Simplify computation of reduction dependences

This simplifies the construction of the input for the reduction dependence
computation and at the same time removes an assumption that expects the schedule
to be of 2D + 1 form (the odd dimensions giving textual order, the even
dimensions the loop iterations).

llvm-svn: 223621

diff --git a/polly/lib/Analysis/Dependences.cpp b/polly/lib/Analysis/Dependences.cpp
index 71d8780..c9cc778 100644 (file)
--- a/polly/lib/Analysis/Dependences.cpp
+++ b/polly/lib/Analysis/Dependences.cpp
@@ -102,17 +102,11 @@ void Dependences::collectInfo(Scop &S, isl_union_map **Read,
         // but as we transformed the access domain we need the scattering
         // to match the new access domains, thus we need
         //   [Stmt[i0, i1] -> MemAcc_A[i0 + i1]] -> [0, i0, 2, i1, 0]
+        isl_map *Scatter = Stmt->getScattering();
+        Scatter = isl_map_apply_domain(
+            Scatter, isl_map_reverse(isl_map_domain_map(isl_map_copy(accdom))));
         accdom = isl_map_range_map(accdom);
-
-        isl_map *stmt_scatter = Stmt->getScattering();
-        isl_set *scatter_dom = isl_map_domain(isl_map_copy(accdom));
-        isl_set *scatter_ran = isl_map_range(stmt_scatter);
-        isl_map *scatter =
-            isl_map_from_domain_and_range(scatter_dom, scatter_ran);
-        for (unsigned u = 0, e = Stmt->getNumIterators(); u != e; u++)
-          scatter =
-              isl_map_equate(scatter, isl_dim_out, 2 * u + 1, isl_dim_in, u);
-        *AccessSchedule = isl_union_map_add_map(*AccessSchedule, scatter);
+        *AccessSchedule = isl_union_map_add_map(*AccessSchedule, Scatter);
       }
 
       if (MA->isRead())