set = isl_set_compute_divs(set);
build->pending = isl_set_intersect(build->pending,
isl_set_copy(set));
- if (isl_ast_build_has_stride(build, build->depth))
+ if (isl_ast_build_has_stride(build, build->depth)) {
build->domain = isl_set_eliminate(build->domain,
isl_dim_set, build->depth, 1);
+ build->domain = isl_set_compute_divs(build->domain);
+ }
} else {
isl_basic_set *generated, *pending;
/* Set the stride and offset of the current dimension to the given
* value and expression.
+ *
+ * If we had already found a stride before, then the two strides
+ * are combined into a single stride.
+ *
+ * In particular, if the new stride information is of the form
+ *
+ * i = f + s (...)
+ *
+ * and the old stride information is of the form
+ *
+ * i = f2 + s2 (...)
+ *
+ * then we compute the extended gcd of s and s2
+ *
+ * a s + b s2 = g,
+ *
+ * with g = gcd(s,s2), multiply the first equation with t1 = b s2/g
+ * and the second with t2 = a s1/g.
+ * This results in
+ *
+ * i = (b s2 + a s1)/g i = t1 f + t2 f2 + (s s2)/g (...)
+ *
+ * so that t1 f + t2 f2 is the combined offset and (s s2)/g = lcm(s,s2)
+ * is the combined stride.
*/
static __isl_give isl_ast_build *set_stride(__isl_take isl_ast_build *build,
isl_int stride, __isl_take isl_aff *offset)
goto error;
pos = build->depth;
+
+ if (isl_ast_build_has_stride(build, pos)) {
+ isl_int stride2, a, b, g;
+ isl_aff *offset2;
+
+ isl_int_init(stride2);
+ isl_int_init(a);
+ isl_int_init(b);
+ isl_int_init(g);
+
+ isl_vec_get_element(build->strides, pos, &stride2);
+ isl_int_gcdext(g, a, b, stride, stride2);
+ isl_int_mul(a, a, stride);
+ isl_int_divexact(a, a, g);
+ isl_int_divexact(stride2, stride2, g);
+ isl_int_mul(b, b, stride2);
+ isl_int_mul(stride, stride, stride2);
+
+ offset2 = isl_multi_aff_get_aff(build->offsets, pos);
+ offset2 = isl_aff_scale(offset2, a);
+ offset = isl_aff_scale(offset, b);
+ offset = isl_aff_add(offset, offset2);
+
+ isl_int_clear(stride2);
+ isl_int_clear(a);
+ isl_int_clear(b);
+ isl_int_clear(g);
+ }
+
build->strides = isl_vec_set_element(build->strides, pos, stride);
build->offsets = isl_multi_aff_set_aff(build->offsets, pos, offset);
if (!build->strides || !build->offsets)
return build;
}
-/* Compute x, y and g such that g = gcd(a,b) and a*x+b*y = g */
-static void euclid(isl_int a, isl_int b, isl_int *x, isl_int *y, isl_int *g)
-{
- isl_int c, d, e, f, tmp;
-
- isl_int_init(c);
- isl_int_init(d);
- isl_int_init(e);
- isl_int_init(f);
- isl_int_init(tmp);
- isl_int_abs(c, a);
- isl_int_abs(d, b);
- isl_int_set_si(e, 1);
- isl_int_set_si(f, 0);
- while (isl_int_is_pos(d)) {
- isl_int_tdiv_q(tmp, c, d);
- isl_int_mul(tmp, tmp, f);
- isl_int_sub(e, e, tmp);
- isl_int_tdiv_q(tmp, c, d);
- isl_int_mul(tmp, tmp, d);
- isl_int_sub(c, c, tmp);
- isl_int_swap(c, d);
- isl_int_swap(e, f);
- }
- isl_int_set(*g, c);
- if (isl_int_is_zero(a))
- isl_int_set_si(*x, 0);
- else if (isl_int_is_pos(a))
- isl_int_set(*x, e);
- else
- isl_int_neg(*x, e);
- if (isl_int_is_zero(b))
- isl_int_set_si(*y, 0);
- else {
- isl_int_mul(tmp, a, *x);
- isl_int_sub(tmp, c, tmp);
- isl_int_divexact(*y, tmp, b);
- }
- isl_int_clear(c);
- isl_int_clear(d);
- isl_int_clear(e);
- isl_int_clear(f);
- isl_int_clear(tmp);
-}
-
/* Information used inside detect_stride.
*
* "build" may be updated by detect_stride to include stride information.
if (!isl_int_is_zero(stride) && !isl_int_is_one(stride)) {
isl_aff *aff;
- euclid(v, stride, &a, &b, &gcd);
+ isl_int_gcdext(gcd, a, b, v, stride);
aff = isl_constraint_get_aff(c);
for (i = 0; i < n_div; ++i)
return !involves;
}
+/* Plug in the known values (fixed affine expressions in terms of
+ * parameters and outer loop iterators) of all loop iterators
+ * in the domain of "umap".
+ *
+ * We simply precompose "umap" with build->values.
+ */
+__isl_give isl_union_map *isl_ast_build_substitute_values_union_map_domain(
+ __isl_keep isl_ast_build *build, __isl_take isl_union_map *umap)
+{
+ isl_multi_aff *values;
+
+ if (!build)
+ return isl_union_map_free(umap);
+
+ values = isl_multi_aff_copy(build->values);
+ umap = isl_union_map_preimage_domain_multi_aff(umap, values);
+
+ return umap;
+}
+
/* Is the current dimension known to attain only a single value?
*/
int isl_ast_build_has_value(__isl_keep isl_ast_build *build)