------- Comment #4 from borntraeger at de dot ibm dot com 2010-05-28 07:24 ------- Created an attachment (id=20767) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20767&action=view) Patch that makes loop invariant prefetches backend specfic
Three observations: 1. the patch had a bug which let to wrong calculation in some cases This commit should be applied to improve some other testcases: http://gcc.gnu.org/viewcvs?view=revision&revision=159816 2. The first patch was written in a way to allow the backend to enable this feature or not. Feedback was given that this should not be backend specific. Here is a patch that makes this feature backend specific again. We enable this on s390 since useless prefetches are pretty cheap. 3. As a long term goal we could enhance profile directed feedback to make this decision better. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44297
