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-rw-r--r--erts/emulator/beam/utils.c253
1 files changed, 234 insertions, 19 deletions
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 9fd53e941d..f79cb8db7d 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -2512,7 +2512,18 @@ Sint erts_cmp_rel_opt(Eterm a, Eterm* a_base, Eterm b, Eterm* b_base, int exact)
Sint erts_cmp(Eterm a, Eterm b, int exact)
#endif
{
- DECLARE_WSTACK(stack);
+#define PSTACK_TYPE struct erts_cmp_hashmap_state
+ struct erts_cmp_hashmap_state {
+ Sint wstack_rollback;
+ int was_exact;
+ Eterm *ap;
+ Eterm *bp;
+ Eterm min_key;
+ Sint cmp_res; /* result so far -1,0,+1 */
+ };
+ PSTACK_DECLARE(hmap_stack, 1);
+ WSTACK_DECLARE(stack);
+ WSTACK_DECLARE(b_stack); /* only used by hashmaps */
Eterm* aa;
Eterm* bb;
int i;
@@ -2528,6 +2539,26 @@ Sint erts_cmp(Eterm a, Eterm b, int exact)
Uint32 *anum;
Uint32 *bnum;
+/* The WSTACK contains naked Eterms and Operations marked with header-tags */
+#define OP_BITS 4
+#define OP_MASK 0xF
+#define TERM_ARRAY_OP 0
+#define SWITCH_EXACT_OFF_OP 1
+#define HASHMAP_PHASE1_ARE_KEYS_EQUAL 2
+#define HASHMAP_PHASE1_IS_MIN_KEY 3
+#define HASHMAP_PHASE1_CMP_VALUES 4
+#define HASHMAP_PHASE2_ARE_KEYS_EQUAL 5
+#define HASHMAP_PHASE2_IS_MIN_KEY_A 6
+#define HASHMAP_PHASE2_IS_MIN_KEY_B 7
+
+
+#define OP_WORD(OP) (((OP) << _TAG_PRIMARY_SIZE) | TAG_PRIMARY_HEADER)
+#define TERM_ARRAY_OP_WORD(SZ) OP_WORD(((SZ) << OP_BITS) | TERM_ARRAY_OP)
+
+#define GET_OP(WORD) (ASSERT(is_header(WORD)), ((WORD) >> _TAG_PRIMARY_SIZE) & OP_MASK)
+#define GET_OP_ARG(WORD) (ASSERT(is_header(WORD)), ((WORD) >> (OP_BITS + _TAG_PRIMARY_SIZE)))
+
+
#define RETURN_NEQ(cmp) { j=(cmp); ASSERT(j != 0); goto not_equal; }
#define ON_CMP_GOTO(cmp) if ((j=(cmp)) == 0) goto pop_next; else goto not_equal
@@ -2543,6 +2574,8 @@ Sint erts_cmp(Eterm a, Eterm b, int exact)
} while (0)
+bodyrecur:
+ j = 0;
tailrecur:
if (is_same(a,a_base,b,b_base)) { /* Equal values or pointers. */
goto pop_next;
@@ -2692,28 +2725,60 @@ tailrecur_ne:
}
else {
/* Value array */
- WSTACK_PUSH3(stack, i, (UWord)(bb+1), (UWord)(aa+1) | TAG_PRIMARY_HEADER);
- /* Marker to switch back from 'exact' compare */
- WSTACK_PUSH(stack, (UWord)NULL | TAG_PRIMARY_HEADER);
+ WSTACK_PUSH3(stack, (UWord)(bb+1), (UWord)(aa+1), TERM_ARRAY_OP_WORD(i));
+ /* Switch back from 'exact' key compare */
+ WSTACK_PUSH(stack, OP_WORD(SWITCH_EXACT_OFF_OP));
/* Now do 'exact' compare of key tuples */
a = *aa;
b = *bb;
exact = 1;
- goto tailrecur;
+ goto bodyrecur;
}
case (_TAG_HEADER_HASHMAP >> _TAG_PRIMARY_SIZE) :
{
+ struct erts_cmp_hashmap_state* sp;
if (!is_hashmap_rel(b,b_base)) {
a_tag = HASHMAP_DEF;
goto mixed_types;
}
- i = (((hashmap_head_t*) hashmap_val_rel(a,a_base))->size -
- ((hashmap_head_t*) hashmap_val_rel(b,b_base))->size);
+ i = hashmap_size_rel(a,a_base) - hashmap_size_rel(b,b_base);
if (i) {
RETURN_NEQ(i);
}
- ON_CMP_GOTO(hashmap_cmp(a, b));
+ if (hashmap_size_rel(a,a_base) == 0) {
+ goto pop_next;
+ }
+
+ /* Hashmap compare strategy:
+ Phase 1. While keys are identical
+ Do synchronous stepping through leafs of both trees in hash
+ order. Maintain value compare result of minimal key.
+
+ Phase 2. If key diff was found in phase 1
+ Ignore values from now on.
+ Continue iterate trees by always advancing the one
+ lagging behind hash-wise. Identical keys are skipped.
+ A minimal key can only be candidate as tie-breaker if we
+ have passed that hash value in the other tree (which means
+ the key did not exist in the other tree).
+ */
+
+ sp = PSTACK_PUSH(hmap_stack);
+ hashmap_iterator_init(&stack, a);
+ hashmap_iterator_init(&b_stack, b);
+ sp->ap = hashmap_iterator_next(&stack);
+ sp->bp = hashmap_iterator_next(&b_stack);
+ sp->cmp_res = 0;
+ ASSERT(sp->ap && sp->bp);
+
+ a = CAR(sp->ap);
+ b = CAR(sp->bp);
+ sp->was_exact = exact;
+ exact = 1;
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE1_ARE_KEYS_EQUAL));
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
}
case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
if (!is_float_rel(b,b_base)) {
@@ -3074,8 +3139,7 @@ term_array: /* arrays in 'aa' and 'bb', length in 'i' */
goto not_equal;
}
} else {
- /* (ab)Use TAG_PRIMARY_HEADER to recognize a term_array */
- WSTACK_PUSH3(stack, i, (UWord)bb, (UWord)aa | TAG_PRIMARY_HEADER);
+ WSTACK_PUSH3(stack, (UWord)bb, (UWord)aa, TERM_ARRAY_OP_WORD(i));
goto tailrecur_ne;
}
}
@@ -3087,28 +3151,179 @@ term_array: /* arrays in 'aa' and 'bb', length in 'i' */
pop_next:
if (!WSTACK_ISEMPTY(stack)) {
UWord something = WSTACK_POP(stack);
- if (primary_tag((Eterm) something) == TAG_PRIMARY_HEADER) { /* a term_array */
- if (something == ((UWord)NULL | TAG_PRIMARY_HEADER)) {
+ struct erts_cmp_hashmap_state* sp;
+ if (primary_tag((Eterm) something) == TAG_PRIMARY_HEADER) { /* an operation */
+ switch (GET_OP(something)) {
+ case TERM_ARRAY_OP:
+ i = GET_OP_ARG(something);
+ aa = (Eterm*)WSTACK_POP(stack);
+ bb = (Eterm*) WSTACK_POP(stack);
+ goto term_array;
+
+ case SWITCH_EXACT_OFF_OP:
/* Done with exact compare of map keys, switch back */
ASSERT(exact);
exact = 0;
goto pop_next;
- }
- aa = (Eterm *)something;
- bb = (Eterm*) WSTACK_POP(stack);
- i = WSTACK_POP(stack);
- goto term_array;
+
+ case HASHMAP_PHASE1_ARE_KEYS_EQUAL: {
+ sp = PSTACK_TOP(hmap_stack);
+ if (j) {
+ /* Key diff found, enter phase 2 */
+ if (hashmap_key_hash_cmp(sp->ap, sp->bp) < 0) {
+ sp->min_key = CAR(sp->ap);
+ sp->cmp_res = -1;
+ sp->ap = hashmap_iterator_next(&stack);
+ }
+ else {
+ sp->min_key = CAR(sp->bp);
+ sp->cmp_res = 1;
+ sp->bp = hashmap_iterator_next(&b_stack);
+ }
+ exact = 1; /* only exact key compares in phase 2 */
+ goto case_HASHMAP_PHASE2_LOOP;
+ }
+
+ /* No key diff found so far, compare values if min key */
+
+ if (sp->cmp_res) {
+ a = CAR(sp->ap);
+ b = sp->min_key;
+ exact = 1;
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE1_IS_MIN_KEY));
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
+ }
+ /* no min key-value found yet */
+ a = CDR(sp->ap);
+ b = CDR(sp->bp);
+ exact = sp->was_exact;
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE1_CMP_VALUES));
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
+ }
+ case HASHMAP_PHASE1_IS_MIN_KEY:
+ sp = PSTACK_TOP(hmap_stack);
+ if (j < 0) {
+ a = CDR(sp->ap);
+ b = CDR(sp->bp);
+ exact = sp->was_exact;
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE1_CMP_VALUES));
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
+ }
+ goto case_HASHMAP_PHASE1_LOOP;
+
+ case HASHMAP_PHASE1_CMP_VALUES:
+ sp = PSTACK_TOP(hmap_stack);
+ if (j) {
+ sp->cmp_res = j;
+ sp->min_key = CAR(sp->ap);
+ }
+ case_HASHMAP_PHASE1_LOOP:
+ sp->ap = hashmap_iterator_next(&stack);
+ sp->bp = hashmap_iterator_next(&b_stack);
+ if (!sp->ap) {
+ /* end of maps with identical keys */
+ ASSERT(!sp->bp);
+ j = sp->cmp_res;
+ exact = sp->was_exact;
+ (void) PSTACK_POP(hmap_stack);
+ ON_CMP_GOTO(j);
+ }
+ a = CAR(sp->ap);
+ b = CAR(sp->bp);
+ exact = 1;
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE1_ARE_KEYS_EQUAL));
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
+
+ case_HASHMAP_PHASE2_LOOP:
+ if (sp->ap && sp->bp) {
+ a = CAR(sp->ap);
+ b = CAR(sp->bp);
+ ASSERT(exact);
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE2_ARE_KEYS_EQUAL));
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
+ }
+ goto case_HASHMAP_PHASE2_NEXT_STEP;
+
+ case HASHMAP_PHASE2_ARE_KEYS_EQUAL:
+ sp = PSTACK_TOP(hmap_stack);
+ if (j == 0) {
+ /* keys are equal, skip them */
+ sp->ap = hashmap_iterator_next(&stack);
+ sp->bp = hashmap_iterator_next(&b_stack);
+ goto case_HASHMAP_PHASE2_LOOP;
+ }
+ /* fall through */
+ case_HASHMAP_PHASE2_NEXT_STEP:
+ if (sp->ap || sp->bp) {
+ if (hashmap_key_hash_cmp(sp->ap, sp->bp) < 0) {
+ ASSERT(sp->ap);
+ a = CAR(sp->ap);
+ b = sp->min_key;
+ ASSERT(exact);
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE2_IS_MIN_KEY_A));
+ }
+ else { /* hash_cmp > 0 */
+ ASSERT(sp->bp);
+ a = CAR(sp->bp);
+ b = sp->min_key;
+ ASSERT(exact);
+ WSTACK_PUSH(stack, OP_WORD(HASHMAP_PHASE2_IS_MIN_KEY_B));
+ }
+ sp->wstack_rollback = WSTACK_COUNT(stack);
+ goto bodyrecur;
+ }
+ /* End of both maps */
+ j = sp->cmp_res;
+ exact = sp->was_exact;
+ (void) PSTACK_POP(hmap_stack);
+ ON_CMP_GOTO(j);
+
+ case HASHMAP_PHASE2_IS_MIN_KEY_A:
+ sp = PSTACK_TOP(hmap_stack);
+ if (j < 0) {
+ sp->min_key = CAR(sp->ap);
+ sp->cmp_res = -1;
+ }
+ sp->ap = hashmap_iterator_next(&stack);
+ goto case_HASHMAP_PHASE2_LOOP;
+
+ case HASHMAP_PHASE2_IS_MIN_KEY_B:
+ sp = PSTACK_TOP(hmap_stack);
+ if (j < 0) {
+ sp->min_key = CAR(sp->bp);
+ sp->cmp_res = 1;
+ }
+ sp->bp = hashmap_iterator_next(&b_stack);
+ goto case_HASHMAP_PHASE2_LOOP;
+
+ default:
+ ASSERT(!"Invalid cmp op");
+ } /* switch */
}
a = (Eterm) something;
b = (Eterm) WSTACK_POP(stack);
goto tailrecur;
}
- DESTROY_WSTACK(stack);
+ ASSERT(PSTACK_IS_EMPTY(hmap_stack));
+ PSTACK_DESTROY(hmap_stack);
+ WSTACK_DESTROY(stack);
+ WSTACK_DESTROY(b_stack);
return 0;
not_equal:
- DESTROY_WSTACK(stack);
+ if (!PSTACK_IS_EMPTY(hmap_stack)) {
+ WSTACK_ROLLBACK(stack, PSTACK_TOP(hmap_stack)->wstack_rollback);
+ goto pop_next;
+ }
+ PSTACK_DESTROY(hmap_stack);
+ WSTACK_DESTROY(stack);
+ WSTACK_DESTROY(b_stack);
return j;
#undef CMP_NODES
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-27 03:37:15 +0000