[Bug target/36079] cld instruction is not emitted anymore.

["ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #1 from ubizjak at gmail dot com  2008-04-29 13:15 -------
Since there are many workarounds for this problem I think that this problem
should be fixed elsewhere by either (a) fixing the kernel or (b) fixing the
application that is affected by the problem

a) A two-liner patch to the kernel. This is the approach that major
distribution have taken.

b) The fix is to add explicit cld at the beginning of the function that can be
called from exception handler and uses string operations.

Due to the nature of the problem, it is very unlikely that this problem will
hit real word applications. OTOH, cld instruction has non-negligible
performance impact. Adding -mcld to compile flags in order to emit cld at the
beginning of every function that uses stringops will introduce certain
performance hit. 


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36079