From 1bf0064a40d3ed511d8da880abfd5f7b38e1f37b Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Fri, 20 Jul 2012 13:51:33 +0200
Subject: [PATCH] add isl_aff_pullback_multi_aff

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 doc/user.pod      | 11 ++++++++++
 include/isl/aff.h |  3 +++
 isl_aff.c         | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)

diff --git a/doc/user.pod b/doc/user.pod
index f5ca6e67..426a943f 100644
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -3480,6 +3480,17 @@ rounding towards zero.  C<isl_pw_aff_tdiv_r> computes the corresponding
 remainder.
 
 	#include <isl/aff.h>
+	__isl_give isl_aff *isl_aff_pullback_multi_aff(
+		__isl_take isl_aff *aff,
+		__isl_take isl_multi_aff *ma);
+
+This function precomposes the input expression by the given
+C<isl_multi_aff>.  In other words, the C<isl_multi_aff> is plugged
+into the affine expression.
+Objects of type C<isl_multi_aff> are described in
+L</"Piecewise Multiple Quasi Affine Expressions">.
+
+	#include <isl/aff.h>
 	__isl_give isl_basic_set *isl_aff_zero_basic_set(
 		__isl_take isl_aff *aff);
 	__isl_give isl_basic_set *isl_aff_neg_basic_set(
diff --git a/include/isl/aff.h b/include/isl/aff.h
index a84dd7e9..d5527f94 100644
--- a/include/isl/aff.h
+++ b/include/isl/aff.h
@@ -101,6 +101,9 @@ __isl_give isl_aff *isl_aff_gist(__isl_take isl_aff *aff,
 __isl_give isl_aff *isl_aff_gist_params(__isl_take isl_aff *aff,
 	__isl_take isl_set *context);
 
+__isl_give isl_aff *isl_aff_pullback_multi_aff(__isl_take isl_aff *aff,
+	__isl_take isl_multi_aff *ma);
+
 __isl_give isl_basic_set *isl_aff_zero_basic_set(__isl_take isl_aff *aff);
 __isl_give isl_basic_set *isl_aff_neg_basic_set(__isl_take isl_aff *aff);
 
diff --git a/isl_aff.c b/isl_aff.c
index 91740694..1117f4dc 100644
--- a/isl_aff.c
+++ b/isl_aff.c
@@ -3488,6 +3488,70 @@ void isl_seq_preimage(isl_int *dst, isl_int *src,
 	}
 }
 
+/* Compute the pullback of "aff" by the function represented by "ma".
+ * In other words, plug in "ma" in "aff".  The result is an affine expression
+ * defined over the domain space of "ma".
+ *
+ * If "aff" is represented by
+ *
+ *	(a(p) + b x + c(divs))/d
+ *
+ * and ma is represented by
+ *
+ *	x = D(p) + F(y) + G(divs')
+ *
+ * then the result is
+ *
+ *	(a(p) + b D(p) + b F(y) + b G(divs') + c(divs))/d
+ *
+ * The divs in the local space of the input are similarly adjusted
+ * through a call to isl_local_space_preimage_multi_aff.
+ */
+__isl_give isl_aff *isl_aff_pullback_multi_aff(__isl_take isl_aff *aff,
+	__isl_take isl_multi_aff *ma)
+{
+	isl_aff *res = NULL;
+	isl_local_space *ls;
+	int n_div_aff, n_div_ma;
+	isl_int f, c1, c2, g;
+
+	ma = isl_multi_aff_align_divs(ma);
+	if (!aff || !ma)
+		goto error;
+
+	n_div_aff = isl_aff_dim(aff, isl_dim_div);
+	n_div_ma = ma->n ? isl_aff_dim(ma->p[0], isl_dim_div) : 0;
+
+	ls = isl_aff_get_domain_local_space(aff);
+	ls = isl_local_space_preimage_multi_aff(ls, isl_multi_aff_copy(ma));
+	res = isl_aff_alloc(ls);
+	if (!res)
+		goto error;
+
+	isl_int_init(f);
+	isl_int_init(c1);
+	isl_int_init(c2);
+	isl_int_init(g);
+
+	isl_seq_preimage(res->v->el, aff->v->el, ma, n_div_ma, n_div_aff,
+			f, c1, c2, g, 1);
+
+	isl_int_clear(f);
+	isl_int_clear(c1);
+	isl_int_clear(c2);
+	isl_int_clear(g);
+
+	isl_aff_free(aff);
+	isl_multi_aff_free(ma);
+	res = isl_aff_normalize(res);
+	return res;
+error:
+	isl_aff_free(aff);
+	isl_multi_aff_free(ma);
+	isl_aff_free(res);
+	return NULL;
+}
+
 /* Extend the local space of "dst" to include the divs
  * in the local space of "src".
  */
-- 
2.11.4.GIT