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comparison src/share/vm/opto/regmask.cpp @ 0:a61af66fc99e jdk7-b24

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author duke
date Sat, 01 Dec 2007 00:00:00 +0000
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1 /*
2 * Copyright 1997-2006 Sun Microsystems, Inc. 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.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_regmask.cpp.incl"
27
28 #define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */
29
30 //-------------Non-zero bit search methods used by RegMask---------------------
31 // Find lowest 1, or return 32 if empty
32 int find_lowest_bit( uint32 mask ) {
33 int n = 0;
34 if( (mask & 0xffff) == 0 ) {
35 mask >>= 16;
36 n += 16;
37 }
38 if( (mask & 0xff) == 0 ) {
39 mask >>= 8;
40 n += 8;
41 }
42 if( (mask & 0xf) == 0 ) {
43 mask >>= 4;
44 n += 4;
45 }
46 if( (mask & 0x3) == 0 ) {
47 mask >>= 2;
48 n += 2;
49 }
50 if( (mask & 0x1) == 0 ) {
51 mask >>= 1;
52 n += 1;
53 }
54 if( mask == 0 ) {
55 n = 32;
56 }
57 return n;
58 }
59
60 // Find highest 1, or return 32 if empty
61 int find_hihghest_bit( uint32 mask ) {
62 int n = 0;
63 if( mask > 0xffff ) {
64 mask >>= 16;
65 n += 16;
66 }
67 if( mask > 0xff ) {
68 mask >>= 8;
69 n += 8;
70 }
71 if( mask > 0xf ) {
72 mask >>= 4;
73 n += 4;
74 }
75 if( mask > 0x3 ) {
76 mask >>= 2;
77 n += 2;
78 }
79 if( mask > 0x1 ) {
80 mask >>= 1;
81 n += 1;
82 }
83 if( mask == 0 ) {
84 n = 32;
85 }
86 return n;
87 }
88
89 //------------------------------dump-------------------------------------------
90
91 #ifndef PRODUCT
92 void OptoReg::dump( int r ) {
93 switch( r ) {
94 case Special: tty->print("r---"); break;
95 case Bad: tty->print("rBAD"); break;
96 default:
97 if( r < _last_Mach_Reg ) tty->print(Matcher::regName[r]);
98 else tty->print("rS%d",r);
99 break;
100 }
101 }
102 #endif
103
104
105 //=============================================================================
106 const RegMask RegMask::Empty(
107 # define BODY(I) 0,
108 FORALL_BODY
109 # undef BODY
110 0
111 );
112
113 //------------------------------find_first_pair--------------------------------
114 // Find the lowest-numbered register pair in the mask. Return the
115 // HIGHEST register number in the pair, or BAD if no pairs.
116 OptoReg::Name RegMask::find_first_pair() const {
117 VerifyPairs();
118 for( int i = 0; i < RM_SIZE; i++ ) {
119 if( _A[i] ) { // Found some bits
120 int bit = _A[i] & -_A[i]; // Extract low bit
121 // Convert to bit number, return hi bit in pair
122 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);
123 }
124 }
125 return OptoReg::Bad;
126 }
127
128 //------------------------------ClearToPairs-----------------------------------
129 // Clear out partial bits; leave only bit pairs
130 void RegMask::ClearToPairs() {
131 for( int i = 0; i < RM_SIZE; i++ ) {
132 int bits = _A[i];
133 bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair
134 bits |= (bits>>1); // Smear 1 hi-bit into a pair
135 _A[i] = bits;
136 }
137 VerifyPairs();
138 }
139
140 //------------------------------SmearToPairs-----------------------------------
141 // Smear out partial bits; leave only bit pairs
142 void RegMask::SmearToPairs() {
143 for( int i = 0; i < RM_SIZE; i++ ) {
144 int bits = _A[i];
145 bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair
146 bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair
147 _A[i] = bits;
148 }
149 VerifyPairs();
150 }
151
152 //------------------------------is_aligned_pairs-------------------------------
153 bool RegMask::is_aligned_Pairs() const {
154 // Assert that the register mask contains only bit pairs.
155 for( int i = 0; i < RM_SIZE; i++ ) {
156 int bits = _A[i];
157 while( bits ) { // Check bits for pairing
158 int bit = bits & -bits; // Extract low bit
159 // Low bit is not odd means its mis-aligned.
160 if( (bit & 0x55555555) == 0 ) return false;
161 bits -= bit; // Remove bit from mask
162 // Check for aligned adjacent bit
163 if( (bits & (bit<<1)) == 0 ) return false;
164 bits -= (bit<<1); // Remove other halve of pair
165 }
166 }
167 return true;
168 }
169
170 //------------------------------is_bound1--------------------------------------
171 // Return TRUE if the mask contains a single bit
172 int RegMask::is_bound1() const {
173 if( is_AllStack() ) return false;
174 int bit = -1; // Set to hold the one bit allowed
175 for( int i = 0; i < RM_SIZE; i++ ) {
176 if( _A[i] ) { // Found some bits
177 if( bit != -1 ) return false; // Already had bits, so fail
178 bit = _A[i] & -_A[i]; // Extract 1 bit from mask
179 if( bit != _A[i] ) return false; // Found many bits, so fail
180 }
181 }
182 // True for both the empty mask and for a single bit
183 return true;
184 }
185
186 //------------------------------is_bound2--------------------------------------
187 // Return TRUE if the mask contains an adjacent pair of bits and no other bits.
188 int RegMask::is_bound2() const {
189 if( is_AllStack() ) return false;
190
191 int bit = -1; // Set to hold the one bit allowed
192 for( int i = 0; i < RM_SIZE; i++ ) {
193 if( _A[i] ) { // Found some bits
194 if( bit != -1 ) return false; // Already had bits, so fail
195 bit = _A[i] & -(_A[i]); // Extract 1 bit from mask
196 if( (bit << 1) != 0 ) { // Bit pair stays in same word?
197 if( (bit | (bit<<1)) != _A[i] )
198 return false; // Require adjacent bit pair and no more bits
199 } else { // Else its a split-pair case
200 if( bit != _A[i] ) return false; // Found many bits, so fail
201 i++; // Skip iteration forward
202 if( _A[i] != 1 ) return false; // Require 1 lo bit in next word
203 }
204 }
205 }
206 // True for both the empty mask and for a bit pair
207 return true;
208 }
209
210 //------------------------------is_UP------------------------------------------
211 // UP means register only, Register plus stack, or stack only is DOWN
212 bool RegMask::is_UP() const {
213 // Quick common case check for DOWN (any stack slot is legal)
214 if( is_AllStack() )
215 return false;
216 // Slower check for any stack bits set (also DOWN)
217 if( overlap(Matcher::STACK_ONLY_mask) )
218 return false;
219 // Not DOWN, so must be UP
220 return true;
221 }
222
223 //------------------------------Size-------------------------------------------
224 // Compute size of register mask in bits
225 uint RegMask::Size() const {
226 extern uint8 bitsInByte[256];
227 uint sum = 0;
228 for( int i = 0; i < RM_SIZE; i++ )
229 sum +=
230 bitsInByte[(_A[i]>>24) & 0xff] +
231 bitsInByte[(_A[i]>>16) & 0xff] +
232 bitsInByte[(_A[i]>> 8) & 0xff] +
233 bitsInByte[ _A[i] & 0xff];
234 return sum;
235 }
236
237 #ifndef PRODUCT
238 //------------------------------print------------------------------------------
239 void RegMask::dump( ) const {
240 tty->print("[");
241 RegMask rm = *this; // Structure copy into local temp
242
243 OptoReg::Name start = rm.find_first_elem(); // Get a register
244 if( OptoReg::is_valid(start) ) { // Check for empty mask
245 rm.Remove(start); // Yank from mask
246 OptoReg::dump(start); // Print register
247 OptoReg::Name last = start;
248
249 // Now I have printed an initial register.
250 // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".
251 // Begin looping over the remaining registers.
252 while( 1 ) { //
253 OptoReg::Name reg = rm.find_first_elem(); // Get a register
254 if( !OptoReg::is_valid(reg) )
255 break; // Empty mask, end loop
256 rm.Remove(reg); // Yank from mask
257
258 if( last+1 == reg ) { // See if they are adjacent
259 // Adjacent registers just collect into long runs, no printing.
260 last = reg;
261 } else { // Ending some kind of run
262 if( start == last ) { // 1-register run; no special printing
263 } else if( start+1 == last ) {
264 tty->print(","); // 2-register run; print as "rX,rY"
265 OptoReg::dump(last);
266 } else { // Multi-register run; print as "rX-rZ"
267 tty->print("-");
268 OptoReg::dump(last);
269 }
270 tty->print(","); // Seperate start of new run
271 start = last = reg; // Start a new register run
272 OptoReg::dump(start); // Print register
273 } // End of if ending a register run or not
274 } // End of while regmask not empty
275
276 if( start == last ) { // 1-register run; no special printing
277 } else if( start+1 == last ) {
278 tty->print(","); // 2-register run; print as "rX,rY"
279 OptoReg::dump(last);
280 } else { // Multi-register run; print as "rX-rZ"
281 tty->print("-");
282 OptoReg::dump(last);
283 }
284 if( rm.is_AllStack() ) tty->print("...");
285 }
286 tty->print("]");
287 }
288 #endif