Add 4 new rounding modes to round() function

NEWS

@@ -14,6 +14,9 @@ PHP                                                                        NEWS
 - Standard:
   . Added $before_needle argument to strrchr(). (HypeMC)
 
+- Standard:
+  . Added 4 new rounding modes to the round(). (Jorg Sowa)
+
 17 Aug 2023, PHP 8.3.0beta3
 
 - Core:
@@ -155,6 +158,7 @@ PHP                                                                        NEWS
     (Marc Bennewitz)
   . Added usage of posix_spawn for proc_open when supported by OS.
     (Cristian Rodriguez)
+  . Added 4 new rounding modes to the round(). (Jorg Sowa)
 
 - Streams:
   . Implemented GH-11242 (_php_stream_copy_to_mem: Allow specifying a maximum

ext/standard/basic_functions.stub.php

@@ -375,6 +375,26 @@
  * @cvalue PHP_ROUND_HALF_ODD
  */
 const PHP_ROUND_HALF_ODD = UNKNOWN;
+/**
+ * @var int
+ * @cvalue PHP_ROUND_CEILING
+ */
+const PHP_ROUND_CEILING = UNKNOWN;
+/**
+ * @var int
+ * @cvalue PHP_ROUND_FLOOR
+ */
+const PHP_ROUND_FLOOR = UNKNOWN;
+/**
+ * @var int
+ * @cvalue PHP_ROUND_TOWARD_ZERO
+ */
+const PHP_ROUND_TOWARD_ZERO = UNKNOWN;
+/**
+ * @var int
+ * @cvalue PHP_ROUND_AWAY_FROM_ZERO
+ */
+const PHP_ROUND_AWAY_FROM_ZERO = UNKNOWN;
 
 /* crypt.c */
 

ext/standard/math.c

@@ -95,24 +95,56 @@ static inline double php_intpow10(int power) {
 static inline double php_round_helper(double value, int mode) {
 	double tmp_value;
 
-	if (value >= 0.0) {
-		tmp_value = floor(value + 0.5);
-		if ((mode == PHP_ROUND_HALF_DOWN && value == (-0.5 + tmp_value)) ||
-			(mode == PHP_ROUND_HALF_EVEN && value == (0.5 + 2 * floor(tmp_value/2.0))) ||
-			(mode == PHP_ROUND_HALF_ODD  && value == (0.5 + 2 * floor(tmp_value/2.0) - 1.0)))
-		{
-			tmp_value = tmp_value - 1.0;
-		}
-	} else {
-		tmp_value = ceil(value - 0.5);
-		if ((mode == PHP_ROUND_HALF_DOWN && value == (0.5 + tmp_value)) ||
-			(mode == PHP_ROUND_HALF_EVEN && value == (-0.5 + 2 * ceil(tmp_value/2.0))) ||
-			(mode == PHP_ROUND_HALF_ODD  && value == (-0.5 + 2 * ceil(tmp_value/2.0) + 1.0)))
-		{
-			tmp_value = tmp_value + 1.0;
-		}
+	switch (mode) {
+		case PHP_ROUND_HALF_UP:
+			if (value >= 0.0) {
+				tmp_value = floor(value + 0.5);
+			} else {
+				tmp_value= ceil(value - 0.5);
+			}
+			break;
+		case PHP_ROUND_HALF_DOWN:
+			if (value >= 0.0) {
+				tmp_value = ceil(value - 0.5);
+			} else {
+				tmp_value = floor(value + 0.5);
+			}
+			break;
+		case PHP_ROUND_CEILING:
+			tmp_value = ceil(value);
+			break;
+		case PHP_ROUND_FLOOR:
+			tmp_value = floor(value);
+			break;
+		case PHP_ROUND_TOWARD_ZERO:
+			if(value >= 0.0) {
+				tmp_value = floor(value);
+			} else {
+				tmp_value = ceil(value);
+			}
+			break;
+		case PHP_ROUND_AWAY_FROM_ZERO:
+			if(value >= 0.0) {
+				tmp_value = ceil(value);
+			} else {
+				tmp_value = floor(value);
+			}
+			break;
+		case PHP_ROUND_HALF_EVEN:
+			tmp_value = floor(value + 0.5);
+			if (tmp_value == value + 0.5 && value == (0.5 + 2 * floor(tmp_value/2.0))) {
+				tmp_value = tmp_value - 1.0;
+			}
+			break;
+		case PHP_ROUND_HALF_ODD:
+			tmp_value = floor(value + 0.5);
+			if (tmp_value == value + 0.5 && value == (0.5 + 2 * floor(tmp_value/2.0) - 1.0)) {
+				tmp_value = tmp_value - 1.0;
+			}
+			break;
+		default:
+			ZEND_ASSERT(0 && "Unexpected type");
 	}
-
 	return tmp_value;
 }
 /* }}} */

ext/standard/php_math.h

@@ -103,7 +103,7 @@ PHPAPI zend_string * _php_math_zvaltobase(zval *arg, int base);
 #endif
 
 #ifndef PHP_ROUND_HALF_DOWN
-#define PHP_ROUND_HALF_DOWN      0x02    /* Down == towards zero */
+#define PHP_ROUND_HALF_DOWN      0x02    /* Arithmetic rounding, down == towards zero */
 #endif
 
 #ifndef PHP_ROUND_HALF_EVEN
@@ -114,4 +114,20 @@ PHPAPI zend_string * _php_math_zvaltobase(zval *arg, int base);
 #define PHP_ROUND_HALF_ODD       0x04
 #endif
 
+#ifndef PHP_ROUND_CEILING
+#define PHP_ROUND_CEILING        0x05
+#endif
+
+#ifndef PHP_ROUND_FLOOR
+#define PHP_ROUND_FLOOR          0x06
+#endif
+
+#ifndef PHP_ROUND_TOWARD_ZERO
+#define PHP_ROUND_TOWARD_ZERO    0x07
+#endif
+
+#ifndef PHP_ROUND_AWAY_FROM_ZERO
+#define PHP_ROUND_AWAY_FROM_ZERO 0x08
+#endif
+
 #endif /* PHP_MATH_H */