7068051: SIGSEGV in PhaseIdealLoop::build_loop_late_post
Summary: Removed predicate cloning from loop peeling optimization and from split fall-in paths.
Reviewed-by: never
/*
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* accompanied this code).
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#ifndef SHARE_VM_OPTO_PHASEX_HPP
#define SHARE_VM_OPTO_PHASEX_HPP
#include "libadt/dict.hpp"
#include "libadt/vectset.hpp"
#include "memory/resourceArea.hpp"
#include "opto/memnode.hpp"
#include "opto/node.hpp"
#include "opto/phase.hpp"
#include "opto/type.hpp"
class Compile;
class ConINode;
class ConLNode;
class Node;
class Type;
class PhaseTransform;
class PhaseGVN;
class PhaseIterGVN;
class PhaseCCP;
class PhasePeephole;
class PhaseRegAlloc;
//-----------------------------------------------------------------------------
// Expandable closed hash-table of nodes, initialized to NULL.
// Note that the constructor just zeros things
// Storage is reclaimed when the Arena's lifetime is over.
class NodeHash : public StackObj {
protected:
Arena *_a; // Arena to allocate in
uint _max; // Size of table (power of 2)
uint _inserts; // For grow and debug, count of hash_inserts
uint _insert_limit; // 'grow' when _inserts reaches _insert_limit
Node **_table; // Hash table of Node pointers
Node *_sentinel; // Replaces deleted entries in hash table
public:
NodeHash(uint est_max_size);
NodeHash(Arena *arena, uint est_max_size);
NodeHash(NodeHash *use_this_state);
#ifdef ASSERT
~NodeHash(); // Unlock all nodes upon destruction of table.
void operator=(const NodeHash&); // Unlock all nodes upon replacement of table.
#endif
Node *hash_find(const Node*);// Find an equivalent version in hash table
Node *hash_find_insert(Node*);// If not in table insert else return found node
void hash_insert(Node*); // Insert into hash table
bool hash_delete(const Node*);// Replace with _sentinel in hash table
void check_grow() {
_inserts++;
if( _inserts == _insert_limit ) { grow(); }
assert( _inserts <= _insert_limit, "hash table overflow");
assert( _inserts < _max, "hash table overflow" );
}
static uint round_up(uint); // Round up to nearest power of 2
void grow(); // Grow _table to next power of 2 and rehash
// Return 75% of _max, rounded up.
uint insert_limit() const { return _max - (_max>>2); }
void clear(); // Set all entries to NULL, keep storage.
// Size of hash table
uint size() const { return _max; }
// Return Node* at index in table
Node *at(uint table_index) {
assert(table_index < _max, "Must be within table");
return _table[table_index];
}
void remove_useless_nodes(VectorSet &useful); // replace with sentinel
Node *sentinel() { return _sentinel; }
#ifndef PRODUCT
Node *find_index(uint idx); // For debugging
void dump(); // For debugging, dump statistics
#endif
uint _grows; // For debugging, count of table grow()s
uint _look_probes; // For debugging, count of hash probes
uint _lookup_hits; // For debugging, count of hash_finds
uint _lookup_misses; // For debugging, count of hash_finds
uint _insert_probes; // For debugging, count of hash probes
uint _delete_probes; // For debugging, count of hash probes for deletes
uint _delete_hits; // For debugging, count of hash probes for deletes
uint _delete_misses; // For debugging, count of hash probes for deletes
uint _total_inserts; // For debugging, total inserts into hash table
uint _total_insert_probes; // For debugging, total probes while inserting
};
//-----------------------------------------------------------------------------
// Map dense integer indices to Types. Uses classic doubling-array trick.
// Abstractly provides an infinite array of Type*'s, initialized to NULL.
// Note that the constructor just zeros things, and since I use Arena
// allocation I do not need a destructor to reclaim storage.
// Despite the general name, this class is customized for use by PhaseTransform.
class Type_Array : public StackObj {
Arena *_a; // Arena to allocate in
uint _max;
const Type **_types;
void grow( uint i ); // Grow array node to fit
const Type *operator[] ( uint i ) const // Lookup, or NULL for not mapped
{ return (i<_max) ? _types[i] : (Type*)NULL; }
friend class PhaseTransform;
public:
Type_Array(Arena *a) : _a(a), _max(0), _types(0) {}
Type_Array(Type_Array *ta) : _a(ta->_a), _max(ta->_max), _types(ta->_types) { }
const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];}
// Extend the mapping: index i maps to Type *n.
void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; }
uint Size() const { return _max; }
#ifndef PRODUCT
void dump() const;
#endif
};
//------------------------------PhaseRemoveUseless-----------------------------
// Remove useless nodes from GVN hash-table, worklist, and graph
class PhaseRemoveUseless : public Phase {
protected:
Unique_Node_List _useful; // Nodes reachable from root
// list is allocated from current resource area
public:
PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist );
Unique_Node_List *get_useful() { return &_useful; }
};
//------------------------------PhaseTransform---------------------------------
// Phases that analyze, then transform. Constructing the Phase object does any
// global or slow analysis. The results are cached later for a fast
// transformation pass. When the Phase object is deleted the cached analysis
// results are deleted.
class PhaseTransform : public Phase {
protected:
Arena* _arena;
Node_Array _nodes; // Map old node indices to new nodes.
Type_Array _types; // Map old node indices to Types.
// ConNode caches:
enum { _icon_min = -1 * HeapWordSize,
_icon_max = 16 * HeapWordSize,
_lcon_min = _icon_min,
_lcon_max = _icon_max,
_zcon_max = (uint)T_CONFLICT
};
ConINode* _icons[_icon_max - _icon_min + 1]; // cached jint constant nodes
ConLNode* _lcons[_lcon_max - _lcon_min + 1]; // cached jlong constant nodes
ConNode* _zcons[_zcon_max + 1]; // cached is_zero_type nodes
void init_con_caches();
// Support both int and long caches because either might be an intptr_t,
// so they show up frequently in address computations.
public:
PhaseTransform( PhaseNumber pnum );
PhaseTransform( Arena *arena, PhaseNumber pnum );
PhaseTransform( PhaseTransform *phase, PhaseNumber pnum );
Arena* arena() { return _arena; }
Type_Array& types() { return _types; }
// _nodes is used in varying ways by subclasses, which define local accessors
public:
// Get a previously recorded type for the node n.
// This type must already have been recorded.
// If you want the type of a very new (untransformed) node,
// you must use type_or_null, and test the result for NULL.
const Type* type(const Node* n) const {
const Type* t = _types.fast_lookup(n->_idx);
assert(t != NULL, "must set before get");
return t;
}
// Get a previously recorded type for the node n,
// or else return NULL if there is none.
const Type* type_or_null(const Node* n) const {
return _types.fast_lookup(n->_idx);
}
// Record a type for a node.
void set_type(const Node* n, const Type *t) {
assert(t != NULL, "type must not be null");
_types.map(n->_idx, t);
}
// Record an initial type for a node, the node's bottom type.
void set_type_bottom(const Node* n) {
// Use this for initialization when bottom_type() (or better) is not handy.
// Usually the initialization shoudl be to n->Value(this) instead,
// or a hand-optimized value like Type::MEMORY or Type::CONTROL.
assert(_types[n->_idx] == NULL, "must set the initial type just once");
_types.map(n->_idx, n->bottom_type());
}
// Make sure the types array is big enough to record a size for the node n.
// (In product builds, we never want to do range checks on the types array!)
void ensure_type_or_null(const Node* n) {
if (n->_idx >= _types.Size())
_types.map(n->_idx, NULL); // Grow the types array as needed.
}
// Utility functions:
const TypeInt* find_int_type( Node* n);
const TypeLong* find_long_type(Node* n);
jint find_int_con( Node* n, jint value_if_unknown) {
const TypeInt* t = find_int_type(n);
return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
}
jlong find_long_con(Node* n, jlong value_if_unknown) {
const TypeLong* t = find_long_type(n);
return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
}
// Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc.
// Same as transform(ConNode::make(t)).
ConNode* makecon(const Type* t);
virtual ConNode* uncached_makecon(const Type* t) // override in PhaseValues
{ ShouldNotCallThis(); return NULL; }
// Fast int or long constant. Same as TypeInt::make(i) or TypeLong::make(l).
ConINode* intcon(jint i);
ConLNode* longcon(jlong l);
// Fast zero or null constant. Same as makecon(Type::get_zero_type(bt)).
ConNode* zerocon(BasicType bt);
// Return a node which computes the same function as this node, but
// in a faster or cheaper fashion.
virtual Node *transform( Node *n ) = 0;
// Return whether two Nodes are equivalent.
// Must not be recursive, since the recursive version is built from this.
// For pessimistic optimizations this is simply pointer equivalence.
bool eqv(const Node* n1, const Node* n2) const { return n1 == n2; }
// Return whether two Nodes are equivalent, after stripping casting.
bool eqv_uncast(const Node* n1, const Node* n2) const {
return eqv(n1->uncast(), n2->uncast());
}
// For pessimistic passes, the return type must monotonically narrow.
// For optimistic passes, the return type must monotonically widen.
// It is possible to get into a "death march" in either type of pass,
// where the types are continually moving but it will take 2**31 or
// more steps to converge. This doesn't happen on most normal loops.
//
// Here is an example of a deadly loop for an optimistic pass, along
// with a partial trace of inferred types:
// x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L;
// 0 1 join([0..max], 1)
// [0..1] [1..2] join([0..max], [1..2])
// [0..2] [1..3] join([0..max], [1..3])
// ... ... ...
// [0..max] [min]u[1..max] join([0..max], [min..max])
// [0..max] ==> fixpoint
// We would have proven, the hard way, that the iteration space is all
// non-negative ints, with the loop terminating due to 32-bit overflow.
//
// Here is the corresponding example for a pessimistic pass:
// x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L;
// int int join([0..max], int)
// [0..max] [-1..max-1] join([0..max], [-1..max-1])
// [0..max-1] [-1..max-2] join([0..max], [-1..max-2])
// ... ... ...
// [0..1] [-1..0] join([0..max], [-1..0])
// 0 -1 join([0..max], -1)
// 0 == fixpoint
// We would have proven, the hard way, that the iteration space is {0}.
// (Usually, other optimizations will make the "if (x >= 0)" fold up
// before we get into trouble. But not always.)
//
// It's a pleasant thing to observe that the pessimistic pass
// will make short work of the optimistic pass's deadly loop,
// and vice versa. That is a good example of the complementary
// purposes of the CCP (optimistic) vs. GVN (pessimistic) phases.
//
// In any case, only widen or narrow a few times before going to the
// correct flavor of top or bottom.
//
// This call only needs to be made once as the data flows around any
// given cycle. We do it at Phis, and nowhere else.
// The types presented are the new type of a phi (computed by PhiNode::Value)
// and the previously computed type, last time the phi was visited.
//
// The third argument is upper limit for the saturated value,
// if the phase wishes to widen the new_type.
// If the phase is narrowing, the old type provides a lower limit.
// Caller guarantees that old_type and new_type are no higher than limit_type.
virtual const Type* saturate(const Type* new_type, const Type* old_type,
const Type* limit_type) const
{ ShouldNotCallThis(); return NULL; }
#ifndef PRODUCT
void dump_old2new_map() const;
void dump_new( uint new_lidx ) const;
void dump_types() const;
void dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl = true);
void dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited);
uint _count_progress; // For profiling, count transforms that make progress
void set_progress() { ++_count_progress; assert( allow_progress(),"No progress allowed during verification"); }
void clear_progress() { _count_progress = 0; }
uint made_progress() const { return _count_progress; }
uint _count_transforms; // For profiling, count transforms performed
void set_transforms() { ++_count_transforms; }
void clear_transforms() { _count_transforms = 0; }
uint made_transforms() const{ return _count_transforms; }
bool _allow_progress; // progress not allowed during verification pass
void set_allow_progress(bool allow) { _allow_progress = allow; }
bool allow_progress() { return _allow_progress; }
#endif
};
//------------------------------PhaseValues------------------------------------
// Phase infrastructure to support values
class PhaseValues : public PhaseTransform {
protected:
NodeHash _table; // Hash table for value-numbering
public:
PhaseValues( Arena *arena, uint est_max_size );
PhaseValues( PhaseValues *pt );
PhaseValues( PhaseValues *ptv, const char *dummy );
NOT_PRODUCT( ~PhaseValues(); )
virtual PhaseIterGVN *is_IterGVN() { return 0; }
// Some Ideal and other transforms delete --> modify --> insert values
bool hash_delete(Node *n) { return _table.hash_delete(n); }
void hash_insert(Node *n) { _table.hash_insert(n); }
Node *hash_find_insert(Node *n){ return _table.hash_find_insert(n); }
Node *hash_find(const Node *n) { return _table.hash_find(n); }
// Used after parsing to eliminate values that are no longer in program
void remove_useless_nodes(VectorSet &useful) {
_table.remove_useless_nodes(useful);
// this may invalidate cached cons so reset the cache
init_con_caches();
}
virtual ConNode* uncached_makecon(const Type* t); // override from PhaseTransform
virtual const Type* saturate(const Type* new_type, const Type* old_type,
const Type* limit_type) const
{ return new_type; }
#ifndef PRODUCT
uint _count_new_values; // For profiling, count new values produced
void inc_new_values() { ++_count_new_values; }
void clear_new_values() { _count_new_values = 0; }
uint made_new_values() const { return _count_new_values; }
#endif
};
//------------------------------PhaseGVN---------------------------------------
// Phase for performing local, pessimistic GVN-style optimizations.
class PhaseGVN : public PhaseValues {
public:
PhaseGVN( Arena *arena, uint est_max_size ) : PhaseValues( arena, est_max_size ) {}
PhaseGVN( PhaseGVN *gvn ) : PhaseValues( gvn ) {}
PhaseGVN( PhaseGVN *gvn, const char *dummy ) : PhaseValues( gvn, dummy ) {}
// Return a node which computes the same function as this node, but
// in a faster or cheaper fashion.
Node *transform( Node *n );
Node *transform_no_reclaim( Node *n );
// Check for a simple dead loop when a data node references itself.
DEBUG_ONLY(void dead_loop_check(Node *n);)
};
//------------------------------PhaseIterGVN-----------------------------------
// Phase for iteratively performing local, pessimistic GVN-style optimizations.
// and ideal transformations on the graph.
class PhaseIterGVN : public PhaseGVN {
private:
bool _delay_transform; // When true simply register the node when calling transform
// instead of actually optimizing it
// Idealize old Node 'n' with respect to its inputs and its value
virtual Node *transform_old( Node *a_node );
// Subsume users of node 'old' into node 'nn'
void subsume_node( Node *old, Node *nn );
protected:
// Idealize new Node 'n' with respect to its inputs and its value
virtual Node *transform( Node *a_node );
// Warm up hash table, type table and initial worklist
void init_worklist( Node *a_root );
virtual const Type* saturate(const Type* new_type, const Type* old_type,
const Type* limit_type) const;
// Usually returns new_type. Returns old_type if new_type is only a slight
// improvement, such that it would take many (>>10) steps to reach 2**32.
public:
PhaseIterGVN( PhaseIterGVN *igvn ); // Used by CCP constructor
PhaseIterGVN( PhaseGVN *gvn ); // Used after Parser
PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ); // Used after +VerifyOpto
virtual PhaseIterGVN *is_IterGVN() { return this; }
Unique_Node_List _worklist; // Iterative worklist
// Given def-use info and an initial worklist, apply Node::Ideal,
// Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU
// and dominator info to a fixed point.
void optimize();
// Register a new node with the iter GVN pass without transforming it.
// Used when we need to restructure a Region/Phi area and all the Regions
// and Phis need to complete this one big transform before any other
// transforms can be triggered on the region.
// Optional 'orig' is an earlier version of this node.
// It is significant only for debugging and profiling.
Node* register_new_node_with_optimizer(Node* n, Node* orig = NULL);
// Kill a globally dead Node. It is allowed to have uses which are
// assumed dead and left 'in limbo'.
void remove_globally_dead_node( Node *dead );
// Kill all inputs to a dead node, recursively making more dead nodes.
// The Node must be dead locally, i.e., have no uses.
void remove_dead_node( Node *dead ) {
assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead");
remove_globally_dead_node(dead);
}
// Add users of 'n' to worklist
void add_users_to_worklist0( Node *n );
void add_users_to_worklist ( Node *n );
// Replace old node with new one.
void replace_node( Node *old, Node *nn ) {
add_users_to_worklist(old);
hash_delete(old); // Yank from hash before hacking edges
subsume_node(old, nn);
}
bool delay_transform() const { return _delay_transform; }
void set_delay_transform(bool delay) {
_delay_transform = delay;
}
// Clone loop predicates. Defined in loopTransform.cpp.
Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check);
// Create a new if below new_entry for the predicate to be cloned
ProjNode* create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
Deoptimization::DeoptReason reason);
#ifndef PRODUCT
protected:
// Sub-quadratic implementation of VerifyIterativeGVN.
unsigned long _verify_counter;
unsigned long _verify_full_passes;
enum { _verify_window_size = 30 };
Node* _verify_window[_verify_window_size];
void verify_step(Node* n);
#endif
};
//------------------------------PhaseCCP---------------------------------------
// Phase for performing global Conditional Constant Propagation.
// Should be replaced with combined CCP & GVN someday.
class PhaseCCP : public PhaseIterGVN {
// Non-recursive. Use analysis to transform single Node.
virtual Node *transform_once( Node *n );
public:
PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants
NOT_PRODUCT( ~PhaseCCP(); )
// Worklist algorithm identifies constants
void analyze();
// Recursive traversal of program. Used analysis to modify program.
virtual Node *transform( Node *n );
// Do any transformation after analysis
void do_transform();
virtual const Type* saturate(const Type* new_type, const Type* old_type,
const Type* limit_type) const;
// Returns new_type->widen(old_type), which increments the widen bits until
// giving up with TypeInt::INT or TypeLong::LONG.
// Result is clipped to limit_type if necessary.
#ifndef PRODUCT
static uint _total_invokes; // For profiling, count invocations
void inc_invokes() { ++PhaseCCP::_total_invokes; }
static uint _total_constants; // For profiling, count constants found
uint _count_constants;
void clear_constants() { _count_constants = 0; }
void inc_constants() { ++_count_constants; }
uint count_constants() const { return _count_constants; }
static void print_statistics();
#endif
};
//------------------------------PhasePeephole----------------------------------
// Phase for performing peephole optimizations on register allocated basic blocks.
class PhasePeephole : public PhaseTransform {
PhaseRegAlloc *_regalloc;
PhaseCFG &_cfg;
// Recursive traversal of program. Pure function is unused in this phase
virtual Node *transform( Node *n );
public:
PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg );
NOT_PRODUCT( ~PhasePeephole(); )
// Do any transformation after analysis
void do_transform();
#ifndef PRODUCT
static uint _total_peepholes; // For profiling, count peephole rules applied
uint _count_peepholes;
void clear_peepholes() { _count_peepholes = 0; }
void inc_peepholes() { ++_count_peepholes; }
uint count_peepholes() const { return _count_peepholes; }
static void print_statistics();
#endif
};
#endif // SHARE_VM_OPTO_PHASEX_HPP