src/share/vm/opto/regmask.hpp

Sat, 01 Dec 2007 00:00:00 +0000

author
duke
date
Sat, 01 Dec 2007 00:00:00 +0000
changeset 435
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duke@435 1 /*
duke@435 2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 // Some fun naming (textual) substitutions:
duke@435 26 //
duke@435 27 // RegMask::get_low_elem() ==> RegMask::find_first_elem()
duke@435 28 // RegMask::Special ==> RegMask::Empty
duke@435 29 // RegMask::_flags ==> RegMask::is_AllStack()
duke@435 30 // RegMask::operator<<=() ==> RegMask::Insert()
duke@435 31 // RegMask::operator>>=() ==> RegMask::Remove()
duke@435 32 // RegMask::Union() ==> RegMask::OR
duke@435 33 // RegMask::Inter() ==> RegMask::AND
duke@435 34 //
duke@435 35 // OptoRegister::RegName ==> OptoReg::Name
duke@435 36 //
duke@435 37 // OptoReg::stack0() ==> _last_Mach_Reg or ZERO in core version
duke@435 38 //
duke@435 39 // numregs in chaitin ==> proper degree in chaitin
duke@435 40
duke@435 41 //-------------Non-zero bit search methods used by RegMask---------------------
duke@435 42 // Find lowest 1, or return 32 if empty
duke@435 43 int find_lowest_bit( uint32 mask );
duke@435 44 // Find highest 1, or return 32 if empty
duke@435 45 int find_hihghest_bit( uint32 mask );
duke@435 46
duke@435 47 //------------------------------RegMask----------------------------------------
duke@435 48 // The ADL file describes how to print the machine-specific registers, as well
duke@435 49 // as any notion of register classes. We provide a register mask, which is
duke@435 50 // just a collection of Register numbers.
duke@435 51
duke@435 52 // The ADLC defines 2 macros, RM_SIZE and FORALL_BODY.
duke@435 53 // RM_SIZE is the size of a register mask in words.
duke@435 54 // FORALL_BODY replicates a BODY macro once per word in the register mask.
duke@435 55 // The usage is somewhat clumsy and limited to the regmask.[h,c]pp files.
duke@435 56 // However, it means the ADLC can redefine the unroll macro and all loops
duke@435 57 // over register masks will be unrolled by the correct amount.
duke@435 58
duke@435 59 class RegMask VALUE_OBJ_CLASS_SPEC {
duke@435 60 union {
duke@435 61 double _dummy_force_double_alignment[RM_SIZE>>1];
duke@435 62 // Array of Register Mask bits. This array is large enough to cover
duke@435 63 // all the machine registers and all parameters that need to be passed
duke@435 64 // on the stack (stack registers) up to some interesting limit. Methods
duke@435 65 // that need more parameters will NOT be compiled. On Intel, the limit
duke@435 66 // is something like 90+ parameters.
duke@435 67 int _A[RM_SIZE];
duke@435 68 };
duke@435 69
duke@435 70 enum {
duke@435 71 _WordBits = BitsPerInt,
duke@435 72 _LogWordBits = LogBitsPerInt,
duke@435 73 _RM_SIZE = RM_SIZE // local constant, imported, then hidden by #undef
duke@435 74 };
duke@435 75
duke@435 76 public:
duke@435 77 enum { CHUNK_SIZE = RM_SIZE*_WordBits };
duke@435 78
duke@435 79 // SlotsPerLong is 2, since slots are 32 bits and longs are 64 bits.
duke@435 80 // Also, consider the maximum alignment size for a normally allocated
duke@435 81 // value. Since we allocate register pairs but not register quads (at
duke@435 82 // present), this alignment is SlotsPerLong (== 2). A normally
duke@435 83 // aligned allocated register is either a single register, or a pair
duke@435 84 // of adjacent registers, the lower-numbered being even.
duke@435 85 // See also is_aligned_Pairs() below, and the padding added before
duke@435 86 // Matcher::_new_SP to keep allocated pairs aligned properly.
duke@435 87 // If we ever go to quad-word allocations, SlotsPerQuad will become
duke@435 88 // the controlling alignment constraint. Note that this alignment
duke@435 89 // requirement is internal to the allocator, and independent of any
duke@435 90 // particular platform.
duke@435 91 enum { SlotsPerLong = 2 };
duke@435 92
duke@435 93 // A constructor only used by the ADLC output. All mask fields are filled
duke@435 94 // in directly. Calls to this look something like RM(1,2,3,4);
duke@435 95 RegMask(
duke@435 96 # define BODY(I) int a##I,
duke@435 97 FORALL_BODY
duke@435 98 # undef BODY
duke@435 99 int dummy = 0 ) {
duke@435 100 # define BODY(I) _A[I] = a##I;
duke@435 101 FORALL_BODY
duke@435 102 # undef BODY
duke@435 103 }
duke@435 104
duke@435 105 // Handy copying constructor
duke@435 106 RegMask( RegMask *rm ) {
duke@435 107 # define BODY(I) _A[I] = rm->_A[I];
duke@435 108 FORALL_BODY
duke@435 109 # undef BODY
duke@435 110 }
duke@435 111
duke@435 112 // Construct an empty mask
duke@435 113 RegMask( ) { Clear(); }
duke@435 114
duke@435 115 // Construct a mask with a single bit
duke@435 116 RegMask( OptoReg::Name reg ) { Clear(); Insert(reg); }
duke@435 117
duke@435 118 // Check for register being in mask
duke@435 119 int Member( OptoReg::Name reg ) const {
duke@435 120 assert( reg < CHUNK_SIZE, "" );
duke@435 121 return _A[reg>>_LogWordBits] & (1<<(reg&(_WordBits-1)));
duke@435 122 }
duke@435 123
duke@435 124 // The last bit in the register mask indicates that the mask should repeat
duke@435 125 // indefinitely with ONE bits. Returns TRUE if mask is infinite or
duke@435 126 // unbounded in size. Returns FALSE if mask is finite size.
duke@435 127 int is_AllStack() const { return _A[RM_SIZE-1] >> (_WordBits-1); }
duke@435 128
duke@435 129 // Work around an -xO3 optimization problme in WS6U1. The old way:
duke@435 130 // void set_AllStack() { _A[RM_SIZE-1] |= (1<<(_WordBits-1)); }
duke@435 131 // will cause _A[RM_SIZE-1] to be clobbered, not updated when set_AllStack()
duke@435 132 // follows an Insert() loop, like the one found in init_spill_mask(). Using
duke@435 133 // Insert() instead works because the index into _A in computed instead of
duke@435 134 // constant. See bug 4665841.
duke@435 135 void set_AllStack() { Insert(OptoReg::Name(CHUNK_SIZE-1)); }
duke@435 136
duke@435 137 // Test for being a not-empty mask.
duke@435 138 int is_NotEmpty( ) const {
duke@435 139 int tmp = 0;
duke@435 140 # define BODY(I) tmp |= _A[I];
duke@435 141 FORALL_BODY
duke@435 142 # undef BODY
duke@435 143 return tmp;
duke@435 144 }
duke@435 145
duke@435 146 // Find lowest-numbered register from mask, or BAD if mask is empty.
duke@435 147 OptoReg::Name find_first_elem() const {
duke@435 148 int base, bits;
duke@435 149 # define BODY(I) if( (bits = _A[I]) != 0 ) base = I<<_LogWordBits; else
duke@435 150 FORALL_BODY
duke@435 151 # undef BODY
duke@435 152 { base = OptoReg::Bad; bits = 1<<0; }
duke@435 153 return OptoReg::Name(base + find_lowest_bit(bits));
duke@435 154 }
duke@435 155 // Get highest-numbered register from mask, or BAD if mask is empty.
duke@435 156 OptoReg::Name find_last_elem() const {
duke@435 157 int base, bits;
duke@435 158 # define BODY(I) if( (bits = _A[RM_SIZE-1-I]) != 0 ) base = (RM_SIZE-1-I)<<_LogWordBits; else
duke@435 159 FORALL_BODY
duke@435 160 # undef BODY
duke@435 161 { base = OptoReg::Bad; bits = 1<<0; }
duke@435 162 return OptoReg::Name(base + find_hihghest_bit(bits));
duke@435 163 }
duke@435 164
duke@435 165 // Find the lowest-numbered register pair in the mask. Return the
duke@435 166 // HIGHEST register number in the pair, or BAD if no pairs.
duke@435 167 // Assert that the mask contains only bit pairs.
duke@435 168 OptoReg::Name find_first_pair() const;
duke@435 169
duke@435 170 // Clear out partial bits; leave only aligned adjacent bit pairs.
duke@435 171 void ClearToPairs();
duke@435 172 // Smear out partial bits; leave only aligned adjacent bit pairs.
duke@435 173 void SmearToPairs();
duke@435 174 // Verify that the mask contains only aligned adjacent bit pairs
duke@435 175 void VerifyPairs() const { assert( is_aligned_Pairs(), "mask is not aligned, adjacent pairs" ); }
duke@435 176 // Test that the mask contains only aligned adjacent bit pairs
duke@435 177 bool is_aligned_Pairs() const;
duke@435 178
duke@435 179 // mask is a pair of misaligned registers
duke@435 180 bool is_misaligned_Pair() const { return Size()==2 && !is_aligned_Pairs();}
duke@435 181 // Test for single register
duke@435 182 int is_bound1() const;
duke@435 183 // Test for a single adjacent pair
duke@435 184 int is_bound2() const;
duke@435 185
duke@435 186 // Fast overlap test. Non-zero if any registers in common.
duke@435 187 int overlap( const RegMask &rm ) const {
duke@435 188 return
duke@435 189 # define BODY(I) (_A[I] & rm._A[I]) |
duke@435 190 FORALL_BODY
duke@435 191 # undef BODY
duke@435 192 0 ;
duke@435 193 }
duke@435 194
duke@435 195 // Special test for register pressure based splitting
duke@435 196 // UP means register only, Register plus stack, or stack only is DOWN
duke@435 197 bool is_UP() const;
duke@435 198
duke@435 199 // Clear a register mask
duke@435 200 void Clear( ) {
duke@435 201 # define BODY(I) _A[I] = 0;
duke@435 202 FORALL_BODY
duke@435 203 # undef BODY
duke@435 204 }
duke@435 205
duke@435 206 // Fill a register mask with 1's
duke@435 207 void Set_All( ) {
duke@435 208 # define BODY(I) _A[I] = -1;
duke@435 209 FORALL_BODY
duke@435 210 # undef BODY
duke@435 211 }
duke@435 212
duke@435 213 // Insert register into mask
duke@435 214 void Insert( OptoReg::Name reg ) {
duke@435 215 assert( reg < CHUNK_SIZE, "" );
duke@435 216 _A[reg>>_LogWordBits] |= (1<<(reg&(_WordBits-1)));
duke@435 217 }
duke@435 218
duke@435 219 // Remove register from mask
duke@435 220 void Remove( OptoReg::Name reg ) {
duke@435 221 assert( reg < CHUNK_SIZE, "" );
duke@435 222 _A[reg>>_LogWordBits] &= ~(1<<(reg&(_WordBits-1)));
duke@435 223 }
duke@435 224
duke@435 225 // OR 'rm' into 'this'
duke@435 226 void OR( const RegMask &rm ) {
duke@435 227 # define BODY(I) this->_A[I] |= rm._A[I];
duke@435 228 FORALL_BODY
duke@435 229 # undef BODY
duke@435 230 }
duke@435 231
duke@435 232 // AND 'rm' into 'this'
duke@435 233 void AND( const RegMask &rm ) {
duke@435 234 # define BODY(I) this->_A[I] &= rm._A[I];
duke@435 235 FORALL_BODY
duke@435 236 # undef BODY
duke@435 237 }
duke@435 238
duke@435 239 // Subtract 'rm' from 'this'
duke@435 240 void SUBTRACT( const RegMask &rm ) {
duke@435 241 # define BODY(I) _A[I] &= ~rm._A[I];
duke@435 242 FORALL_BODY
duke@435 243 # undef BODY
duke@435 244 }
duke@435 245
duke@435 246 // Compute size of register mask: number of bits
duke@435 247 uint Size() const;
duke@435 248
duke@435 249 #ifndef PRODUCT
duke@435 250 void print() const { dump(); }
duke@435 251 void dump() const; // Print a mask
duke@435 252 #endif
duke@435 253
duke@435 254 static const RegMask Empty; // Common empty mask
duke@435 255
duke@435 256 static bool can_represent(OptoReg::Name reg) {
duke@435 257 // NOTE: -1 in computation reflects the usage of the last
duke@435 258 // bit of the regmask as an infinite stack flag.
duke@435 259 return (int)reg < (int)(CHUNK_SIZE-1);
duke@435 260 }
duke@435 261 };
duke@435 262
duke@435 263 // Do not use this constant directly in client code!
duke@435 264 #undef RM_SIZE

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