From df3bff8d4d480b6431da2fb479dcf905b0b1b65b Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sat, 8 Mar 2008 20:28:57 +0100
Subject: [PATCH] introduce evalue_shift_variables

---
 barvinok/evalue.h |  1 +
 bernoulli.c       | 32 ++------------------------------
 evalue.c          | 15 +++++++++++++++
 3 files changed, 18 insertions(+), 30 deletions(-)

diff --git a/barvinok/evalue.h b/barvinok/evalue.h
index 069f672..ac385e4 100644
--- a/barvinok/evalue.h
+++ b/barvinok/evalue.h
@@ -129,6 +129,7 @@ evalue *affine2evalue(Value *coeff, Value denom, int nvar);
 void evalue_substitute(evalue *e, evalue **subs);
 void evalue_backsubstitute(evalue *e, Matrix *CP, unsigned MaxRays);
 evalue *evalue_polynomial(Vector *c, const evalue* X);
+void evalue_shift_variables(evalue *e, int n);
 
 struct evalue_section {
     Polyhedron *D;
diff --git a/bernoulli.c b/bernoulli.c
index 494e968..c40c5a2 100644
--- a/bernoulli.c
+++ b/bernoulli.c
@@ -151,40 +151,12 @@ struct poly_list *faulhaber_compute(int n)
     return bernoulli_faulhaber_compute(n, &faulhaber, 1);
 }
 
-/* shift variables in polynomial one down */
-static void shift(evalue *e)
-{
-    int i;
-    if (value_notzero_p(e->d))
-	return;
-    assert(e->x.p->type == polynomial || e->x.p->type == fractional);
-    if (e->x.p->type == polynomial) {
-	assert(e->x.p->pos > 1);
-	e->x.p->pos--;
-    }
-    for (i = 0; i < e->x.p->size; ++i)
-	shift(&e->x.p->arr[i]);
-}
-
-/* shift variables in polynomial n up */
-static void unshift(evalue *e, unsigned n)
-{
-    int i;
-    if (value_notzero_p(e->d))
-	return;
-    assert(e->x.p->type == polynomial || e->x.p->type == fractional);
-    if (e->x.p->type == polynomial)
-	e->x.p->pos += n;
-    for (i = 0; i < e->x.p->size; ++i)
-	unshift(&e->x.p->arr[i], n);
-}
-
 static evalue *shifted_copy(const evalue *src)
 {
     evalue *e = ALLOC(evalue);
     value_init(e->d);
     evalue_copy(e, src);
-    shift(e);
+    evalue_shift_variables(e, -1);
     return e;
 }
 
@@ -903,7 +875,7 @@ static evalue *sum_over_polytope_with_equalities(Polyhedron *P, evalue *E,
 					 new_nparam);
 	else
 	    subs[nvar+j] = evalue_var(j);
-	unshift(subs[nvar+j], new_dim-new_nparam);
+	evalue_shift_variables(subs[nvar+j], new_dim-new_nparam);
     }
 
     E = evalue_dup(E);
diff --git a/evalue.c b/evalue.c
index 4ee1f1d..7754fff 100644
--- a/evalue.c
+++ b/evalue.c
@@ -4360,3 +4360,18 @@ evalue *evalue_from_section_array(struct evalue_section *s, int n)
     }
     return res;
 }
+
+/* shift variables in polynomial n up */
+void evalue_shift_variables(evalue *e, int n)
+{
+    int i;
+    if (value_notzero_p(e->d))
+	return;
+    assert(e->x.p->type == polynomial || e->x.p->type == fractional);
+    if (e->x.p->type == polynomial) {
+	assert(e->x.p->pos + n >= 1);
+	e->x.p->pos += n;
+    }
+    for (i = 0; i < e->x.p->size; ++i)
+	evalue_shift_variables(&e->x.p->arr[i], n);
+}
-- 
2.11.4.GIT