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Re: Does unrolling prevents doloop optimizations?
Hello,
> By "this change" I mean just commenting out the check in
> doloop_condition_get. After applying the patch that introduced DOLOOP
> patterns for SPU (http://gcc.gnu.org/ml/gcc-patches/2007-01/msg01470.html)
> we needed this hack in order to be able to use the doloop_condition_get to
> return the register decremented by the branch instruction for any unrolled
> loop (The unroller changed originally GE loops to EQ ). Where can this check
> be required? Note that we did not touched the similar check in
> doloop_modify. We tested this on our SPU branch and saw no regressions.
hmmm.... I see now that modulo-sched.c:doloop_register_get uses
doloop_condition_get, which is why this may affect something. Anyway,
changing doloop_condition_get is wrong. Just teach modulo-sched to use
number of iterations analysis from loop-iv.c instead of the
doloop_register_get hack,
Zdenek