src/hotspot/share/adlc/dict2.cpp
changeset 47216 71c04702a3d5
parent 22234 da823d78ad65
child 51050 96ea37459ca7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/adlc/dict2.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,356 @@
+/*
+ * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+// Dictionaries - An Abstract Data Type
+
+#include "adlc.hpp"
+
+// #include "dict.hpp"
+
+
+//------------------------------data-----------------------------------------
+// String hash tables
+#define MAXID 20
+static char initflag = 0;       // True after 1st initialization
+static char shft[MAXID + 1] = {1,2,3,4,5,6,7,1,2,3,4,5,6,7,1,2,3,4,5,6,7};
+static short xsum[MAXID];
+
+//------------------------------bucket---------------------------------------
+class bucket {
+public:
+  int          _cnt, _max;      // Size of bucket
+  const void **_keyvals;        // Array of keys and values
+};
+
+//------------------------------Dict-----------------------------------------
+// The dictionary is kept has a hash table.  The hash table is a even power
+// of two, for nice modulo operations.  Each bucket in the hash table points
+// to a linear list of key-value pairs; each key & value is just a (void *).
+// The list starts with a count.  A hash lookup finds the list head, then a
+// simple linear scan finds the key.  If the table gets too full, it's
+// doubled in size; the total amount of EXTRA times all hash functions are
+// computed for the doubling is no more than the current size - thus the
+// doubling in size costs no more than a constant factor in speed.
+Dict::Dict(CmpKey initcmp, Hash inithash) : _hash(inithash), _cmp(initcmp), _arena(NULL) {
+  init();
+}
+
+Dict::Dict(CmpKey initcmp, Hash inithash, Arena *arena) : _hash(inithash), _cmp(initcmp), _arena(arena) {
+  init();
+}
+
+void Dict::init() {
+  int i;
+
+  // Precompute table of null character hashes
+  if (!initflag) {              // Not initializated yet?
+    xsum[0] = (short) ((1 << shft[0]) + 1);  // Initialize
+    for( i = 1; i < MAXID; i++) {
+      xsum[i] = (short) ((1 << shft[i]) + 1 + xsum[i-1]);
+    }
+    initflag = 1;               // Never again
+  }
+
+  _size = 16;                   // Size is a power of 2
+  _cnt = 0;                     // Dictionary is empty
+  _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket) * _size);
+  memset(_bin, 0, sizeof(bucket) * _size);
+}
+
+//------------------------------~Dict------------------------------------------
+// Delete an existing dictionary.
+Dict::~Dict() {
+}
+
+//------------------------------Clear----------------------------------------
+// Zap to empty; ready for re-use
+void Dict::Clear() {
+  _cnt = 0;                     // Empty contents
+  for( int i=0; i<_size; i++ )
+    _bin[i]._cnt = 0;           // Empty buckets, but leave allocated
+  // Leave _size & _bin alone, under the assumption that dictionary will
+  // grow to this size again.
+}
+
+//------------------------------doubhash---------------------------------------
+// Double hash table size.  If can't do so, just suffer.  If can, then run
+// thru old hash table, moving things to new table.  Note that since hash
+// table doubled, exactly 1 new bit is exposed in the mask - so everything
+// in the old table ends up on 1 of two lists in the new table; a hi and a
+// lo list depending on the value of the bit.
+void Dict::doubhash(void) {
+  int oldsize = _size;
+  _size <<= 1;                  // Double in size
+  _bin = (bucket*)_arena->Arealloc( _bin, sizeof(bucket)*oldsize, sizeof(bucket)*_size );
+  memset( &_bin[oldsize], 0, oldsize*sizeof(bucket) );
+  // Rehash things to spread into new table
+  for( int i=0; i < oldsize; i++) { // For complete OLD table do
+    bucket *b = &_bin[i];       // Handy shortcut for _bin[i]
+    if( !b->_keyvals ) continue;        // Skip empties fast
+
+    bucket *nb = &_bin[i+oldsize];  // New bucket shortcut
+    int j = b->_max;                // Trim new bucket to nearest power of 2
+    while( j > b->_cnt ) j >>= 1;   // above old bucket _cnt
+    if( !j ) j = 1;             // Handle zero-sized buckets
+    nb->_max = j<<1;
+    // Allocate worst case space for key-value pairs
+    nb->_keyvals = (const void**)_arena->Amalloc_4( sizeof(void *)*nb->_max*2 );
+    int nbcnt = 0;
+
+    for( j=0; j<b->_cnt; j++ ) {  // Rehash all keys in this bucket
+      const void *key = b->_keyvals[j+j];
+      if( (_hash( key ) & (_size-1)) != i ) { // Moving to hi bucket?
+        nb->_keyvals[nbcnt+nbcnt] = key;
+        nb->_keyvals[nbcnt+nbcnt+1] = b->_keyvals[j+j+1];
+        nb->_cnt = nbcnt = nbcnt+1;
+        b->_cnt--;              // Remove key/value from lo bucket
+        b->_keyvals[j+j  ] = b->_keyvals[b->_cnt+b->_cnt  ];
+        b->_keyvals[j+j+1] = b->_keyvals[b->_cnt+b->_cnt+1];
+        j--;                    // Hash compacted element also
+      }
+    } // End of for all key-value pairs in bucket
+  } // End of for all buckets
+
+
+}
+
+//------------------------------Dict-----------------------------------------
+// Deep copy a dictionary.
+Dict::Dict( const Dict &d ) : _size(d._size), _cnt(d._cnt), _hash(d._hash),_cmp(d._cmp), _arena(d._arena) {
+  _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size);
+  memcpy( _bin, d._bin, sizeof(bucket)*_size );
+  for( int i=0; i<_size; i++ ) {
+    if( !_bin[i]._keyvals ) continue;
+    _bin[i]._keyvals=(const void**)_arena->Amalloc_4( sizeof(void *)*_bin[i]._max*2);
+    memcpy( _bin[i]._keyvals, d._bin[i]._keyvals,_bin[i]._cnt*2*sizeof(void*));
+  }
+}
+
+//------------------------------Dict-----------------------------------------
+// Deep copy a dictionary.
+Dict &Dict::operator =( const Dict &d ) {
+  if( _size < d._size ) {       // If must have more buckets
+    _arena = d._arena;
+    _bin = (bucket*)_arena->Arealloc( _bin, sizeof(bucket)*_size, sizeof(bucket)*d._size );
+    memset( &_bin[_size], 0, (d._size-_size)*sizeof(bucket) );
+    _size = d._size;
+  }
+  for( int i=0; i<_size; i++ ) // All buckets are empty
+    _bin[i]._cnt = 0;           // But leave bucket allocations alone
+  _cnt = d._cnt;
+  *(Hash*)(&_hash) = d._hash;
+  *(CmpKey*)(&_cmp) = d._cmp;
+  for(int k=0; k<_size; k++ ) {
+    bucket *b = &d._bin[k];     // Shortcut to source bucket
+    for( int j=0; j<b->_cnt; j++ )
+      Insert( b->_keyvals[j+j], b->_keyvals[j+j+1] );
+  }
+  return *this;
+}
+
+//------------------------------Insert---------------------------------------
+// Insert or replace a key/value pair in the given dictionary.  If the
+// dictionary is too full, it's size is doubled.  The prior value being
+// replaced is returned (NULL if this is a 1st insertion of that key).  If
+// an old value is found, it's swapped with the prior key-value pair on the
+// list.  This moves a commonly searched-for value towards the list head.
+const void *Dict::Insert(const void *key, const void *val) {
+  int hash = _hash( key );      // Get hash key
+  int i = hash & (_size-1);     // Get hash key, corrected for size
+  bucket *b = &_bin[i];         // Handy shortcut
+  for( int j=0; j<b->_cnt; j++ )
+    if( !_cmp(key,b->_keyvals[j+j]) ) {
+      const void *prior = b->_keyvals[j+j+1];
+      b->_keyvals[j+j  ] = key; // Insert current key-value
+      b->_keyvals[j+j+1] = val;
+      return prior;             // Return prior
+    }
+
+  if( ++_cnt > _size ) {        // Hash table is full
+    doubhash();                 // Grow whole table if too full
+    i = hash & (_size-1);       // Rehash
+    b = &_bin[i];               // Handy shortcut
+  }
+  if( b->_cnt == b->_max ) {    // Must grow bucket?
+    if( !b->_keyvals ) {
+      b->_max = 2;              // Initial bucket size
+      b->_keyvals = (const void**)_arena->Amalloc_4( sizeof(void *)*b->_max*2 );
+    } else {
+      b->_keyvals = (const void**)_arena->Arealloc( b->_keyvals, sizeof(void *)*b->_max*2, sizeof(void *)*b->_max*4 );
+      b->_max <<= 1;            // Double bucket
+    }
+  }
+  b->_keyvals[b->_cnt+b->_cnt  ] = key;
+  b->_keyvals[b->_cnt+b->_cnt+1] = val;
+  b->_cnt++;
+  return NULL;                  // Nothing found prior
+}
+
+//------------------------------Delete---------------------------------------
+// Find & remove a value from dictionary. Return old value.
+const void *Dict::Delete(void *key) {
+  int i = _hash( key ) & (_size-1);     // Get hash key, corrected for size
+  bucket *b = &_bin[i];         // Handy shortcut
+  for( int j=0; j<b->_cnt; j++ )
+    if( !_cmp(key,b->_keyvals[j+j]) ) {
+      const void *prior = b->_keyvals[j+j+1];
+      b->_cnt--;                // Remove key/value from lo bucket
+      b->_keyvals[j+j  ] = b->_keyvals[b->_cnt+b->_cnt  ];
+      b->_keyvals[j+j+1] = b->_keyvals[b->_cnt+b->_cnt+1];
+      _cnt--;                   // One less thing in table
+      return prior;
+    }
+  return NULL;
+}
+
+//------------------------------FindDict-------------------------------------
+// Find a key-value pair in the given dictionary.  If not found, return NULL.
+// If found, move key-value pair towards head of list.
+const void *Dict::operator [](const void *key) const {
+  int i = _hash( key ) & (_size-1);     // Get hash key, corrected for size
+  bucket *b = &_bin[i];         // Handy shortcut
+  for( int j=0; j<b->_cnt; j++ )
+    if( !_cmp(key,b->_keyvals[j+j]) )
+      return b->_keyvals[j+j+1];
+  return NULL;
+}
+
+//------------------------------CmpDict--------------------------------------
+// CmpDict compares two dictionaries; they must have the same keys (their
+// keys must match using CmpKey) and they must have the same values (pointer
+// comparison).  If so 1 is returned, if not 0 is returned.
+int Dict::operator ==(const Dict &d2) const {
+  if( _cnt != d2._cnt ) return 0;
+  if( _hash != d2._hash ) return 0;
+  if( _cmp != d2._cmp ) return 0;
+  for( int i=0; i < _size; i++) {       // For complete hash table do
+    bucket *b = &_bin[i];       // Handy shortcut
+    if( b->_cnt != d2._bin[i]._cnt ) return 0;
+    if( memcmp(b->_keyvals, d2._bin[i]._keyvals, b->_cnt*2*sizeof(void*) ) )
+      return 0;                 // Key-value pairs must match
+  }
+  return 1;                     // All match, is OK
+}
+
+
+//------------------------------print----------------------------------------
+static void printvoid(const void* x) { printf("%p", x);  }
+void Dict::print() {
+  print(printvoid, printvoid);
+}
+void Dict::print(PrintKeyOrValue print_key, PrintKeyOrValue print_value) {
+  for( int i=0; i < _size; i++) {       // For complete hash table do
+    bucket *b = &_bin[i];       // Handy shortcut
+    for( int j=0; j<b->_cnt; j++ ) {
+      print_key(  b->_keyvals[j+j  ]);
+      printf(" -> ");
+      print_value(b->_keyvals[j+j+1]);
+      printf("\n");
+    }
+  }
+}
+
+//------------------------------Hashing Functions----------------------------
+// Convert string to hash key.  This algorithm implements a universal hash
+// function with the multipliers frozen (ok, so it's not universal).  The
+// multipliers (and allowable characters) are all odd, so the resultant sum
+// is odd - guaranteed not divisible by any power of two, so the hash tables
+// can be any power of two with good results.  Also, I choose multipliers
+// that have only 2 bits set (the low is always set to be odd) so
+// multiplication requires only shifts and adds.  Characters are required to
+// be in the range 0-127 (I double & add 1 to force oddness).  Keys are
+// limited to MAXID characters in length.  Experimental evidence on 150K of
+// C text shows excellent spreading of values for any size hash table.
+int hashstr(const void *t) {
+  register char c, k = 0;
+  register int sum = 0;
+  register const char *s = (const char *)t;
+
+  while (((c = s[k]) != '\0') && (k < MAXID-1)) { // Get characters till nul
+    c = (char) ((c << 1) + 1);    // Characters are always odd!
+    sum += c + (c << shft[k++]);  // Universal hash function
+  }
+  assert(k < (MAXID), "Exceeded maximum name length");
+  return (int)((sum+xsum[k]) >> 1); // Hash key, un-modulo'd table size
+}
+
+//------------------------------hashptr--------------------------------------
+// Slimey cheap hash function; no guaranteed performance.  Better than the
+// default for pointers, especially on MS-DOS machines.
+int hashptr(const void *key) {
+#ifdef __TURBOC__
+    return (int)((intptr_t)key >> 16);
+#else  // __TURBOC__
+    return (int)((intptr_t)key >> 2);
+#endif
+}
+
+// Slimey cheap hash function; no guaranteed performance.
+int hashkey(const void *key) {
+  return (int)((intptr_t)key);
+}
+
+//------------------------------Key Comparator Functions---------------------
+int cmpstr(const void *k1, const void *k2) {
+  return strcmp((const char *)k1,(const char *)k2);
+}
+
+// Cheap key comparator.
+int cmpkey(const void *key1, const void *key2) {
+  if (key1 == key2) return 0;
+  intptr_t delta = (intptr_t)key1 - (intptr_t)key2;
+  if (delta > 0) return 1;
+  return -1;
+}
+
+//=============================================================================
+//------------------------------reset------------------------------------------
+// Create an iterator and initialize the first variables.
+void DictI::reset( const Dict *dict ) {
+  _d = dict;                    // The dictionary
+  _i = (int)-1;         // Before the first bin
+  _j = 0;                       // Nothing left in the current bin
+  ++(*this);                    // Step to first real value
+}
+
+//------------------------------next-------------------------------------------
+// Find the next key-value pair in the dictionary, or return a NULL key and
+// value.
+void DictI::operator ++(void) {
+  if( _j-- ) {                  // Still working in current bin?
+    _key   = _d->_bin[_i]._keyvals[_j+_j];
+    _value = _d->_bin[_i]._keyvals[_j+_j+1];
+    return;
+  }
+
+  while( ++_i < _d->_size ) {   // Else scan for non-zero bucket
+    _j = _d->_bin[_i]._cnt;
+    if( !_j ) continue;
+    _j--;
+    _key   = _d->_bin[_i]._keyvals[_j+_j];
+    _value = _d->_bin[_i]._keyvals[_j+_j+1];
+    return;
+  }
+  _key = _value = NULL;
+}