When recog_for_combine fails to recognize a pattern as-is, it re-tries
with the clobbers stripped away. When it eventually fails, and the
caller try_combine tries to split the pattern, the clobbers are
gone, thus causing combine failures for bridge splitters that need
patch is here:
Subject: Bug 20291
Module name: gcc
Changes by: email@example.com 2005-03-15 12:39:06
gcc : ChangeLog combine.c
* combine.c (try_combine): If splitting fails, re-try with
original combined pattern, i.e. before clobber stripping.
Fixed in mainline with patch applied today.