Derive run-time conditions for delinearization

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

1 files changed, 1 insertions, 1 deletions

diff --git a/polly/lib/CodeGen/IslAst.cpp b/polly/lib/CodeGen/IslAst.cpp
index fd08be2850c..da4ef7b7056 100644
--- a/polly/lib/CodeGen/IslAst.cpp
+++ b/polly/lib/CodeGen/IslAst.cpp
@@ -341,7 +341,7 @@ void IslAst::buildRunCondition(__isl_keep isl_ast_build *Context) {
   PwZero = isl_pw_aff_intersect_domain(
       PwZero, isl_set_complement(S->getAssumedContext()));
 
-  isl_pw_aff *Cond = isl_pw_aff_union_max(PwZero, PwOne);
+  isl_pw_aff *Cond = isl_pw_aff_union_max(PwOne, PwZero);
 
   RunCondition = isl_ast_build_expr_from_pw_aff(Context, Cond);
 }