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
As our delinearization works optimistically, we need in some cases run-time
checks that verify our optimistic assumptions. A simple example is the
following code:
void foo(long n, long m, long o, double A[n][m][o]) {
for (long i = 0; i < 100; i++)
for (long j = 0; j < 150; j++)
for (long k = 0; k < 200; k++)
A[i][j][k] = 1.0;
}
After clang linearized the access to A and we delinearized it again to
A[i][j][k] we need to ensure that we do not access the delinearized array
out of bounds (this information is not available in LLVM-IR). Hence, we
need to verify the following constraints at run-time:
CHECK: Assumed Context:
CHECK: [o, m] -> { : m >= 150 and o >= 200 }
llvm-svn: 212198
We do this currently only for test cases where we have integer offsets that
clearly access array dimensions out-of-bound.
-; for (long i = 0; i < n; i++)
-; for (long j = 0; j < m; j++)
-; for (long k = 0; k < o; k++)
+; for (long i = 0; i < n - 3; i++)
+; for (long j = 4; j < m; j++)
+; for (long k = 0; k < o - 7; k++)
; A[i+3][j-4][k+7] = 1.0;
This will be helpful if we later want to simplify the access functions under the
assumption that they do not access memory out of bounds.
llvm-svn: 210179
At the moment we can handle such arrays only by conservatively assuming that
each access to such an array may touch any element in the array. It would be
great if we could improve Polly/LLVM at some point, such that we can
recover the multi-dimensionality of the accesses.
llvm-svn: 163619
Tobias Grosser