Added a missing simplification

Author: Lunderberg

src/arith/rewrite_simplify.cc

@@ -907,6 +907,8 @@ PrimExpr RewriteSimplifier::Impl::VisitExpr_(const FloorDivNode* op) {
     TVM_TRY_REWRITE(floordiv(x * c1, x), c1);
     TVM_TRY_REWRITE(floordiv(c1 * x, x), c1);
 
+    TVM_TRY_REWRITE(floordiv(floormod(x, 2) + 1, 2), floormod(x, 2));
+
     // Rules involving 2-operands.
     TVM_TRY_REWRITE_IF(floordiv(min(x * c1, y), c2), min(x * floordiv(c1, c2), floordiv(y, c2)),
                        c2.Eval()->value > 0 && c1.Eval()->value % c2.Eval()->value == 0);

tests/python/unittest/test_arith_rewrite_simplify.py

@@ -584,6 +584,7 @@ class TestFloorModTwo(BaseCompare):
         TestCase(fld(x, 2) - fld(x - 1, 2), flm(x, 2) * -1 + 1),
         TestCase(fld(x + 5, 2) - fld(x - 2, 2), flm(x, 2) + 3),
         TestCase(fld(x + 5, 2) - fld(x - 3, 2), 4),
+        TestCase(fld(flm(x, 2) + 1, 2), flm(x, 2)),
         # Sum of floordiv and floormod to yield floordiv
         TestCase(fld(x + 1, 2) - flm(x, 2), fld(x, 2)),
         TestCase(fld(x, 2) + flm(x, 2), fld(x + 1, 2)),