1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25 #ifndef SHARE_VM_OPTO_REGMASK_HPP
26 #define SHARE_VM_OPTO_REGMASK_HPP
27
28 #include "code/vmreg.hpp"
29 #include "libadt/port.hpp"
30 #include "opto/optoreg.hpp"
31 #ifdef TARGET_ARCH_MODEL_x86_32
32 # include "adfiles/adGlobals_x86_32.hpp"
33 #endif
34 #ifdef TARGET_ARCH_MODEL_x86_64
35 # include "adfiles/adGlobals_x86_64.hpp"
36 #endif
37 #ifdef TARGET_ARCH_MODEL_sparc
38 # include "adfiles/adGlobals_sparc.hpp"
39 #endif
40 #ifdef TARGET_ARCH_MODEL_zero
41 # include "adfiles/adGlobals_zero.hpp"
42 #endif
43
44 // Some fun naming (textual) substitutions:
45 //
46 // RegMask::get_low_elem() ==> RegMask::find_first_elem()
47 // RegMask::Special ==> RegMask::Empty
48 // RegMask::_flags ==> RegMask::is_AllStack()
49 // RegMask::operator<<=() ==> RegMask::Insert()
50 // RegMask::operator>>=() ==> RegMask::Remove()
51 // RegMask::Union() ==> RegMask::OR
52 // RegMask::Inter() ==> RegMask::AND
53 //
54 // OptoRegister::RegName ==> OptoReg::Name
55 //
56 // OptoReg::stack0() ==> _last_Mach_Reg or ZERO in core version
57 //
58 // numregs in chaitin ==> proper degree in chaitin
59
60 //-------------Non-zero bit search methods used by RegMask---------------------
61 // Find lowest 1, or return 32 if empty
62 int find_lowest_bit( uint32 mask );
63 // Find highest 1, or return 32 if empty
64 int find_hihghest_bit( uint32 mask );
65
66 //------------------------------RegMask----------------------------------------
67 // The ADL file describes how to print the machine-specific registers, as well
68 // as any notion of register classes. We provide a register mask, which is
69 // just a collection of Register numbers.
70
71 // The ADLC defines 2 macros, RM_SIZE and FORALL_BODY.
72 // RM_SIZE is the size of a register mask in words.
73 // FORALL_BODY replicates a BODY macro once per word in the register mask.
74 // The usage is somewhat clumsy and limited to the regmask.[h,c]pp files.
75 // However, it means the ADLC can redefine the unroll macro and all loops
76 // over register masks will be unrolled by the correct amount.
77
78 class RegMask VALUE_OBJ_CLASS_SPEC {
79 union {
80 double _dummy_force_double_alignment[RM_SIZE>>1];
81 // Array of Register Mask bits. This array is large enough to cover
82 // all the machine registers and all parameters that need to be passed
83 // on the stack (stack registers) up to some interesting limit. Methods
84 // that need more parameters will NOT be compiled. On Intel, the limit
85 // is something like 90+ parameters.
86 int _A[RM_SIZE];
87 };
88
89 enum {
90 _WordBits = BitsPerInt,
91 _LogWordBits = LogBitsPerInt,
92 _RM_SIZE = RM_SIZE // local constant, imported, then hidden by #undef
93 };
94
95 public:
96 enum { CHUNK_SIZE = RM_SIZE*_WordBits };
97
98 // SlotsPerLong is 2, since slots are 32 bits and longs are 64 bits.
99 // Also, consider the maximum alignment size for a normally allocated
100 // value. Since we allocate register pairs but not register quads (at
101 // present), this alignment is SlotsPerLong (== 2). A normally
102 // aligned allocated register is either a single register, or a pair
103 // of adjacent registers, the lower-numbered being even.
104 // See also is_aligned_Pairs() below, and the padding added before
105 // Matcher::_new_SP to keep allocated pairs aligned properly.
106 // If we ever go to quad-word allocations, SlotsPerQuad will become
107 // the controlling alignment constraint. Note that this alignment
108 // requirement is internal to the allocator, and independent of any
109 // particular platform.
110 enum { SlotsPerLong = 2 };
111
112 // A constructor only used by the ADLC output. All mask fields are filled
113 // in directly. Calls to this look something like RM(1,2,3,4);
114 RegMask(
115 # define BODY(I) int a##I,
116 FORALL_BODY
117 # undef BODY
118 int dummy = 0 ) {
119 # define BODY(I) _A[I] = a##I;
120 FORALL_BODY
121 # undef BODY
122 }
123
124 // Handy copying constructor
125 RegMask( RegMask *rm ) {
126 # define BODY(I) _A[I] = rm->_A[I];
127 FORALL_BODY
128 # undef BODY
129 }
130
131 // Construct an empty mask
132 RegMask( ) { Clear(); }
133
134 // Construct a mask with a single bit
135 RegMask( OptoReg::Name reg ) { Clear(); Insert(reg); }
136
137 // Check for register being in mask
138 int Member( OptoReg::Name reg ) const {
139 assert( reg < CHUNK_SIZE, "" );
140 return _A[reg>>_LogWordBits] & (1<<(reg&(_WordBits-1)));
141 }
142
143 // The last bit in the register mask indicates that the mask should repeat
144 // indefinitely with ONE bits. Returns TRUE if mask is infinite or
145 // unbounded in size. Returns FALSE if mask is finite size.
146 int is_AllStack() const { return _A[RM_SIZE-1] >> (_WordBits-1); }
147
148 // Work around an -xO3 optimization problme in WS6U1. The old way:
149 // void set_AllStack() { _A[RM_SIZE-1] |= (1<<(_WordBits-1)); }
150 // will cause _A[RM_SIZE-1] to be clobbered, not updated when set_AllStack()
151 // follows an Insert() loop, like the one found in init_spill_mask(). Using
152 // Insert() instead works because the index into _A in computed instead of
153 // constant. See bug 4665841.
154 void set_AllStack() { Insert(OptoReg::Name(CHUNK_SIZE-1)); }
155
156 // Test for being a not-empty mask.
157 int is_NotEmpty( ) const {
158 int tmp = 0;
159 # define BODY(I) tmp |= _A[I];
160 FORALL_BODY
161 # undef BODY
162 return tmp;
163 }
164
165 // Find lowest-numbered register from mask, or BAD if mask is empty.
166 OptoReg::Name find_first_elem() const {
167 int base, bits;
168 # define BODY(I) if( (bits = _A[I]) != 0 ) base = I<<_LogWordBits; else
169 FORALL_BODY
170 # undef BODY
171 { base = OptoReg::Bad; bits = 1<<0; }
172 return OptoReg::Name(base + find_lowest_bit(bits));
173 }
174 // Get highest-numbered register from mask, or BAD if mask is empty.
175 OptoReg::Name find_last_elem() const {
176 int base, bits;
177 # define BODY(I) if( (bits = _A[RM_SIZE-1-I]) != 0 ) base = (RM_SIZE-1-I)<<_LogWordBits; else
178 FORALL_BODY
179 # undef BODY
180 { base = OptoReg::Bad; bits = 1<<0; }
181 return OptoReg::Name(base + find_hihghest_bit(bits));
182 }
183
184 // Find the lowest-numbered register pair in the mask. Return the
185 // HIGHEST register number in the pair, or BAD if no pairs.
186 // Assert that the mask contains only bit pairs.
187 OptoReg::Name find_first_pair() const;
188
189 // Clear out partial bits; leave only aligned adjacent bit pairs.
190 void ClearToPairs();
191 // Smear out partial bits; leave only aligned adjacent bit pairs.
192 void SmearToPairs();
193 // Verify that the mask contains only aligned adjacent bit pairs
194 void VerifyPairs() const { assert( is_aligned_Pairs(), "mask is not aligned, adjacent pairs" ); }
195 // Test that the mask contains only aligned adjacent bit pairs
196 bool is_aligned_Pairs() const;
197
198 // mask is a pair of misaligned registers
199 bool is_misaligned_Pair() const { return Size()==2 && !is_aligned_Pairs();}
200 // Test for single register
201 int is_bound1() const;
202 // Test for a single adjacent pair
203 int is_bound2() const;
204
205 // Fast overlap test. Non-zero if any registers in common.
206 int overlap( const RegMask &rm ) const {
207 return
208 # define BODY(I) (_A[I] & rm._A[I]) |
209 FORALL_BODY
210 # undef BODY
211 0 ;
212 }
213
214 // Special test for register pressure based splitting
215 // UP means register only, Register plus stack, or stack only is DOWN
216 bool is_UP() const;
217
218 // Clear a register mask
219 void Clear( ) {
220 # define BODY(I) _A[I] = 0;
221 FORALL_BODY
222 # undef BODY
223 }
224
225 // Fill a register mask with 1's
226 void Set_All( ) {
227 # define BODY(I) _A[I] = -1;
228 FORALL_BODY
229 # undef BODY
230 }
231
232 // Insert register into mask
233 void Insert( OptoReg::Name reg ) {
234 assert( reg < CHUNK_SIZE, "" );
235 _A[reg>>_LogWordBits] |= (1<<(reg&(_WordBits-1)));
236 }
237
238 // Remove register from mask
239 void Remove( OptoReg::Name reg ) {
240 assert( reg < CHUNK_SIZE, "" );
241 _A[reg>>_LogWordBits] &= ~(1<<(reg&(_WordBits-1)));
242 }
243
244 // OR 'rm' into 'this'
245 void OR( const RegMask &rm ) {
246 # define BODY(I) this->_A[I] |= rm._A[I];
247 FORALL_BODY
248 # undef BODY
249 }
250
251 // AND 'rm' into 'this'
252 void AND( const RegMask &rm ) {
253 # define BODY(I) this->_A[I] &= rm._A[I];
254 FORALL_BODY
255 # undef BODY
256 }
257
258 // Subtract 'rm' from 'this'
259 void SUBTRACT( const RegMask &rm ) {
260 # define BODY(I) _A[I] &= ~rm._A[I];
261 FORALL_BODY
262 # undef BODY
263 }
264
265 // Compute size of register mask: number of bits
266 uint Size() const;
267
268 #ifndef PRODUCT
269 void print() const { dump(); }
270 void dump() const; // Print a mask
271 #endif
272
273 static const RegMask Empty; // Common empty mask
274
275 static bool can_represent(OptoReg::Name reg) {
276 // NOTE: -1 in computation reflects the usage of the last
277 // bit of the regmask as an infinite stack flag.
278 return (int)reg < (int)(CHUNK_SIZE-1);
279 }
280 };
281
282 // Do not use this constant directly in client code!
283 #undef RM_SIZE
284
285 #endif // SHARE_VM_OPTO_REGMASK_HPP