From: cuz <cuz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Mon, 25 Nov 2002 15:03:54 +0000 (+0000)
Subject: Overhauled paragraph about register variables
X-Git-Tag: V2.12.0~2006
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=192a6536f70475fcb4a5b3d8b816ad435c3efe0f;p=cc65

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 ad45aad0a..23f04ee7e 100644
--- 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/.