[Bug target/48774] [4.6/4.7 Regression] gcc-4.6.0 optimization regression on x86_64-unknown-linux-gnu

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48774

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-02 17:31:17 UTC ---
Created attachment 24169
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24169
gcc47-pr48774.patch

Untested fix.  The additional condition could be changed to just CCCmode check,
or on the other side have:
 || !(TARGET_USE_BT || optimize_function_for_size_p (cfun))
in as well.  Or *bt<mode> would need to be represented in RTL in some different
way, where the setting of Carry is natural to the operation and couldn't be
confused with testqi.