Overhauled paragraph about register variables

git-svn-id: svn://svn.cc65.org/cc65/trunk@1634 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/doc/coding.sgml b/doc/coding.sgml
index ad45aad0a2bd46bc11296671dee22812c4455479..23f04ee7ed61f7d31dd01063e8982a0ac8ba2282 100644 (file)
--- a/doc/coding.sgml
+++ b/doc/coding.sgml
@@ -308,12 +308,11 @@ easy to see, that - apart from the additional code that is needed to save and
 restore the values - you need to make heavy use of a variable to justify the
 overhead.
 
-An exception are pointers, especially char pointers. The optimizer has code to
-detect and transform the most common pointer operations if the pointer
-variable is a register variable. Declaring heavily used character pointers as
-register may give significant gains in speed and size.
+As a general rule: Use register variables only for pointers that are
+dereferenced several times in your function, or for heavily used induction
+variables in a loop (with several 100 accesses).
 
-And remember: Register variables must be enabled with <tt/-Or/.
+And remember: Register variables must be enabled with <tt/-r/ or <tt/-Or/.