7177923: SIGBUS on sparc in compiled code for java.util.Calendar.clear()
Summary: disable vectorization of a memory access with more elements per vector than one which is used for alignment on sparc
Reviewed-by: twisti
/*
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#ifndef SHARE_VM_OPTO_SUPERWORD_HPP
#define SHARE_VM_OPTO_SUPERWORD_HPP
#include "opto/connode.hpp"
#include "opto/loopnode.hpp"
#include "opto/node.hpp"
#include "opto/phaseX.hpp"
#include "opto/vectornode.hpp"
#include "utilities/growableArray.hpp"
//
// S U P E R W O R D T R A N S F O R M
//
// SuperWords are short, fixed length vectors.
//
// Algorithm from:
//
// Exploiting SuperWord Level Parallelism with
// Multimedia Instruction Sets
// by
// Samuel Larsen and Saman Amarasighe
// MIT Laboratory for Computer Science
// date
// May 2000
// published in
// ACM SIGPLAN Notices
// Proceedings of ACM PLDI '00, Volume 35 Issue 5
//
// Definition 3.1 A Pack is an n-tuple, <s1, ...,sn>, where
// s1,...,sn are independent isomorphic statements in a basic
// block.
//
// Definition 3.2 A PackSet is a set of Packs.
//
// Definition 3.3 A Pair is a Pack of size two, where the
// first statement is considered the left element, and the
// second statement is considered the right element.
class SWPointer;
class OrderedPair;
// ========================= Dependence Graph =====================
class DepMem;
//------------------------------DepEdge---------------------------
// An edge in the dependence graph. The edges incident to a dependence
// node are threaded through _next_in for incoming edges and _next_out
// for outgoing edges.
class DepEdge : public ResourceObj {
protected:
DepMem* _pred;
DepMem* _succ;
DepEdge* _next_in; // list of in edges, null terminated
DepEdge* _next_out; // list of out edges, null terminated
public:
DepEdge(DepMem* pred, DepMem* succ, DepEdge* next_in, DepEdge* next_out) :
_pred(pred), _succ(succ), _next_in(next_in), _next_out(next_out) {}
DepEdge* next_in() { return _next_in; }
DepEdge* next_out() { return _next_out; }
DepMem* pred() { return _pred; }
DepMem* succ() { return _succ; }
void print();
};
//------------------------------DepMem---------------------------
// A node in the dependence graph. _in_head starts the threaded list of
// incoming edges, and _out_head starts the list of outgoing edges.
class DepMem : public ResourceObj {
protected:
Node* _node; // Corresponding ideal node
DepEdge* _in_head; // Head of list of in edges, null terminated
DepEdge* _out_head; // Head of list of out edges, null terminated
public:
DepMem(Node* node) : _node(node), _in_head(NULL), _out_head(NULL) {}
Node* node() { return _node; }
DepEdge* in_head() { return _in_head; }
DepEdge* out_head() { return _out_head; }
void set_in_head(DepEdge* hd) { _in_head = hd; }
void set_out_head(DepEdge* hd) { _out_head = hd; }
int in_cnt(); // Incoming edge count
int out_cnt(); // Outgoing edge count
void print();
};
//------------------------------DepGraph---------------------------
class DepGraph VALUE_OBJ_CLASS_SPEC {
protected:
Arena* _arena;
GrowableArray<DepMem*> _map;
DepMem* _root;
DepMem* _tail;
public:
DepGraph(Arena* a) : _arena(a), _map(a, 8, 0, NULL) {
_root = new (_arena) DepMem(NULL);
_tail = new (_arena) DepMem(NULL);
}
DepMem* root() { return _root; }
DepMem* tail() { return _tail; }
// Return dependence node corresponding to an ideal node
DepMem* dep(Node* node) { return _map.at(node->_idx); }
// Make a new dependence graph node for an ideal node.
DepMem* make_node(Node* node);
// Make a new dependence graph edge dprec->dsucc
DepEdge* make_edge(DepMem* dpred, DepMem* dsucc);
DepEdge* make_edge(Node* pred, Node* succ) { return make_edge(dep(pred), dep(succ)); }
DepEdge* make_edge(DepMem* pred, Node* succ) { return make_edge(pred, dep(succ)); }
DepEdge* make_edge(Node* pred, DepMem* succ) { return make_edge(dep(pred), succ); }
void init() { _map.clear(); } // initialize
void print(Node* n) { dep(n)->print(); }
void print(DepMem* d) { d->print(); }
};
//------------------------------DepPreds---------------------------
// Iterator over predecessors in the dependence graph and
// non-memory-graph inputs of ideal nodes.
class DepPreds : public StackObj {
private:
Node* _n;
int _next_idx, _end_idx;
DepEdge* _dep_next;
Node* _current;
bool _done;
public:
DepPreds(Node* n, DepGraph& dg);
Node* current() { return _current; }
bool done() { return _done; }
void next();
};
//------------------------------DepSuccs---------------------------
// Iterator over successors in the dependence graph and
// non-memory-graph outputs of ideal nodes.
class DepSuccs : public StackObj {
private:
Node* _n;
int _next_idx, _end_idx;
DepEdge* _dep_next;
Node* _current;
bool _done;
public:
DepSuccs(Node* n, DepGraph& dg);
Node* current() { return _current; }
bool done() { return _done; }
void next();
};
// ========================= SuperWord =====================
// -----------------------------SWNodeInfo---------------------------------
// Per node info needed by SuperWord
class SWNodeInfo VALUE_OBJ_CLASS_SPEC {
public:
int _alignment; // memory alignment for a node
int _depth; // Max expression (DAG) depth from block start
const Type* _velt_type; // vector element type
Node_List* _my_pack; // pack containing this node
SWNodeInfo() : _alignment(-1), _depth(0), _velt_type(NULL), _my_pack(NULL) {}
static const SWNodeInfo initial;
};
// -----------------------------SuperWord---------------------------------
// Transforms scalar operations into packed (superword) operations.
class SuperWord : public ResourceObj {
private:
PhaseIdealLoop* _phase;
Arena* _arena;
PhaseIterGVN &_igvn;
enum consts { top_align = -1, bottom_align = -666 };
GrowableArray<Node_List*> _packset; // Packs for the current block
GrowableArray<int> _bb_idx; // Map from Node _idx to index within block
GrowableArray<Node*> _block; // Nodes in current block
GrowableArray<Node*> _data_entry; // Nodes with all inputs from outside
GrowableArray<Node*> _mem_slice_head; // Memory slice head nodes
GrowableArray<Node*> _mem_slice_tail; // Memory slice tail nodes
GrowableArray<SWNodeInfo> _node_info; // Info needed per node
MemNode* _align_to_ref; // Memory reference that pre-loop will align to
GrowableArray<OrderedPair> _disjoint_ptrs; // runtime disambiguated pointer pairs
DepGraph _dg; // Dependence graph
// Scratch pads
VectorSet _visited; // Visited set
VectorSet _post_visited; // Post-visited set
Node_Stack _n_idx_list; // List of (node,index) pairs
GrowableArray<Node*> _nlist; // List of nodes
GrowableArray<Node*> _stk; // Stack of nodes
public:
SuperWord(PhaseIdealLoop* phase);
void transform_loop(IdealLoopTree* lpt);
// Accessors for SWPointer
PhaseIdealLoop* phase() { return _phase; }
IdealLoopTree* lpt() { return _lpt; }
PhiNode* iv() { return _iv; }
private:
IdealLoopTree* _lpt; // Current loop tree node
LoopNode* _lp; // Current LoopNode
Node* _bb; // Current basic block
PhiNode* _iv; // Induction var
// Accessors
Arena* arena() { return _arena; }
Node* bb() { return _bb; }
void set_bb(Node* bb) { _bb = bb; }
void set_lpt(IdealLoopTree* lpt) { _lpt = lpt; }
LoopNode* lp() { return _lp; }
void set_lp(LoopNode* lp) { _lp = lp;
_iv = lp->as_CountedLoop()->phi()->as_Phi(); }
int iv_stride() { return lp()->as_CountedLoop()->stride_con(); }
int vector_width(Node* n) {
BasicType bt = velt_basic_type(n);
return MIN2(ABS(iv_stride()), Matcher::max_vector_size(bt));
}
int vector_width_in_bytes(Node* n) {
BasicType bt = velt_basic_type(n);
return vector_width(n)*type2aelembytes(bt);
}
MemNode* align_to_ref() { return _align_to_ref; }
void set_align_to_ref(MemNode* m) { _align_to_ref = m; }
Node* ctrl(Node* n) const { return _phase->has_ctrl(n) ? _phase->get_ctrl(n) : n; }
// block accessors
bool in_bb(Node* n) { return n != NULL && n->outcnt() > 0 && ctrl(n) == _bb; }
int bb_idx(Node* n) { assert(in_bb(n), "must be"); return _bb_idx.at(n->_idx); }
void set_bb_idx(Node* n, int i) { _bb_idx.at_put_grow(n->_idx, i); }
// visited set accessors
void visited_clear() { _visited.Clear(); }
void visited_set(Node* n) { return _visited.set(bb_idx(n)); }
int visited_test(Node* n) { return _visited.test(bb_idx(n)); }
int visited_test_set(Node* n) { return _visited.test_set(bb_idx(n)); }
void post_visited_clear() { _post_visited.Clear(); }
void post_visited_set(Node* n) { return _post_visited.set(bb_idx(n)); }
int post_visited_test(Node* n) { return _post_visited.test(bb_idx(n)); }
// Ensure node_info contains element "i"
void grow_node_info(int i) { if (i >= _node_info.length()) _node_info.at_put_grow(i, SWNodeInfo::initial); }
// memory alignment for a node
int alignment(Node* n) { return _node_info.adr_at(bb_idx(n))->_alignment; }
void set_alignment(Node* n, int a) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_alignment = a; }
// Max expression (DAG) depth from beginning of the block for each node
int depth(Node* n) { return _node_info.adr_at(bb_idx(n))->_depth; }
void set_depth(Node* n, int d) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_depth = d; }
// vector element type
const Type* velt_type(Node* n) { return _node_info.adr_at(bb_idx(n))->_velt_type; }
BasicType velt_basic_type(Node* n) { return velt_type(n)->array_element_basic_type(); }
void set_velt_type(Node* n, const Type* t) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_velt_type = t; }
bool same_velt_type(Node* n1, Node* n2);
// my_pack
Node_List* my_pack(Node* n) { return !in_bb(n) ? NULL : _node_info.adr_at(bb_idx(n))->_my_pack; }
void set_my_pack(Node* n, Node_List* p) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_my_pack = p; }
// methods
// Extract the superword level parallelism
void SLP_extract();
// Find the adjacent memory references and create pack pairs for them.
void find_adjacent_refs();
// Find a memory reference to align the loop induction variable to.
MemNode* find_align_to_ref(Node_List &memops);
// Calculate loop's iv adjustment for this memory ops.
int get_iv_adjustment(MemNode* mem);
// Can the preloop align the reference to position zero in the vector?
bool ref_is_alignable(SWPointer& p);
// Construct dependency graph.
void dependence_graph();
// Return a memory slice (node list) in predecessor order starting at "start"
void mem_slice_preds(Node* start, Node* stop, GrowableArray<Node*> &preds);
// Can s1 and s2 be in a pack with s1 immediately preceding s2 and s1 aligned at "align"
bool stmts_can_pack(Node* s1, Node* s2, int align);
// Does s exist in a pack at position pos?
bool exists_at(Node* s, uint pos);
// Is s1 immediately before s2 in memory?
bool are_adjacent_refs(Node* s1, Node* s2);
// Are s1 and s2 similar?
bool isomorphic(Node* s1, Node* s2);
// Is there no data path from s1 to s2 or s2 to s1?
bool independent(Node* s1, Node* s2);
// Helper for independent
bool independent_path(Node* shallow, Node* deep, uint dp=0);
void set_alignment(Node* s1, Node* s2, int align);
int data_size(Node* s);
// Extend packset by following use->def and def->use links from pack members.
void extend_packlist();
// Extend the packset by visiting operand definitions of nodes in pack p
bool follow_use_defs(Node_List* p);
// Extend the packset by visiting uses of nodes in pack p
bool follow_def_uses(Node_List* p);
// Estimate the savings from executing s1 and s2 as a pack
int est_savings(Node* s1, Node* s2);
int adjacent_profit(Node* s1, Node* s2);
int pack_cost(int ct);
int unpack_cost(int ct);
// Combine packs A and B with A.last == B.first into A.first..,A.last,B.second,..B.last
void combine_packs();
// Construct the map from nodes to packs.
void construct_my_pack_map();
// Remove packs that are not implemented or not profitable.
void filter_packs();
// Adjust the memory graph for the packed operations
void schedule();
// Remove "current" from its current position in the memory graph and insert
// it after the appropriate insert points (lip or uip);
void remove_and_insert(MemNode *current, MemNode *prev, MemNode *lip, Node *uip, Unique_Node_List &schd_before);
// Within a store pack, schedule stores together by moving out the sandwiched memory ops according
// to dependence info; and within a load pack, move loads down to the last executed load.
void co_locate_pack(Node_List* p);
// Convert packs into vector node operations
void output();
// Create a vector operand for the nodes in pack p for operand: in(opd_idx)
Node* vector_opd(Node_List* p, int opd_idx);
// Can code be generated for pack p?
bool implemented(Node_List* p);
// For pack p, are all operands and all uses (with in the block) vector?
bool profitable(Node_List* p);
// If a use of pack p is not a vector use, then replace the use with an extract operation.
void insert_extracts(Node_List* p);
// Is use->in(u_idx) a vector use?
bool is_vector_use(Node* use, int u_idx);
// Construct reverse postorder list of block members
void construct_bb();
// Initialize per node info
void initialize_bb();
// Insert n into block after pos
void bb_insert_after(Node* n, int pos);
// Compute max depth for expressions from beginning of block
void compute_max_depth();
// Compute necessary vector element type for expressions
void compute_vector_element_type();
// Are s1 and s2 in a pack pair and ordered as s1,s2?
bool in_packset(Node* s1, Node* s2);
// Is s in pack p?
Node_List* in_pack(Node* s, Node_List* p);
// Remove the pack at position pos in the packset
void remove_pack_at(int pos);
// Return the node executed first in pack p.
Node* executed_first(Node_List* p);
// Return the node executed last in pack p.
Node* executed_last(Node_List* p);
// Alignment within a vector memory reference
int memory_alignment(MemNode* s, int iv_adjust_in_bytes);
// (Start, end] half-open range defining which operands are vector
void vector_opd_range(Node* n, uint* start, uint* end);
// Smallest type containing range of values
const Type* container_type(Node* n);
// Adjust pre-loop limit so that in main loop, a load/store reference
// to align_to_ref will be a position zero in the vector.
void align_initial_loop_index(MemNode* align_to_ref);
// Find pre loop end from main loop. Returns null if none.
CountedLoopEndNode* get_pre_loop_end(CountedLoopNode *cl);
// Is the use of d1 in u1 at the same operand position as d2 in u2?
bool opnd_positions_match(Node* d1, Node* u1, Node* d2, Node* u2);
void init();
// print methods
void print_packset();
void print_pack(Node_List* p);
void print_bb();
void print_stmt(Node* s);
char* blank(uint depth);
};
//------------------------------SWPointer---------------------------
// Information about an address for dependence checking and vector alignment
class SWPointer VALUE_OBJ_CLASS_SPEC {
protected:
MemNode* _mem; // My memory reference node
SuperWord* _slp; // SuperWord class
Node* _base; // NULL if unsafe nonheap reference
Node* _adr; // address pointer
jint _scale; // multipler for iv (in bytes), 0 if no loop iv
jint _offset; // constant offset (in bytes)
Node* _invar; // invariant offset (in bytes), NULL if none
bool _negate_invar; // if true then use: (0 - _invar)
PhaseIdealLoop* phase() { return _slp->phase(); }
IdealLoopTree* lpt() { return _slp->lpt(); }
PhiNode* iv() { return _slp->iv(); } // Induction var
bool invariant(Node* n) {
Node *n_c = phase()->get_ctrl(n);
return !lpt()->is_member(phase()->get_loop(n_c));
}
// Match: k*iv + offset
bool scaled_iv_plus_offset(Node* n);
// Match: k*iv where k is a constant that's not zero
bool scaled_iv(Node* n);
// Match: offset is (k [+/- invariant])
bool offset_plus_k(Node* n, bool negate = false);
public:
enum CMP {
Less = 1,
Greater = 2,
Equal = 4,
NotEqual = (Less | Greater),
NotComparable = (Less | Greater | Equal)
};
SWPointer(MemNode* mem, SuperWord* slp);
// Following is used to create a temporary object during
// the pattern match of an address expression.
SWPointer(SWPointer* p);
bool valid() { return _adr != NULL; }
bool has_iv() { return _scale != 0; }
Node* base() { return _base; }
Node* adr() { return _adr; }
MemNode* mem() { return _mem; }
int scale_in_bytes() { return _scale; }
Node* invar() { return _invar; }
bool negate_invar() { return _negate_invar; }
int offset_in_bytes() { return _offset; }
int memory_size() { return _mem->memory_size(); }
// Comparable?
int cmp(SWPointer& q) {
if (valid() && q.valid() &&
(_adr == q._adr || _base == _adr && q._base == q._adr) &&
_scale == q._scale &&
_invar == q._invar &&
_negate_invar == q._negate_invar) {
bool overlap = q._offset < _offset + memory_size() &&
_offset < q._offset + q.memory_size();
return overlap ? Equal : (_offset < q._offset ? Less : Greater);
} else {
return NotComparable;
}
}
bool not_equal(SWPointer& q) { return not_equal(cmp(q)); }
bool equal(SWPointer& q) { return equal(cmp(q)); }
bool comparable(SWPointer& q) { return comparable(cmp(q)); }
static bool not_equal(int cmp) { return cmp <= NotEqual; }
static bool equal(int cmp) { return cmp == Equal; }
static bool comparable(int cmp) { return cmp < NotComparable; }
void print();
};
//------------------------------OrderedPair---------------------------
// Ordered pair of Node*.
class OrderedPair VALUE_OBJ_CLASS_SPEC {
protected:
Node* _p1;
Node* _p2;
public:
OrderedPair() : _p1(NULL), _p2(NULL) {}
OrderedPair(Node* p1, Node* p2) {
if (p1->_idx < p2->_idx) {
_p1 = p1; _p2 = p2;
} else {
_p1 = p2; _p2 = p1;
}
}
bool operator==(const OrderedPair &rhs) {
return _p1 == rhs._p1 && _p2 == rhs._p2;
}
void print() { tty->print(" (%d, %d)", _p1->_idx, _p2->_idx); }
static const OrderedPair initial;
};
#endif // SHARE_VM_OPTO_SUPERWORD_HPP