1
0
mirror of https://github.com/cc65/cc65.git synced 2024-09-24 00:55:41 +00:00

Overhauled paragraph about register variables

git-svn-id: svn://svn.cc65.org/cc65/trunk@1634 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2002-11-25 15:03:54 +00:00
parent 5f812a3269
commit 192a6536f7

View File

@ -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/.