Scops that only read seem generally uninteresting and scops that only write are
most likely initializations where there is also little to optimize. To not
waste compile time we bail early.
Differential Revision: http://reviews.llvm.org/D7735
llvm-svn: 229820
This allows us to skip ast and code generation if we did not optimize
a SCoP and will not generate parallel or alias annotations. The
initial heuristic to exit is simple but allows improvements later on.
All failing test cases have been modified to disable early exit, thus
to keep their coverage.
Differential Revision: http://reviews.llvm.org/D7254
llvm-svn: 228851
Schedule dimensions that have the same constant value accross all statements do
not carry any information, but due to the increased dimensionality of the
schedule cost compile time. To not pay this cost, we remove constant dimensions
if possible.
llvm-svn: 225067
SCEV based code generation has been the default for two weeks after having
been tested for a long time. We now drop the support the non-scev-based code
generation.
llvm-svn: 222978
This patch includes tests where we actually need to adjust the CHECK lines
for SCEV based code generation. Besides these adjustments we add explicit
calls to -polly-codegen-scev=[true|false] and make sure we test both cases.
llvm-svn: 222112
BeforeBB
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v
GuardBB
/ \
__ PreHeaderBB \
/ \ / |
latch HeaderBB |
\ / \ /
< \ /
\ /
ExitBB
This does not only remove the need for an explicit loop rotate pass, but it also
gives us the possibility to skip the construction of the guard condition in case
the loop is known to be executed at least once. We do not yet exploit this, but
by implementing this analysis in the isl code generator we should be able to
remove more guards than the generic loop rotate pass can. Another point is that
loop rotation can introduce additional PHI nodes, which may hide that a loop can
be executed in parallel. This change avoids this complication and will make it
easier to move the openmp code generation into a separate pass.
llvm-svn: 181986
Tobias Grosser