22 files changed, 394 insertions, 70 deletions

diff --git a/src/arch/avx2.h b/src/arch/avx2.h
index 74aad53..1c7248b 100644
--- a/src/arch/avx2.h
+++ b/src/arch/avx2.h
@@ -437,5 +437,27 @@ is_eo_even(cube_t cube)
         e = _mm256_slli_epi16(e, 7-EOSHIFT);
         mask = _mm256_movemask_epi8(e);
 
-        return popcount_u32(mask) % 2;
+        return popcount_u32(mask) % 2 == 0;
+}
+
+STATIC_INLINE uint64_t
+coord_epudsep(cube_t cube)
+{
+        uint8_t aux[32];
+
+        _mm256_storeu_si256((__m256i_u *)aux, cube);
+        return coord_epudsep_array(aux + 16);
+}
+
+STATIC_INLINE cube_t
+invcoord_epudsep(uint64_t i)
+{
+        cube_t cube, elow;
+        uint8_t e[32];
+
+        invcoord_epudsep_array(i, e+16);
+        elow = _mm256_load_si256((__m256i *)e);
+        cube = _mm256_set_epi64x(SOLVED_H, 0, 0, SOLVED_L);
+
+        return _mm256_or_si256(elow, cube);
 }
diff --git a/src/arch/common.h b/src/arch/common.h
index d76b65f..f06f8d7 100644
--- a/src/arch/common.h
+++ b/src/arch/common.h
@@ -29,6 +29,8 @@ STATIC_INLINE uint64_t coord_cocsep(cube_t);
 STATIC_INLINE uint64_t coord_eo(cube_t);
 STATIC_INLINE uint64_t coord_esep(cube_t);
 STATIC_INLINE cube_t invcoord_esep(uint64_t);
+STATIC_INLINE uint64_t coord_epudsep(cube_t);
+STATIC_INLINE cube_t invcoord_epudsep(uint64_t);
 
 STATIC_INLINE bool is_eo_even(cube_t);
 
@@ -38,6 +40,8 @@ STATIC_INLINE void set_eo(cube_t [static 1], uint64_t);
 
 STATIC_INLINE void invcoord_esep_array(uint64_t, uint64_t, uint8_t[static 12]);
 STATIC_INLINE cube_t invcoord_eoesep(uint64_t);
+STATIC_INLINE uint64_t coord_epudsep_array(const uint8_t [8]);
+STATIC_INLINE void invcoord_epudsep_array(uint64_t, uint8_t [8]);
 
 STATIC_INLINE uint64_t coord_cp(cube_t);
 STATIC_INLINE cube_t invcoord_cp(uint64_t);
@@ -85,3 +89,38 @@ invcoord_eoesep(uint64_t i)
 
         return c;
 }
+
+STATIC_INLINE uint64_t
+coord_epudsep_array(const uint8_t e[8])
+{
+        uint8_t i, k, is;
+        uint64_t ret;
+
+        ret = 0;
+        k = 4;
+        for (i = 0; i < 8; i++) {
+                is = (e[i] & UINT8_C(4)) >> UINT8_C(2);
+                ret += is * binomial[7-i][k];
+                k -= is;
+        }
+
+        return ret;
+}
+
+STATIC_INLINE void
+invcoord_epudsep_array(uint64_t c, uint8_t ret[8])
+{
+        uint8_t i, k, is, x, y;
+
+        k = 4;
+        x = 0;
+        y = 4;
+        for (i = 0; i < 8; i++) {
+                is = c >= binomial[7-i][k];
+                ret[i] = is*y + (1-is)*x;
+                y += is;
+                x += 1-is;
+                c -= is * binomial[7-i][k];
+                k -= is;
+        }
+}
diff --git a/src/arch/neon.h b/src/arch/neon.h
index 2c35c58..9871125 100644
--- a/src/arch/neon.h
+++ b/src/arch/neon.h
@@ -453,7 +453,7 @@ invcoord_cp(uint64_t i)
 {
         return (cube_t) {
                 .corner = indextoperm_8x8(i),
-                .edge = vcombine_u8(vld1_u8(SOLVED_L), vld1_u8(SOLVED_H)) 
+                .edge = vcombine_u8(vld1_u8(SOLVED_L), vld1_u8(SOLVED_H))
         };
 }
 
@@ -515,3 +515,24 @@ is_eo_even(cube_t cube)
 
         return count % 2 == 0;
 }
+
+STATIC_INLINE uint64_t
+coord_epudsep(cube_t cube)
+{
+        uint8_t e[8];
+
+        vst1_u8(e, vget_low_u8(cube.edge));
+        return coord_epudsep_array(e);
+}
+
+STATIC_INLINE cube_t
+invcoord_epudsep(uint64_t i)
+{
+        uint8_t e[8];
+
+        invcoord_epudsep_array(i, e);
+        return (cube_t) {
+                .corner = vld1_u8(SOLVED_L),
+                .edge = vcombine_u8(vld1_u8(e), vld1_u8(SOLVED_H))
+        };
+}
diff --git a/src/arch/portable.h b/src/arch/portable.h
index d673f15..c7f2de0 100644
--- a/src/arch/portable.h
+++ b/src/arch/portable.h
@@ -367,3 +367,19 @@ is_eo_even(cube_t cube)
 
         return count % 2 == 0;
 }
+
+STATIC_INLINE uint64_t
+coord_epudsep(cube_t cube)
+{
+        return coord_epudsep_array(cube.edge);
+}
+
+STATIC_INLINE cube_t
+invcoord_epudsep(uint64_t c)
+{
+        cube_t ret;
+
+        ret = SOLVED_CUBE;
+        invcoord_epudsep_array(c, ret.edge);
+        return ret;
+}
diff --git a/src/core/constants.h b/src/core/constants.h
index 3e6941d..26f6916 100644
--- a/src/core/constants.h
+++ b/src/core/constants.h
@@ -360,6 +360,10 @@
     MM18_FACE(MOVE_U) | MM18_FACE(MOVE_D) |\
     MM_SINGLE(MOVE_R2) | MM_SINGLE(MOVE_L2) |\
     MM_SINGLE(MOVE_F2) | MM_SINGLE(MOVE_B2))
+#define MM18_DRHTR       (\
+    MM18_FACE(MOVE_U) | MM_SINGLE(MOVE_D) | MM_SINGLE(MOVE_D3) |\
+    MM_SINGLE(MOVE_R2) | MM_SINGLE(MOVE_L2) |\
+    MM_SINGLE(MOVE_F2) | MM_SINGLE(MOVE_B2))
 #define MM18_DR_NOD      (MM18_DR & ~MM18_FACE(MOVE_D))
 #define MM18_HTR         (MM18_ALLMOVES & ~MM18_NOHALFTURNS)
 
diff --git a/src/solvers/coord/common.h b/src/solvers/coord/common.h
index 5b5f57b..5f2435d 100644
--- a/src/solvers/coord/common.h
+++ b/src/solvers/coord/common.h
@@ -12,6 +12,9 @@ STATIC bool coord_can_switch(const coord_t [static 1], const unsigned char *,
 STATIC bool coord_is_solved(
     const coord_t [static 1], uint64_t, const unsigned char *);
 
+STATIC cube_t coordinate_merge_ce(cube_t, cube_t);
+STATIC cube_t coordinate_merge_ec(cube_t, cube_t);
+
 STATIC uint64_t
 coord_coord_generic(
         const coord_t coord[static 1],
@@ -19,13 +22,11 @@ coord_coord_generic(
         const unsigned char *data
 )
 {
-        const unsigned char *datanoinfo;
         const uint32_t *data32;
         uint32_t d;
         cube_t tr;
 
-        datanoinfo = data + INFOSIZE;
-        data32 = (const uint32_t *)datanoinfo;
+        data32 = (const uint32_t *)(data + INFOSIZE);
         d = data32[coord->sym.coord(c)];
         tr = transform(c, COORD_TTREP(d));
 
@@ -197,3 +198,20 @@ coord_is_solved(
 {
         return coord->is_solved == NULL ? i == 0 : coord->is_solved(i, data);
 }
+
+STATIC cube_t
+coordinate_merge_ce(cube_t corners, cube_t edges)
+{
+        cube_t merged;
+
+        merged = corners;
+        copy_edges(&merged, edges);
+
+        return merged;
+}
+
+STATIC cube_t
+coordinate_merge_ec(cube_t edges, cube_t corners)
+{
+        return coordinate_merge_ce(corners, edges);
+}
diff --git a/src/solvers/coord/coord.h b/src/solvers/coord/coord.h
index beb1b6a..db40239 100644
--- a/src/solvers/coord/coord.h
+++ b/src/solvers/coord/coord.h
@@ -7,6 +7,7 @@
 #include "drslice.h"
 #include "cpepe.h"
 #include "drfin.h"
+#include "htr.h"
 #include "list.h"
 #include "utils.h"
 #include "gendata.h"
diff --git a/src/solvers/coord/cpepe.h b/src/solvers/coord/cpepe.h
index 9c9bffc..7035400 100644
--- a/src/solvers/coord/cpepe.h
+++ b/src/solvers/coord/cpepe.h
@@ -1,4 +1,3 @@
-STATIC cube_t coordinate_cpepe_merge(const cube_t, const cube_t);
 STATIC uint64_t coordinate_cpepe_coord(const cube_t, const unsigned char *);
 STATIC cube_t coordinate_cpepe_cube(uint64_t, const unsigned char *);
 STATIC bool coordinate_cpepe_isnasty(uint64_t, const unsigned char *);
@@ -15,6 +14,7 @@ STATIC coord_t coordinate_cpepe = {
         .moves_mask_gendata = MM18_DR,
         .moves_mask_solve = MM18_DR,
         .is_admissible = &solution_always_valid,
+        .solution_prune = NULL,
         .is_solvable = &is_drfinnoe_solvable,
         .is_solved = NULL,
         .allow_niss = false,
@@ -44,21 +44,10 @@ STATIC coord_t coordinate_cpepe = {
                 .max2 = FACT_4,
                 .coord2 = &coord_epe,
                 .cube2 = &invcoord_epe,
-                .merge = &coordinate_cpepe_merge,
+                .merge = &coordinate_merge_ce,
         },
 };
 
-STATIC cube_t
-coordinate_cpepe_merge(const cube_t c1, const cube_t c2)
-{
-        cube_t merged;
-
-        merged = c1;
-        copy_edges(&merged, c2);
-
-        return merged;
-}
-
 STATIC uint64_t
 coordinate_cpepe_coord(const cube_t cube, const unsigned char *data)
 {
diff --git a/src/solvers/coord/dr.h b/src/solvers/coord/dr.h
index 03473df..8100910 100644
--- a/src/solvers/coord/dr.h
+++ b/src/solvers/coord/dr.h
@@ -3,7 +3,6 @@
 
 STATIC uint64_t coord_dreoesep_nosym(cube_t);
 STATIC cube_t invcoord_dreoesep_nosym(uint64_t);
-STATIC cube_t coordinate_dr_merge(cube_t, cube_t);
 
 STATIC uint64_t coordinate_dr_coord(cube_t, const unsigned char *);
 STATIC cube_t coordinate_dr_cube(uint64_t, const unsigned char *);
@@ -23,6 +22,7 @@ STATIC coord_t coordinate_dr = {
         .moves_mask_gendata = MM18_ALLMOVES,
         .moves_mask_solve = MM18_ALLMOVES,
         .is_admissible = &solution_lastqt_cw,
+        .solution_prune = NULL,
         .is_solvable = &is_eoco_solvable,
         .is_solved = NULL,
         .allow_niss = true,
@@ -50,7 +50,7 @@ STATIC coord_t coordinate_dr = {
                 .max2 = POW_3_7,
                 .coord2 = &coord_co,
                 .cube2 = &invcoord_co,
-                .merge = &coordinate_dr_merge,
+                .merge = &coordinate_merge_ec,
         },
 };
 
@@ -79,17 +79,6 @@ invcoord_dreoesep_nosym(uint64_t coord)
         return cube;
 }
 
-STATIC cube_t
-coordinate_dr_merge(cube_t c1, cube_t c2)
-{
-        cube_t merged;
-
-        merged = c1;
-        copy_corners(&merged, c2);
-
-        return merged;
-}
-
 STATIC uint64_t
 coordinate_dr_coord(cube_t cube, const unsigned char *data)
 {
diff --git a/src/solvers/coord/dreo.h b/src/solvers/coord/dreo.h
index f563129..c5cacac 100644
--- a/src/solvers/coord/dreo.h
+++ b/src/solvers/coord/dreo.h
@@ -2,7 +2,6 @@
 
 STATIC uint64_t coord_dresep_nosym(cube_t);
 STATIC cube_t invcoord_dresep_nosym(uint64_t);
-STATIC cube_t coordinate_dreo_merge(cube_t, cube_t);
 
 STATIC uint64_t coordinate_dreo_coord(cube_t, const unsigned char *);
 STATIC cube_t coordinate_dreo_cube(uint64_t, const unsigned char *);
@@ -22,6 +21,7 @@ STATIC coord_t coordinate_dreo = {
         .moves_mask_gendata = MM18_EO,
         .moves_mask_solve = MM18_EO,
         .is_admissible = &solution_lastqt_cw,
+        .solution_prune = NULL,
         .is_solvable = &is_dreo_solvable,
         .is_solved = NULL,
         .allow_niss = true,
@@ -47,7 +47,7 @@ STATIC coord_t coordinate_dreo = {
                 .max2 = POW_3_7,
                 .coord2 = &coord_co,
                 .cube2 = &invcoord_co,
-                .merge = &coordinate_dreo_merge,
+                .merge = &coordinate_merge_ec,
         },
 };
 
@@ -63,17 +63,6 @@ invcoord_dresep_nosym(uint64_t coord)
         return invcoord_esep(coord * COMB_8_4);
 }
 
-STATIC cube_t
-coordinate_dreo_merge(cube_t c1, cube_t c2)
-{
-        cube_t merged;
-
-        merged = c1;
-        copy_corners(&merged, c2);
-
-        return merged;
-}
-
 STATIC uint64_t
 coordinate_dreo_coord(cube_t cube, const unsigned char *data)
 {
diff --git a/src/solvers/coord/drfinnoe.h b/src/solvers/coord/drfinnoe.h
index 4370779..63f4edf 100644
--- a/src/solvers/coord/drfinnoe.h
+++ b/src/solvers/coord/drfinnoe.h
@@ -13,7 +13,6 @@ In the worst case, it is a bug to be fixed, but I find it unlikely.
 
 #define CLASSES_CP_16 2768
 
-STATIC cube_t coordinate_drfinnoe_merge(cube_t, cube_t);
 STATIC uint64_t coordinate_drfinnoe_coord(cube_t, const unsigned char *);
 STATIC cube_t coordinate_drfinnoe_cube(uint64_t, const unsigned char *);
 STATIC bool coordinate_drfinnoe_isnasty(uint64_t, const unsigned char *);
@@ -32,6 +31,7 @@ STATIC coord_t coordinate_drfinnoe = {
         .moves_mask_gendata = MM18_DR,
         .moves_mask_solve = MM18_DR,
         .is_admissible = &solution_always_valid,
+        .solution_prune = NULL,
         .is_solvable = &is_drfinnoe_solvable,
         .is_solved = NULL,
         .allow_niss = false,
@@ -62,21 +62,10 @@ STATIC coord_t coordinate_drfinnoe = {
                 .max2 = FACT_8,
                 .coord2 = &coord_epud,
                 .cube2 = &invcoord_epud,
-                .merge = &coordinate_drfinnoe_merge,
+                .merge = &coordinate_merge_ce,
         },
 };
 
-STATIC cube_t
-coordinate_drfinnoe_merge(cube_t c1, cube_t c2)
-{
-        cube_t merged;
-
-        merged = c1;
-        copy_edges(&merged, c2);
-
-        return merged;
-}
-
 STATIC uint64_t
 coordinate_drfinnoe_coord(cube_t cube, const unsigned char *data)
 {
diff --git a/src/solvers/coord/drslice.h b/src/solvers/coord/drslice.h
index c9403f8..42699f8 100644
--- a/src/solvers/coord/drslice.h
+++ b/src/solvers/coord/drslice.h
@@ -5,7 +5,6 @@ much of the code of DRFINNOE. We could make the pruning table 4x smaller
 if we reduced the coordinate by rotations. TODO.
 */
 
-STATIC cube_t coordinate_drslice_merge(cube_t, cube_t);
 STATIC uint64_t coordinate_drslice_coord(cube_t, const unsigned char *);
 STATIC cube_t coordinate_drslice_cube(uint64_t, const unsigned char *);
 STATIC bool coordinate_drslice_isnasty(uint64_t, const unsigned char *);
@@ -24,6 +23,7 @@ STATIC coord_t coordinate_drslice = {
         .moves_mask_gendata = MM18_DR,
         .moves_mask_solve = MM18_DR_NOD,
         .is_admissible = &solution_always_valid,
+        .solution_prune = NULL,
         .is_solvable = &is_drslice_solvable,
         .is_solved = &is_drslice_solved,
         .allow_niss = false,
@@ -54,21 +54,10 @@ STATIC coord_t coordinate_drslice = {
                 .max2 = FACT_8,
                 .coord2 = &coord_epud,
                 .cube2 = &invcoord_epud,
-                .merge = &coordinate_drslice_merge,
+                .merge = &coordinate_merge_ce,
         },
 };
 
-STATIC cube_t
-coordinate_drslice_merge(cube_t c1, cube_t c2)
-{
-        cube_t merged;
-
-        merged = c1;
-        copy_edges(&merged, c2);
-
-        return merged;
-}
-
 STATIC uint64_t
 coordinate_drslice_coord(cube_t cube, const unsigned char *data)
 {
diff --git a/src/solvers/coord/eo.h b/src/solvers/coord/eo.h
index 5c823a1..42196af 100644
--- a/src/solvers/coord/eo.h
+++ b/src/solvers/coord/eo.h
@@ -14,6 +14,7 @@ STATIC coord_t coordinate_eo = {
         .moves_mask_gendata = MM18_ALLMOVES,
         .moves_mask_solve = MM18_ALLMOVES,
         .is_admissible = &solution_lastqt_cw,
+        .solution_prune = NULL,
         .is_solvable = &is_eo_even,
         .is_solved = NULL,
         .allow_niss = true,
diff --git a/src/solvers/coord/htr.h b/src/solvers/coord/htr.h
new file mode 100644
index 0000000..cfd451b
--- /dev/null
+++ b/src/solvers/coord/htr.h
@@ -0,0 +1,125 @@
+STATIC uint64_t coordinate_htr_coord(cube_t, const unsigned char *);
+STATIC cube_t coordinate_htr_cube(uint64_t, const unsigned char *);
+STATIC bool coordinate_htr_isnasty(uint64_t, const unsigned char *);
+STATIC size_t coordinate_htr_gendata(unsigned char *);
+
+STATIC bool htr_checkmoves(bool *, uint8_t, const uint8_t *);
+STATIC bool htr_solution_prune(const solution_moves_t [static 1]);
+STATIC bool is_cp_htr(uint64_t, const unsigned char *);
+
+STATIC coord_t coordinate_htr = {
+        .name = "HTR",
+        .coord = &coordinate_htr_coord,
+        .cube = &coordinate_htr_cube,
+        .isnasty = &coordinate_htr_isnasty,
+        .gendata = coordinate_htr_gendata,
+        .max = CLASSES_CP_16 * COMB_8_4,
+        .trans_mask = TM_UDFIX,
+        .moves_mask_gendata = MM18_DR,
+        .moves_mask_solve = MM18_DRHTR,
+        .is_admissible = &solution_lastqt_cw,
+        .solution_prune = &htr_solution_prune,
+        .is_solvable = &is_drfinnoe_solvable,
+        .is_solved = &is_cp_htr,
+        .allow_niss = true,
+        .pruning_distribution = {
+                [0] = 22,
+                [1] = 18,
+                [2] = 86,
+                [3] = 268,
+                [4] = 920,
+                [5] = 4042,
+                [6] = 12716,
+                [7] = 24852,
+                [8] = 33116,
+                [9] = 45032,
+                [10] = 47144,
+                [11] = 21676,
+                [12] = 3692,
+                [13] = 176
+        },
+        .pruning_max = 13,
+        .sym = {
+                .classes = CLASSES_CP_16,
+                .max = FACT_8,
+                .coord = &coord_cp,
+                .cube = &invcoord_cp,
+                .max2 = COMB_8_4,
+                .coord2 = &coord_epudsep,
+                .cube2 = &invcoord_epudsep,
+                .merge = &coordinate_merge_ce,
+        },
+};
+
+STATIC uint64_t
+coordinate_htr_coord(cube_t cube, const unsigned char *data)
+{
+        return coord_coord_generic(&coordinate_htr, cube, data);
+}
+
+STATIC cube_t
+coordinate_htr_cube(uint64_t i, const unsigned char *data)
+{
+        return coord_cube_generic(&coordinate_htr, i, data);
+}
+
+STATIC bool
+coordinate_htr_isnasty(uint64_t i, const unsigned char *data)
+{
+        return coord_isnasty_generic(&coordinate_htr, i, data);
+}
+
+STATIC size_t
+coordinate_htr_gendata(unsigned char *data)
+{
+        return coord_gendata_generic(&coordinate_htr, data);
+}
+
+STATIC bool
+htr_checkmoves(bool *f, uint8_t n, const uint8_t *moves)
+{
+        uint8_t i;
+        bool is_d, is_u;
+
+        for (i = 0; i < n; i++) {
+                is_d = moves[i] == MOVE_D || moves[i] == MOVE_D3;
+                is_u = moves[i] == MOVE_U || moves[i] == MOVE_U3;
+                if (is_d && *f)
+                        return true;
+                *f = *f || is_d || is_u;
+
+                if (i < n-1 && moveaxis(moves[i]) == 0 &&
+                    parallel(moves[i], moves[i+1]))
+                        return true;
+        }
+
+        return false;
+}
+
+STATIC bool
+htr_solution_prune(const solution_moves_t s[static 1])
+{
+        bool f;
+
+        f = false;
+
+        return htr_checkmoves(&f, s->nmoves, s->moves) ||
+               htr_checkmoves(&f, s->npremoves, s->premoves);
+}
+
+STATIC bool
+is_cp_htr(uint64_t i, const unsigned char *data)
+{
+        static uint8_t is_cp16_htr_table[DIV_ROUND_UP(CLASSES_CP_16, 8)] = {
+                [0] = 81, [7] = 144, [8] = 16, [25] = 130, [26] = 34,
+                [37] = 64, [38] = 48, [39] = 8, [212] = 20, [226] = 32,
+                [227] = 2, [298] = 160, [300] = 128, [301] = 1
+        };
+
+        uint64_t e, c;
+
+        e = i % COMB_8_4;
+        c = i / COMB_8_4;
+
+        return e == 0 && is_cp16_htr_table[c / 8] & (UINT8_C(1) << (c % 8));
+}
diff --git a/src/solvers/coord/list.h b/src/solvers/coord/list.h
index 7bc8041..9b59969 100644
--- a/src/solvers/coord/list.h
+++ b/src/solvers/coord/list.h
@@ -5,6 +5,7 @@ coord_t *all_coordinates[] = {
         &coordinate_drfinnoe,
         &coordinate_drslice,
         &coordinate_cpepe,
+        &coordinate_htr,
         NULL
 };
 
diff --git a/src/solvers/coord/solve.h b/src/solvers/coord/solve.h
index 72bc064..54309b1 100644
--- a/src/solvers/coord/solve.h
+++ b/src/solvers/coord/solve.h
@@ -155,6 +155,10 @@ solve_coord_dfs(dfsarg_solve_coord_t arg[static 1])
         int64_t n, ret;
         cube_t backup_cube, backup_inverse;
 
+        if (arg->coord->solution_prune != NULL &&
+            arg->coord->solution_prune(arg->solution_moves))
+                return 0;
+
         coord = arg->coord->coord(arg->cube, arg->coord_data);
         if (coord_is_solved(arg->coord, coord, arg->coord_data)) {
                 if (!coord_solution_admissible(arg))
diff --git a/src/solvers/coord/types_macros.h b/src/solvers/coord/types_macros.h
index 73484ba..98f9822 100644
--- a/src/solvers/coord/types_macros.h
+++ b/src/solvers/coord/types_macros.h
@@ -28,6 +28,7 @@ typedef struct {
         uint64_t moves_mask_solve;
         uint64_t trans_mask;
         bool (*is_admissible)(const solution_moves_t[static 1]);
+        bool (*solution_prune)(const solution_moves_t[static 1]);
         bool (*is_solvable)(cube_t);
         bool (*is_solved)(uint64_t, const unsigned char *);
         uint64_t pruning_distribution[INFO_DISTRIBUTION_LEN];
diff --git a/test/083_invcoord_epudsep/00_all.in b/test/083_invcoord_epudsep/00_all.in
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/083_invcoord_epudsep/00_all.in
diff --git a/test/083_invcoord_epudsep/00_all.out b/test/083_invcoord_epudsep/00_all.out
new file mode 100644
index 0000000..d6109db
--- /dev/null
+++ b/test/083_invcoord_epudsep/00_all.out
@@ -0,0 +1 @@
+All good
diff --git a/test/083_invcoord_epudsep/invcoord_epudsep_tests.c b/test/083_invcoord_epudsep/invcoord_epudsep_tests.c
new file mode 100644
index 0000000..709e5d8
--- /dev/null
+++ b/test/083_invcoord_epudsep/invcoord_epudsep_tests.c
@@ -0,0 +1,32 @@
+#include "../test.h"
+
+#define COMB_8_4 70
+
+uint64_t coord_epudsep(cube_t);
+cube_t invcoord_epudsep(uint64_t);
+
+void run(void) {
+        oriented_cube_t cube;
+        uint64_t coord, coord2;
+
+        cube.orientation = 0;
+
+        /* Test all possible values for CP coordinate */
+        for (coord = 0; coord < COMB_8_4; coord++) {
+                cube.cube = invcoord_epudsep(coord);
+
+                if (!isconsistent(cube)) {
+                        printf("Not consistent\n");
+                        return;
+                }
+
+                coord2 = coord_epudsep(cube.cube);
+                if (coord != coord2) {
+                        printf("Error: invcoord of %" PRIu64
+                            " returns %" PRIu64 "\n", coord, coord2);
+                        return;
+                }
+        }
+
+        printf("All good\n");
+}
diff --git a/tools/419_solvetest_HTR_from_UD/scrambles.h b/tools/419_solvetest_HTR_from_UD/scrambles.h
new file mode 100644
index 0000000..749da60
--- /dev/null
+++ b/tools/419_solvetest_HTR_from_UD/scrambles.h
@@ -0,0 +1,84 @@
+struct {
+        char *scramble;
+        char *solutions;
+} s[] = {
+[0] = {
+        .scramble = "U F2 U' R2 U L2 B2 L2 U D2 R2 L2 F2",
+        .solutions =
+                "(U F2 R2 B2 R2 U)\n"
+                "(U F2 L2 B2 L2 U)\n"
+                "(D R2 F2 R2 B2 U)\n"
+                "(D R2 B2 R2 F2 U)\n"
+},
+[1] = {
+        .scramble = "U L2 F2 U F2 U' D' L2 B2 U F2 D' R2 U'",
+        .solutions =
+                "(U F2 U F2 U' F2 U L2 U)\n"
+                "(U F2 U' F2 U L2 U' F2 U)\n"
+                "U R2 U L2 U (U L2 F2 U)\n"
+                "D B2 U F2 U (U R2 B2 U)\n"
+                "R2 U (U F2 U' F2 U L2 U)\n"
+                "R2 U (U' F2 U L2 U' F2 U)\n"
+},
+[2] = {
+        .scramble = "R2 L2 U2 B2 L2 U' R2 U F2 D R2 D' B2",
+        .solutions =
+                "B2 U2 R2 U F2 U\n"
+},
+[3] = {
+        .scramble = "R2 D2 R2 F2 U L2 B2 D L2 F2 D L2",
+        .solutions =
+                "R2 D' B2 U R2 U\n"
+                "(F2 U' F2 U F2 U)\n"
+},
+[4] = {
+        .scramble = "D F2 D F2 U' F2 B2 L2 U' D2 L2",
+        .solutions =
+                "(D F2 U L2 U' F2 U)\n"
+                "(D' B2 U' B2 U R2 U)\n"
+                "L2 U (U L2 U B2 U)\n"
+},
+[5] = {
+        .scramble = "R2 B2 R2 L2 U B2 D' L2 D F2 D' B2 D' L2 U",
+        .solutions =
+                "U R2 U' F2 U (U B2 U' F2 U)\n"
+                "F2 D B2 U L2 U2 B2 U (B2 U)\n"
+                "F2 D B2 U' B2 U2 L2 U (B2 U)\n"
+                "F2 D F2 U F2 U2 L2 U (B2 U)\n"
+                "F2 D F2 U' L2 U2 F2 U (B2 U)\n"
+},
+[6] = {
+        .scramble = "F2 U2 B2 R2 D' R2 U2 L2 B2 L2 D R2 D",
+        .solutions =
+                "(L2 U B2 L2 U F2 U)\n"
+                "U2 B2 U (L2 U L2 U)\n"
+},
+[7] = {
+        .scramble = "D2 B2 L2 F2 D B2 U B2 R2 B2 D2 R2 D'",
+        .solutions =
+                "U B2 U' L2 U\n"
+},
+[8] = {
+        .scramble = "U2 B2 U' R2 B2 U' R2 B2 U' B2 D' R2 D L2 D'",
+        .solutions =
+                "U R2 U' F2 U L2 U2 B2 U\n"
+                "U R2 U' F2 U' B2 U2 L2 U\n"
+                "U R2 U' B2 U F2 U2 L2 U\n"
+                "U R2 U' B2 U' L2 U2 F2 U\n"
+                "U2 L2 U (B2 U B2 U' L2 U)\n"
+                "U' L2 B2 U' R2 U (U2 F2 U)\n"
+                "D B2 U' L2 U (R2 U2 B2 U)\n"
+},
+[9] = {
+        .scramble = "B2 R2 U R2 U' L2 D F2 R2 U2 R2 L2 U",
+        .solutions =
+                "D B2 L2 U' L2 U R2 U\n"
+                "(L2 U R2 U' R2 U F2 U)\n"
+                "(L2 U' R2 U F2 U' R2 U)\n"
+                "D (B2 R2 U R2 U' L2 U)\n"
+                "B2 D (R2 U F2 U' L2 U)\n"
+},
+{
+        .scramble = "", /* End-of-list signal */
+}
+};
diff --git a/tools/419_solvetest_HTR_from_UD/solvetest.c b/tools/419_solvetest_HTR_from_UD/solvetest.c
new file mode 100644
index 0000000..b5de5f4
--- /dev/null
+++ b/tools/419_solvetest_HTR_from_UD/solvetest.c
@@ -0,0 +1,9 @@
+#define SOLVER       "coord_HTR_UF"
+#define NISSFLAG     NISSY_NISSFLAG_ALL
+#define MINMOVES     0
+#define MAXMOVES     20
+#define MAXSOLUTIONS 500
+#define OPTIMAL      0
+
+#include "scrambles.h"
+#include "../solvetest.h"