairing

      int bit = bits & -bits;   // Extract low bit

      // Low bit is not odd means its mis-aligned.

      if( (bit & 0x55555555) == 0 ) return false;

      bits -= bit;              // Remove bit from mask

      // Check for aligned adjacent bit

      if( (bits & (bit<<1)) == 0 ) return false;

      bits -= (bit<<1);         // Remove other halve of pair

    }

  }

  return true;

}

//------------------------------is_bound1--------------------------------------

// Return TRUE if the mask contains a single bit

int RegMask::is_bound1() const {

  if( is_AllStack() ) return false;

  int bit = -1;                 // Set to hold the one bit allowed

  for( int i = 0; i < RM_SIZE; i++ ) {

    if( _A[i] ) {               // Found some bits

      if( bit != -1 ) return false; // Already had bits, so fail

      bit = _A[i] & -_A[i];     // Extract 1 bit from mask

      if( bit != _A[i] ) return false; // Found many bits, so fail

    }

  }

  // True for both the empty mask and for a single bit

  return true;

}

//------------------------------is_bound2--------------------------------------

// Return TRUE if the mask contains an adjacent pair of bits and no other bits.

int RegMask::is_bound2() const {

  if( is_AllStack() ) return false;

  int bit = -1;                 // Set to hold the one bit allowed

  for( int i = 0; i < RM_SIZE; i++ ) {

    if( _A[i] ) {               // Found some bits

      if( bit != -1 ) return false; // Already had bits, so fail

      bit = _A[i] & -(_A[i]);   // Extract 1 bit from mask

      if( (bit << 1) != 0 ) {   // Bit pair stays in same word?

        if( (bit | (bit<<1)) != _A[i] )

          return false;         // Require adjacent bit pair and no more bits

      } else {                  // Else its a split-pair case

        if( bit != _A[i] ) return false; // Found many bits, so fail

        i++;                    // Skip iteration forward

        if( _A[i] != 1 ) return false; // Require 1 lo bit in next word

      }

    }

  }

  // True for both the empty mask and for a bit pair

  return true;

}

//------------------------------is_UP------------------------------------------

// UP means register only, Register plus stack, or stack only is DOWN

bool RegMask::is_UP() const {

  // Quick common case check for DOWN (any stack slot is legal)

  if( is_AllStack() )

    return false;

  // Slower check for any stack bits set (also DOWN)

  if( overlap(Matcher::STACK_ONLY_mask) )

    return false;

  // Not DOWN, so must be UP

  return true;

}

//------------------------------Size-------------------------------------------

// Compute size of register mask in bits

uint RegMask::Size() const {

  extern uint8 bitsInByte[256];

  uint sum = 0;

  for( int i = 0; i < RM_SIZE; i++ )

    sum +=

      bitsInByte[(_A[i]>>24) & 0xff] +

      bitsInByte[(_A[i]>>16) & 0xff] +

      bitsInByte[(_A[i]>> 8) & 0xff] +

      bitsInByte[ _A[i]      & 0xff];

  return sum;

}

#ifndef PRODUCT

//------------------------------print------------------------------------------

void RegMask::dump( ) const {

  tty->print("[");

  RegMask rm = *this;           // Structure copy into local temp

  OptoReg::Name start = rm.find_first_elem(); // Get a register

  if( OptoReg::is_valid(start) ) { // Check for empty mask

    rm.Remove(start);           // Yank from mask

    OptoReg::dump(start);       // Print register

    OptoReg::Name last = start;

    // Now I have printed an initial register.

    // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".

    // Begin looping over the remaining registers.

    while( 1 ) {                //

      OptoReg::Name reg = rm.find_first_elem(); // Get a register

      if( !OptoReg::is_valid(reg) )

        break;                  // Empty mask, end loop

      rm.Remove(reg);           // Yank from mask

      if( last+1 == reg ) {     // See if they are adjacent

        // Adjacent registers just collect into long runs, no printing.

        last = reg;

      } else {                  // Ending some kind of run

        if( start == last ) {   // 1-register run; no special printing

        } else if( start+1 == last ) {

          tty->print(",");      // 2-register run; print as "rX,rY"

          OptoReg::dump(last);

        } else {                // Multi-register run; print as "rX-rZ"

          tty->print("-");

          OptoReg::dump(last);

        }

        tty->print(",");        // Seperate start of new run

        start = last = reg;     // Start a new register run

        OptoReg::dump(start); // Print register

      } // End of if ending a register run or not

    } // End of while regmask not empty

    if( start == last ) {       // 1-register run; no special printing

    } else if( start+1 == last ) {

      tty->print(",");          // 2-register run; print as "rX,rY"

      OptoReg::dump(last);

    } else {                    // Multi-register run; print as "rX-rZ"

      tty->print("-");

      OptoReg::dump(last);

    }

    if( rm.is_AllStack() ) tty->print("...");

  }

  tty->print("]");

}

#endif