From: Nicholas Clark <nick@ccl4.org>
Date: Thu, 16 Mar 2006 22:20:57 +0000 (+0000)
Subject: Note that it's worth looking to downsize variables in the interpreter
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=c1ab7b38fcd3bc8e1433bc0b361e5e875c51124e;p=p5sagit%2Fp5-mst-13.2.git

Note that it's worth looking to downsize variables in the interpreter
structure.

p4raw-id: //depot/perl@27524
---

diff --git a/pod/perltodo.pod b/pod/perltodo.pod
index be129d8..1648ab4 100644
--- a/pod/perltodo.pod
+++ b/pod/perltodo.pod
@@ -371,6 +371,16 @@ since a change over a year earlier. Had this been spotted before release, it
 could have been removed, but now it has to remain in the 5.8.x releases to
 keep the structure the same size, to retain binary compatibility.
 
+It's probably worth checking if all need to be the types they are. For example
+
+    PERLVAR(Ierror_count, I32)	/* how many errors so far, max 10 */
+
+might work as well if stored in a signed (or unsigned) 8 bit value, if the
+comment is accurate. C<PL_multi_open> and C<PL_multi_close> can probably
+become C<char>s. Finding variables to downsize coupled with rearrangement
+could shrink the interpreter structure; a size saving which is multiplied by
+the number of threads running.
+
 =head2 am I hot or not?
 
 The idea of F<pp_hot.c> is that it contains the I<hot> ops, the ops that are