1 /*
2 * Copyright (c) 1997, 2014, 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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "opto/ad.hpp"
27 #include "opto/compile.hpp"
28 #include "opto/regmask.hpp"
29
30 #define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */
31
32 //-------------Non-zero bit search methods used by RegMask---------------------
33 // Find lowest 1, or return 32 if empty
34 int find_lowest_bit( uint32_t mask ) {
35 int n = 0;
36 if( (mask & 0xffff) == 0 ) {
37 mask >>= 16;
38 n += 16;
39 }
40 if( (mask & 0xff) == 0 ) {
41 mask >>= 8;
42 n += 8;
43 }
44 if( (mask & 0xf) == 0 ) {
45 mask >>= 4;
46 n += 4;
47 }
48 if( (mask & 0x3) == 0 ) {
49 mask >>= 2;
50 n += 2;
51 }
52 if( (mask & 0x1) == 0 ) {
53 mask >>= 1;
54 n += 1;
55 }
56 if( mask == 0 ) {
57 n = 32;
58 }
59 return n;
60 }
61
62 // Find highest 1, or return 32 if empty
63 int find_hihghest_bit( uint32_t mask ) {
64 int n = 0;
65 if( mask > 0xffff ) {
66 mask >>= 16;
67 n += 16;
68 }
69 if( mask > 0xff ) {
70 mask >>= 8;
71 n += 8;
72 }
73 if( mask > 0xf ) {
74 mask >>= 4;
75 n += 4;
76 }
77 if( mask > 0x3 ) {
78 mask >>= 2;
79 n += 2;
80 }
81 if( mask > 0x1 ) {
82 mask >>= 1;
83 n += 1;
84 }
85 if( mask == 0 ) {
86 n = 32;
87 }
88 return n;
89 }
90
91 //------------------------------dump-------------------------------------------
92
93 #ifndef PRODUCT
94 void OptoReg::dump(int r, outputStream *st) {
95 switch (r) {
96 case Special: st->print("r---"); break;
97 case Bad: st->print("rBAD"); break;
98 default:
99 if (r < _last_Mach_Reg) st->print("%s", Matcher::regName[r]);
100 else st->print("rS%d",r);
101 break;
102 }
103 }
104 #endif
105
106
107 //=============================================================================
108 const RegMask RegMask::Empty(
109 # define BODY(I) 0,
110 FORALL_BODY
111 # undef BODY
112 0
113 );
114
115 //=============================================================================
116 bool RegMask::is_vector(uint ireg) {
117 return (ireg == Op_VecS || ireg == Op_VecD || ireg == Op_VecX || ireg == Op_VecY);
118 }
119
120 int RegMask::num_registers(uint ireg) {
121 switch(ireg) {
122 case Op_VecY:
123 return 8;
124 case Op_VecX:
125 return 4;
126 case Op_VecD:
127 case Op_RegD:
128 case Op_RegL:
129 #ifdef _LP64
130 case Op_RegP:
131 #endif
132 return 2;
133 }
134 // Op_VecS and the rest ideal registers.
135 return 1;
136 }
137
138 //------------------------------find_first_pair--------------------------------
139 // Find the lowest-numbered register pair in the mask. Return the
140 // HIGHEST register number in the pair, or BAD if no pairs.
141 OptoReg::Name RegMask::find_first_pair() const {
142 verify_pairs();
143 for( int i = 0; i < RM_SIZE; i++ ) {
144 if( _A[i] ) { // Found some bits
145 int bit = _A[i] & -_A[i]; // Extract low bit
146 // Convert to bit number, return hi bit in pair
147 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);
148 }
149 }
150 return OptoReg::Bad;
151 }
152
153 //------------------------------ClearToPairs-----------------------------------
154 // Clear out partial bits; leave only bit pairs
155 void RegMask::clear_to_pairs() {
156 for( int i = 0; i < RM_SIZE; i++ ) {
157 int bits = _A[i];
158 bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair
159 bits |= (bits>>1); // Smear 1 hi-bit into a pair
160 _A[i] = bits;
161 }
162 verify_pairs();
163 }
164
165 //------------------------------SmearToPairs-----------------------------------
166 // Smear out partial bits; leave only bit pairs
167 void RegMask::smear_to_pairs() {
168 for( int i = 0; i < RM_SIZE; i++ ) {
169 int bits = _A[i];
170 bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair
171 bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair
172 _A[i] = bits;
173 }
174 verify_pairs();
175 }
176
177 //------------------------------is_aligned_pairs-------------------------------
178 bool RegMask::is_aligned_pairs() const {
179 // Assert that the register mask contains only bit pairs.
180 for( int i = 0; i < RM_SIZE; i++ ) {
181 int bits = _A[i];
182 while( bits ) { // Check bits for pairing
183 int bit = bits & -bits; // Extract low bit
184 // Low bit is not odd means its mis-aligned.
185 if( (bit & 0x55555555) == 0 ) return false;
186 bits -= bit; // Remove bit from mask
187 // Check for aligned adjacent bit
188 if( (bits & (bit<<1)) == 0 ) return false;
189 bits -= (bit<<1); // Remove other halve of pair
190 }
191 }
192 return true;
193 }
194
195 //------------------------------is_bound1--------------------------------------
196 // Return TRUE if the mask contains a single bit
197 int RegMask::is_bound1() const {
198 if( is_AllStack() ) return false;
199 int bit = -1; // Set to hold the one bit allowed
200 for( int i = 0; i < RM_SIZE; i++ ) {
201 if( _A[i] ) { // Found some bits
202 if( bit != -1 ) return false; // Already had bits, so fail
203 bit = _A[i] & -_A[i]; // Extract 1 bit from mask
204 if( bit != _A[i] ) return false; // Found many bits, so fail
205 }
206 }
207 // True for both the empty mask and for a single bit
208 return true;
209 }
210
211 //------------------------------is_bound2--------------------------------------
212 // Return TRUE if the mask contains an adjacent pair of bits and no other bits.
213 int RegMask::is_bound_pair() const {
214 if( is_AllStack() ) return false;
215
216 int bit = -1; // Set to hold the one bit allowed
217 for( int i = 0; i < RM_SIZE; i++ ) {
218 if( _A[i] ) { // Found some bits
219 if( bit != -1 ) return false; // Already had bits, so fail
220 bit = _A[i] & -(_A[i]); // Extract 1 bit from mask
221 if( (bit << 1) != 0 ) { // Bit pair stays in same word?
222 if( (bit | (bit<<1)) != _A[i] )
223 return false; // Require adjacent bit pair and no more bits
224 } else { // Else its a split-pair case
225 if( bit != _A[i] ) return false; // Found many bits, so fail
226 i++; // Skip iteration forward
227 if( i >= RM_SIZE || _A[i] != 1 )
228 return false; // Require 1 lo bit in next word
229 }
230 }
231 }
232 // True for both the empty mask and for a bit pair
233 return true;
234 }
235
236 static int low_bits[3] = { 0x55555555, 0x11111111, 0x01010101 };
237 //------------------------------find_first_set---------------------------------
238 // Find the lowest-numbered register set in the mask. Return the
239 // HIGHEST register number in the set, or BAD if no sets.
240 // Works also for size 1.
241 OptoReg::Name RegMask::find_first_set(const int size) const {
242 verify_sets(size);
243 for (int i = 0; i < RM_SIZE; i++) {
244 if (_A[i]) { // Found some bits
245 int bit = _A[i] & -_A[i]; // Extract low bit
246 // Convert to bit number, return hi bit in pair
247 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+(size-1));
248 }
249 }
250 return OptoReg::Bad;
251 }
252
253 //------------------------------clear_to_sets----------------------------------
254 // Clear out partial bits; leave only aligned adjacent bit pairs
255 void RegMask::clear_to_sets(const int size) {
256 if (size == 1) return;
257 assert(2 <= size && size <= 8, "update low bits table");
258 assert(is_power_of_2(size), "sanity");
259 int low_bits_mask = low_bits[size>>2];
260 for (int i = 0; i < RM_SIZE; i++) {
261 int bits = _A[i];
262 int sets = (bits & low_bits_mask);
263 for (int j = 1; j < size; j++) {
264 sets = (bits & (sets<<1)); // filter bits which produce whole sets
265 }
266 sets |= (sets>>1); // Smear 1 hi-bit into a set
267 if (size > 2) {
268 sets |= (sets>>2); // Smear 2 hi-bits into a set
269 if (size > 4) {
270 sets |= (sets>>4); // Smear 4 hi-bits into a set
271 }
272 }
273 _A[i] = sets;
274 }
275 verify_sets(size);
276 }
277
278 //------------------------------smear_to_sets----------------------------------
279 // Smear out partial bits to aligned adjacent bit sets
280 void RegMask::smear_to_sets(const int size) {
281 if (size == 1) return;
282 assert(2 <= size && size <= 8, "update low bits table");
283 assert(is_power_of_2(size), "sanity");
284 int low_bits_mask = low_bits[size>>2];
285 for (int i = 0; i < RM_SIZE; i++) {
286 int bits = _A[i];
287 int sets = 0;
288 for (int j = 0; j < size; j++) {
289 sets |= (bits & low_bits_mask); // collect partial bits
290 bits = bits>>1;
291 }
292 sets |= (sets<<1); // Smear 1 lo-bit into a set
293 if (size > 2) {
294 sets |= (sets<<2); // Smear 2 lo-bits into a set
295 if (size > 4) {
296 sets |= (sets<<4); // Smear 4 lo-bits into a set
297 }
298 }
299 _A[i] = sets;
300 }
301 verify_sets(size);
302 }
303
304 //------------------------------is_aligned_set--------------------------------
305 bool RegMask::is_aligned_sets(const int size) const {
306 if (size == 1) return true;
307 assert(2 <= size && size <= 8, "update low bits table");
308 assert(is_power_of_2(size), "sanity");
309 int low_bits_mask = low_bits[size>>2];
310 // Assert that the register mask contains only bit sets.
311 for (int i = 0; i < RM_SIZE; i++) {
312 int bits = _A[i];
313 while (bits) { // Check bits for pairing
314 int bit = bits & -bits; // Extract low bit
315 // Low bit is not odd means its mis-aligned.
316 if ((bit & low_bits_mask) == 0) return false;
317 // Do extra work since (bit << size) may overflow.
318 int hi_bit = bit << (size-1); // high bit
319 int set = hi_bit + ((hi_bit-1) & ~(bit-1));
320 // Check for aligned adjacent bits in this set
321 if ((bits & set) != set) return false;
322 bits -= set; // Remove this set
323 }
324 }
325 return true;
326 }
327
328 //------------------------------is_bound_set-----------------------------------
329 // Return TRUE if the mask contains one adjacent set of bits and no other bits.
330 // Works also for size 1.
331 int RegMask::is_bound_set(const int size) const {
332 if( is_AllStack() ) return false;
333 assert(1 <= size && size <= 8, "update low bits table");
334 int bit = -1; // Set to hold the one bit allowed
335 for (int i = 0; i < RM_SIZE; i++) {
336 if (_A[i] ) { // Found some bits
337 if (bit != -1)
338 return false; // Already had bits, so fail
339 bit = _A[i] & -_A[i]; // Extract low bit from mask
340 int hi_bit = bit << (size-1); // high bit
341 if (hi_bit != 0) { // Bit set stays in same word?
342 int set = hi_bit + ((hi_bit-1) & ~(bit-1));
343 if (set != _A[i])
344 return false; // Require adjacent bit set and no more bits
345 } else { // Else its a split-set case
346 if (((-1) & ~(bit-1)) != _A[i])
347 return false; // Found many bits, so fail
348 i++; // Skip iteration forward and check high part
349 // The lower 24 bits should be 0 since it is split case and size <= 8.
350 int set = bit>>24;
351 set = set & -set; // Remove sign extension.
352 set = (((set << size) - 1) >> 8);
353 if (i >= RM_SIZE || _A[i] != set)
354 return false; // Require expected low bits in next word
355 }
356 }
357 }
358 // True for both the empty mask and for a bit set
359 return true;
360 }
361
362 //------------------------------is_UP------------------------------------------
363 // UP means register only, Register plus stack, or stack only is DOWN
364 bool RegMask::is_UP() const {
365 // Quick common case check for DOWN (any stack slot is legal)
366 if( is_AllStack() )
367 return false;
368 // Slower check for any stack bits set (also DOWN)
369 if( overlap(Matcher::STACK_ONLY_mask) )
370 return false;
371 // Not DOWN, so must be UP
372 return true;
373 }
374
375 //------------------------------Size-------------------------------------------
376 // Compute size of register mask in bits
377 uint RegMask::Size() const {
378 extern uint8_t bitsInByte[256];
379 uint sum = 0;
380 for( int i = 0; i < RM_SIZE; i++ )
381 sum +=
382 bitsInByte[(_A[i]>>24) & 0xff] +
383 bitsInByte[(_A[i]>>16) & 0xff] +
384 bitsInByte[(_A[i]>> 8) & 0xff] +
385 bitsInByte[ _A[i] & 0xff];
386 return sum;
387 }
388
389 #ifndef PRODUCT
390 //------------------------------print------------------------------------------
391 void RegMask::dump(outputStream *st) const {
392 st->print("[");
393 RegMask rm = *this; // Structure copy into local temp
394
395 OptoReg::Name start = rm.find_first_elem(); // Get a register
396 if (OptoReg::is_valid(start)) { // Check for empty mask
397 rm.Remove(start); // Yank from mask
398 OptoReg::dump(start, st); // Print register
399 OptoReg::Name last = start;
400
401 // Now I have printed an initial register.
402 // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".
403 // Begin looping over the remaining registers.
404 while (1) { //
405 OptoReg::Name reg = rm.find_first_elem(); // Get a register
406 if (!OptoReg::is_valid(reg))
407 break; // Empty mask, end loop
408 rm.Remove(reg); // Yank from mask
409
410 if (last+1 == reg) { // See if they are adjacent
411 // Adjacent registers just collect into long runs, no printing.
412 last = reg;
413 } else { // Ending some kind of run
414 if (start == last) { // 1-register run; no special printing
415 } else if (start+1 == last) {
416 st->print(","); // 2-register run; print as "rX,rY"
417 OptoReg::dump(last, st);
418 } else { // Multi-register run; print as "rX-rZ"
419 st->print("-");
420 OptoReg::dump(last, st);
421 }
422 st->print(","); // Seperate start of new run
423 start = last = reg; // Start a new register run
424 OptoReg::dump(start, st); // Print register
425 } // End of if ending a register run or not
426 } // End of while regmask not empty
427
428 if (start == last) { // 1-register run; no special printing
429 } else if (start+1 == last) {
430 st->print(","); // 2-register run; print as "rX,rY"
431 OptoReg::dump(last, st);
432 } else { // Multi-register run; print as "rX-rZ"
433 st->print("-");
434 OptoReg::dump(last, st);
435 }
436 if (rm.is_AllStack()) st->print("...");
437 }
438 st->print("]");
439 }
440 #endif