Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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.

  *

  */

 // Some fun naming (textual) substitutions:

 //

 // RegMask::get_low_elem() ==> RegMask::find_first_elem()

 // RegMask::Special        ==> RegMask::Empty

 // RegMask::_flags         ==> RegMask::is_AllStack()

 // RegMask::operator<<=()  ==> RegMask::Insert()

 // RegMask::operator>>=()  ==> RegMask::Remove()

 // RegMask::Union()        ==> RegMask::OR

 // RegMask::Inter()        ==> RegMask::AND

 //

 // OptoRegister::RegName   ==> OptoReg::Name

 //

 // OptoReg::stack0()       ==> _last_Mach_Reg  or ZERO in core version

 //

 // numregs in chaitin      ==> proper degree in chaitin

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

 // Find lowest 1, or return 32 if empty

 int find_lowest_bit( uint32 mask );

 // Find highest 1, or return 32 if empty

 int find_hihghest_bit( uint32 mask );

 //------------------------------RegMask----------------------------------------

 // The ADL file describes how to print the machine-specific registers, as well

 // as any notion of register classes.  We provide a register mask, which is

 // just a collection of Register numbers.

 // The ADLC defines 2 macros, RM_SIZE and FORALL_BODY.

 // RM_SIZE is the size of a register mask in words.

 // FORALL_BODY replicates a BODY macro once per word in the register mask.

 // The usage is somewhat clumsy and limited to the regmask.[h,c]pp files.

 // However, it means the ADLC can redefine the unroll macro and all loops

 // over register masks will be unrolled by the correct amount.

 class RegMask VALUE_OBJ_CLASS_SPEC {

   union {

     double _dummy_force_double_alignment[RM_SIZE>>1];

     // Array of Register Mask bits.  This array is large enough to cover

     // all the machine registers and all parameters that need to be passed

     // on the stack (stack registers) up to some interesting limit.  Methods

     // that need more parameters will NOT be compiled.  On Intel, the limit

     // is something like 90+ parameters.

     int _A[RM_SIZE];

   };

   enum {

     _WordBits    = BitsPerInt,

     _LogWordBits = LogBitsPerInt,

     _RM_SIZE     = RM_SIZE   // local constant, imported, then hidden by #undef

   };

 public:

   enum { CHUNK_SIZE = RM_SIZE*_WordBits };

   // SlotsPerLong is 2, since slots are 32 bits and longs are 64 bits.

   // Also, consider the maximum alignment size for a normally allocated

   // value.  Since we allocate register pairs but not register quads (at

   // present), this alignment is SlotsPerLong (== 2).  A normally

   // aligned allocated register is either a single register, or a pair

   // of adjacent registers, the lower-numbered being even.

   // See also is_aligned_Pairs() below, and the padding added before

   // Matcher::_new_SP to keep allocated pairs aligned properly.

   // If we ever go to quad-word allocations, SlotsPerQuad will become

   // the controlling alignment constraint.  Note that this alignment

   // requirement is internal to the allocator, and independent of any

   // particular platform.

   enum { SlotsPerLong = 2 };

   // A constructor only used by the ADLC output.  All mask fields are filled

   // in directly.  Calls to this look something like RM(1,2,3,4);

   RegMask(

 #   define BODY(I) int a##I,

     FORALL_BODY

 #   undef BODY

     int dummy = 0 ) {

 #   define BODY(I) _A[I] = a##I;

     FORALL_BODY

 #   undef BODY

   }

   // Handy copying constructor

   RegMask( RegMask *rm ) {

 #   define BODY(I) _A[I] = rm->_A[I];

     FORALL_BODY

 #   undef BODY

   }

   // Construct an empty mask

   RegMask( ) { Clear(); }

   // Construct a mask with a single bit

   RegMask( OptoReg::Name reg ) { Clear(); Insert(reg); }

   // Check for register being in mask

   int Member( OptoReg::Name reg ) const {

     assert( reg < CHUNK_SIZE, "" );

     return _A[reg>>_LogWordBits] & (1<<(reg&(_WordBits-1)));

   }

   // The last bit in the register mask indicates that the mask should repeat

   // indefinitely with ONE bits.  Returns TRUE if mask is infinite or

   // unbounded in size.  Returns FALSE if mask is finite size.

   int is_AllStack() const { return _A[RM_SIZE-1] >> (_WordBits-1); }

   // Work around an -xO3 optimization problme in WS6U1. The old way:

   //   void set_AllStack() { _A[RM_SIZE-1] |= (1<<(_WordBits-1)); }

   // will cause _A[RM_SIZE-1] to be clobbered, not updated when set_AllStack()

   // follows an Insert() loop, like the one found in init_spill_mask(). Using

   // Insert() instead works because the index into _A in computed instead of

   // constant.  See bug 4665841.

   void set_AllStack() { Insert(OptoReg::Name(CHUNK_SIZE-1)); }

   // Test for being a not-empty mask.

   int is_NotEmpty( ) const {

     int tmp = 0;

 #   define BODY(I) tmp |= _A[I];

     FORALL_BODY

 #   undef BODY

     return tmp;

   }

   // Find lowest-numbered register from mask, or BAD if mask is empty.

   OptoReg::Name find_first_elem() const {

     int base, bits;

 #   define BODY(I) if( (bits = _A[I]) != 0 ) base = I<<_LogWordBits; else

     FORALL_BODY

 #   undef BODY

       { base = OptoReg::Bad; bits = 1<<0; }

     return OptoReg::Name(base + find_lowest_bit(bits));

   }

   // Get highest-numbered register from mask, or BAD if mask is empty.

   OptoReg::Name find_last_elem() const {

     int base, bits;

 #   define BODY(I) if( (bits = _A[RM_SIZE-1-I]) != 0 ) base = (RM_SIZE-1-I)<<_LogWordBits; else

     FORALL_BODY

 #   undef BODY

       { base = OptoReg::Bad; bits = 1<<0; }

     return OptoReg::Name(base + find_hihghest_bit(bits));

   }

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

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

   // Assert that the mask contains only bit pairs.

   OptoReg::Name find_first_pair() const;

   // Clear out partial bits; leave only aligned adjacent bit pairs.

   void ClearToPairs();

   // Smear out partial bits; leave only aligned adjacent bit pairs.

   void SmearToPairs();

   // Verify that the mask contains only aligned adjacent bit pairs

   void VerifyPairs() const { assert( is_aligned_Pairs(), "mask is not aligned, adjacent pairs" ); }

   // Test that the mask contains only aligned adjacent bit pairs

   bool is_aligned_Pairs() const;

   // mask is a pair of misaligned registers

   bool is_misaligned_Pair() const { return Size()==2 && !is_aligned_Pairs();}

   // Test for single register

   int is_bound1() const;

   // Test for a single adjacent pair

   int is_bound2() const;

   // Fast overlap test.  Non-zero if any registers in common.

   int overlap( const RegMask &rm ) const {

     return

 #   define BODY(I) (_A[I] & rm._A[I]) |

     FORALL_BODY

 #   undef BODY

     0 ;

   }

   // Special test for register pressure based splitting

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

   bool is_UP() const;

   // Clear a register mask

   void Clear( ) {

 #   define BODY(I) _A[I] = 0;

     FORALL_BODY

 #   undef BODY

   }

   // Fill a register mask with 1's

   void Set_All( ) {

 #   define BODY(I) _A[I] = -1;

     FORALL_BODY

 #   undef BODY

   }

   // Insert register into mask

   void Insert( OptoReg::Name reg ) {

     assert( reg < CHUNK_SIZE, "" );

     _A[reg>>_LogWordBits] |= (1<<(reg&(_WordBits-1)));

   }

   // Remove register from mask

   void Remove( OptoReg::Name reg ) {

     assert( reg < CHUNK_SIZE, "" );

     _A[reg>>_LogWordBits] &= ~(1<<(reg&(_WordBits-1)));

   }

   // OR 'rm' into 'this'

   void OR( const RegMask &rm ) {

 #   define BODY(I) this->_A[I] |= rm._A[I];

     FORALL_BODY

 #   undef BODY

   }

   // AND 'rm' into 'this'

   void AND( const RegMask &rm ) {

 #   define BODY(I) this->_A[I] &= rm._A[I];

     FORALL_BODY

 #   undef BODY

   }

   // Subtract 'rm' from 'this'

   void SUBTRACT( const RegMask &rm ) {

 #   define BODY(I) _A[I] &= ~rm._A[I];

     FORALL_BODY

 #   undef BODY

   }

   // Compute size of register mask: number of bits

   uint Size() const;

 #ifndef PRODUCT

   void print() const { dump(); }

   void dump() const;            // Print a mask

 #endif

   static const RegMask Empty;   // Common empty mask

   static bool can_represent(OptoReg::Name reg) {

     // NOTE: -1 in computation reflects the usage of the last

     //       bit of the regmask as an infinite stack flag.

     return (int)reg < (int)(CHUNK_SIZE-1);

   }

 };

 // Do not use this constant directly in client code!

 #undef RM_SIZE