perldelta - Fill in the last remaining "todo"

1 files changed, 17 insertions, 3 deletions

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 186500ddcc..e6de0c7b63 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -1,6 +1,3 @@
-=for todo
-
-869747506f/00051dd553 (merijn) - gcc 4.9 by default does some optimizations that break perl / -fwrapv is broken prior to gcc-4.3 (#121505)
 
 =encoding utf8
 
@@ -141,6 +138,23 @@ allow a user override.
 
 =back
 
+=head1 Configuration and Compilation
+
+=over 4
+
+=item *
+
+By default, B<gcc> 4.9 does some optimizations that break perl.  The B<-fwrapv>
+option disables those optimizations (and probably others), so for B<gcc> 4.9
+(and later, since the optimizations probably won't go away), F<Configure> now
+adds B<-fwrapv> unless the user requests B<-fno-wrapv>, which disables
+B<-fwrapv>, or B<-fsanitize=undefined>, which turns the overflows B<-fwrapv>
+ignores into runtime errors.  (This is not done prior to B<gcc> 4.3, since
+B<-fwrapv> was broken then.)
+[L<perl #121505|https://rt.perl.org/Public/Bug/Display.html?id=121505>]
+
+=back
+
 =head1 Platform Support
 
 =head2 Platform-Specific Notes