0
|
1 /*
|
|
2 * Copyright 2002-2007 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/_buildOopMap.cpp.incl"
|
|
27
|
|
28 // The functions in this file builds OopMaps after all scheduling is done.
|
|
29 //
|
|
30 // OopMaps contain a list of all registers and stack-slots containing oops (so
|
|
31 // they can be updated by GC). OopMaps also contain a list of derived-pointer
|
|
32 // base-pointer pairs. When the base is moved, the derived pointer moves to
|
|
33 // follow it. Finally, any registers holding callee-save values are also
|
|
34 // recorded. These might contain oops, but only the caller knows.
|
|
35 //
|
|
36 // BuildOopMaps implements a simple forward reaching-defs solution. At each
|
|
37 // GC point we'll have the reaching-def Nodes. If the reaching Nodes are
|
|
38 // typed as pointers (no offset), then they are oops. Pointers+offsets are
|
|
39 // derived pointers, and bases can be found from them. Finally, we'll also
|
|
40 // track reaching callee-save values. Note that a copy of a callee-save value
|
|
41 // "kills" it's source, so that only 1 copy of a callee-save value is alive at
|
|
42 // a time.
|
|
43 //
|
|
44 // We run a simple bitvector liveness pass to help trim out dead oops. Due to
|
|
45 // irreducible loops, we can have a reaching def of an oop that only reaches
|
|
46 // along one path and no way to know if it's valid or not on the other path.
|
|
47 // The bitvectors are quite dense and the liveness pass is fast.
|
|
48 //
|
|
49 // At GC points, we consult this information to build OopMaps. All reaching
|
|
50 // defs typed as oops are added to the OopMap. Only 1 instance of a
|
|
51 // callee-save register can be recorded. For derived pointers, we'll have to
|
|
52 // find and record the register holding the base.
|
|
53 //
|
|
54 // The reaching def's is a simple 1-pass worklist approach. I tried a clever
|
|
55 // breadth-first approach but it was worse (showed O(n^2) in the
|
|
56 // pick-next-block code).
|
|
57 //
|
|
58 // The relevent data is kept in a struct of arrays (it could just as well be
|
|
59 // an array of structs, but the struct-of-arrays is generally a little more
|
|
60 // efficient). The arrays are indexed by register number (including
|
|
61 // stack-slots as registers) and so is bounded by 200 to 300 elements in
|
|
62 // practice. One array will map to a reaching def Node (or NULL for
|
|
63 // conflict/dead). The other array will map to a callee-saved register or
|
|
64 // OptoReg::Bad for not-callee-saved.
|
|
65
|
|
66
|
|
67 //------------------------------OopFlow----------------------------------------
|
|
68 // Structure to pass around
|
|
69 struct OopFlow : public ResourceObj {
|
|
70 short *_callees; // Array mapping register to callee-saved
|
|
71 Node **_defs; // array mapping register to reaching def
|
|
72 // or NULL if dead/conflict
|
|
73 // OopFlow structs, when not being actively modified, describe the _end_ of
|
|
74 // this block.
|
|
75 Block *_b; // Block for this struct
|
|
76 OopFlow *_next; // Next free OopFlow
|
|
77
|
|
78 OopFlow( short *callees, Node **defs ) : _callees(callees), _defs(defs),
|
|
79 _b(NULL), _next(NULL) { }
|
|
80
|
|
81 // Given reaching-defs for this block start, compute it for this block end
|
|
82 void compute_reach( PhaseRegAlloc *regalloc, int max_reg, Dict *safehash );
|
|
83
|
|
84 // Merge these two OopFlows into the 'this' pointer.
|
|
85 void merge( OopFlow *flow, int max_reg );
|
|
86
|
|
87 // Copy a 'flow' over an existing flow
|
|
88 void clone( OopFlow *flow, int max_size);
|
|
89
|
|
90 // Make a new OopFlow from scratch
|
|
91 static OopFlow *make( Arena *A, int max_size );
|
|
92
|
|
93 // Build an oopmap from the current flow info
|
|
94 OopMap *build_oop_map( Node *n, int max_reg, PhaseRegAlloc *regalloc, int* live );
|
|
95 };
|
|
96
|
|
97 //------------------------------compute_reach----------------------------------
|
|
98 // Given reaching-defs for this block start, compute it for this block end
|
|
99 void OopFlow::compute_reach( PhaseRegAlloc *regalloc, int max_reg, Dict *safehash ) {
|
|
100
|
|
101 for( uint i=0; i<_b->_nodes.size(); i++ ) {
|
|
102 Node *n = _b->_nodes[i];
|
|
103
|
|
104 if( n->jvms() ) { // Build an OopMap here?
|
|
105 JVMState *jvms = n->jvms();
|
|
106 // no map needed for leaf calls
|
|
107 if( n->is_MachSafePoint() && !n->is_MachCallLeaf() ) {
|
|
108 int *live = (int*) (*safehash)[n];
|
|
109 assert( live, "must find live" );
|
|
110 n->as_MachSafePoint()->set_oop_map( build_oop_map(n,max_reg,regalloc, live) );
|
|
111 }
|
|
112 }
|
|
113
|
|
114 // Assign new reaching def's.
|
|
115 // Note that I padded the _defs and _callees arrays so it's legal
|
|
116 // to index at _defs[OptoReg::Bad].
|
|
117 OptoReg::Name first = regalloc->get_reg_first(n);
|
|
118 OptoReg::Name second = regalloc->get_reg_second(n);
|
|
119 _defs[first] = n;
|
|
120 _defs[second] = n;
|
|
121
|
|
122 // Pass callee-save info around copies
|
|
123 int idx = n->is_Copy();
|
|
124 if( idx ) { // Copies move callee-save info
|
|
125 OptoReg::Name old_first = regalloc->get_reg_first(n->in(idx));
|
|
126 OptoReg::Name old_second = regalloc->get_reg_second(n->in(idx));
|
|
127 int tmp_first = _callees[old_first];
|
|
128 int tmp_second = _callees[old_second];
|
|
129 _callees[old_first] = OptoReg::Bad; // callee-save is moved, dead in old location
|
|
130 _callees[old_second] = OptoReg::Bad;
|
|
131 _callees[first] = tmp_first;
|
|
132 _callees[second] = tmp_second;
|
|
133 } else if( n->is_Phi() ) { // Phis do not mod callee-saves
|
|
134 assert( _callees[first] == _callees[regalloc->get_reg_first(n->in(1))], "" );
|
|
135 assert( _callees[second] == _callees[regalloc->get_reg_second(n->in(1))], "" );
|
|
136 assert( _callees[first] == _callees[regalloc->get_reg_first(n->in(n->req()-1))], "" );
|
|
137 assert( _callees[second] == _callees[regalloc->get_reg_second(n->in(n->req()-1))], "" );
|
|
138 } else {
|
|
139 _callees[first] = OptoReg::Bad; // No longer holding a callee-save value
|
|
140 _callees[second] = OptoReg::Bad;
|
|
141
|
|
142 // Find base case for callee saves
|
|
143 if( n->is_Proj() && n->in(0)->is_Start() ) {
|
|
144 if( OptoReg::is_reg(first) &&
|
|
145 regalloc->_matcher.is_save_on_entry(first) )
|
|
146 _callees[first] = first;
|
|
147 if( OptoReg::is_reg(second) &&
|
|
148 regalloc->_matcher.is_save_on_entry(second) )
|
|
149 _callees[second] = second;
|
|
150 }
|
|
151 }
|
|
152 }
|
|
153 }
|
|
154
|
|
155 //------------------------------merge------------------------------------------
|
|
156 // Merge the given flow into the 'this' flow
|
|
157 void OopFlow::merge( OopFlow *flow, int max_reg ) {
|
|
158 assert( _b == NULL, "merging into a happy flow" );
|
|
159 assert( flow->_b, "this flow is still alive" );
|
|
160 assert( flow != this, "no self flow" );
|
|
161
|
|
162 // Do the merge. If there are any differences, drop to 'bottom' which
|
|
163 // is OptoReg::Bad or NULL depending.
|
|
164 for( int i=0; i<max_reg; i++ ) {
|
|
165 // Merge the callee-save's
|
|
166 if( _callees[i] != flow->_callees[i] )
|
|
167 _callees[i] = OptoReg::Bad;
|
|
168 // Merge the reaching defs
|
|
169 if( _defs[i] != flow->_defs[i] )
|
|
170 _defs[i] = NULL;
|
|
171 }
|
|
172
|
|
173 }
|
|
174
|
|
175 //------------------------------clone------------------------------------------
|
|
176 void OopFlow::clone( OopFlow *flow, int max_size ) {
|
|
177 _b = flow->_b;
|
|
178 memcpy( _callees, flow->_callees, sizeof(short)*max_size);
|
|
179 memcpy( _defs , flow->_defs , sizeof(Node*)*max_size);
|
|
180 }
|
|
181
|
|
182 //------------------------------make-------------------------------------------
|
|
183 OopFlow *OopFlow::make( Arena *A, int max_size ) {
|
|
184 short *callees = NEW_ARENA_ARRAY(A,short,max_size+1);
|
|
185 Node **defs = NEW_ARENA_ARRAY(A,Node*,max_size+1);
|
|
186 debug_only( memset(defs,0,(max_size+1)*sizeof(Node*)) );
|
|
187 OopFlow *flow = new (A) OopFlow(callees+1, defs+1);
|
|
188 assert( &flow->_callees[OptoReg::Bad] == callees, "Ok to index at OptoReg::Bad" );
|
|
189 assert( &flow->_defs [OptoReg::Bad] == defs , "Ok to index at OptoReg::Bad" );
|
|
190 return flow;
|
|
191 }
|
|
192
|
|
193 //------------------------------bit twiddlers----------------------------------
|
|
194 static int get_live_bit( int *live, int reg ) {
|
|
195 return live[reg>>LogBitsPerInt] & (1<<(reg&(BitsPerInt-1))); }
|
|
196 static void set_live_bit( int *live, int reg ) {
|
|
197 live[reg>>LogBitsPerInt] |= (1<<(reg&(BitsPerInt-1))); }
|
|
198 static void clr_live_bit( int *live, int reg ) {
|
|
199 live[reg>>LogBitsPerInt] &= ~(1<<(reg&(BitsPerInt-1))); }
|
|
200
|
|
201 //------------------------------build_oop_map----------------------------------
|
|
202 // Build an oopmap from the current flow info
|
|
203 OopMap *OopFlow::build_oop_map( Node *n, int max_reg, PhaseRegAlloc *regalloc, int* live ) {
|
|
204 int framesize = regalloc->_framesize;
|
|
205 int max_inarg_slot = OptoReg::reg2stack(regalloc->_matcher._new_SP);
|
|
206 debug_only( char *dup_check = NEW_RESOURCE_ARRAY(char,OptoReg::stack0());
|
|
207 memset(dup_check,0,OptoReg::stack0()) );
|
|
208
|
|
209 OopMap *omap = new OopMap( framesize, max_inarg_slot );
|
|
210 MachCallNode *mcall = n->is_MachCall() ? n->as_MachCall() : NULL;
|
|
211 JVMState* jvms = n->jvms();
|
|
212
|
|
213 // For all registers do...
|
|
214 for( int reg=0; reg<max_reg; reg++ ) {
|
|
215 if( get_live_bit(live,reg) == 0 )
|
|
216 continue; // Ignore if not live
|
|
217
|
|
218 // %%% C2 can use 2 OptoRegs when the physical register is only one 64bit
|
|
219 // register in that case we'll get an non-concrete register for the second
|
|
220 // half. We only need to tell the map the register once!
|
|
221 //
|
|
222 // However for the moment we disable this change and leave things as they
|
|
223 // were.
|
|
224
|
|
225 VMReg r = OptoReg::as_VMReg(OptoReg::Name(reg), framesize, max_inarg_slot);
|
|
226
|
|
227 if (false && r->is_reg() && !r->is_concrete()) {
|
|
228 continue;
|
|
229 }
|
|
230
|
|
231 // See if dead (no reaching def).
|
|
232 Node *def = _defs[reg]; // Get reaching def
|
|
233 assert( def, "since live better have reaching def" );
|
|
234
|
|
235 // Classify the reaching def as oop, derived, callee-save, dead, or other
|
|
236 const Type *t = def->bottom_type();
|
|
237 if( t->isa_oop_ptr() ) { // Oop or derived?
|
|
238 assert( !OptoReg::is_valid(_callees[reg]), "oop can't be callee save" );
|
|
239 #ifdef _LP64
|
|
240 // 64-bit pointers record oop-ishness on 2 aligned adjacent registers.
|
|
241 // Make sure both are record from the same reaching def, but do not
|
|
242 // put both into the oopmap.
|
|
243 if( (reg&1) == 1 ) { // High half of oop-pair?
|
|
244 assert( _defs[reg-1] == _defs[reg], "both halves from same reaching def" );
|
|
245 continue; // Do not record high parts in oopmap
|
|
246 }
|
|
247 #endif
|
|
248
|
|
249 // Check for a legal reg name in the oopMap and bailout if it is not.
|
|
250 if (!omap->legal_vm_reg_name(r)) {
|
|
251 regalloc->C->record_method_not_compilable("illegal oopMap register name");
|
|
252 continue;
|
|
253 }
|
|
254 if( t->is_ptr()->_offset == 0 ) { // Not derived?
|
|
255 if( mcall ) {
|
|
256 // Outgoing argument GC mask responsibility belongs to the callee,
|
|
257 // not the caller. Inspect the inputs to the call, to see if
|
|
258 // this live-range is one of them.
|
|
259 uint cnt = mcall->tf()->domain()->cnt();
|
|
260 uint j;
|
|
261 for( j = TypeFunc::Parms; j < cnt; j++)
|
|
262 if( mcall->in(j) == def )
|
|
263 break; // reaching def is an argument oop
|
|
264 if( j < cnt ) // arg oops dont go in GC map
|
|
265 continue; // Continue on to the next register
|
|
266 }
|
|
267 omap->set_oop(r);
|
|
268 } else { // Else it's derived.
|
|
269 // Find the base of the derived value.
|
|
270 uint i;
|
|
271 // Fast, common case, scan
|
|
272 for( i = jvms->oopoff(); i < n->req(); i+=2 )
|
|
273 if( n->in(i) == def ) break; // Common case
|
|
274 if( i == n->req() ) { // Missed, try a more generous scan
|
|
275 // Scan again, but this time peek through copies
|
|
276 for( i = jvms->oopoff(); i < n->req(); i+=2 ) {
|
|
277 Node *m = n->in(i); // Get initial derived value
|
|
278 while( 1 ) {
|
|
279 Node *d = def; // Get initial reaching def
|
|
280 while( 1 ) { // Follow copies of reaching def to end
|
|
281 if( m == d ) goto found; // breaks 3 loops
|
|
282 int idx = d->is_Copy();
|
|
283 if( !idx ) break;
|
|
284 d = d->in(idx); // Link through copy
|
|
285 }
|
|
286 int idx = m->is_Copy();
|
|
287 if( !idx ) break;
|
|
288 m = m->in(idx);
|
|
289 }
|
|
290 }
|
|
291 guarantee( 0, "must find derived/base pair" );
|
|
292 }
|
|
293 found: ;
|
|
294 Node *base = n->in(i+1); // Base is other half of pair
|
|
295 int breg = regalloc->get_reg_first(base);
|
|
296 VMReg b = OptoReg::as_VMReg(OptoReg::Name(breg), framesize, max_inarg_slot);
|
|
297
|
|
298 // I record liveness at safepoints BEFORE I make the inputs
|
|
299 // live. This is because argument oops are NOT live at a
|
|
300 // safepoint (or at least they cannot appear in the oopmap).
|
|
301 // Thus bases of base/derived pairs might not be in the
|
|
302 // liveness data but they need to appear in the oopmap.
|
|
303 if( get_live_bit(live,breg) == 0 ) {// Not live?
|
|
304 // Flag it, so next derived pointer won't re-insert into oopmap
|
|
305 set_live_bit(live,breg);
|
|
306 // Already missed our turn?
|
|
307 if( breg < reg ) {
|
|
308 if (b->is_stack() || b->is_concrete() || true ) {
|
|
309 omap->set_oop( b);
|
|
310 }
|
|
311 }
|
|
312 }
|
|
313 if (b->is_stack() || b->is_concrete() || true ) {
|
|
314 omap->set_derived_oop( r, b);
|
|
315 }
|
|
316 }
|
|
317
|
|
318 } else if( OptoReg::is_valid(_callees[reg])) { // callee-save?
|
|
319 // It's a callee-save value
|
|
320 assert( dup_check[_callees[reg]]==0, "trying to callee save same reg twice" );
|
|
321 debug_only( dup_check[_callees[reg]]=1; )
|
|
322 VMReg callee = OptoReg::as_VMReg(OptoReg::Name(_callees[reg]));
|
|
323 if ( callee->is_concrete() || true ) {
|
|
324 omap->set_callee_saved( r, callee);
|
|
325 }
|
|
326
|
|
327 } else {
|
|
328 // Other - some reaching non-oop value
|
|
329 omap->set_value( r);
|
|
330 }
|
|
331
|
|
332 }
|
|
333
|
|
334 #ifdef ASSERT
|
|
335 /* Nice, Intel-only assert
|
|
336 int cnt_callee_saves=0;
|
|
337 int reg2 = 0;
|
|
338 while (OptoReg::is_reg(reg2)) {
|
|
339 if( dup_check[reg2] != 0) cnt_callee_saves++;
|
|
340 assert( cnt_callee_saves==3 || cnt_callee_saves==5, "missed some callee-save" );
|
|
341 reg2++;
|
|
342 }
|
|
343 */
|
|
344 #endif
|
|
345
|
|
346 return omap;
|
|
347 }
|
|
348
|
|
349 //------------------------------do_liveness------------------------------------
|
|
350 // Compute backwards liveness on registers
|
|
351 static void do_liveness( PhaseRegAlloc *regalloc, PhaseCFG *cfg, Block_List *worklist, int max_reg_ints, Arena *A, Dict *safehash ) {
|
|
352 int *live = NEW_ARENA_ARRAY(A, int, (cfg->_num_blocks+1) * max_reg_ints);
|
|
353 int *tmp_live = &live[cfg->_num_blocks * max_reg_ints];
|
|
354 Node *root = cfg->C->root();
|
|
355 // On CISC platforms, get the node representing the stack pointer that regalloc
|
|
356 // used for spills
|
|
357 Node *fp = NodeSentinel;
|
|
358 if (UseCISCSpill && root->req() > 1) {
|
|
359 fp = root->in(1)->in(TypeFunc::FramePtr);
|
|
360 }
|
|
361 memset( live, 0, cfg->_num_blocks * (max_reg_ints<<LogBytesPerInt) );
|
|
362 // Push preds onto worklist
|
|
363 for( uint i=1; i<root->req(); i++ )
|
|
364 worklist->push(cfg->_bbs[root->in(i)->_idx]);
|
|
365
|
|
366 // ZKM.jar includes tiny infinite loops which are unreached from below.
|
|
367 // If we missed any blocks, we'll retry here after pushing all missed
|
|
368 // blocks on the worklist. Normally this outer loop never trips more
|
|
369 // than once.
|
|
370 while( 1 ) {
|
|
371
|
|
372 while( worklist->size() ) { // Standard worklist algorithm
|
|
373 Block *b = worklist->rpop();
|
|
374
|
|
375 // Copy first successor into my tmp_live space
|
|
376 int s0num = b->_succs[0]->_pre_order;
|
|
377 int *t = &live[s0num*max_reg_ints];
|
|
378 for( int i=0; i<max_reg_ints; i++ )
|
|
379 tmp_live[i] = t[i];
|
|
380
|
|
381 // OR in the remaining live registers
|
|
382 for( uint j=1; j<b->_num_succs; j++ ) {
|
|
383 uint sjnum = b->_succs[j]->_pre_order;
|
|
384 int *t = &live[sjnum*max_reg_ints];
|
|
385 for( int i=0; i<max_reg_ints; i++ )
|
|
386 tmp_live[i] |= t[i];
|
|
387 }
|
|
388
|
|
389 // Now walk tmp_live up the block backwards, computing live
|
|
390 for( int k=b->_nodes.size()-1; k>=0; k-- ) {
|
|
391 Node *n = b->_nodes[k];
|
|
392 // KILL def'd bits
|
|
393 int first = regalloc->get_reg_first(n);
|
|
394 int second = regalloc->get_reg_second(n);
|
|
395 if( OptoReg::is_valid(first) ) clr_live_bit(tmp_live,first);
|
|
396 if( OptoReg::is_valid(second) ) clr_live_bit(tmp_live,second);
|
|
397
|
|
398 MachNode *m = n->is_Mach() ? n->as_Mach() : NULL;
|
|
399
|
|
400 // Check if m is potentially a CISC alternate instruction (i.e, possibly
|
|
401 // synthesized by RegAlloc from a conventional instruction and a
|
|
402 // spilled input)
|
|
403 bool is_cisc_alternate = false;
|
|
404 if (UseCISCSpill && m) {
|
|
405 is_cisc_alternate = m->is_cisc_alternate();
|
|
406 }
|
|
407
|
|
408 // GEN use'd bits
|
|
409 for( uint l=1; l<n->req(); l++ ) {
|
|
410 Node *def = n->in(l);
|
|
411 assert(def != 0, "input edge required");
|
|
412 int first = regalloc->get_reg_first(def);
|
|
413 int second = regalloc->get_reg_second(def);
|
|
414 if( OptoReg::is_valid(first) ) set_live_bit(tmp_live,first);
|
|
415 if( OptoReg::is_valid(second) ) set_live_bit(tmp_live,second);
|
|
416 // If we use the stack pointer in a cisc-alternative instruction,
|
|
417 // check for use as a memory operand. Then reconstruct the RegName
|
|
418 // for this stack location, and set the appropriate bit in the
|
|
419 // live vector 4987749.
|
|
420 if (is_cisc_alternate && def == fp) {
|
|
421 const TypePtr *adr_type = NULL;
|
|
422 intptr_t offset;
|
|
423 const Node* base = m->get_base_and_disp(offset, adr_type);
|
|
424 if (base == NodeSentinel) {
|
|
425 // Machnode has multiple memory inputs. We are unable to reason
|
|
426 // with these, but are presuming (with trepidation) that not any of
|
|
427 // them are oops. This can be fixed by making get_base_and_disp()
|
|
428 // look at a specific input instead of all inputs.
|
|
429 assert(!def->bottom_type()->isa_oop_ptr(), "expecting non-oop mem input");
|
|
430 } else if (base != fp || offset == Type::OffsetBot) {
|
|
431 // Do nothing: the fp operand is either not from a memory use
|
|
432 // (base == NULL) OR the fp is used in a non-memory context
|
|
433 // (base is some other register) OR the offset is not constant,
|
|
434 // so it is not a stack slot.
|
|
435 } else {
|
|
436 assert(offset >= 0, "unexpected negative offset");
|
|
437 offset -= (offset % jintSize); // count the whole word
|
|
438 int stack_reg = regalloc->offset2reg(offset);
|
|
439 if (OptoReg::is_stack(stack_reg)) {
|
|
440 set_live_bit(tmp_live, stack_reg);
|
|
441 } else {
|
|
442 assert(false, "stack_reg not on stack?");
|
|
443 }
|
|
444 }
|
|
445 }
|
|
446 }
|
|
447
|
|
448 if( n->jvms() ) { // Record liveness at safepoint
|
|
449
|
|
450 // This placement of this stanza means inputs to calls are
|
|
451 // considered live at the callsite's OopMap. Argument oops are
|
|
452 // hence live, but NOT included in the oopmap. See cutout in
|
|
453 // build_oop_map. Debug oops are live (and in OopMap).
|
|
454 int *n_live = NEW_ARENA_ARRAY(A, int, max_reg_ints);
|
|
455 for( int l=0; l<max_reg_ints; l++ )
|
|
456 n_live[l] = tmp_live[l];
|
|
457 safehash->Insert(n,n_live);
|
|
458 }
|
|
459
|
|
460 }
|
|
461
|
|
462 // Now at block top, see if we have any changes. If so, propagate
|
|
463 // to prior blocks.
|
|
464 int *old_live = &live[b->_pre_order*max_reg_ints];
|
|
465 int l;
|
|
466 for( l=0; l<max_reg_ints; l++ )
|
|
467 if( tmp_live[l] != old_live[l] )
|
|
468 break;
|
|
469 if( l<max_reg_ints ) { // Change!
|
|
470 // Copy in new value
|
|
471 for( l=0; l<max_reg_ints; l++ )
|
|
472 old_live[l] = tmp_live[l];
|
|
473 // Push preds onto worklist
|
|
474 for( l=1; l<(int)b->num_preds(); l++ )
|
|
475 worklist->push(cfg->_bbs[b->pred(l)->_idx]);
|
|
476 }
|
|
477 }
|
|
478
|
|
479 // Scan for any missing safepoints. Happens to infinite loops
|
|
480 // ala ZKM.jar
|
|
481 uint i;
|
|
482 for( i=1; i<cfg->_num_blocks; i++ ) {
|
|
483 Block *b = cfg->_blocks[i];
|
|
484 uint j;
|
|
485 for( j=1; j<b->_nodes.size(); j++ )
|
|
486 if( b->_nodes[j]->jvms() &&
|
|
487 (*safehash)[b->_nodes[j]] == NULL )
|
|
488 break;
|
|
489 if( j<b->_nodes.size() ) break;
|
|
490 }
|
|
491 if( i == cfg->_num_blocks )
|
|
492 break; // Got 'em all
|
|
493 #ifndef PRODUCT
|
|
494 if( PrintOpto && Verbose )
|
|
495 tty->print_cr("retripping live calc");
|
|
496 #endif
|
|
497 // Force the issue (expensively): recheck everybody
|
|
498 for( i=1; i<cfg->_num_blocks; i++ )
|
|
499 worklist->push(cfg->_blocks[i]);
|
|
500 }
|
|
501
|
|
502 }
|
|
503
|
|
504 //------------------------------BuildOopMaps-----------------------------------
|
|
505 // Collect GC mask info - where are all the OOPs?
|
|
506 void Compile::BuildOopMaps() {
|
|
507 NOT_PRODUCT( TracePhase t3("bldOopMaps", &_t_buildOopMaps, TimeCompiler); )
|
|
508 // Can't resource-mark because I need to leave all those OopMaps around,
|
|
509 // or else I need to resource-mark some arena other than the default.
|
|
510 // ResourceMark rm; // Reclaim all OopFlows when done
|
|
511 int max_reg = _regalloc->_max_reg; // Current array extent
|
|
512
|
|
513 Arena *A = Thread::current()->resource_area();
|
|
514 Block_List worklist; // Worklist of pending blocks
|
|
515
|
|
516 int max_reg_ints = round_to(max_reg, BitsPerInt)>>LogBitsPerInt;
|
|
517 Dict *safehash = NULL; // Used for assert only
|
|
518 // Compute a backwards liveness per register. Needs a bitarray of
|
|
519 // #blocks x (#registers, rounded up to ints)
|
|
520 safehash = new Dict(cmpkey,hashkey,A);
|
|
521 do_liveness( _regalloc, _cfg, &worklist, max_reg_ints, A, safehash );
|
|
522 OopFlow *free_list = NULL; // Free, unused
|
|
523
|
|
524 // Array mapping blocks to completed oopflows
|
|
525 OopFlow **flows = NEW_ARENA_ARRAY(A, OopFlow*, _cfg->_num_blocks);
|
|
526 memset( flows, 0, _cfg->_num_blocks*sizeof(OopFlow*) );
|
|
527
|
|
528
|
|
529 // Do the first block 'by hand' to prime the worklist
|
|
530 Block *entry = _cfg->_blocks[1];
|
|
531 OopFlow *rootflow = OopFlow::make(A,max_reg);
|
|
532 // Initialize to 'bottom' (not 'top')
|
|
533 memset( rootflow->_callees, OptoReg::Bad, max_reg*sizeof(short) );
|
|
534 memset( rootflow->_defs , 0, max_reg*sizeof(Node*) );
|
|
535 flows[entry->_pre_order] = rootflow;
|
|
536
|
|
537 // Do the first block 'by hand' to prime the worklist
|
|
538 rootflow->_b = entry;
|
|
539 rootflow->compute_reach( _regalloc, max_reg, safehash );
|
|
540 for( uint i=0; i<entry->_num_succs; i++ )
|
|
541 worklist.push(entry->_succs[i]);
|
|
542
|
|
543 // Now worklist contains blocks which have some, but perhaps not all,
|
|
544 // predecessors visited.
|
|
545 while( worklist.size() ) {
|
|
546 // Scan for a block with all predecessors visited, or any randoms slob
|
|
547 // otherwise. All-preds-visited order allows me to recycle OopFlow
|
|
548 // structures rapidly and cut down on the memory footprint.
|
|
549 // Note: not all predecessors might be visited yet (must happen for
|
|
550 // irreducible loops). This is OK, since every live value must have the
|
|
551 // SAME reaching def for the block, so any reaching def is OK.
|
|
552 uint i;
|
|
553
|
|
554 Block *b = worklist.pop();
|
|
555 // Ignore root block
|
|
556 if( b == _cfg->_broot ) continue;
|
|
557 // Block is already done? Happens if block has several predecessors,
|
|
558 // he can get on the worklist more than once.
|
|
559 if( flows[b->_pre_order] ) continue;
|
|
560
|
|
561 // If this block has a visited predecessor AND that predecessor has this
|
|
562 // last block as his only undone child, we can move the OopFlow from the
|
|
563 // pred to this block. Otherwise we have to grab a new OopFlow.
|
|
564 OopFlow *flow = NULL; // Flag for finding optimized flow
|
|
565 Block *pred = (Block*)0xdeadbeef;
|
|
566 uint j;
|
|
567 // Scan this block's preds to find a done predecessor
|
|
568 for( j=1; j<b->num_preds(); j++ ) {
|
|
569 Block *p = _cfg->_bbs[b->pred(j)->_idx];
|
|
570 OopFlow *p_flow = flows[p->_pre_order];
|
|
571 if( p_flow ) { // Predecessor is done
|
|
572 assert( p_flow->_b == p, "cross check" );
|
|
573 pred = p; // Record some predecessor
|
|
574 // If all successors of p are done except for 'b', then we can carry
|
|
575 // p_flow forward to 'b' without copying, otherwise we have to draw
|
|
576 // from the free_list and clone data.
|
|
577 uint k;
|
|
578 for( k=0; k<p->_num_succs; k++ )
|
|
579 if( !flows[p->_succs[k]->_pre_order] &&
|
|
580 p->_succs[k] != b )
|
|
581 break;
|
|
582
|
|
583 // Either carry-forward the now-unused OopFlow for b's use
|
|
584 // or draw a new one from the free list
|
|
585 if( k==p->_num_succs ) {
|
|
586 flow = p_flow;
|
|
587 break; // Found an ideal pred, use him
|
|
588 }
|
|
589 }
|
|
590 }
|
|
591
|
|
592 if( flow ) {
|
|
593 // We have an OopFlow that's the last-use of a predecessor.
|
|
594 // Carry it forward.
|
|
595 } else { // Draw a new OopFlow from the freelist
|
|
596 if( !free_list )
|
|
597 free_list = OopFlow::make(A,max_reg);
|
|
598 flow = free_list;
|
|
599 assert( flow->_b == NULL, "oopFlow is not free" );
|
|
600 free_list = flow->_next;
|
|
601 flow->_next = NULL;
|
|
602
|
|
603 // Copy/clone over the data
|
|
604 flow->clone(flows[pred->_pre_order], max_reg);
|
|
605 }
|
|
606
|
|
607 // Mark flow for block. Blocks can only be flowed over once,
|
|
608 // because after the first time they are guarded from entering
|
|
609 // this code again.
|
|
610 assert( flow->_b == pred, "have some prior flow" );
|
|
611 flow->_b = NULL;
|
|
612
|
|
613 // Now push flow forward
|
|
614 flows[b->_pre_order] = flow;// Mark flow for this block
|
|
615 flow->_b = b;
|
|
616 flow->compute_reach( _regalloc, max_reg, safehash );
|
|
617
|
|
618 // Now push children onto worklist
|
|
619 for( i=0; i<b->_num_succs; i++ )
|
|
620 worklist.push(b->_succs[i]);
|
|
621
|
|
622 }
|
|
623 }
|