add isl_pw_aff_union_min

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/doc/user.pod b/doc/user.pod
index 1a815ef..1702909 100644 (file)
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -2700,6 +2700,9 @@ for elements in C<cond> and equal to C<pwaff_false> for elements
 not in C<cond>.
 
        #include <isl/aff.h>
+       __isl_give isl_pw_aff *isl_pw_aff_union_min(
+               __isl_take isl_pw_aff *pwaff1,
+               __isl_take isl_pw_aff *pwaff2);
        __isl_give isl_pw_aff *isl_pw_aff_union_max(
                __isl_take isl_pw_aff *pwaff1,
                __isl_take isl_pw_aff *pwaff2);

diff --git a/include/isl/aff.h b/include/isl/aff.h
index c789a95..f30977a 100644 (file)
--- a/include/isl/aff.h
+++ b/include/isl/aff.h
@@ -101,6 +101,8 @@ __isl_give isl_pw_aff *isl_pw_aff_alloc(__isl_take isl_set *set,
 
 int isl_pw_aff_is_empty(__isl_keep isl_pw_aff *pwaff);
 
+__isl_give isl_pw_aff *isl_pw_aff_union_min(__isl_take isl_pw_aff *pwaff1,
+       __isl_take isl_pw_aff *pwaff2);
 __isl_give isl_pw_aff *isl_pw_aff_union_max(__isl_take isl_pw_aff *pwaff1,
        __isl_take isl_pw_aff *pwaff2);
 

diff --git a/isl_aff.c b/isl_aff.c
index 0c7f17d..0712f2d 100644 (file)
--- a/isl_aff.c
+++ b/isl_aff.c
@@ -1146,12 +1146,15 @@ error:
 
 /* Compute a piecewise quasi-affine expression with a domain that
  * is the union of those of pwaff1 and pwaff2 and such that on each
- * cell, the quasi-affine expression is the maximum of those of pwaff1
- * and pwaff2.  If only one of pwaff1 or pwaff2 is defined on a given
- * cell, then the associated expression is the defined one.
+ * cell, the quasi-affine expression is the better (according to cmp)
+ * of those of pwaff1 and pwaff2.  If only one of pwaff1 or pwaff2
+ * is defined on a given cell, then the associated expression
+ * is the defined one.
  */
-static __isl_give isl_pw_aff *pw_aff_union_max(__isl_take isl_pw_aff *pwaff1,
-       __isl_take isl_pw_aff *pwaff2)
+static __isl_give isl_pw_aff *pw_aff_union_opt(__isl_take isl_pw_aff *pwaff1,
+       __isl_take isl_pw_aff *pwaff2,
+       __isl_give isl_basic_set *(*cmp)(__isl_take isl_aff *aff1,
+                                       __isl_take isl_aff *aff2))
 {
        int i, j, n;
        isl_pw_aff *res;
@@ -1183,22 +1186,22 @@ static __isl_give isl_pw_aff *pw_aff_union_max(__isl_take isl_pw_aff *pwaff1,
                set = isl_set_copy(pwaff1->p[i].set);
                for (j = 0; j < pwaff2->n; ++j) {
                        struct isl_set *common;
-                       isl_set *ge;
+                       isl_set *better;
 
                        common = isl_set_intersect(
                                        isl_set_copy(pwaff1->p[i].set),
                                        isl_set_copy(pwaff2->p[j].set));
-                       ge = isl_set_from_basic_set(isl_aff_ge_basic_set(
+                       better = isl_set_from_basic_set(cmp(
                                        isl_aff_copy(pwaff2->p[j].aff),
                                        isl_aff_copy(pwaff1->p[i].aff)));
-                       ge = isl_set_intersect(common, ge);
-                       if (isl_set_plain_is_empty(ge)) {
-                               isl_set_free(ge);
+                       better = isl_set_intersect(common, better);
+                       if (isl_set_plain_is_empty(better)) {
+                               isl_set_free(better);
                                continue;
                        }
-                       set = isl_set_subtract(set, isl_set_copy(ge));
+                       set = isl_set_subtract(set, isl_set_copy(better));
 
-                       res = isl_pw_aff_add_piece(res, ge,
+                       res = isl_pw_aff_add_piece(res, better,
                                                isl_aff_copy(pwaff2->p[j].aff));
                }
                res = isl_pw_aff_add_piece(res, set,
@@ -1224,12 +1227,43 @@ error:
        return NULL;
 }
 
+/* Compute a piecewise quasi-affine expression with a domain that
+ * is the union of those of pwaff1 and pwaff2 and such that on each
+ * cell, the quasi-affine expression is the maximum of those of pwaff1
+ * and pwaff2.  If only one of pwaff1 or pwaff2 is defined on a given
+ * cell, then the associated expression is the defined one.
+ */
+static __isl_give isl_pw_aff *pw_aff_union_max(__isl_take isl_pw_aff *pwaff1,
+       __isl_take isl_pw_aff *pwaff2)
+{
+       return pw_aff_union_opt(pwaff1, pwaff2, &isl_aff_ge_basic_set);
+}
+
 __isl_give isl_pw_aff *isl_pw_aff_union_max(__isl_take isl_pw_aff *pwaff1,
        __isl_take isl_pw_aff *pwaff2)
 {
        return align_params_pw_pw_and(pwaff1, pwaff2, &pw_aff_union_max);
 }
 
+/* Compute a piecewise quasi-affine expression with a domain that
+ * is the union of those of pwaff1 and pwaff2 and such that on each
+ * cell, the quasi-affine expression is the minimum of those of pwaff1
+ * and pwaff2.  If only one of pwaff1 or pwaff2 is defined on a given
+ * cell, then the associated expression is the defined one.
+ */
+static __isl_give isl_pw_aff *pw_aff_union_min(__isl_take isl_pw_aff *pwaff1,
+       __isl_take isl_pw_aff *pwaff2)
+{
+       return pw_aff_union_opt(pwaff1, pwaff2, &isl_aff_le_basic_set);
+}
+
+__isl_give isl_pw_aff *isl_pw_aff_union_min(__isl_take isl_pw_aff *pwaff1,
+       __isl_take isl_pw_aff *pwaff2)
+{
+       return isl_pw_aff_align_params_pw_pw_and(pwaff1, pwaff2,
+                                                       &pw_aff_union_min);
+}
+
 /* Construct a map with as domain the domain of pwaff and
  * one-dimensional range corresponding to the affine expressions.
  */