isl_aff_scale: special case scaling by a factor of the denominator

[platform/upstream/isl.git] / isl_aff.c

diff --git a/isl_aff.c b/isl_aff.c
index ae57b81..3acb3f5 100644 (file)
--- a/isl_aff.c
+++ b/isl_aff.c
@@ -1214,6 +1214,11 @@ __isl_give isl_aff *isl_aff_scale(__isl_take isl_aff *aff, isl_int f)
        if (!aff->v)
                return isl_aff_free(aff);
 
+       if (isl_int_is_pos(f) && isl_int_is_divisible_by(aff->v->el[0], f)) {
+               isl_int_divexact(aff->v->el[0], aff->v->el[0], f);
+               return aff;
+       }
+
        isl_int_init(gcd);
        isl_int_gcd(gcd, aff->v->el[0], f);
        isl_int_divexact(aff->v->el[0], aff->v->el[0], gcd);