Merge branch 'PHP-8.6'

* PHP-8.6:
  Fix GH-24063: SCCP merges 0.0 and -0.0 into a single constant (#24064)

Author: arnaud-lb

Zend/Optimizer/sccp.c

@@ -1951,6 +1951,28 @@ static void sccp_mark_feasible_successors(
 	scdf_mark_edge_feasible(scdf, block_num, block->successors[s]);
 }
 
+/* Unlike zend_is_identical(), this does not treat 0.0 and -0.0 as the same value.
+ * Returns int to be usable as compare_func_t. */
+static int sccp_values_differ(const void *p1, const void *p2)
+{
+	const zval *a = p1;
+	const zval *b = p2;
+
+	if (Z_TYPE_P(a) != Z_TYPE_P(b)) {
+		return 1;
+	}
+	if (Z_TYPE_P(a) == IS_DOUBLE) {
+		return memcmp(&Z_DVAL_P(a), &Z_DVAL_P(b), sizeof(double)) != 0;
+	}
+	if (Z_TYPE_P(a) == IS_ARRAY) {
+		return Z_ARRVAL_P(a) != Z_ARRVAL_P(b)
+			&& zend_hash_compare(Z_ARRVAL_P(a), Z_ARRVAL_P(b), sccp_values_differ, 1) != 0;
+	}
+	ZEND_ASSERT(IS_PARTIAL_ARRAY(a) || IS_PARTIAL_OBJECT(a)
+		|| ((1 << Z_TYPE_P(a)) & (MAY_BE_UNDEF|MAY_BE_NULL|MAY_BE_BOOL|MAY_BE_LONG|MAY_BE_STRING)));
+	return !zend_is_identical(a, b);
+}
+
 static void join_hash_tables(HashTable *ret, const HashTable *ht1, const HashTable *ht2)
 {
 	zend_ulong index;
@@ -1963,7 +1985,7 @@ static void join_hash_tables(HashTable *ret, const HashTable *ht1, const HashTab
 		} else {
 			val2 = zend_hash_index_find(ht2, index);
 		}
-		if (val2 && zend_is_identical(val1, val2)) {
+		if (val2 && !sccp_values_differ(val1, val2)) {
 			if (key) {
 				val1 = zend_hash_add_new(ret, key, val1);
 			} else {
@@ -2031,7 +2053,7 @@ static void join_phi_values(zval *a, const zval *b, bool escape) {
 			zval_ptr_dtor_nogc(a);
 			MAKE_BOT(a);
 		}
-	} else if (!zend_is_identical(a, b)) {
+	} else if (sccp_values_differ(a, b)) {
 		if (join_partial_arrays(a, b) == FAILURE) {
 			zval_ptr_dtor_nogc(a);
 			MAKE_BOT(a);

ext/opcache/tests/opt/gh24063.phpt

@@ -0,0 +1,46 @@
+--TEST--
+GH-24063 (SCCP merges 0.0 and -0.0 into a single constant)
+--EXTENSIONS--
+opcache
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.optimization_level=-1
+--FILE--
+<?php
+
+function scalar(float $n): float
+{
+    $r = $n < 0 ? -0.0 : 0.0;
+    return $r;
+}
+
+function arr(float $n): array
+{
+    $r = $n < 0 ? [-0.0] : [0.0];
+    return $r;
+}
+
+function partial(float $n, $x): float
+{
+    $a = ['x' => $x];
+    if ($n < 0) {
+        $a['k'] = -0.0;
+    } else {
+        $a['k'] = 0.0;
+    }
+    return $a['k'];
+}
+
+var_dump(scalar(1.0), scalar(-1.0));
+var_dump(arr(1.0)[0], arr(-1.0)[0]);
+var_dump(partial(1.0, 1), partial(-1.0, 1));
+
+?>
+--EXPECT--
+float(0)
+float(-0)
+float(0)
+float(-0)
+float(0)
+float(-0)