From a9f0521e8990ca7c6bafc89abb0b8bb42d4094dd Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Tue, 9 Apr 2013 18:33:48 +0200
Subject: [PATCH] add isl_aff_set_constant_val

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 doc/user.pod      |  6 +++++-
 include/isl/aff.h |  3 +++
 isl_aff.c         | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/doc/user.pod b/doc/user.pod
index f4cae685..6410eec3 100644
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -3669,6 +3669,8 @@ It can be modified using
 		__isl_take isl_aff *aff, isl_int v);
 	__isl_give isl_aff *isl_aff_set_constant_si(
 		__isl_take isl_aff *aff, int v);
+	__isl_give isl_aff *isl_aff_set_constant_val(
+		__isl_take isl_aff *aff, __isl_take isl_val *v);
 	__isl_give isl_aff *isl_aff_set_coefficient(
 		__isl_take isl_aff *aff,
 		enum isl_dim_type type, int pos, isl_int v);
@@ -3712,8 +3714,10 @@ It can be modified using
 		__isl_take isl_pw_aff *pwaff,
 		enum isl_dim_type type, unsigned first, unsigned n);
 
-Note that the C<set_constant> and C<set_coefficient> functions
+Note that C<isl_aff_set_constant>, C<isl_aff_set_constant_si>,
+C<isl_aff_set_coefficient> and C<isl_aff_set_coefficient_si>
 set the I<numerator> of the constant or coefficient, while
+C<isl_aff_set_constant_val> sets the constant as a whole.
 C<add_constant> and C<add_coefficient> add an integer value to
 the possibly rational constant or coefficient.
 The C<add_constant_num> functions add an integer value to
diff --git a/include/isl/aff.h b/include/isl/aff.h
index b86b304f..f76bfb46 100644
--- a/include/isl/aff.h
+++ b/include/isl/aff.h
@@ -8,6 +8,7 @@
 #include <isl/list.h>
 #include <isl/multi.h>
 #include <isl/union_set_type.h>
+#include <isl/val.h>
 #include <isl/vec.h>
 
 #if defined(__cplusplus)
@@ -41,6 +42,8 @@ int isl_aff_get_coefficient(__isl_keep isl_aff *aff,
 int isl_aff_get_denominator(__isl_keep isl_aff *aff, isl_int *v);
 __isl_give isl_aff *isl_aff_set_constant(__isl_take isl_aff *aff, isl_int v);
 __isl_give isl_aff *isl_aff_set_constant_si(__isl_take isl_aff *aff, int v);
+__isl_give isl_aff *isl_aff_set_constant_val(__isl_take isl_aff *aff,
+	__isl_take isl_val *v);
 __isl_give isl_aff *isl_aff_set_coefficient(__isl_take isl_aff *aff,
 	enum isl_dim_type type, int pos, isl_int v);
 __isl_give isl_aff *isl_aff_set_coefficient_si(__isl_take isl_aff *aff,
diff --git a/isl_aff.c b/isl_aff.c
index 1156d098..a0b780bc 100644
--- a/isl_aff.c
+++ b/isl_aff.c
@@ -22,6 +22,7 @@
 #include <isl/constraint.h>
 #include <isl/seq.h>
 #include <isl/set.h>
+#include <isl_val_private.h>
 #include <isl_config.h>
 
 #undef BASE
@@ -469,6 +470,53 @@ __isl_give isl_aff *isl_aff_set_constant(__isl_take isl_aff *aff, isl_int v)
 	return aff;
 }
 
+/* Replace the constant term of "aff" by "v".
+ */
+__isl_give isl_aff *isl_aff_set_constant_val(__isl_take isl_aff *aff,
+	__isl_take isl_val *v)
+{
+	if (!aff || !v)
+		goto error;
+
+	if (!isl_val_is_rat(v))
+		isl_die(isl_aff_get_ctx(aff), isl_error_invalid,
+			"expecting rational value", goto error);
+
+	if (isl_int_eq(aff->v->el[1], v->n) &&
+	    isl_int_eq(aff->v->el[0], v->d)) {
+		isl_val_free(v);
+		return aff;
+	}
+
+	aff = isl_aff_cow(aff);
+	if (!aff)
+		goto error;
+	aff->v = isl_vec_cow(aff->v);
+	if (!aff->v)
+		goto error;
+
+	if (isl_int_eq(aff->v->el[0], v->d)) {
+		isl_int_set(aff->v->el[1], v->n);
+	} else if (isl_int_is_one(v->d)) {
+		isl_int_mul(aff->v->el[1], aff->v->el[0], v->n);
+	} else {
+		isl_seq_scale(aff->v->el + 1,
+				aff->v->el + 1, v->d, aff->v->size - 1);
+		isl_int_mul(aff->v->el[1], aff->v->el[0], v->n);
+		isl_int_mul(aff->v->el[0], aff->v->el[0], v->d);
+		aff->v = isl_vec_normalize(aff->v);
+		if (!aff->v)
+			goto error;
+	}
+
+	isl_val_free(v);
+	return aff;
+error:
+	isl_aff_free(aff);
+	isl_val_free(v);
+	return NULL;
+}
+
 __isl_give isl_aff *isl_aff_add_constant(__isl_take isl_aff *aff, isl_int v)
 {
 	if (isl_int_is_zero(v))
-- 
2.11.4.GIT