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/matcher.hpp"
29 #include "opto/node.hpp"
30 #include "opto/regmask.hpp"
31
32 #define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */
33
34 //-------------Non-zero bit search methods used by RegMask---------------------
35 // Find lowest 1, or return 32 if empty
36 int find_lowest_bit( uint32_t mask ) {
37 int n = 0;
38 if( (mask & 0xffff) == 0 ) {
39 mask >>= 16;
40 n += 16;
41 }
42 if( (mask & 0xff) == 0 ) {
43 mask >>= 8;
44 n += 8;
45 }
46 if( (mask & 0xf) == 0 ) {
47 mask >>= 4;
48 n += 4;
49 }
50 if( (mask & 0x3) == 0 ) {
51 mask >>= 2;
52 n += 2;
53 }
54 if( (mask & 0x1) == 0 ) {
55 mask >>= 1;
56 n += 1;
57 }
58 if( mask == 0 ) {
59 n = 32;
60 }
61 return n;
62 }
63
64 // Find highest 1, or return 32 if empty
65 int find_hihghest_bit( uint32_t mask ) {
66 int n = 0;
67 if( mask > 0xffff ) {
68 mask >>= 16;
69 n += 16;
70 }
71 if( mask > 0xff ) {
72 mask >>= 8;
73 n += 8;
74 }
75 if( mask > 0xf ) {
76 mask >>= 4;
77 n += 4;
78 }
79 if( mask > 0x3 ) {
80 mask >>= 2;
81 n += 2;
82 }
83 if( mask > 0x1 ) {
84 mask >>= 1;
85 n += 1;
86 }
87 if( mask == 0 ) {
88 n = 32;
89 }
90 return n;
91 }
92
93 //------------------------------dump-------------------------------------------
94
95 #ifndef PRODUCT
96 void OptoReg::dump(int r, outputStream *st) {
97 switch (r) {
98 case Special: st->print("r---"); break;
99 case Bad: st->print("rBAD"); break;
100 default:
101 if (r < _last_Mach_Reg) st->print("%s", Matcher::regName[r]);
102 else st->print("rS%d",r);
103 break;
104 }
105 }
106 #endif
107
108
109 //=============================================================================
110 const RegMask RegMask::Empty(
111 # define BODY(I) 0,
112 FORALL_BODY
113 # undef BODY
114 0
115 );
116
117 //=============================================================================
118 bool RegMask::is_vector(uint ireg) {
119 return (ireg == Op_VecS || ireg == Op_VecD ||
120 ireg == Op_VecX || ireg == Op_VecY || ireg == Op_VecZ );
121 }
122
123 int RegMask::num_registers(uint ireg) {
124 switch(ireg) {
125 case Op_VecZ:
126 return 16;
127 case Op_VecY:
128 return 8;
129 case Op_VecX:
130 return 4;
131 case Op_VecD:
132 case Op_RegD:
133 case Op_RegL:
134 #ifdef _LP64
135 case Op_RegP:
136 #endif
137 return 2;
138 }
139 // Op_VecS and the rest ideal registers.
140 return 1;
141 }
142
143 //------------------------------find_first_pair--------------------------------
144 // Find the lowest-numbered register pair in the mask. Return the
145 // HIGHEST register number in the pair, or BAD if no pairs.
146 OptoReg::Name RegMask::find_first_pair() const {
147 verify_pairs();
148 for( int i = 0; i < RM_SIZE; i++ ) {
149 if( _A[i] ) { // Found some bits
150 int bit = _A[i] & -_A[i]; // Extract low bit
151 // Convert to bit number, return hi bit in pair
152 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);
153 }
154 }
155 return OptoReg::Bad;
156 }
157
158 //------------------------------ClearToPairs-----------------------------------
159 // Clear out partial bits; leave only bit pairs
160 void RegMask::clear_to_pairs() {
161 for( int i = 0; i < RM_SIZE; i++ ) {
162 int bits = _A[i];
163 bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair
164 bits |= (bits>>1); // Smear 1 hi-bit into a pair
165 _A[i] = bits;
166 }
167 verify_pairs();
168 }
169
170 //------------------------------SmearToPairs-----------------------------------
171 // Smear out partial bits; leave only bit pairs
172 void RegMask::smear_to_pairs() {
173 for( int i = 0; i < RM_SIZE; i++ ) {
174 int bits = _A[i];
175 bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair
176 bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair
177 _A[i] = bits;
178 }
179 verify_pairs();
180 }
181
182 //------------------------------is_aligned_pairs-------------------------------
183 bool RegMask::is_aligned_pairs() const {
184 // Assert that the register mask contains only bit pairs.
185 for( int i = 0; i < RM_SIZE; i++ ) {
186 int bits = _A[i];
187 while( bits ) { // Check bits for pairing
188 int bit = bits & -bits; // Extract low bit
189 // Low bit is not odd means its mis-aligned.
190 if( (bit & 0x55555555) == 0 ) return false;
191 bits -= bit; // Remove bit from mask
192 // Check for aligned adjacent bit
193 if( (bits & (bit<<1)) == 0 ) return false;
194 bits -= (bit<<1); // Remove other halve of pair
195 }
196 }
197 return true;
198 }
199
200 //------------------------------is_bound1--------------------------------------
201 // Return TRUE if the mask contains a single bit
202 int RegMask::is_bound1() const {
203 if( is_AllStack() ) return false;
204 int bit = -1; // Set to hold the one bit allowed
205 for( int i = 0; i < RM_SIZE; i++ ) {
206 if( _A[i] ) { // Found some bits
207 if( bit != -1 ) return false; // Already had bits, so fail
208 bit = _A[i] & -_A[i]; // Extract 1 bit from mask
209 if( bit != _A[i] ) return false; // Found many bits, so fail
210 }
211 }
212 // True for both the empty mask and for a single bit
213 return true;
214 }
215
216 //------------------------------is_bound2--------------------------------------
217 // Return TRUE if the mask contains an adjacent pair of bits and no other bits.
218 int RegMask::is_bound_pair() const {
219 if( is_AllStack() ) return false;
220
221 int bit = -1; // Set to hold the one bit allowed
222 for( int i = 0; i < RM_SIZE; i++ ) {
223 if( _A[i] ) { // Found some bits
224 if( bit != -1 ) return false; // Already had bits, so fail
225 bit = _A[i] & -(_A[i]); // Extract 1 bit from mask
226 if( (bit << 1) != 0 ) { // Bit pair stays in same word?
227 if( (bit | (bit<<1)) != _A[i] )
228 return false; // Require adjacent bit pair and no more bits
229 } else { // Else its a split-pair case
230 if( bit != _A[i] ) return false; // Found many bits, so fail
231 i++; // Skip iteration forward
232 if( i >= RM_SIZE || _A[i] != 1 )
233 return false; // Require 1 lo bit in next word
234 }
235 }
236 }
237 // True for both the empty mask and for a bit pair
238 return true;
239 }
240
241 // only indicies of power 2 are accessed, so index 3 is only filled in for storage.
242 static int low_bits[5] = { 0x55555555, 0x11111111, 0x01010101, 0x00000000, 0x00010001 };
243 //------------------------------find_first_set---------------------------------
244 // Find the lowest-numbered register set in the mask. Return the
245 // HIGHEST register number in the set, or BAD if no sets.
246 // Works also for size 1.
247 OptoReg::Name RegMask::find_first_set(const int size) const {
248 verify_sets(size);
249 for (int i = 0; i < RM_SIZE; i++) {
250 if (_A[i]) { // Found some bits
251 int bit = _A[i] & -_A[i]; // Extract low bit
252 // Convert to bit number, return hi bit in pair
253 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+(size-1));
254 }
255 }
256 return OptoReg::Bad;
257 }
258
259 //------------------------------clear_to_sets----------------------------------
260 // Clear out partial bits; leave only aligned adjacent bit pairs
261 void RegMask::clear_to_sets(const int size) {
262 if (size == 1) return;
263 assert(2 <= size && size <= 16, "update low bits table");
264 assert(is_power_of_2(size), "sanity");
265 int low_bits_mask = low_bits[size>>2];
266 for (int i = 0; i < RM_SIZE; i++) {
267 int bits = _A[i];
268 int sets = (bits & low_bits_mask);
269 for (int j = 1; j < size; j++) {
270 sets = (bits & (sets<<1)); // filter bits which produce whole sets
271 }
272 sets |= (sets>>1); // Smear 1 hi-bit into a set
273 if (size > 2) {
274 sets |= (sets>>2); // Smear 2 hi-bits into a set
275 if (size > 4) {
276 sets |= (sets>>4); // Smear 4 hi-bits into a set
277 if (size > 8) {
278 sets |= (sets>>8); // Smear 8 hi-bits into a set
279 }
280 }
281 }
282 _A[i] = sets;
283 }
284 verify_sets(size);
285 }
286
287 //------------------------------smear_to_sets----------------------------------
288 // Smear out partial bits to aligned adjacent bit sets
289 void RegMask::smear_to_sets(const int size) {
290 if (size == 1) return;
291 assert(2 <= size && size <= 16, "update low bits table");
292 assert(is_power_of_2(size), "sanity");
293 int low_bits_mask = low_bits[size>>2];
294 for (int i = 0; i < RM_SIZE; i++) {
295 int bits = _A[i];
296 int sets = 0;
297 for (int j = 0; j < size; j++) {
298 sets |= (bits & low_bits_mask); // collect partial bits
299 bits = bits>>1;
300 }
301 sets |= (sets<<1); // Smear 1 lo-bit into a set
302 if (size > 2) {
303 sets |= (sets<<2); // Smear 2 lo-bits into a set
304 if (size > 4) {
305 sets |= (sets<<4); // Smear 4 lo-bits into a set
306 if (size > 8) {
307 sets |= (sets<<8); // Smear 8 lo-bits into a set
308 }
309 }
310 }
311 _A[i] = sets;
312 }
313 verify_sets(size);
314 }
315
316 //------------------------------is_aligned_set--------------------------------
317 bool RegMask::is_aligned_sets(const int size) const {
318 if (size == 1) return true;
319 assert(2 <= size && size <= 16, "update low bits table");
320 assert(is_power_of_2(size), "sanity");
321 int low_bits_mask = low_bits[size>>2];
322 // Assert that the register mask contains only bit sets.
323 for (int i = 0; i < RM_SIZE; i++) {
324 int bits = _A[i];
325 while (bits) { // Check bits for pairing
326 int bit = bits & -bits; // Extract low bit
327 // Low bit is not odd means its mis-aligned.
328 if ((bit & low_bits_mask) == 0) return false;
329 // Do extra work since (bit << size) may overflow.
330 int hi_bit = bit << (size-1); // high bit
331 int set = hi_bit + ((hi_bit-1) & ~(bit-1));
332 // Check for aligned adjacent bits in this set
333 if ((bits & set) != set) return false;
334 bits -= set; // Remove this set
335 }
336 }
337 return true;
338 }
339
340 //------------------------------is_bound_set-----------------------------------
341 // Return TRUE if the mask contains one adjacent set of bits and no other bits.
342 // Works also for size 1.
343 int RegMask::is_bound_set(const int size) const {
344 if( is_AllStack() ) return false;
345 assert(1 <= size && size <= 16, "update low bits table");
346 int bit = -1; // Set to hold the one bit allowed
347 for (int i = 0; i < RM_SIZE; i++) {
348 if (_A[i] ) { // Found some bits
349 if (bit != -1)
350 return false; // Already had bits, so fail
351 bit = _A[i] & -_A[i]; // Extract low bit from mask
352 int hi_bit = bit << (size-1); // high bit
353 if (hi_bit != 0) { // Bit set stays in same word?
354 int set = hi_bit + ((hi_bit-1) & ~(bit-1));
355 if (set != _A[i])
356 return false; // Require adjacent bit set and no more bits
357 } else { // Else its a split-set case
358 if (((-1) & ~(bit-1)) != _A[i])
359 return false; // Found many bits, so fail
360 i++; // Skip iteration forward and check high part
361 // The lower (32-size) bits should be 0 since it is split case.
362 int clear_bit_size = 32-size;
363 int shift_back_size = 32-clear_bit_size;
364 int set = bit>>clear_bit_size;
365 set = set & -set; // Remove sign extension.
366 set = (((set << size) - 1) >> shift_back_size);
367 if (i >= RM_SIZE || _A[i] != set)
368 return false; // Require expected low bits in next word
369 }
370 }
371 }
372 // True for both the empty mask and for a bit set
373 return true;
374 }
375
376 //------------------------------is_UP------------------------------------------
377 // UP means register only, Register plus stack, or stack only is DOWN
378 bool RegMask::is_UP() const {
379 // Quick common case check for DOWN (any stack slot is legal)
380 if( is_AllStack() )
381 return false;
382 // Slower check for any stack bits set (also DOWN)
383 if( overlap(Matcher::STACK_ONLY_mask) )
384 return false;
385 // Not DOWN, so must be UP
386 return true;
387 }
388
389 //------------------------------Size-------------------------------------------
390 // Compute size of register mask in bits
391 uint RegMask::Size() const {
392 extern uint8_t bitsInByte[512];
393 uint sum = 0;
394 for( int i = 0; i < RM_SIZE; i++ )
395 sum +=
396 bitsInByte[(_A[i]>>24) & 0xff] +
397 bitsInByte[(_A[i]>>16) & 0xff] +
398 bitsInByte[(_A[i]>> 8) & 0xff] +
399 bitsInByte[ _A[i] & 0xff];
400 return sum;
401 }
402
403 #ifndef PRODUCT
404 //------------------------------print------------------------------------------
405 void RegMask::dump(outputStream *st) const {
406 st->print("[");
407 RegMask rm = *this; // Structure copy into local temp
408
409 OptoReg::Name start = rm.find_first_elem(); // Get a register
410 if (OptoReg::is_valid(start)) { // Check for empty mask
411 rm.Remove(start); // Yank from mask
412 OptoReg::dump(start, st); // Print register
413 OptoReg::Name last = start;
414
415 // Now I have printed an initial register.
416 // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".
417 // Begin looping over the remaining registers.
418 while (1) { //
419 OptoReg::Name reg = rm.find_first_elem(); // Get a register
420 if (!OptoReg::is_valid(reg))
421 break; // Empty mask, end loop
422 rm.Remove(reg); // Yank from mask
423
424 if (last+1 == reg) { // See if they are adjacent
425 // Adjacent registers just collect into long runs, no printing.
426 last = reg;
427 } else { // Ending some kind of run
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 st->print(","); // Seperate start of new run
437 start = last = reg; // Start a new register run
438 OptoReg::dump(start, st); // Print register
439 } // End of if ending a register run or not
440 } // End of while regmask not empty
441
442 if (start == last) { // 1-register run; no special printing
443 } else if (start+1 == last) {
444 st->print(","); // 2-register run; print as "rX,rY"
445 OptoReg::dump(last, st);
446 } else { // Multi-register run; print as "rX-rZ"
447 st->print("-");
448 OptoReg::dump(last, st);
449 }
450 if (rm.is_AllStack()) st->print("...");
451 }
452 st->print("]");
453 }
454 #endif