1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/ci/ciTypeFlow.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,714 @@
1.4 +/*
1.5 + * Copyright 2000-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +
1.29 +class ciTypeFlow : public ResourceObj {
1.30 +private:
1.31 + ciEnv* _env;
1.32 + ciMethod* _method;
1.33 + ciMethodBlocks* _methodBlocks;
1.34 + int _osr_bci;
1.35 +
1.36 + // information cached from the method:
1.37 + int _max_locals;
1.38 + int _max_stack;
1.39 + int _code_size;
1.40 +
1.41 + const char* _failure_reason;
1.42 +
1.43 +public:
1.44 + class StateVector;
1.45 + class Block;
1.46 +
1.47 + // Build a type flow analyzer
1.48 + // Do an OSR analysis if osr_bci >= 0.
1.49 + ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci = InvocationEntryBci);
1.50 +
1.51 + // Accessors
1.52 + ciMethod* method() const { return _method; }
1.53 + ciEnv* env() { return _env; }
1.54 + Arena* arena() { return _env->arena(); }
1.55 + bool is_osr_flow() const{ return _osr_bci != InvocationEntryBci; }
1.56 + int start_bci() const { return is_osr_flow()? _osr_bci: 0; }
1.57 + int max_locals() const { return _max_locals; }
1.58 + int max_stack() const { return _max_stack; }
1.59 + int max_cells() const { return _max_locals + _max_stack; }
1.60 + int code_size() const { return _code_size; }
1.61 +
1.62 + // Represents information about an "active" jsr call. This
1.63 + // class represents a call to the routine at some entry address
1.64 + // with some distinct return address.
1.65 + class JsrRecord : public ResourceObj {
1.66 + private:
1.67 + int _entry_address;
1.68 + int _return_address;
1.69 + public:
1.70 + JsrRecord(int entry_address, int return_address) {
1.71 + _entry_address = entry_address;
1.72 + _return_address = return_address;
1.73 + }
1.74 +
1.75 + int entry_address() const { return _entry_address; }
1.76 + int return_address() const { return _return_address; }
1.77 +
1.78 + void print_on(outputStream* st) const {
1.79 +#ifndef PRODUCT
1.80 + st->print("%d->%d", entry_address(), return_address());
1.81 +#endif
1.82 + }
1.83 + };
1.84 +
1.85 + // A JsrSet represents some set of JsrRecords. This class
1.86 + // is used to record a set of all jsr routines which we permit
1.87 + // execution to return (ret) from.
1.88 + //
1.89 + // During abstract interpretation, JsrSets are used to determine
1.90 + // whether two paths which reach a given block are unique, and
1.91 + // should be cloned apart, or are compatible, and should merge
1.92 + // together.
1.93 + //
1.94 + // Note that different amounts of effort can be expended determining
1.95 + // if paths are compatible. <DISCUSSION>
1.96 + class JsrSet : public ResourceObj {
1.97 + private:
1.98 + GrowableArray<JsrRecord*>* _set;
1.99 +
1.100 + JsrRecord* record_at(int i) {
1.101 + return _set->at(i);
1.102 + }
1.103 +
1.104 + // Insert the given JsrRecord into the JsrSet, maintaining the order
1.105 + // of the set and replacing any element with the same entry address.
1.106 + void insert_jsr_record(JsrRecord* record);
1.107 +
1.108 + // Remove the JsrRecord with the given return address from the JsrSet.
1.109 + void remove_jsr_record(int return_address);
1.110 +
1.111 + public:
1.112 + JsrSet(Arena* arena, int default_len = 4);
1.113 +
1.114 + // Copy this JsrSet.
1.115 + void copy_into(JsrSet* jsrs);
1.116 +
1.117 + // Is this JsrSet compatible with some other JsrSet?
1.118 + bool is_compatible_with(JsrSet* other);
1.119 +
1.120 + // Apply the effect of a single bytecode to the JsrSet.
1.121 + void apply_control(ciTypeFlow* analyzer,
1.122 + ciBytecodeStream* str,
1.123 + StateVector* state);
1.124 +
1.125 + // What is the cardinality of this set?
1.126 + int size() const { return _set->length(); }
1.127 +
1.128 + void print_on(outputStream* st) const PRODUCT_RETURN;
1.129 + };
1.130 +
1.131 + // Used as a combined index for locals and temps
1.132 + enum Cell {
1.133 + Cell_0
1.134 + };
1.135 +
1.136 + // A StateVector summarizes the type information at some
1.137 + // point in the program
1.138 + class StateVector : public ResourceObj {
1.139 + private:
1.140 + ciType** _types;
1.141 + int _stack_size;
1.142 + int _monitor_count;
1.143 + ciTypeFlow* _outer;
1.144 +
1.145 + int _trap_bci;
1.146 + int _trap_index;
1.147 +
1.148 + static ciType* type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer);
1.149 +
1.150 + public:
1.151 + // Special elements in our type lattice.
1.152 + enum {
1.153 + T_TOP = T_VOID, // why not?
1.154 + T_BOTTOM = T_CONFLICT,
1.155 + T_LONG2 = T_SHORT, // 2nd word of T_LONG
1.156 + T_DOUBLE2 = T_CHAR, // 2nd word of T_DOUBLE
1.157 + T_NULL = T_BYTE // for now.
1.158 + };
1.159 + static ciType* top_type() { return ciType::make((BasicType)T_TOP); }
1.160 + static ciType* bottom_type() { return ciType::make((BasicType)T_BOTTOM); }
1.161 + static ciType* long2_type() { return ciType::make((BasicType)T_LONG2); }
1.162 + static ciType* double2_type(){ return ciType::make((BasicType)T_DOUBLE2); }
1.163 + static ciType* null_type() { return ciType::make((BasicType)T_NULL); }
1.164 +
1.165 + static ciType* half_type(ciType* t) {
1.166 + switch (t->basic_type()) {
1.167 + case T_LONG: return long2_type();
1.168 + case T_DOUBLE: return double2_type();
1.169 + default: ShouldNotReachHere(); return NULL;
1.170 + }
1.171 + }
1.172 +
1.173 + // The meet operation for our type lattice.
1.174 + ciType* type_meet(ciType* t1, ciType* t2) {
1.175 + return type_meet_internal(t1, t2, outer());
1.176 + }
1.177 +
1.178 + // Accessors
1.179 + ciTypeFlow* outer() const { return _outer; }
1.180 +
1.181 + int stack_size() const { return _stack_size; }
1.182 + void set_stack_size(int ss) { _stack_size = ss; }
1.183 +
1.184 + int monitor_count() const { return _monitor_count; }
1.185 + void set_monitor_count(int mc) { _monitor_count = mc; }
1.186 +
1.187 + static Cell start_cell() { return (Cell)0; }
1.188 + static Cell next_cell(Cell c) { return (Cell)(((int)c) + 1); }
1.189 + Cell limit_cell() const {
1.190 + return (Cell)(outer()->max_locals() + stack_size());
1.191 + }
1.192 +
1.193 + // Cell creation
1.194 + Cell local(int lnum) const {
1.195 + assert(lnum < outer()->max_locals(), "index check");
1.196 + return (Cell)(lnum);
1.197 + }
1.198 +
1.199 + Cell stack(int snum) const {
1.200 + assert(snum < stack_size(), "index check");
1.201 + return (Cell)(outer()->max_locals() + snum);
1.202 + }
1.203 +
1.204 + Cell tos() const { return stack(stack_size()-1); }
1.205 +
1.206 + // For external use only:
1.207 + ciType* local_type_at(int i) const { return type_at(local(i)); }
1.208 + ciType* stack_type_at(int i) const { return type_at(stack(i)); }
1.209 +
1.210 + // Accessors for the type of some Cell c
1.211 + ciType* type_at(Cell c) const {
1.212 + assert(start_cell() <= c && c < limit_cell(), "out of bounds");
1.213 + return _types[c];
1.214 + }
1.215 +
1.216 + void set_type_at(Cell c, ciType* type) {
1.217 + assert(start_cell() <= c && c < limit_cell(), "out of bounds");
1.218 + _types[c] = type;
1.219 + }
1.220 +
1.221 + // Top-of-stack operations.
1.222 + void set_type_at_tos(ciType* type) { set_type_at(tos(), type); }
1.223 + ciType* type_at_tos() const { return type_at(tos()); }
1.224 +
1.225 + void push(ciType* type) {
1.226 + _stack_size++;
1.227 + set_type_at_tos(type);
1.228 + }
1.229 + void pop() {
1.230 + debug_only(set_type_at_tos(bottom_type()));
1.231 + _stack_size--;
1.232 + }
1.233 + ciType* pop_value() {
1.234 + ciType* t = type_at_tos();
1.235 + pop();
1.236 + return t;
1.237 + }
1.238 +
1.239 + // Convenience operations.
1.240 + bool is_reference(ciType* type) const {
1.241 + return type == null_type() || !type->is_primitive_type();
1.242 + }
1.243 + bool is_int(ciType* type) const {
1.244 + return type->basic_type() == T_INT;
1.245 + }
1.246 + bool is_long(ciType* type) const {
1.247 + return type->basic_type() == T_LONG;
1.248 + }
1.249 + bool is_float(ciType* type) const {
1.250 + return type->basic_type() == T_FLOAT;
1.251 + }
1.252 + bool is_double(ciType* type) const {
1.253 + return type->basic_type() == T_DOUBLE;
1.254 + }
1.255 +
1.256 + void push_translate(ciType* type);
1.257 +
1.258 + void push_int() {
1.259 + push(ciType::make(T_INT));
1.260 + }
1.261 + void pop_int() {
1.262 + assert(is_int(type_at_tos()), "must be integer");
1.263 + pop();
1.264 + }
1.265 + void check_int(Cell c) {
1.266 + assert(is_int(type_at(c)), "must be integer");
1.267 + }
1.268 + void push_double() {
1.269 + push(ciType::make(T_DOUBLE));
1.270 + push(double2_type());
1.271 + }
1.272 + void pop_double() {
1.273 + assert(type_at_tos() == double2_type(), "must be 2nd half");
1.274 + pop();
1.275 + assert(is_double(type_at_tos()), "must be double");
1.276 + pop();
1.277 + }
1.278 + void push_float() {
1.279 + push(ciType::make(T_FLOAT));
1.280 + }
1.281 + void pop_float() {
1.282 + assert(is_float(type_at_tos()), "must be float");
1.283 + pop();
1.284 + }
1.285 + void push_long() {
1.286 + push(ciType::make(T_LONG));
1.287 + push(long2_type());
1.288 + }
1.289 + void pop_long() {
1.290 + assert(type_at_tos() == long2_type(), "must be 2nd half");
1.291 + pop();
1.292 + assert(is_long(type_at_tos()), "must be long");
1.293 + pop();
1.294 + }
1.295 + void push_object(ciKlass* klass) {
1.296 + push(klass);
1.297 + }
1.298 + void pop_object() {
1.299 + assert(is_reference(type_at_tos()), "must be reference type");
1.300 + pop();
1.301 + }
1.302 + void pop_array() {
1.303 + assert(type_at_tos() == null_type() ||
1.304 + type_at_tos()->is_array_klass(), "must be array type");
1.305 + pop();
1.306 + }
1.307 + // pop_objArray and pop_typeArray narrow the tos to ciObjArrayKlass
1.308 + // or ciTypeArrayKlass (resp.). In the rare case that an explicit
1.309 + // null is popped from the stack, we return NULL. Caller beware.
1.310 + ciObjArrayKlass* pop_objArray() {
1.311 + ciType* array = pop_value();
1.312 + if (array == null_type()) return NULL;
1.313 + assert(array->is_obj_array_klass(), "must be object array type");
1.314 + return array->as_obj_array_klass();
1.315 + }
1.316 + ciTypeArrayKlass* pop_typeArray() {
1.317 + ciType* array = pop_value();
1.318 + if (array == null_type()) return NULL;
1.319 + assert(array->is_type_array_klass(), "must be prim array type");
1.320 + return array->as_type_array_klass();
1.321 + }
1.322 + void push_null() {
1.323 + push(null_type());
1.324 + }
1.325 + void do_null_assert(ciKlass* unloaded_klass);
1.326 +
1.327 + // Helper convenience routines.
1.328 + void do_aaload(ciBytecodeStream* str);
1.329 + void do_checkcast(ciBytecodeStream* str);
1.330 + void do_getfield(ciBytecodeStream* str);
1.331 + void do_getstatic(ciBytecodeStream* str);
1.332 + void do_invoke(ciBytecodeStream* str, bool has_receiver);
1.333 + void do_jsr(ciBytecodeStream* str);
1.334 + void do_ldc(ciBytecodeStream* str);
1.335 + void do_multianewarray(ciBytecodeStream* str);
1.336 + void do_new(ciBytecodeStream* str);
1.337 + void do_newarray(ciBytecodeStream* str);
1.338 + void do_putfield(ciBytecodeStream* str);
1.339 + void do_putstatic(ciBytecodeStream* str);
1.340 + void do_ret(ciBytecodeStream* str);
1.341 +
1.342 + void overwrite_local_double_long(int index) {
1.343 + // Invalidate the previous local if it contains first half of
1.344 + // a double or long value since it's seconf half is being overwritten.
1.345 + int prev_index = index - 1;
1.346 + if (prev_index >= 0 &&
1.347 + (is_double(type_at(local(prev_index))) ||
1.348 + is_long(type_at(local(prev_index))))) {
1.349 + set_type_at(local(prev_index), bottom_type());
1.350 + }
1.351 + }
1.352 +
1.353 + void load_local_object(int index) {
1.354 + ciType* type = type_at(local(index));
1.355 + assert(is_reference(type), "must be reference type");
1.356 + push(type);
1.357 + }
1.358 + void store_local_object(int index) {
1.359 + ciType* type = pop_value();
1.360 + assert(is_reference(type) || type->is_return_address(),
1.361 + "must be reference type or return address");
1.362 + overwrite_local_double_long(index);
1.363 + set_type_at(local(index), type);
1.364 + }
1.365 +
1.366 + void load_local_double(int index) {
1.367 + ciType* type = type_at(local(index));
1.368 + ciType* type2 = type_at(local(index+1));
1.369 + assert(is_double(type), "must be double type");
1.370 + assert(type2 == double2_type(), "must be 2nd half");
1.371 + push(type);
1.372 + push(double2_type());
1.373 + }
1.374 + void store_local_double(int index) {
1.375 + ciType* type2 = pop_value();
1.376 + ciType* type = pop_value();
1.377 + assert(is_double(type), "must be double");
1.378 + assert(type2 == double2_type(), "must be 2nd half");
1.379 + overwrite_local_double_long(index);
1.380 + set_type_at(local(index), type);
1.381 + set_type_at(local(index+1), type2);
1.382 + }
1.383 +
1.384 + void load_local_float(int index) {
1.385 + ciType* type = type_at(local(index));
1.386 + assert(is_float(type), "must be float type");
1.387 + push(type);
1.388 + }
1.389 + void store_local_float(int index) {
1.390 + ciType* type = pop_value();
1.391 + assert(is_float(type), "must be float type");
1.392 + overwrite_local_double_long(index);
1.393 + set_type_at(local(index), type);
1.394 + }
1.395 +
1.396 + void load_local_int(int index) {
1.397 + ciType* type = type_at(local(index));
1.398 + assert(is_int(type), "must be int type");
1.399 + push(type);
1.400 + }
1.401 + void store_local_int(int index) {
1.402 + ciType* type = pop_value();
1.403 + assert(is_int(type), "must be int type");
1.404 + overwrite_local_double_long(index);
1.405 + set_type_at(local(index), type);
1.406 + }
1.407 +
1.408 + void load_local_long(int index) {
1.409 + ciType* type = type_at(local(index));
1.410 + ciType* type2 = type_at(local(index+1));
1.411 + assert(is_long(type), "must be long type");
1.412 + assert(type2 == long2_type(), "must be 2nd half");
1.413 + push(type);
1.414 + push(long2_type());
1.415 + }
1.416 + void store_local_long(int index) {
1.417 + ciType* type2 = pop_value();
1.418 + ciType* type = pop_value();
1.419 + assert(is_long(type), "must be long");
1.420 + assert(type2 == long2_type(), "must be 2nd half");
1.421 + overwrite_local_double_long(index);
1.422 + set_type_at(local(index), type);
1.423 + set_type_at(local(index+1), type2);
1.424 + }
1.425 +
1.426 + // Stop interpretation of this path with a trap.
1.427 + void trap(ciBytecodeStream* str, ciKlass* klass, int index);
1.428 +
1.429 + public:
1.430 + StateVector(ciTypeFlow* outer);
1.431 +
1.432 + // Copy our value into some other StateVector
1.433 + void copy_into(StateVector* copy) const;
1.434 +
1.435 + // Meets this StateVector with another, destructively modifying this
1.436 + // one. Returns true if any modification takes place.
1.437 + bool meet(const StateVector* incoming);
1.438 +
1.439 + // Ditto, except that the incoming state is coming from an exception.
1.440 + bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming);
1.441 +
1.442 + // Apply the effect of one bytecode to this StateVector
1.443 + bool apply_one_bytecode(ciBytecodeStream* stream);
1.444 +
1.445 + // What is the bci of the trap?
1.446 + int trap_bci() { return _trap_bci; }
1.447 +
1.448 + // What is the index associated with the trap?
1.449 + int trap_index() { return _trap_index; }
1.450 +
1.451 + void print_cell_on(outputStream* st, Cell c) const PRODUCT_RETURN;
1.452 + void print_on(outputStream* st) const PRODUCT_RETURN;
1.453 + };
1.454 +
1.455 + // Parameter for "find_block" calls:
1.456 + // Describes the difference between a public and private copy.
1.457 + enum CreateOption {
1.458 + create_public_copy,
1.459 + create_private_copy,
1.460 + no_create
1.461 + };
1.462 +
1.463 + // A basic block
1.464 + class Block : public ResourceObj {
1.465 + private:
1.466 + ciBlock* _ciblock;
1.467 + GrowableArray<Block*>* _exceptions;
1.468 + GrowableArray<ciInstanceKlass*>* _exc_klasses;
1.469 + GrowableArray<Block*>* _successors;
1.470 + StateVector* _state;
1.471 + JsrSet* _jsrs;
1.472 +
1.473 + int _trap_bci;
1.474 + int _trap_index;
1.475 +
1.476 + // A reasonable approximation to pre-order, provided.to the client.
1.477 + int _pre_order;
1.478 +
1.479 + // Has this block been cloned for some special purpose?
1.480 + bool _private_copy;
1.481 +
1.482 + // A pointer used for our internal work list
1.483 + Block* _next;
1.484 + bool _on_work_list;
1.485 +
1.486 + ciBlock* ciblock() const { return _ciblock; }
1.487 + StateVector* state() const { return _state; }
1.488 +
1.489 + // Compute the exceptional successors and types for this Block.
1.490 + void compute_exceptions();
1.491 +
1.492 + public:
1.493 + // constructors
1.494 + Block(ciTypeFlow* outer, ciBlock* ciblk, JsrSet* jsrs);
1.495 +
1.496 + void set_trap(int trap_bci, int trap_index) {
1.497 + _trap_bci = trap_bci;
1.498 + _trap_index = trap_index;
1.499 + assert(has_trap(), "");
1.500 + }
1.501 + bool has_trap() const { return _trap_bci != -1; }
1.502 + int trap_bci() const { assert(has_trap(), ""); return _trap_bci; }
1.503 + int trap_index() const { assert(has_trap(), ""); return _trap_index; }
1.504 +
1.505 + // accessors
1.506 + ciTypeFlow* outer() const { return state()->outer(); }
1.507 + int start() const { return _ciblock->start_bci(); }
1.508 + int limit() const { return _ciblock->limit_bci(); }
1.509 + int control() const { return _ciblock->control_bci(); }
1.510 +
1.511 + bool is_private_copy() const { return _private_copy; }
1.512 + void set_private_copy(bool z);
1.513 + int private_copy_count() const { return outer()->private_copy_count(ciblock()->index(), _jsrs); }
1.514 +
1.515 + // access to entry state
1.516 + int stack_size() const { return _state->stack_size(); }
1.517 + int monitor_count() const { return _state->monitor_count(); }
1.518 + ciType* local_type_at(int i) const { return _state->local_type_at(i); }
1.519 + ciType* stack_type_at(int i) const { return _state->stack_type_at(i); }
1.520 +
1.521 + // Get the successors for this Block.
1.522 + GrowableArray<Block*>* successors(ciBytecodeStream* str,
1.523 + StateVector* state,
1.524 + JsrSet* jsrs);
1.525 + GrowableArray<Block*>* successors() {
1.526 + assert(_successors != NULL, "must be filled in");
1.527 + return _successors;
1.528 + }
1.529 +
1.530 + // Helper function for "successors" when making private copies of
1.531 + // loop heads for C2.
1.532 + Block * clone_loop_head(ciTypeFlow* analyzer,
1.533 + int branch_bci,
1.534 + Block* target,
1.535 + JsrSet* jsrs);
1.536 +
1.537 + // Get the exceptional successors for this Block.
1.538 + GrowableArray<Block*>* exceptions() {
1.539 + if (_exceptions == NULL) {
1.540 + compute_exceptions();
1.541 + }
1.542 + return _exceptions;
1.543 + }
1.544 +
1.545 + // Get the exception klasses corresponding to the
1.546 + // exceptional successors for this Block.
1.547 + GrowableArray<ciInstanceKlass*>* exc_klasses() {
1.548 + if (_exc_klasses == NULL) {
1.549 + compute_exceptions();
1.550 + }
1.551 + return _exc_klasses;
1.552 + }
1.553 +
1.554 + // Is this Block compatible with a given JsrSet?
1.555 + bool is_compatible_with(JsrSet* other) {
1.556 + return _jsrs->is_compatible_with(other);
1.557 + }
1.558 +
1.559 + // Copy the value of our state vector into another.
1.560 + void copy_state_into(StateVector* copy) const {
1.561 + _state->copy_into(copy);
1.562 + }
1.563 +
1.564 + // Copy the value of our JsrSet into another
1.565 + void copy_jsrs_into(JsrSet* copy) const {
1.566 + _jsrs->copy_into(copy);
1.567 + }
1.568 +
1.569 + // Meets the start state of this block with another state, destructively
1.570 + // modifying this one. Returns true if any modification takes place.
1.571 + bool meet(const StateVector* incoming) {
1.572 + return state()->meet(incoming);
1.573 + }
1.574 +
1.575 + // Ditto, except that the incoming state is coming from an
1.576 + // exception path. This means the stack is replaced by the
1.577 + // appropriate exception type.
1.578 + bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming) {
1.579 + return state()->meet_exception(exc, incoming);
1.580 + }
1.581 +
1.582 + // Work list manipulation
1.583 + void set_next(Block* block) { _next = block; }
1.584 + Block* next() const { return _next; }
1.585 +
1.586 + void set_on_work_list(bool c) { _on_work_list = c; }
1.587 + bool is_on_work_list() const { return _on_work_list; }
1.588 +
1.589 + bool has_pre_order() const { return _pre_order >= 0; }
1.590 + void set_pre_order(int po) { assert(!has_pre_order() && po >= 0, ""); _pre_order = po; }
1.591 + int pre_order() const { assert(has_pre_order(), ""); return _pre_order; }
1.592 + bool is_start() const { return _pre_order == outer()->start_block_num(); }
1.593 +
1.594 + // A ranking used in determining order within the work list.
1.595 + bool is_simpler_than(Block* other);
1.596 +
1.597 + void print_value_on(outputStream* st) const PRODUCT_RETURN;
1.598 + void print_on(outputStream* st) const PRODUCT_RETURN;
1.599 + };
1.600 +
1.601 + // Standard indexes of successors, for various bytecodes.
1.602 + enum {
1.603 + FALL_THROUGH = 0, // normal control
1.604 + IF_NOT_TAKEN = 0, // the not-taken branch of an if (i.e., fall-through)
1.605 + IF_TAKEN = 1, // the taken branch of an if
1.606 + GOTO_TARGET = 0, // unique successor for goto, jsr, or ret
1.607 + SWITCH_DEFAULT = 0, // default branch of a switch
1.608 + SWITCH_CASES = 1 // first index for any non-default switch branches
1.609 + // Unlike in other blocks, the successors of a switch are listed uniquely.
1.610 + };
1.611 +
1.612 +private:
1.613 + // A mapping from pre_order to Blocks. This array is created
1.614 + // only at the end of the flow.
1.615 + Block** _block_map;
1.616 +
1.617 + // For each ciBlock index, a list of Blocks which share this ciBlock.
1.618 + GrowableArray<Block*>** _idx_to_blocklist;
1.619 + // count of ciBlocks
1.620 + int _ciblock_count;
1.621 +
1.622 + // Tells if a given instruction is able to generate an exception edge.
1.623 + bool can_trap(ciBytecodeStream& str);
1.624 +
1.625 +public:
1.626 + // Return the block beginning at bci which has a JsrSet compatible
1.627 + // with jsrs.
1.628 + Block* block_at(int bci, JsrSet* set, CreateOption option = create_public_copy);
1.629 +
1.630 + // block factory
1.631 + Block* get_block_for(int ciBlockIndex, JsrSet* jsrs, CreateOption option = create_public_copy);
1.632 +
1.633 + // How many of the blocks have the private_copy bit set?
1.634 + int private_copy_count(int ciBlockIndex, JsrSet* jsrs) const;
1.635 +
1.636 + // Return an existing block containing bci which has a JsrSet compatible
1.637 + // with jsrs, or NULL if there is none.
1.638 + Block* existing_block_at(int bci, JsrSet* set) { return block_at(bci, set, no_create); }
1.639 +
1.640 + // Tell whether the flow analysis has encountered an error of some sort.
1.641 + bool failing() { return env()->failing() || _failure_reason != NULL; }
1.642 +
1.643 + // Reason this compilation is failing, such as "too many basic blocks".
1.644 + const char* failure_reason() { return _failure_reason; }
1.645 +
1.646 + // Note a failure.
1.647 + void record_failure(const char* reason);
1.648 +
1.649 + // Return the block of a given pre-order number.
1.650 + int have_block_count() const { return _block_map != NULL; }
1.651 + int block_count() const { assert(have_block_count(), "");
1.652 + return _next_pre_order; }
1.653 + Block* pre_order_at(int po) const { assert(0 <= po && po < block_count(), "out of bounds");
1.654 + return _block_map[po]; }
1.655 + Block* start_block() const { return pre_order_at(start_block_num()); }
1.656 + int start_block_num() const { return 0; }
1.657 +
1.658 +private:
1.659 + // A work list used during flow analysis.
1.660 + Block* _work_list;
1.661 +
1.662 + // Next Block::_pre_order. After mapping, doubles as block_count.
1.663 + int _next_pre_order;
1.664 +
1.665 + // Are there more blocks on the work list?
1.666 + bool work_list_empty() { return _work_list == NULL; }
1.667 +
1.668 + // Get the next basic block from our work list.
1.669 + Block* work_list_next();
1.670 +
1.671 + // Add a basic block to our work list.
1.672 + void add_to_work_list(Block* block);
1.673 +
1.674 + // State used for make_jsr_record
1.675 + int _jsr_count;
1.676 + GrowableArray<JsrRecord*>* _jsr_records;
1.677 +
1.678 +public:
1.679 + // Make a JsrRecord for a given (entry, return) pair, if such a record
1.680 + // does not already exist.
1.681 + JsrRecord* make_jsr_record(int entry_address, int return_address);
1.682 +
1.683 +private:
1.684 + // Get the initial state for start_bci:
1.685 + const StateVector* get_start_state();
1.686 +
1.687 + // Merge the current state into all exceptional successors at the
1.688 + // current point in the code.
1.689 + void flow_exceptions(GrowableArray<Block*>* exceptions,
1.690 + GrowableArray<ciInstanceKlass*>* exc_klasses,
1.691 + StateVector* state);
1.692 +
1.693 + // Merge the current state into all successors at the current point
1.694 + // in the code.
1.695 + void flow_successors(GrowableArray<Block*>* successors,
1.696 + StateVector* state);
1.697 +
1.698 + // Interpret the effects of the bytecodes on the incoming state
1.699 + // vector of a basic block. Push the changed state to succeeding
1.700 + // basic blocks.
1.701 + void flow_block(Block* block,
1.702 + StateVector* scratch_state,
1.703 + JsrSet* scratch_jsrs);
1.704 +
1.705 + // Perform the type flow analysis, creating and cloning Blocks as
1.706 + // necessary.
1.707 + void flow_types();
1.708 +
1.709 + // Create the block map, which indexes blocks in pre_order.
1.710 + void map_blocks();
1.711 +
1.712 +public:
1.713 + // Perform type inference flow analysis.
1.714 + void do_flow();
1.715 +
1.716 + void print_on(outputStream* st) const PRODUCT_RETURN;
1.717 +};
