isl_tab: optionally save dual solution

[platform/upstream/isl.git] / isl_lp.c

diff --git a/isl_lp.c b/isl_lp.c
index d9da0d5..9f8c314 100644 (file)
--- a/isl_lp.c
+++ b/isl_lp.c
@@ -1,9 +1,54 @@
 #include "isl_ctx.h"
 #include "isl_lp.h"
 #include "isl_lp_piplib.h"
+#include "isl_tab.h"
+#include "isl_map_private.h"
 
+enum isl_lp_result isl_tab_solve_lp(struct isl_basic_map *bmap, int maximize,
+                                     isl_int *f, isl_int denom, isl_int *opt,
+                                     isl_int *opt_denom)
+{
+       struct isl_tab *tab;
+       enum isl_lp_result res;
+       unsigned dim = isl_basic_map_total_dim(bmap);
+
+       if (maximize)
+               isl_seq_neg(f, f, 1 + dim);
+
+       bmap = isl_basic_map_gauss(bmap, NULL);
+       tab = isl_tab_from_basic_map(bmap);
+       res = isl_tab_min(bmap->ctx, tab, f, bmap->ctx->one, opt, opt_denom, 0);
+       isl_tab_free(bmap->ctx, tab);
+
+       if (maximize)
+               isl_seq_neg(f, f, 1 + dim);
+
+       return res;
+}
+
+/* Given a basic map "bmap" and an affine combination of the variables "f"
+ * with denominator "denom", set *opt/*opt_denom to the minimal
+ * (or maximal if "maximize" is true) value attained by f/d over "bmap",
+ * assuming the basic map is not empty and the expression cannot attain
+ * arbitrarily small (or large) values.
+ * If opt_denom is NULL, then *opt is rounded up (or down)
+ * to the nearest integer.
+ * The return value reflects the nature of the result (empty, unbounded,
+ * minmimal or maximal value returned in *opt).
+ */
 enum isl_lp_result isl_solve_lp(struct isl_basic_map *bmap, int maximize,
-                                     isl_int *f, isl_int denom, isl_int *opt)
+                                     isl_int *f, isl_int d, isl_int *opt,
+                                     isl_int *opt_denom)
 {
-       return isl_pip_solve_lp(bmap, maximize, f, denom, opt);
+       if (!bmap)
+               return isl_lp_error;
+
+       switch (bmap->ctx->lp_solver) {
+       case ISL_LP_PIP:
+               return isl_pip_solve_lp(bmap, maximize, f, d, opt, opt_denom);
+       case ISL_LP_TAB:
+               return isl_tab_solve_lp(bmap, maximize, f, d, opt, opt_denom);
+       default:
+               return isl_lp_error;
+       }
 }