1 /*
2 * Copyright (c) 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/addnode.hpp"
27 #include "opto/castnode.hpp"
28 #include "opto/connode.hpp"
29 #include "opto/matcher.hpp"
30 #include "opto/phaseX.hpp"
31 #include "opto/subnode.hpp"
32 #include "opto/type.hpp"
33
34 //=============================================================================
35 // If input is already higher or equal to cast type, then this is an identity.
36 Node *ConstraintCastNode::Identity( PhaseTransform *phase ) {
37 return phase->type(in(1))->higher_equal_speculative(_type) ? in(1) : this;
38 }
39
40 //------------------------------Value------------------------------------------
41 // Take 'join' of input and cast-up type
42 const Type *ConstraintCastNode::Value( PhaseTransform *phase ) const {
43 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
44 const Type* ft = phase->type(in(1))->filter_speculative(_type);
45
46 #ifdef ASSERT
47 // Previous versions of this function had some special case logic,
48 // which is no longer necessary. Make sure of the required effects.
49 switch (Opcode()) {
50 case Op_CastII:
51 {
52 const Type* t1 = phase->type(in(1));
53 if( t1 == Type::TOP ) assert(ft == Type::TOP, "special case #1");
54 const Type* rt = t1->join_speculative(_type);
55 if (rt->empty()) assert(ft == Type::TOP, "special case #2");
56 break;
57 }
58 case Op_CastPP:
59 if (phase->type(in(1)) == TypePtr::NULL_PTR &&
60 _type->isa_ptr() && _type->is_ptr()->_ptr == TypePtr::NotNull)
61 assert(ft == Type::TOP, "special case #3");
62 break;
63 }
64 #endif //ASSERT
65
66 return ft;
67 }
68
69 //------------------------------Ideal------------------------------------------
70 // Return a node which is more "ideal" than the current node. Strip out
71 // control copies
72 Node *ConstraintCastNode::Ideal(PhaseGVN *phase, bool can_reshape){
73 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
74 }
75
76 //------------------------------Ideal_DU_postCCP-------------------------------
77 // Throw away cast after constant propagation
78 Node *ConstraintCastNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {
79 const Type *t = ccp->type(in(1));
80 ccp->hash_delete(this);
81 set_type(t); // Turn into ID function
82 ccp->hash_insert(this);
83 return this;
84 }
85
86 uint CastIINode::size_of() const {
87 return sizeof(*this);
88 }
89
90 uint CastIINode::cmp(const Node &n) const {
91 return TypeNode::cmp(n) && ((CastIINode&)n)._carry_dependency == _carry_dependency;
92 }
93
94 Node *CastIINode::Identity(PhaseTransform *phase) {
95 if (_carry_dependency) {
96 return this;
97 }
98 return ConstraintCastNode::Identity(phase);
99 }
100
101 const Type *CastIINode::Value(PhaseTransform *phase) const {
102 const Type *res = ConstraintCastNode::Value(phase);
103
104 // Try to improve the type of the CastII if we recognize a CmpI/If
105 // pattern.
106 if (_carry_dependency) {
107 if (in(0) != NULL && in(0)->in(0) != NULL && in(0)->in(0)->is_If()) {
108 assert(in(0)->is_IfFalse() || in(0)->is_IfTrue(), "should be If proj");
109 Node* proj = in(0);
110 if (proj->in(0)->in(1)->is_Bool()) {
111 Node* b = proj->in(0)->in(1);
112 if (b->in(1)->Opcode() == Op_CmpI) {
113 Node* cmp = b->in(1);
114 if (cmp->in(1) == in(1) && phase->type(cmp->in(2))->isa_int()) {
115 const TypeInt* in2_t = phase->type(cmp->in(2))->is_int();
116 const Type* t = TypeInt::INT;
117 BoolTest test = b->as_Bool()->_test;
118 if (proj->is_IfFalse()) {
119 test = test.negate();
120 }
121 BoolTest::mask m = test._test;
122 jlong lo_long = min_jint;
123 jlong hi_long = max_jint;
124 if (m == BoolTest::le || m == BoolTest::lt) {
125 hi_long = in2_t->_hi;
126 if (m == BoolTest::lt) {
127 hi_long -= 1;
128 }
129 } else if (m == BoolTest::ge || m == BoolTest::gt) {
130 lo_long = in2_t->_lo;
131 if (m == BoolTest::gt) {
132 lo_long += 1;
133 }
134 } else if (m == BoolTest::eq) {
135 lo_long = in2_t->_lo;
136 hi_long = in2_t->_hi;
137 } else if (m == BoolTest::ne) {
138 // can't do any better
139 } else {
140 stringStream ss;
141 test.dump_on(&ss);
142 fatal(err_msg_res("unexpected comparison %s", ss.as_string()));
143 }
144 int lo_int = (int)lo_long;
145 int hi_int = (int)hi_long;
146
147 if (lo_long != (jlong)lo_int) {
148 lo_int = min_jint;
149 }
150 if (hi_long != (jlong)hi_int) {
151 hi_int = max_jint;
152 }
153
154 t = TypeInt::make(lo_int, hi_int, Type::WidenMax);
155
156 res = res->filter_speculative(t);
157
158 return res;
159 }
160 }
161 }
162 }
163 }
164 return res;
165 }
166
167 Node *CastIINode::Ideal_DU_postCCP(PhaseCCP *ccp) {
168 if (_carry_dependency) {
169 return NULL;
170 }
171 return ConstraintCastNode::Ideal_DU_postCCP(ccp);
172 }
173
174 #ifndef PRODUCT
175 void CastIINode::dump_spec(outputStream *st) const {
176 TypeNode::dump_spec(st);
177 if (_carry_dependency) {
178 st->print(" carry dependency");
179 }
180 }
181 #endif
182
183 //=============================================================================
184
185 //------------------------------Ideal_DU_postCCP-------------------------------
186 // If not converting int->oop, throw away cast after constant propagation
187 Node *CastPPNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {
188 const Type *t = ccp->type(in(1));
189 if (!t->isa_oop_ptr() || ((in(1)->is_DecodeN()) && Matcher::gen_narrow_oop_implicit_null_checks())) {
190 return NULL; // do not transform raw pointers or narrow oops
191 }
192 return ConstraintCastNode::Ideal_DU_postCCP(ccp);
193 }
194
195
196
197 //=============================================================================
198 //------------------------------Identity---------------------------------------
199 // If input is already higher or equal to cast type, then this is an identity.
200 Node *CheckCastPPNode::Identity( PhaseTransform *phase ) {
201 // Toned down to rescue meeting at a Phi 3 different oops all implementing
202 // the same interface. CompileTheWorld starting at 502, kd12rc1.zip.
203 return (phase->type(in(1)) == phase->type(this)) ? in(1) : this;
204 }
205
206 //------------------------------Value------------------------------------------
207 // Take 'join' of input and cast-up type, unless working with an Interface
208 const Type *CheckCastPPNode::Value( PhaseTransform *phase ) const {
209 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
210
211 const Type *inn = phase->type(in(1));
212 if( inn == Type::TOP ) return Type::TOP; // No information yet
213
214 const TypePtr *in_type = inn->isa_ptr();
215 const TypePtr *my_type = _type->isa_ptr();
216 const Type *result = _type;
217 if( in_type != NULL && my_type != NULL ) {
218 TypePtr::PTR in_ptr = in_type->ptr();
219 if( in_ptr == TypePtr::Null ) {
220 result = in_type;
221 } else if( in_ptr == TypePtr::Constant ) {
222 // Casting a constant oop to an interface?
223 // (i.e., a String to a Comparable?)
224 // Then return the interface.
225 const TypeOopPtr *jptr = my_type->isa_oopptr();
226 assert( jptr, "" );
227 result = (jptr->klass()->is_interface() || !in_type->higher_equal(_type))
228 ? my_type->cast_to_ptr_type( TypePtr::NotNull )
229 : in_type;
230 } else {
231 result = my_type->cast_to_ptr_type( my_type->join_ptr(in_ptr) );
232 }
233 }
234
235 // This is the code from TypePtr::xmeet() that prevents us from
236 // having 2 ways to represent the same type. We have to replicate it
237 // here because we don't go through meet/join.
238 if (result->remove_speculative() == result->speculative()) {
239 result = result->remove_speculative();
240 }
241
242 // Same as above: because we don't go through meet/join, remove the
243 // speculative type if we know we won't use it.
244 return result->cleanup_speculative();
245
246 // JOIN NOT DONE HERE BECAUSE OF INTERFACE ISSUES.
247 // FIX THIS (DO THE JOIN) WHEN UNION TYPES APPEAR!
248
249 //
250 // Remove this code after overnight run indicates no performance
251 // loss from not performing JOIN at CheckCastPPNode
252 //
253 // const TypeInstPtr *in_oop = in->isa_instptr();
254 // const TypeInstPtr *my_oop = _type->isa_instptr();
255 // // If either input is an 'interface', return destination type
256 // assert (in_oop == NULL || in_oop->klass() != NULL, "");
257 // assert (my_oop == NULL || my_oop->klass() != NULL, "");
258 // if( (in_oop && in_oop->klass()->is_interface())
259 // ||(my_oop && my_oop->klass()->is_interface()) ) {
260 // TypePtr::PTR in_ptr = in->isa_ptr() ? in->is_ptr()->_ptr : TypePtr::BotPTR;
261 // // Preserve cast away nullness for interfaces
262 // if( in_ptr == TypePtr::NotNull && my_oop && my_oop->_ptr == TypePtr::BotPTR ) {
263 // return my_oop->cast_to_ptr_type(TypePtr::NotNull);
264 // }
265 // return _type;
266 // }
267 //
268 // // Neither the input nor the destination type is an interface,
269 //
270 // // history: JOIN used to cause weird corner case bugs
271 // // return (in == TypeOopPtr::NULL_PTR) ? in : _type;
272 // // JOIN picks up NotNull in common instance-of/check-cast idioms, both oops.
273 // // JOIN does not preserve NotNull in other cases, e.g. RawPtr vs InstPtr
274 // const Type *join = in->join(_type);
275 // // Check if join preserved NotNull'ness for pointers
276 // if( join->isa_ptr() && _type->isa_ptr() ) {
277 // TypePtr::PTR join_ptr = join->is_ptr()->_ptr;
278 // TypePtr::PTR type_ptr = _type->is_ptr()->_ptr;
279 // // If there isn't any NotNull'ness to preserve
280 // // OR if join preserved NotNull'ness then return it
281 // if( type_ptr == TypePtr::BotPTR || type_ptr == TypePtr::Null ||
282 // join_ptr == TypePtr::NotNull || join_ptr == TypePtr::Constant ) {
283 // return join;
284 // }
285 // // ELSE return same old type as before
286 // return _type;
287 // }
288 // // Not joining two pointers
289 // return join;
290 }
291
292 //------------------------------Ideal------------------------------------------
293 // Return a node which is more "ideal" than the current node. Strip out
294 // control copies
295 Node *CheckCastPPNode::Ideal(PhaseGVN *phase, bool can_reshape){
296 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
297 }
298
299 //=============================================================================
300 //------------------------------Value------------------------------------------
301 const Type *CastX2PNode::Value( PhaseTransform *phase ) const {
302 const Type* t = phase->type(in(1));
303 if (t == Type::TOP) return Type::TOP;
304 if (t->base() == Type_X && t->singleton()) {
305 uintptr_t bits = (uintptr_t) t->is_intptr_t()->get_con();
306 if (bits == 0) return TypePtr::NULL_PTR;
307 return TypeRawPtr::make((address) bits);
308 }
309 return CastX2PNode::bottom_type();
310 }
311
312 //------------------------------Idealize---------------------------------------
313 static inline bool fits_in_int(const Type* t, bool but_not_min_int = false) {
314 if (t == Type::TOP) return false;
315 const TypeX* tl = t->is_intptr_t();
316 jint lo = min_jint;
317 jint hi = max_jint;
318 if (but_not_min_int) ++lo; // caller wants to negate the value w/o overflow
319 return (tl->_lo >= lo) && (tl->_hi <= hi);
320 }
321
322 static inline Node* addP_of_X2P(PhaseGVN *phase,
323 Node* base,
324 Node* dispX,
325 bool negate = false) {
326 if (negate) {
327 dispX = new SubXNode(phase->MakeConX(0), phase->transform(dispX));
328 }
329 return new AddPNode(phase->C->top(),
330 phase->transform(new CastX2PNode(base)),
331 phase->transform(dispX));
332 }
333
334 Node *CastX2PNode::Ideal(PhaseGVN *phase, bool can_reshape) {
335 // convert CastX2P(AddX(x, y)) to AddP(CastX2P(x), y) if y fits in an int
336 int op = in(1)->Opcode();
337 Node* x;
338 Node* y;
339 switch (op) {
340 case Op_SubX:
341 x = in(1)->in(1);
342 // Avoid ideal transformations ping-pong between this and AddP for raw pointers.
343 if (phase->find_intptr_t_con(x, -1) == 0)
344 break;
345 y = in(1)->in(2);
346 if (fits_in_int(phase->type(y), true)) {
347 return addP_of_X2P(phase, x, y, true);
348 }
349 break;
350 case Op_AddX:
351 x = in(1)->in(1);
352 y = in(1)->in(2);
353 if (fits_in_int(phase->type(y))) {
354 return addP_of_X2P(phase, x, y);
355 }
356 if (fits_in_int(phase->type(x))) {
357 return addP_of_X2P(phase, y, x);
358 }
359 break;
360 }
361 return NULL;
362 }
363
364 //------------------------------Identity---------------------------------------
365 Node *CastX2PNode::Identity( PhaseTransform *phase ) {
366 if (in(1)->Opcode() == Op_CastP2X) return in(1)->in(1);
367 return this;
368 }
369
370 //=============================================================================
371 //------------------------------Value------------------------------------------
372 const Type *CastP2XNode::Value( PhaseTransform *phase ) const {
373 const Type* t = phase->type(in(1));
374 if (t == Type::TOP) return Type::TOP;
375 if (t->base() == Type::RawPtr && t->singleton()) {
376 uintptr_t bits = (uintptr_t) t->is_rawptr()->get_con();
377 return TypeX::make(bits);
378 }
379 return CastP2XNode::bottom_type();
380 }
381
382 Node *CastP2XNode::Ideal(PhaseGVN *phase, bool can_reshape) {
383 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
384 }
385
386 //------------------------------Identity---------------------------------------
387 Node *CastP2XNode::Identity( PhaseTransform *phase ) {
388 if (in(1)->Opcode() == Op_CastX2P) return in(1)->in(1);
389 return this;
390 }