Define a proper hash table library

Define a proper hash table library, instead of the current ad hoc stuff
used for both labels and macros.  This only implements the actual
library; it is not yet used.

We use a CRC64 as a prehash.  This is almost certainly overkill,
although it is rather efficient (except, arguably, the table lookup)
on 64-bit platforms, and not all that bad on 32-bit platforms.  All we
really need is a function which produces two independent 32-bit
results which are used as the primary and secondary hash
respectively.  Either way, the prehash function is easily replacable
if/when we have a quicker alternative.

3 files changed, 312 insertions, 0 deletions

diff --git a/crc64.c b/crc64.c
new file mode 100644
index 00000000..4a490108
--- /dev/null
+++ b/crc64.c
@@ -0,0 +1,144 @@
+#include <inttypes.h>
+
+static const uint64_t crc64_tab[256] = {
+    UINT64_C(0x0000000000000000), UINT64_C(0x7ad870c830358979),
+    UINT64_C(0xf5b0e190606b12f2), UINT64_C(0x8f689158505e9b8b),
+    UINT64_C(0xc038e5739841b68f), UINT64_C(0xbae095bba8743ff6),
+    UINT64_C(0x358804e3f82aa47d), UINT64_C(0x4f50742bc81f2d04),
+    UINT64_C(0xab28ecb46814fe75), UINT64_C(0xd1f09c7c5821770c),
+    UINT64_C(0x5e980d24087fec87), UINT64_C(0x24407dec384a65fe),
+    UINT64_C(0x6b1009c7f05548fa), UINT64_C(0x11c8790fc060c183),
+    UINT64_C(0x9ea0e857903e5a08), UINT64_C(0xe478989fa00bd371),
+    UINT64_C(0x7d08ff3b88be6f81), UINT64_C(0x07d08ff3b88be6f8),
+    UINT64_C(0x88b81eabe8d57d73), UINT64_C(0xf2606e63d8e0f40a),
+    UINT64_C(0xbd301a4810ffd90e), UINT64_C(0xc7e86a8020ca5077),
+    UINT64_C(0x4880fbd87094cbfc), UINT64_C(0x32588b1040a14285),
+    UINT64_C(0xd620138fe0aa91f4), UINT64_C(0xacf86347d09f188d),
+    UINT64_C(0x2390f21f80c18306), UINT64_C(0x594882d7b0f40a7f),
+    UINT64_C(0x1618f6fc78eb277b), UINT64_C(0x6cc0863448deae02),
+    UINT64_C(0xe3a8176c18803589), UINT64_C(0x997067a428b5bcf0),
+    UINT64_C(0xfa11fe77117cdf02), UINT64_C(0x80c98ebf2149567b),
+    UINT64_C(0x0fa11fe77117cdf0), UINT64_C(0x75796f2f41224489),
+    UINT64_C(0x3a291b04893d698d), UINT64_C(0x40f16bccb908e0f4),
+    UINT64_C(0xcf99fa94e9567b7f), UINT64_C(0xb5418a5cd963f206),
+    UINT64_C(0x513912c379682177), UINT64_C(0x2be1620b495da80e),
+    UINT64_C(0xa489f35319033385), UINT64_C(0xde51839b2936bafc),
+    UINT64_C(0x9101f7b0e12997f8), UINT64_C(0xebd98778d11c1e81),
+    UINT64_C(0x64b116208142850a), UINT64_C(0x1e6966e8b1770c73),
+    UINT64_C(0x8719014c99c2b083), UINT64_C(0xfdc17184a9f739fa),
+    UINT64_C(0x72a9e0dcf9a9a271), UINT64_C(0x08719014c99c2b08),
+    UINT64_C(0x4721e43f0183060c), UINT64_C(0x3df994f731b68f75),
+    UINT64_C(0xb29105af61e814fe), UINT64_C(0xc849756751dd9d87),
+    UINT64_C(0x2c31edf8f1d64ef6), UINT64_C(0x56e99d30c1e3c78f),
+    UINT64_C(0xd9810c6891bd5c04), UINT64_C(0xa3597ca0a188d57d),
+    UINT64_C(0xec09088b6997f879), UINT64_C(0x96d1784359a27100),
+    UINT64_C(0x19b9e91b09fcea8b), UINT64_C(0x636199d339c963f2),
+    UINT64_C(0xdf7adabd7a6e2d6f), UINT64_C(0xa5a2aa754a5ba416),
+    UINT64_C(0x2aca3b2d1a053f9d), UINT64_C(0x50124be52a30b6e4),
+    UINT64_C(0x1f423fcee22f9be0), UINT64_C(0x659a4f06d21a1299),
+    UINT64_C(0xeaf2de5e82448912), UINT64_C(0x902aae96b271006b),
+    UINT64_C(0x74523609127ad31a), UINT64_C(0x0e8a46c1224f5a63),
+    UINT64_C(0x81e2d7997211c1e8), UINT64_C(0xfb3aa75142244891),
+    UINT64_C(0xb46ad37a8a3b6595), UINT64_C(0xceb2a3b2ba0eecec),
+    UINT64_C(0x41da32eaea507767), UINT64_C(0x3b024222da65fe1e),
+    UINT64_C(0xa2722586f2d042ee), UINT64_C(0xd8aa554ec2e5cb97),
+    UINT64_C(0x57c2c41692bb501c), UINT64_C(0x2d1ab4dea28ed965),
+    UINT64_C(0x624ac0f56a91f461), UINT64_C(0x1892b03d5aa47d18),
+    UINT64_C(0x97fa21650afae693), UINT64_C(0xed2251ad3acf6fea),
+    UINT64_C(0x095ac9329ac4bc9b), UINT64_C(0x7382b9faaaf135e2),
+    UINT64_C(0xfcea28a2faafae69), UINT64_C(0x8632586aca9a2710),
+    UINT64_C(0xc9622c4102850a14), UINT64_C(0xb3ba5c8932b0836d),
+    UINT64_C(0x3cd2cdd162ee18e6), UINT64_C(0x460abd1952db919f),
+    UINT64_C(0x256b24ca6b12f26d), UINT64_C(0x5fb354025b277b14),
+    UINT64_C(0xd0dbc55a0b79e09f), UINT64_C(0xaa03b5923b4c69e6),
+    UINT64_C(0xe553c1b9f35344e2), UINT64_C(0x9f8bb171c366cd9b),
+    UINT64_C(0x10e3202993385610), UINT64_C(0x6a3b50e1a30ddf69),
+    UINT64_C(0x8e43c87e03060c18), UINT64_C(0xf49bb8b633338561),
+    UINT64_C(0x7bf329ee636d1eea), UINT64_C(0x012b592653589793),
+    UINT64_C(0x4e7b2d0d9b47ba97), UINT64_C(0x34a35dc5ab7233ee),
+    UINT64_C(0xbbcbcc9dfb2ca865), UINT64_C(0xc113bc55cb19211c),
+    UINT64_C(0x5863dbf1e3ac9dec), UINT64_C(0x22bbab39d3991495),
+    UINT64_C(0xadd33a6183c78f1e), UINT64_C(0xd70b4aa9b3f20667),
+    UINT64_C(0x985b3e827bed2b63), UINT64_C(0xe2834e4a4bd8a21a),
+    UINT64_C(0x6debdf121b863991), UINT64_C(0x1733afda2bb3b0e8),
+    UINT64_C(0xf34b37458bb86399), UINT64_C(0x8993478dbb8deae0),
+    UINT64_C(0x06fbd6d5ebd3716b), UINT64_C(0x7c23a61ddbe6f812),
+    UINT64_C(0x3373d23613f9d516), UINT64_C(0x49aba2fe23cc5c6f),
+    UINT64_C(0xc6c333a67392c7e4), UINT64_C(0xbc1b436e43a74e9d),
+    UINT64_C(0x95ac9329ac4bc9b5), UINT64_C(0xef74e3e19c7e40cc),
+    UINT64_C(0x601c72b9cc20db47), UINT64_C(0x1ac40271fc15523e),
+    UINT64_C(0x5594765a340a7f3a), UINT64_C(0x2f4c0692043ff643),
+    UINT64_C(0xa02497ca54616dc8), UINT64_C(0xdafce7026454e4b1),
+    UINT64_C(0x3e847f9dc45f37c0), UINT64_C(0x445c0f55f46abeb9),
+    UINT64_C(0xcb349e0da4342532), UINT64_C(0xb1eceec59401ac4b),
+    UINT64_C(0xfebc9aee5c1e814f), UINT64_C(0x8464ea266c2b0836),
+    UINT64_C(0x0b0c7b7e3c7593bd), UINT64_C(0x71d40bb60c401ac4),
+    UINT64_C(0xe8a46c1224f5a634), UINT64_C(0x927c1cda14c02f4d),
+    UINT64_C(0x1d148d82449eb4c6), UINT64_C(0x67ccfd4a74ab3dbf),
+    UINT64_C(0x289c8961bcb410bb), UINT64_C(0x5244f9a98c8199c2),
+    UINT64_C(0xdd2c68f1dcdf0249), UINT64_C(0xa7f41839ecea8b30),
+    UINT64_C(0x438c80a64ce15841), UINT64_C(0x3954f06e7cd4d138),
+    UINT64_C(0xb63c61362c8a4ab3), UINT64_C(0xcce411fe1cbfc3ca),
+    UINT64_C(0x83b465d5d4a0eece), UINT64_C(0xf96c151de49567b7),
+    UINT64_C(0x76048445b4cbfc3c), UINT64_C(0x0cdcf48d84fe7545),
+    UINT64_C(0x6fbd6d5ebd3716b7), UINT64_C(0x15651d968d029fce),
+    UINT64_C(0x9a0d8ccedd5c0445), UINT64_C(0xe0d5fc06ed698d3c),
+    UINT64_C(0xaf85882d2576a038), UINT64_C(0xd55df8e515432941),
+    UINT64_C(0x5a3569bd451db2ca), UINT64_C(0x20ed197575283bb3),
+    UINT64_C(0xc49581ead523e8c2), UINT64_C(0xbe4df122e51661bb),
+    UINT64_C(0x3125607ab548fa30), UINT64_C(0x4bfd10b2857d7349),
+    UINT64_C(0x04ad64994d625e4d), UINT64_C(0x7e7514517d57d734),
+    UINT64_C(0xf11d85092d094cbf), UINT64_C(0x8bc5f5c11d3cc5c6),
+    UINT64_C(0x12b5926535897936), UINT64_C(0x686de2ad05bcf04f),
+    UINT64_C(0xe70573f555e26bc4), UINT64_C(0x9ddd033d65d7e2bd),
+    UINT64_C(0xd28d7716adc8cfb9), UINT64_C(0xa85507de9dfd46c0),
+    UINT64_C(0x273d9686cda3dd4b), UINT64_C(0x5de5e64efd965432),
+    UINT64_C(0xb99d7ed15d9d8743), UINT64_C(0xc3450e196da80e3a),
+    UINT64_C(0x4c2d9f413df695b1), UINT64_C(0x36f5ef890dc31cc8),
+    UINT64_C(0x79a59ba2c5dc31cc), UINT64_C(0x037deb6af5e9b8b5),
+    UINT64_C(0x8c157a32a5b7233e), UINT64_C(0xf6cd0afa9582aa47),
+    UINT64_C(0x4ad64994d625e4da), UINT64_C(0x300e395ce6106da3),
+    UINT64_C(0xbf66a804b64ef628), UINT64_C(0xc5bed8cc867b7f51),
+    UINT64_C(0x8aeeace74e645255), UINT64_C(0xf036dc2f7e51db2c),
+    UINT64_C(0x7f5e4d772e0f40a7), UINT64_C(0x05863dbf1e3ac9de),
+    UINT64_C(0xe1fea520be311aaf), UINT64_C(0x9b26d5e88e0493d6),
+    UINT64_C(0x144e44b0de5a085d), UINT64_C(0x6e963478ee6f8124),
+    UINT64_C(0x21c640532670ac20), UINT64_C(0x5b1e309b16452559),
+    UINT64_C(0xd476a1c3461bbed2), UINT64_C(0xaeaed10b762e37ab),
+    UINT64_C(0x37deb6af5e9b8b5b), UINT64_C(0x4d06c6676eae0222),
+    UINT64_C(0xc26e573f3ef099a9), UINT64_C(0xb8b627f70ec510d0),
+    UINT64_C(0xf7e653dcc6da3dd4), UINT64_C(0x8d3e2314f6efb4ad),
+    UINT64_C(0x0256b24ca6b12f26), UINT64_C(0x788ec2849684a65f),
+    UINT64_C(0x9cf65a1b368f752e), UINT64_C(0xe62e2ad306bafc57),
+    UINT64_C(0x6946bb8b56e467dc), UINT64_C(0x139ecb4366d1eea5),
+    UINT64_C(0x5ccebf68aecec3a1), UINT64_C(0x2616cfa09efb4ad8),
+    UINT64_C(0xa97e5ef8cea5d153), UINT64_C(0xd3a62e30fe90582a),
+    UINT64_C(0xb0c7b7e3c7593bd8), UINT64_C(0xca1fc72bf76cb2a1),
+    UINT64_C(0x45775673a732292a), UINT64_C(0x3faf26bb9707a053),
+    UINT64_C(0x70ff52905f188d57), UINT64_C(0x0a2722586f2d042e),
+    UINT64_C(0x854fb3003f739fa5), UINT64_C(0xff97c3c80f4616dc),
+    UINT64_C(0x1bef5b57af4dc5ad), UINT64_C(0x61372b9f9f784cd4),
+    UINT64_C(0xee5fbac7cf26d75f), UINT64_C(0x9487ca0fff135e26),
+    UINT64_C(0xdbd7be24370c7322), UINT64_C(0xa10fceec0739fa5b),
+    UINT64_C(0x2e675fb4576761d0), UINT64_C(0x54bf2f7c6752e8a9),
+    UINT64_C(0xcdcf48d84fe75459), UINT64_C(0xb71738107fd2dd20),
+    UINT64_C(0x387fa9482f8c46ab), UINT64_C(0x42a7d9801fb9cfd2),
+    UINT64_C(0x0df7adabd7a6e2d6), UINT64_C(0x772fdd63e7936baf),
+    UINT64_C(0xf8474c3bb7cdf024), UINT64_C(0x829f3cf387f8795d),
+    UINT64_C(0x66e7a46c27f3aa2c), UINT64_C(0x1c3fd4a417c62355),
+    UINT64_C(0x935745fc4798b8de), UINT64_C(0xe98f353477ad31a7),
+    UINT64_C(0xa6df411fbfb21ca3), UINT64_C(0xdc0731d78f8795da),
+    UINT64_C(0x536fa08fdfd90e51), UINT64_C(0x29b7d047efec8728),
+};
+
+uint64_t crc64(const char *str)
+{
+    uint64_t crc = UINT64_C(0xffffffffffffffff);
+    uint8_t c;
+
+    while ((c = *str++) != 0) {
+	crc = crc64_tab[(uint8_t)crc ^ c] ^ (crc >> 8);
+    }
+
+    return crc;
+}
diff --git a/hashtbl.c b/hashtbl.c
new file mode 100644
index 00000000..2a389733
--- /dev/null
+++ b/hashtbl.c
@@ -0,0 +1,128 @@
+/*
+ * hashtbl.c
+ *
+ * Efficient dictionary hash table class.
+ */
+
+#include <inttypes.h>
+#include <string.h>
+#include "nasm.h"
+#include "hashtbl.h"
+
+#define HASH_INITIAL_SIZE	64
+#define HASH_MAX_LOAD		2 /* Higher = more memory-efficient, slower */
+
+static struct hash_tbl_node *alloc_table(size_t newsize)
+{
+    size_t bytes = newsize*sizeof(struct hash_tbl_node);
+    struct hash_tbl_node *newtbl = nasm_malloc(bytes);
+
+    memset(newtbl, 0, bytes);
+
+    return newtbl;
+}
+
+struct hash_table *hash_init(void)
+{
+    struct hash_table *head = nasm_malloc(sizeof(struct hash_table));
+
+    head->table    = alloc_table(HASH_INITIAL_SIZE);
+    head->load     = 0;
+    head->size     = HASH_INITIAL_SIZE;
+    head->max_load = HASH_INITIAL_SIZE*(HASH_MAX_LOAD-1)/HASH_MAX_LOAD;
+
+    return head;
+}
+
+/*
+ * Find an entry in a hash table.
+ *
+ * On failure, if "insert" is non-NULL, store data in that structure
+ * which can be used to insert that node using hash_add().
+ *
+ * WARNING: this data is only valid until the very next call of
+ * hash_add(); it cannot be "saved" to a later date.
+ */
+void *hash_find(struct hash_table *head, const char *key,
+		struct hash_insert *insert)
+{
+    struct hash_tbl_node *np;
+    uint64_t hash = crc64(key);
+    struct hash_tbl_node *tbl = head->table;
+    size_t mask = head->size-1;
+    size_t pos  = hash & mask;
+    size_t inc  = ((hash >> 32) & mask) | 1;	/* Always odd */
+
+    while ((np = &tbl[pos])->key) {
+	if (hash == np->hash && !strcmp(key, np->key))
+	    return np->data;
+	pos = (pos+inc) & mask;
+    }
+
+    /* Not found.  Store info for insert if requested. */
+    if (insert) {
+	insert->head  = head;
+	insert->hash  = hash;
+	insert->where = np;
+    }
+    return NULL;
+}
+
+/*
+ * Insert node.
+ */
+void hash_add(struct hash_insert *insert, const char *key, void *data)
+{
+    struct hash_table *head  = insert->head;
+    struct hash_tbl_node *np = insert->where;
+
+    /* Insert node.  We can always do this, even if we need to
+       rebalance immediately after. */
+    np->hash = insert->hash;
+    np->key  = key;
+    np->data = data;
+
+    if (++head->load > head->max_load) {
+	/* Need to expand the table */
+	size_t newsize = head->size << 1;
+	struct hash_tbl_node *newtbl = alloc_table(newsize);
+	size_t mask = newsize-1;
+
+	if (head->table) {
+	    struct hash_tbl_node *op;
+	    size_t i;
+
+	    /* Rebalance all the entries */
+	    for (i = 0, op = head->table; i < head->size; i++, op++) {
+		if (op->key) {
+		    size_t pos = op->hash & mask;
+		    size_t inc = ((op->hash >> 32) & mask) | 1;
+		    
+		    while ((np = &newtbl[pos])->data)
+			pos = (pos+inc) & mask;
+
+		    *np = *op;
+		}
+	    }
+	    nasm_free(head->table);
+	}
+
+	head->table    = newtbl;
+	head->size     = newsize;
+	head->max_load = newsize*(HASH_MAX_LOAD-1)/HASH_MAX_LOAD;
+    }
+}
+
+void hash_free(struct hash_table *head, void (*free_func)(char *, void *))
+{
+    size_t i;
+    struct hash_tbl_node *op;
+
+    for (i = 0, op = head->table; i < head->size; i++, op++) {
+	if (op->key)
+	    free_func((char *)op->key, op->data);
+    }
+
+    nasm_free(head->table);
+    nasm_free(head);
+}
diff --git a/hashtbl.h b/hashtbl.h
new file mode 100644
index 00000000..cc3daff9
--- /dev/null
+++ b/hashtbl.h
@@ -0,0 +1,40 @@
+/*
+ * hashtbl.h
+ *
+ * Efficient dictionary hash table class.
+ */
+
+#ifndef NASM_HASHTBL_H
+#define NASM_HASHTBL_H
+
+#include <inttypes.h>
+#include <stddef.h>
+#include "nasmlib.h"
+
+struct hash_tbl_node {
+    uint64_t hash;
+    const char *key;
+    void *data;
+};
+
+struct hash_table {
+    struct hash_tbl_node *table;
+    size_t load;
+    size_t size;
+    size_t max_load;
+};
+
+struct hash_insert {
+    uint64_t hash;
+    struct hash_table *head;
+    struct hash_tbl_node *where;
+};
+
+uint64_t crc64(const char *string);
+struct hash_table *hash_init(void);
+void *hash_find(struct hash_table *head, const char *string,
+		struct hash_insert *insert);
+void hash_add(struct hash_insert *insert, const char *string, void *data);
+void hash_free(struct hash_table *head, void (*free_func)(char *, void *));
+
+#endif /* NASM_HASHTBL_H */