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/compile.hpp"
27 #include "opto/regmask.hpp"
28 #if defined AD_MD_HPP
29 # include AD_MD_HPP
30 #elif defined TARGET_ARCH_MODEL_x86_32
31 # include "adfiles/ad_x86_32.hpp"
32 #elif defined TARGET_ARCH_MODEL_x86_64
33 # include "adfiles/ad_x86_64.hpp"
34 #elif defined TARGET_ARCH_MODEL_sparc
35 # include "adfiles/ad_sparc.hpp"
36 #elif defined TARGET_ARCH_MODEL_zero
37 # include "adfiles/ad_zero.hpp"
38 #elif defined TARGET_ARCH_MODEL_ppc_64
39 # include "adfiles/ad_ppc_64.hpp"
40 #endif
41
42 #define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */
43
44 //-------------Non-zero bit search methods used by RegMask---------------------
45 // Find lowest 1, or return 32 if empty
46 int find_lowest_bit( uint32 mask ) {
47 int n = 0;
48 if( (mask & 0xffff) == 0 ) {
49 mask >>= 16;
50 n += 16;
51 }
52 if( (mask & 0xff) == 0 ) {
53 mask >>= 8;
54 n += 8;
55 }
56 if( (mask & 0xf) == 0 ) {
57 mask >>= 4;
58 n += 4;
59 }
60 if( (mask & 0x3) == 0 ) {
61 mask >>= 2;
62 n += 2;
63 }
64 if( (mask & 0x1) == 0 ) {
65 mask >>= 1;
66 n += 1;
67 }
68 if( mask == 0 ) {
69 n = 32;
70 }
71 return n;
72 }
73
74 // Find highest 1, or return 32 if empty
75 int find_hihghest_bit( uint32 mask ) {
76 int n = 0;
77 if( mask > 0xffff ) {
78 mask >>= 16;
79 n += 16;
80 }
81 if( mask > 0xff ) {
82 mask >>= 8;
83 n += 8;
84 }
85 if( mask > 0xf ) {
86 mask >>= 4;
87 n += 4;
88 }
89 if( mask > 0x3 ) {
90 mask >>= 2;
91 n += 2;
92 }
93 if( mask > 0x1 ) {
94 mask >>= 1;
95 n += 1;
96 }
97 if( mask == 0 ) {
98 n = 32;
99 }
100 return n;
101 }
102
103 //------------------------------dump-------------------------------------------
104
105 #ifndef PRODUCT
106 void OptoReg::dump(int r, outputStream *st) {
107 switch (r) {
108 case Special: st->print("r---"); break;
109 case Bad: st->print("rBAD"); break;
110 default:
111 if (r < _last_Mach_Reg) st->print("%s", Matcher::regName[r]);
112 else st->print("rS%d",r);
113 break;
114 }
115 }
116 #endif
117
118
119 //=============================================================================
120 const RegMask RegMask::Empty(
121 # define BODY(I) 0,
122 FORALL_BODY
123 # undef BODY
124 0
125 );
126
127 //=============================================================================
128 bool RegMask::is_vector(uint ireg) {
129 return (ireg == Op_VecS || ireg == Op_VecD || ireg == Op_VecX || ireg == Op_VecY);
130 }
131
132 int RegMask::num_registers(uint ireg) {
133 switch(ireg) {
134 case Op_VecY:
135 return 8;
136 case Op_VecX:
137 return 4;
138 case Op_VecD:
139 case Op_RegD:
140 case Op_RegL:
141 #ifdef _LP64
142 case Op_RegP:
143 #endif
144 return 2;
145 }
146 // Op_VecS and the rest ideal registers.
147 return 1;
148 }
149
150 //------------------------------find_first_pair--------------------------------
151 // Find the lowest-numbered register pair in the mask. Return the
152 // HIGHEST register number in the pair, or BAD if no pairs.
153 OptoReg::Name RegMask::find_first_pair() const {
154 verify_pairs();
155 for( int i = 0; i < RM_SIZE; i++ ) {
156 if( _A[i] ) { // Found some bits
157 int bit = _A[i] & -_A[i]; // Extract low bit
158 // Convert to bit number, return hi bit in pair
159 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);
160 }
161 }
162 return OptoReg::Bad;
163 }
164
165 //------------------------------ClearToPairs-----------------------------------
166 // Clear out partial bits; leave only bit pairs
167 void RegMask::clear_to_pairs() {
168 for( int i = 0; i < RM_SIZE; i++ ) {
169 int bits = _A[i];
170 bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair
171 bits |= (bits>>1); // Smear 1 hi-bit into a pair
172 _A[i] = bits;
173 }
174 verify_pairs();
175 }
176
177 //------------------------------SmearToPairs-----------------------------------
178 // Smear out partial bits; leave only bit pairs
179 void RegMask::smear_to_pairs() {
180 for( int i = 0; i < RM_SIZE; i++ ) {
181 int bits = _A[i];
182 bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair
183 bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair
184 _A[i] = bits;
185 }
186 verify_pairs();
187 }
188
189 //------------------------------is_aligned_pairs-------------------------------
190 bool RegMask::is_aligned_pairs() const {
191 // Assert that the register mask contains only bit pairs.
192 for( int i = 0; i < RM_SIZE; i++ ) {
193 int bits = _A[i];
194 while( bits ) { // Check bits for pairing
195 int bit = bits & -bits; // Extract low bit
196 // Low bit is not odd means its mis-aligned.
197 if( (bit & 0x55555555) == 0 ) return false;
198 bits -= bit; // Remove bit from mask
199 // Check for aligned adjacent bit
200 if( (bits & (bit<<1)) == 0 ) return false;
201 bits -= (bit<<1); // Remove other halve of pair
202 }
203 }
204 return true;
205 }
206
207 //------------------------------is_bound1--------------------------------------
208 // Return TRUE if the mask contains a single bit
209 int RegMask::is_bound1() const {
210 if( is_AllStack() ) return false;
211 int bit = -1; // Set to hold the one bit allowed
212 for( int i = 0; i < RM_SIZE; i++ ) {
213 if( _A[i] ) { // Found some bits
214 if( bit != -1 ) return false; // Already had bits, so fail
215 bit = _A[i] & -_A[i]; // Extract 1 bit from mask
216 if( bit != _A[i] ) return false; // Found many bits, so fail
217 }
218 }
219 // True for both the empty mask and for a single bit
220 return true;
221 }
222
223 //------------------------------is_bound2--------------------------------------
224 // Return TRUE if the mask contains an adjacent pair of bits and no other bits.
225 int RegMask::is_bound_pair() const {
226 if( is_AllStack() ) return false;
227
228 int bit = -1; // Set to hold the one bit allowed
229 for( int i = 0; i < RM_SIZE; i++ ) {
230 if( _A[i] ) { // Found some bits
231 if( bit != -1 ) return false; // Already had bits, so fail
232 bit = _A[i] & -(_A[i]); // Extract 1 bit from mask
233 if( (bit << 1) != 0 ) { // Bit pair stays in same word?
234 if( (bit | (bit<<1)) != _A[i] )
235 return false; // Require adjacent bit pair and no more bits
236 } else { // Else its a split-pair case
237 if( bit != _A[i] ) return false; // Found many bits, so fail
238 i++; // Skip iteration forward
239 if( i >= RM_SIZE || _A[i] != 1 )
240 return false; // Require 1 lo bit in next word
241 }
242 }
243 }
244 // True for both the empty mask and for a bit pair
245 return true;
246 }
247
248 static int low_bits[3] = { 0x55555555, 0x11111111, 0x01010101 };
249 //------------------------------find_first_set---------------------------------
250 // Find the lowest-numbered register set in the mask. Return the
251 // HIGHEST register number in the set, or BAD if no sets.
252 // Works also for size 1.
253 OptoReg::Name RegMask::find_first_set(const int size) const {
254 verify_sets(size);
255 for (int i = 0; i < RM_SIZE; i++) {
256 if (_A[i]) { // Found some bits
257 int bit = _A[i] & -_A[i]; // Extract low bit
258 // Convert to bit number, return hi bit in pair
259 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+(size-1));
260 }
261 }
262 return OptoReg::Bad;
263 }
264
265 //------------------------------clear_to_sets----------------------------------
266 // Clear out partial bits; leave only aligned adjacent bit pairs
267 void RegMask::clear_to_sets(const int size) {
268 if (size == 1) return;
269 assert(2 <= size && size <= 8, "update low bits table");
270 assert(is_power_of_2(size), "sanity");
271 int low_bits_mask = low_bits[size>>2];
272 for (int i = 0; i < RM_SIZE; i++) {
273 int bits = _A[i];
274 int sets = (bits & low_bits_mask);
275 for (int j = 1; j < size; j++) {
276 sets = (bits & (sets<<1)); // filter bits which produce whole sets
277 }
278 sets |= (sets>>1); // Smear 1 hi-bit into a set
279 if (size > 2) {
280 sets |= (sets>>2); // Smear 2 hi-bits into a set
281 if (size > 4) {
282 sets |= (sets>>4); // Smear 4 hi-bits into a set
283 }
284 }
285 _A[i] = sets;
286 }
287 verify_sets(size);
288 }
289
290 //------------------------------smear_to_sets----------------------------------
291 // Smear out partial bits to aligned adjacent bit sets
292 void RegMask::smear_to_sets(const int size) {
293 if (size == 1) return;
294 assert(2 <= size && size <= 8, "update low bits table");
295 assert(is_power_of_2(size), "sanity");
296 int low_bits_mask = low_bits[size>>2];
297 for (int i = 0; i < RM_SIZE; i++) {
298 int bits = _A[i];
299 int sets = 0;
300 for (int j = 0; j < size; j++) {
301 sets |= (bits & low_bits_mask); // collect partial bits
302 bits = bits>>1;
303 }
304 sets |= (sets<<1); // Smear 1 lo-bit into a set
305 if (size > 2) {
306 sets |= (sets<<2); // Smear 2 lo-bits into a set
307 if (size > 4) {
308 sets |= (sets<<4); // Smear 4 lo-bits into a set
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 <= 8, "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 <= 8, "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 24 bits should be 0 since it is split case and size <= 8.
362 int set = bit>>24;
363 set = set & -set; // Remove sign extension.
364 set = (((set << size) - 1) >> 8);
365 if (i >= RM_SIZE || _A[i] != set)
366 return false; // Require expected low bits in next word
367 }
368 }
369 }
370 // True for both the empty mask and for a bit set
371 return true;
372 }
373
374 //------------------------------is_UP------------------------------------------
375 // UP means register only, Register plus stack, or stack only is DOWN
376 bool RegMask::is_UP() const {
377 // Quick common case check for DOWN (any stack slot is legal)
378 if( is_AllStack() )
379 return false;
380 // Slower check for any stack bits set (also DOWN)
381 if( overlap(Matcher::STACK_ONLY_mask) )
382 return false;
383 // Not DOWN, so must be UP
384 return true;
385 }
386
387 //------------------------------Size-------------------------------------------
388 // Compute size of register mask in bits
389 uint RegMask::Size() const {
390 extern uint8 bitsInByte[256];
391 uint sum = 0;
392 for( int i = 0; i < RM_SIZE; i++ )
393 sum +=
394 bitsInByte[(_A[i]>>24) & 0xff] +
395 bitsInByte[(_A[i]>>16) & 0xff] +
396 bitsInByte[(_A[i]>> 8) & 0xff] +
397 bitsInByte[ _A[i] & 0xff];
398 return sum;
399 }
400
401 #ifndef PRODUCT
402 //------------------------------print------------------------------------------
403 void RegMask::dump(outputStream *st) const {
404 st->print("[");
405 RegMask rm = *this; // Structure copy into local temp
406
407 OptoReg::Name start = rm.find_first_elem(); // Get a register
408 if (OptoReg::is_valid(start)) { // Check for empty mask
409 rm.Remove(start); // Yank from mask
410 OptoReg::dump(start, st); // Print register
411 OptoReg::Name last = start;
412
413 // Now I have printed an initial register.
414 // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".
415 // Begin looping over the remaining registers.
416 while (1) { //
417 OptoReg::Name reg = rm.find_first_elem(); // Get a register
418 if (!OptoReg::is_valid(reg))
419 break; // Empty mask, end loop
420 rm.Remove(reg); // Yank from mask
421
422 if (last+1 == reg) { // See if they are adjacent
423 // Adjacent registers just collect into long runs, no printing.
424 last = reg;
425 } else { // Ending some kind of run
426 if (start == last) { // 1-register run; no special printing
427 } else if (start+1 == last) {
428 st->print(","); // 2-register run; print as "rX,rY"
429 OptoReg::dump(last, st);
430 } else { // Multi-register run; print as "rX-rZ"
431 st->print("-");
432 OptoReg::dump(last, st);
433 }
434 st->print(","); // Seperate start of new run
435 start = last = reg; // Start a new register run
436 OptoReg::dump(start, st); // Print register
437 } // End of if ending a register run or not
438 } // End of while regmask not empty
439
440 if (start == last) { // 1-register run; no special printing
441 } else if (start+1 == last) {
442 st->print(","); // 2-register run; print as "rX,rY"
443 OptoReg::dump(last, st);
444 } else { // Multi-register run; print as "rX-rZ"
445 st->print("-");
446 OptoReg::dump(last, st);
447 }
448 if (rm.is_AllStack()) st->print("...");
449 }
450 st->print("]");
451 }
452 #endif