Index: src/wp-includes/query.php
===================================================================
--- src/wp-includes/query.php	(revision 27472)
+++ src/wp-includes/query.php	(working copy)
@@ -292,6 +292,28 @@
 }
 
 /**
+ * Is the query for a post format archive page?
+ *
+ * If the $format parameter is specified, this function will check
+ * if the query is for one of the formats specified.
+ *
+ * @since 3.9.0
+ * @uses $wp_query
+ *
+ * @param mixed $format Optional. Format slug or array of format slugs, without the post-format prefix.
+ * @return bool
+ */
+function is_post_format_archive( $format = '' ) {
+	global $wp_query;
+
+	if ( ! isset( $wp_query ) ) {
+		return false;
+	}
+
+	return $wp_query->is_post_format_archive( $format );
+}
+
+/**
  * Whether the current URL is within the comments popup window.
  *
  * @see WP_Query::is_comments_popup()
@@ -3944,6 +3966,29 @@
 	}
 
 	/**
+	 * Is the query for a post format archive page?
+	 *
+	 * If the $format parameter is specified, this function will check
+	 * if the query is for one of the formats specified.
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param mixed $format Optional. Format slug or array of format slugs, without the post-format prefix.
+	 * @return bool
+	 */
+	function is_post_format_archive( $format = '' ) {
+		if ( ! empty( $format ) ) {
+			$format = (array) $format;
+
+			foreach ( $format as &$value ) {
+				$value = 'post-format-' . $value;
+			}
+		}
+
+		return $this->is_tax( 'post_format', $format );
+	}
+
+	/**
 	 * Whether the current URL is within the comments popup window.
 	 *
 	 * @since 3.1.0