mt_rand.c

// Resulting code as the diff is hard to read

static uint32_t rand_range32(uint32_t umax) {
	uint32_t result, limit;

	result = php_mt_rand();

	/* Special case where no modulus is required */
	if (UNEXPECTED(umax == UINT32_MAX)) {
		return result;
	}

	/* Increment the max so the range is inclusive of max */
	umax++;

	/* Powers of two are not biased */
	if ((umax & (umax - 1)) == 0) {
		return result & (umax - 1);
	}

	/* Ceiling under which UINT32_MAX % max == 0 */
	limit = UINT32_MAX - (UINT32_MAX % umax) - 1;

	/* Discard numbers over the limit to avoid modulo bias */
	while (UNEXPECTED(result > limit)) {
		result = php_mt_rand();
	}

	return result % umax;
}

#if ZEND_ULONG_MAX > UINT32_MAX
static uint64_t rand_range64(uint64_t umax) {
	uint64_t result, limit;
	
	result = php_mt_rand();
	result = (result << 32) | php_mt_rand();

	/* Special case where no modulus is required */
	if (UNEXPECTED(umax == UINT64_MAX)) {
		return result;
	}

	/* Increment the max so the range is inclusive of max */
	umax++;

	/* Powers of two are not biased */
	if ((umax & (umax - 1)) == 0) {
		return result & (umax - 1);
	}

	/* Ceiling under which UINT64_MAX % max == 0 */
	limit = UINT64_MAX - (UINT64_MAX % umax) - 1;

	/* Discard numbers over the limit to avoid modulo bias */
	while (UNEXPECTED(result > limit)) {
		result = php_mt_rand();
		result = (result << 32) | php_mt_rand();
	}

	return result % umax;
}
#endif

/* {{{ php_mt_rand_range
 */
PHPAPI zend_long php_mt_rand_range(zend_long min, zend_long max)
{
	zend_ulong umax = max - min;

#if ZEND_ULONG_MAX > UINT32_MAX
	if (umax > UINT32_MAX) {
		return (zend_long) (rand_range64(umax) + min);
	}
#endif

	return (zend_long) (rand_range32(umax) + min);
}
/* }}} */

mt_rand.diff

diff --git a/ext/standard/mt_rand.c b/ext/standard/mt_rand.c
index 0e2fe51..3942ddc 100644
--- a/ext/standard/mt_rand.c
+++ b/ext/standard/mt_rand.c
@@ -209,50 +209,81 @@ PHP_FUNCTION(mt_srand)
 }
 /* }}} */
 
-/* {{{ php_mt_rand_range
- */
-PHPAPI zend_long php_mt_rand_range(zend_long min, zend_long max)
-{
-	zend_ulong umax = max - min;
-	zend_ulong limit;
-	zend_ulong result;
+static uint32_t rand_range32(uint32_t umax) {
+	uint32_t result, limit;
 
 	result = php_mt_rand();
-#if ZEND_ULONG_MAX > UINT32_MAX
-	if (umax > UINT32_MAX) {
-		result = (result << 32) | php_mt_rand();
-	}
-#endif
 
 	/* Special case where no modulus is required */
-	if (UNEXPECTED(umax == ZEND_ULONG_MAX)) {
-		return (zend_long)result;
+	if (UNEXPECTED(umax == UINT32_MAX)) {
+		return result;
 	}
 
 	/* Increment the max so the range is inclusive of max */
 	umax++;
 
 	/* Powers of two are not biased */
-	if (EXPECTED((umax & (umax - 1)) != 0)) {
-		/* Ceiling under which ZEND_LONG_MAX % max == 0 */
-		limit = ZEND_ULONG_MAX - (ZEND_ULONG_MAX % umax) - 1;
+	if ((umax & (umax - 1)) == 0) {
+		return result & (umax - 1);
+	}
+
+	/* Ceiling under which UINT32_MAX % max == 0 */
+	limit = UINT32_MAX - (UINT32_MAX % umax) - 1;
+
+	/* Discard numbers over the limit to avoid modulo bias */
+	while (UNEXPECTED(result > limit)) {
+		result = php_mt_rand();
+	}
+
+	return result % umax;
+}
 
-		/* Discard numbers over the limit to avoid modulo bias */
-		while (UNEXPECTED(result > limit)) {
 #if ZEND_ULONG_MAX > UINT32_MAX
-			if (umax > UINT32_MAX) {
-				result = (result << 32) | php_mt_rand();
-			}
-			else {
-				result = php_mt_rand();
-			}
-#else
-			result = php_mt_rand();
+static uint64_t rand_range64(uint64_t umax) {
+	uint64_t result, limit;
+	
+	result = php_mt_rand();
+	result = (result << 32) | php_mt_rand();
+
+	/* Special case where no modulus is required */
+	if (UNEXPECTED(umax == UINT64_MAX)) {
+		return result;
+	}
+
+	/* Increment the max so the range is inclusive of max */
+	umax++;
+
+	/* Powers of two are not biased */
+	if ((umax & (umax - 1)) == 0) {
+		return result & (umax - 1);
+	}
+
+	/* Ceiling under which UINT64_MAX % max == 0 */
+	limit = UINT64_MAX - (UINT64_MAX % umax) - 1;
+
+	/* Discard numbers over the limit to avoid modulo bias */
+	while (UNEXPECTED(result > limit)) {
+		result = php_mt_rand();
+		result = (result << 32) | php_mt_rand();
+	}
+
+	return result % umax;
+}
 #endif
-		}
+
+/* {{{ php_mt_rand_range
+ */
+PHPAPI zend_long php_mt_rand_range(zend_long min, zend_long max)
+{
+	zend_ulong umax = max - min;
+
+#if ZEND_ULONG_MAX > UINT32_MAX
+	if (umax > UINT32_MAX) {
+		return (zend_long) (rand_range64(umax) + min);
 	}
+#endif
 
-	return (zend_long)((result % umax) + min);
+	return (zend_long) (rand_range32(umax) + min);
 }
 /* }}} */