Always use unsigned char * for data buffers

Before this commit I was inconsistently using one of void *, char *
and uint8_t *.

16 files changed, 203 insertions, 193 deletions

diff --git a/src/nissy.c b/src/nissy.c
index f744fa8..dfa1a90 100644
--- a/src/nissy.c
+++ b/src/nissy.c
@@ -14,14 +14,14 @@
 
 long long parse_h48_solver(
     const char *, uint8_t [static 1], uint8_t [static 1]);
-STATIC bool checkdata(const char *, const tableinfo_t [static 1]);
+STATIC bool checkdata(const unsigned char *, const tableinfo_t [static 1]);
 STATIC bool distribution_equal(const uint64_t [static INFO_DISTRIBUTION_LEN],
     const uint64_t [static INFO_DISTRIBUTION_LEN], uint8_t);
 STATIC long long write_result(cube_t, char [static NISSY_SIZE_B32]);
 STATIC size_t my_strnlen(const char *, size_t); 
 STATIC long long nissy_dataid(const char *, char [static NISSY_SIZE_DATAID]);
 STATIC long long nissy_gendata_unsafe(
-    const char *, unsigned long long, char *);
+    const char *, unsigned long long, unsigned char *);
 
 #define GETCUBE_OPTIONS(S, F) { .option = S, .fix = F }
 struct {
@@ -66,7 +66,7 @@ parse_h48_solver_error:
 }
 
 STATIC bool
-checkdata(const char *buf, const tableinfo_t info[static 1])
+checkdata(const unsigned char *buf, const tableinfo_t info[static 1])
 {
         uint64_t distr[INFO_DISTRIBUTION_LEN];
 
@@ -78,10 +78,10 @@ checkdata(const char *buf, const tableinfo_t info[static 1])
                 getdistribution_cocsep(
                     (uint32_t *)((char *)buf + INFOSIZE), distr);
         } else if (!strncmp(info->solver, "h48", 3)) {
-                getdistribution_h48((uint8_t *)buf + INFOSIZE, distr,
+                getdistribution_h48(buf + INFOSIZE, distr,
                     info->h48h, info->bits);
         } else if (!strncmp(info->solver, "coordinate solver for ", 22)) {
-                getdistribution_coord((uint8_t *)buf + INFOSIZE,
+                getdistribution_coord(buf + INFOSIZE,
                     info->solver + 22, distr);
         } else if (!strncmp(info->solver, "eoesep data for h48", 19)) {
                 return true;
@@ -366,7 +366,7 @@ nissy_getcube(
 long long
 nissy_datainfo(
         uint64_t data_size,
-        const char data[data_size]
+        const unsigned char data[data_size]
 )
 {
         uint8_t i;
@@ -405,8 +405,7 @@ nissy_datainfo(
         }
 
         if (info.next != 0)
-                return nissy_datainfo(
-                    data_size - info.next, (char *)data + info.next);
+                return nissy_datainfo(data_size - info.next, data + info.next);
 
         LOG("\n---------\n");
 
@@ -452,7 +451,7 @@ long long
 nissy_gendata(
         const char *solver,
         unsigned long long data_size,
-        char data[data_size]
+        unsigned char data[data_size]
 )
 {
         return nissy_gendata_unsafe(solver, data_size, data);
@@ -462,7 +461,7 @@ STATIC long long
 nissy_gendata_unsafe(
         const char *solver,
         unsigned long long data_size,
-        char *data
+        unsigned char *data
 )
 {
         long long parse_ret;
@@ -497,10 +496,9 @@ nissy_gendata_unsafe(
 long long
 nissy_checkdata(
         unsigned long long data_size,
-        const char data[data_size]
+        const unsigned char data[data_size]
 )
 {
-        char *buf;
         tableinfo_t info;
         int64_t err;
 
@@ -509,7 +507,7 @@ nissy_checkdata(
                 return NISSY_ERROR_DATA;
         }
 
-        for (buf = (char *)data;
+        for (const unsigned char *buf = data;
              (err = readtableinfo(data_size, buf, &info)) == NISSY_OK;
              buf += info.next, data_size -= info.next)
         {
@@ -537,7 +535,7 @@ nissy_solve(
         unsigned optimal,
         unsigned threads,
         unsigned long long data_size,
-        const char data[data_size],
+        const unsigned char data[data_size],
         unsigned sols_size,
         char sols[sols_size],
         long long stats[static NISSY_SIZE_SOLVE_STATS]
diff --git a/src/nissy.h b/src/nissy.h
index c23f338..a5b3015 100644
--- a/src/nissy.h
+++ b/src/nissy.h
@@ -329,7 +329,7 @@ long long
 nissy_gendata(
         const char *solver,
         unsigned long long data_size,
-        char data[data_size]
+        unsigned char data[data_size]
 );
 
 /*
@@ -347,7 +347,7 @@ Return values:
 long long
 nissy_checkdata(
         unsigned long long data_size,
-        const char data[data_size]
+        const unsigned char data[data_size]
 );
 
 /*
@@ -395,7 +395,7 @@ nissy_solve(
         unsigned optimal,
         unsigned threads,
         unsigned long long data_size,
-        const char data[data_size],
+        const unsigned char data[data_size],
         unsigned sols_size,
         char sols[sols_size],
         long long stats[static NISSY_SIZE_SOLVE_STATS]
diff --git a/src/solvers/coord/common.h b/src/solvers/coord/common.h
index 2eb5ad0..8fd405c 100644
--- a/src/solvers/coord/common.h
+++ b/src/solvers/coord/common.h
@@ -1,25 +1,29 @@
 STATIC uint64_t coord_coord_generic(
-    const coord_t [static 1], cube_t, const void *);
+    const coord_t [static 1], cube_t, const unsigned char *);
 STATIC cube_t coord_cube_generic(
-    const coord_t [static 1], uint64_t, const void *);
+    const coord_t [static 1], uint64_t, const unsigned char *);
 STATIC bool coord_isnasty_generic(
-    const coord_t [static 1], uint64_t, const void *);
-STATIC size_t coord_gendata_generic(const coord_t [static 1], void *);
+    const coord_t [static 1], uint64_t, const unsigned char *);
+STATIC size_t coord_gendata_generic(const coord_t [static 1], unsigned char *);
 
 STATIC void append_coord_name(const coord_t [static 1], char *);
 STATIC bool solution_lastqt_cw(const solution_moves_t [static 1]);
-STATIC bool coord_can_switch(
-    const coord_t [static 1], const void *, size_t n, const uint8_t [n]);
+STATIC bool coord_can_switch(const coord_t [static 1], const unsigned char *,
+    size_t n, const uint8_t [n]);
 
 STATIC uint64_t
-coord_coord_generic(const coord_t coord[static 1], cube_t c, const void *data)
+coord_coord_generic(
+        const coord_t coord[static 1],
+        cube_t c,
+        const unsigned char *data
+)
 {
-        const char *datanoinfo;
+        const unsigned char *datanoinfo;
         const uint32_t *data32;
         uint32_t d;
         cube_t tr;
 
-        datanoinfo = (const char *)data + INFOSIZE;
+        datanoinfo = data + INFOSIZE;
         data32 = (const uint32_t *)datanoinfo;
         d = data32[coord->sym.coord(c)];
         tr = transform(c, COORD_TTREP(d));
@@ -28,13 +32,17 @@ coord_coord_generic(const coord_t coord[static 1], cube_t c, const void *data)
 }
 
 STATIC cube_t
-coord_cube_generic(const coord_t coord[static 1], uint64_t i, const void *data)
+coord_cube_generic(
+        const coord_t coord[static 1],
+        uint64_t i,
+        const unsigned char *data
+)
 {
-        const char *datanoinfo;
+        const unsigned char *datanoinfo;
         const uint32_t *rep32;
         cube_t c;
 
-        datanoinfo = (const char *)data + INFOSIZE;
+        datanoinfo = data + INFOSIZE;
         rep32 = (const uint32_t *)(datanoinfo + 4 * (size_t)coord->sym.max);
         c = coord->sym.cube(rep32[i / coord->sym.max2]);
 
@@ -45,14 +53,14 @@ STATIC bool
 coord_isnasty_generic(
         const coord_t coord[static 1],
         uint64_t i,
-        const void *data
+        const unsigned char *data
 )
 {
-        const char *datanoinfo;
+        const unsigned char *datanoinfo;
         const uint32_t *classttrep, *rep32;
         uint32_t r;
 
-        datanoinfo = (const char *)data + INFOSIZE;
+        datanoinfo = data + INFOSIZE;
         classttrep = (const uint32_t *)datanoinfo;
         rep32 = (const uint32_t *)(datanoinfo + 4 * (size_t)coord->sym.max);
         r = rep32[i / coord->sym.max2];
@@ -63,11 +71,11 @@ coord_isnasty_generic(
 STATIC size_t
 coord_gendata_generic(
         const coord_t coord[static 1],
-        void *data
+        unsigned char *data
 )
 {
         uint64_t i, j, n, t, nasty;
-        char *datanoinfo;
+        unsigned char *datanoinfo;
         uint32_t *classttrep, *rep;
         size_t coord_datasize;
         cube_t c;
@@ -78,7 +86,7 @@ coord_gendata_generic(
         if (data == NULL)
                 return coord_datasize;
 
-        datanoinfo = (char *)data + INFOSIZE;
+        datanoinfo = data + INFOSIZE;
         classttrep = (uint32_t *)datanoinfo;
         rep = classttrep + coord->sym.max;
         memset(data, 0xFF, coord_datasize);
@@ -154,7 +162,7 @@ solution_lastqt_cw(const solution_moves_t s[static 1])
 STATIC bool
 coord_can_switch(
         const coord_t coord[static 1],
-        const void *data,
+        const unsigned char *data,
         size_t n,
         const uint8_t moves[n]
 )
diff --git a/src/solvers/coord/dr.h b/src/solvers/coord/dr.h
index 3bc4c6d..e197f8c 100644
--- a/src/solvers/coord/dr.h
+++ b/src/solvers/coord/dr.h
@@ -5,10 +5,10 @@ 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 void *);
-STATIC cube_t coordinate_dr_cube(uint64_t, const void *);
-STATIC bool coordinate_dr_isnasty(uint64_t, const void *);
-STATIC size_t coordinate_dr_gendata(void *);
+STATIC uint64_t coordinate_dr_coord(cube_t, const unsigned char *);
+STATIC cube_t coordinate_dr_cube(uint64_t, const unsigned char *);
+STATIC bool coordinate_dr_isnasty(uint64_t, const unsigned char *);
+STATIC size_t coordinate_dr_gendata(unsigned char *);
 
 STATIC bool is_eoco_solvable(cube_t);
 
@@ -81,25 +81,25 @@ coordinate_dr_merge(cube_t c1, cube_t c2)
 }
 
 STATIC uint64_t
-coordinate_dr_coord(cube_t cube, const void *data)
+coordinate_dr_coord(cube_t cube, const unsigned char *data)
 {
         return coord_coord_generic(&coordinate_dr, cube, data);
 }
 
 STATIC cube_t
-coordinate_dr_cube(uint64_t i, const void *data)
+coordinate_dr_cube(uint64_t i, const unsigned char *data)
 {
         return coord_cube_generic(&coordinate_dr, i, data);
 }
 
 STATIC bool
-coordinate_dr_isnasty(uint64_t i, const void *data)
+coordinate_dr_isnasty(uint64_t i, const unsigned char *data)
 {
         return coord_isnasty_generic(&coordinate_dr, i, data);
 }
 
 STATIC size_t
-coordinate_dr_gendata(void *data)
+coordinate_dr_gendata(unsigned char *data)
 {
         return coord_gendata_generic(&coordinate_dr, data);
 }
diff --git a/src/solvers/coord/dreo.h b/src/solvers/coord/dreo.h
index 37de0d3..2bc8cd1 100644
--- a/src/solvers/coord/dreo.h
+++ b/src/solvers/coord/dreo.h
@@ -4,10 +4,10 @@ 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 void *);
-STATIC cube_t coordinate_dreo_cube(uint64_t, const void *);
-STATIC bool coordinate_dreo_isnasty(uint64_t, const void *);
-STATIC size_t coordinate_dreo_gendata(void *);
+STATIC uint64_t coordinate_dreo_coord(cube_t, const unsigned char *);
+STATIC cube_t coordinate_dreo_cube(uint64_t, const unsigned char *);
+STATIC bool coordinate_dreo_isnasty(uint64_t, const unsigned char *);
+STATIC size_t coordinate_dreo_gendata(unsigned char *);
 
 STATIC bool is_dreo_solvable(cube_t);
 
@@ -63,25 +63,25 @@ coordinate_dreo_merge(cube_t c1, cube_t c2)
 }
 
 STATIC uint64_t
-coordinate_dreo_coord(cube_t cube, const void *data)
+coordinate_dreo_coord(cube_t cube, const unsigned char *data)
 {
         return coord_coord_generic(&coordinate_dreo, cube, data);
 }
 
 STATIC cube_t
-coordinate_dreo_cube(uint64_t i, const void *data)
+coordinate_dreo_cube(uint64_t i, const unsigned char *data)
 {
         return coord_cube_generic(&coordinate_dreo, i, data);
 }
 
 STATIC bool
-coordinate_dreo_isnasty(uint64_t i, const void *data)
+coordinate_dreo_isnasty(uint64_t i, const unsigned char *data)
 {
         return coord_isnasty_generic(&coordinate_dreo, i, data);
 }
 
 STATIC size_t
-coordinate_dreo_gendata(void *data)
+coordinate_dreo_gendata(unsigned char *data)
 {
         return coord_gendata_generic(&coordinate_dreo, data);
 }
diff --git a/src/solvers/coord/eo.h b/src/solvers/coord/eo.h
index a0685c4..c8faaea 100644
--- a/src/solvers/coord/eo.h
+++ b/src/solvers/coord/eo.h
@@ -1,7 +1,7 @@
-STATIC uint64_t coordinate_eo_coord(cube_t, const void *);
-STATIC cube_t coordinate_eo_cube(uint64_t, const void *);
-STATIC bool coordinate_eo_isnasty(uint64_t, const void *);
-STATIC size_t coordinate_eo_gendata(void *);
+STATIC uint64_t coordinate_eo_coord(cube_t, const unsigned char *);
+STATIC cube_t coordinate_eo_cube(uint64_t, const unsigned char *);
+STATIC bool coordinate_eo_isnasty(uint64_t, const unsigned char *);
+STATIC size_t coordinate_eo_gendata(unsigned char *);
 STATIC bool is_eo_even(cube_t);
 
 STATIC coord_t coordinate_eo = {
@@ -24,13 +24,13 @@ STATIC coord_t coordinate_eo = {
 };
 
 STATIC uint64_t
-coordinate_eo_coord(cube_t c, const void *data)
+coordinate_eo_coord(cube_t c, const unsigned char *data)
 {
         return (uint64_t)coord_eo(c);
 }
 
 STATIC cube_t
-coordinate_eo_cube(uint64_t c, const void *data)
+coordinate_eo_cube(uint64_t c, const unsigned char *data)
 {
         cube_t cube = SOLVED_CUBE;
         set_eo(&cube, (int64_t)c);
@@ -38,13 +38,13 @@ coordinate_eo_cube(uint64_t c, const void *data)
 }
 
 STATIC bool
-coordinate_eo_isnasty(uint64_t c, const void *data)
+coordinate_eo_isnasty(uint64_t c, const unsigned char *data)
 {
         return false;
 }
 
 STATIC size_t
-coordinate_eo_gendata(void *data)
+coordinate_eo_gendata(unsigned char *data)
 {
         return 0;
 }
diff --git a/src/solvers/coord/gendata.h b/src/solvers/coord/gendata.h
index ae7b39e..7a974f8 100644
--- a/src/solvers/coord/gendata.h
+++ b/src/solvers/coord/gendata.h
@@ -1,21 +1,21 @@
-STATIC size_t gendata_coord(const coord_t [static 1], void *);
-STATIC int64_t gendata_coord_dispatch(const char *, void *);
+STATIC size_t gendata_coord(const coord_t [static 1], unsigned char *);
+STATIC int64_t gendata_coord_dispatch(const char *, unsigned char *);
 STATIC tableinfo_t genptable_coord(
-    const coord_t [static 1], const void *, uint8_t *);
+    const coord_t [static 1], const unsigned char *, unsigned char *);
 STATIC bool switch_to_fromnew(uint64_t, uint64_t, uint64_t);
-STATIC uint64_t genptable_coord_fillneighbors(
-    const coord_t [static 1], const void *, uint64_t, uint8_t, uint8_t *);
-STATIC uint64_t genptable_coord_fillfromnew(
-    const coord_t [static 1], const void *, uint64_t, uint8_t, uint8_t *);
-STATIC void getdistribution_coord(
-    const uint8_t *, const char *, uint64_t [static INFO_DISTRIBUTION_LEN]);
+STATIC uint64_t genptable_coord_fillneighbors(const coord_t [static 1],
+    const unsigned char *, uint64_t, uint8_t, unsigned char *);
+STATIC uint64_t genptable_coord_fillfromnew(const coord_t [static 1],
+    const unsigned char *, uint64_t, uint8_t, unsigned char *);
+STATIC void getdistribution_coord(const unsigned char *, const char *,
+    uint64_t [static INFO_DISTRIBUTION_LEN]);
 STATIC uint8_t get_coord_pval(
-    const coord_t [static 1], const uint8_t *, uint64_t);
+    const coord_t [static 1], const unsigned char *, uint64_t);
 STATIC void set_coord_pval(
-    const coord_t [static 1], uint8_t *, uint64_t, uint8_t);
+    const coord_t [static 1], unsigned char *, uint64_t, uint8_t);
 
 STATIC int64_t
-gendata_coord_dispatch(const char *coordstr, void *buf)
+gendata_coord_dispatch(const char *coordstr, unsigned char *buf)
 {
         coord_t *coord;
 
@@ -30,14 +30,14 @@ gendata_coord_dispatch(const char *coordstr, void *buf)
 }
 
 STATIC size_t
-gendata_coord(const coord_t coord[static 1], void *buf)
+gendata_coord(const coord_t coord[static 1], unsigned char *buf)
 {
         uint64_t coord_dsize, tablesize, ninfo;
-        void *pruningbuf, *coord_data;
-        uint8_t *table;
+        unsigned char *pruningbuf, *coord_data;
+        unsigned char *table;
         tableinfo_t coord_data_info, pruning_info;
 
-        coord_data = buf == NULL ? NULL : ((uint8_t *)buf) + INFOSIZE;
+        coord_data = buf == NULL ? NULL : buf + INFOSIZE;
         coord_dsize = coord->gendata(coord_data);
         if (coord_dsize == SIZE_MAX)
                 goto gendata_coord_error;
@@ -69,12 +69,12 @@ gendata_coord(const coord_t coord[static 1], void *buf)
 
                 writetableinfo(&coord_data_info, INFOSIZE + coord_dsize, buf);
 
-                pruningbuf = ((uint8_t *)buf) + INFOSIZE + coord_dsize;
+                pruningbuf = buf + INFOSIZE + coord_dsize;
         } else {
                 pruningbuf = buf;
         }
 
-        table = ((uint8_t *)pruningbuf) + INFOSIZE;
+        table = pruningbuf + INFOSIZE;
         pruning_info = genptable_coord(coord, coord_data, table);
         writetableinfo(&pruning_info, INFOSIZE + tablesize, pruningbuf);
 
@@ -89,8 +89,8 @@ gendata_coord_error:
 STATIC tableinfo_t
 genptable_coord(
         const coord_t coord[static 1],
-        const void *data,
-        uint8_t *table
+        const unsigned char *data,
+        unsigned char *table
 )
 {
         uint64_t tablesize, i, d, tot, t, nm;
@@ -161,10 +161,10 @@ switch_to_fromnew(uint64_t done, uint64_t max, uint64_t nm)
 STATIC uint64_t
 genptable_coord_fillneighbors(
         const coord_t coord[static 1],
-        const void *data,
+        const unsigned char *data,
         uint64_t i, 
         uint8_t d,
-        uint8_t *table
+        unsigned char *table
 )
 {
         bool isnasty;
@@ -198,10 +198,10 @@ genptable_coord_fillneighbors(
 STATIC uint64_t
 genptable_coord_fillfromnew(
         const coord_t coord[static 1],
-        const void *data,
+        const unsigned char *data,
         uint64_t i,
         uint8_t d,
-        uint8_t *table
+        unsigned char *table
 )
 {
         bool found;
@@ -251,7 +251,7 @@ genptable_coord_fillfromnew(
 
 STATIC void
 getdistribution_coord(
-        const uint8_t *table,
+        const unsigned char *table,
         const char *coord,
         uint64_t distr[static INFO_DISTRIBUTION_LEN]
 )
@@ -274,7 +274,7 @@ getdistribution_coord(
 STATIC uint8_t
 get_coord_pval(
         const coord_t coord[static 1],
-        const uint8_t *table,
+        const unsigned char *table,
         uint64_t i
 )
 {
@@ -284,7 +284,7 @@ get_coord_pval(
 STATIC void
 set_coord_pval(
         const coord_t coord[static 1],
-        uint8_t *table,
+        unsigned char *table,
         uint64_t i,
         uint8_t val
 )
diff --git a/src/solvers/coord/solve.h b/src/solvers/coord/solve.h
index 072aa27..fb996ac 100644
--- a/src/solvers/coord/solve.h
+++ b/src/solvers/coord/solve.h
@@ -8,16 +8,16 @@ typedef struct {
         uint8_t nissflag;
         bool lastisnormal;
         coord_t *coord;
-        const void *coord_data;
-        const uint8_t *ptable;
+        const unsigned char *coord_data;
+        const unsigned char *ptable;
 } dfsarg_solve_coord_t;
 
 STATIC int64_t solve_coord(cube_t, coord_t [static 1], uint8_t, uint8_t,
-    uint8_t, uint8_t, uint64_t, uint8_t, uint8_t, uint64_t, const void *,
-    size_t n, char [n]);
+    uint8_t, uint8_t, uint64_t, uint8_t, uint8_t, uint64_t,
+    const unsigned char *, size_t n, char [n]);
 STATIC int64_t solve_coord_dispatch(cube_t, const char *, uint8_t, uint8_t,
-    uint8_t, uint64_t, uint8_t, uint8_t, uint64_t, const void *, size_t n,
-    char [n]);
+    uint8_t, uint64_t, uint8_t, uint8_t, uint64_t, const unsigned char *,
+    size_t n, char [n]);
 STATIC bool coord_solution_admissible(const dfsarg_solve_coord_t [static 1]);
 STATIC bool solve_coord_dfs_stop(const dfsarg_solve_coord_t [static 1]);
 STATIC bool coord_continue_onnormal(const dfsarg_solve_coord_t [static 1]);
@@ -209,7 +209,7 @@ solve_coord_dispatch(
         uint8_t optimal,
         uint8_t threads,
         uint64_t data_size,
-        const void *data,
+        const unsigned char *data,
         size_t solutions_size,
         char sols[solutions_size]
 )
@@ -248,7 +248,7 @@ solve_coord(
         uint8_t optimal,
         uint8_t threads,
         uint64_t data_size,
-        const void *data,
+        const unsigned char *data,
         size_t solutions_size,
         char sols[solutions_size]
 )
@@ -257,8 +257,8 @@ solve_coord(
         uint8_t t;
         int64_t ndepth;
         cube_t c;
-        const void *coord_data;
-        const uint8_t *ptable;
+        const unsigned char *coord_data;
+        const unsigned char *ptable;
         dfsarg_solve_coord_t arg;
         tableinfo_t info;
         solution_moves_t solution_moves;
@@ -280,11 +280,11 @@ solve_coord(
         if (info.type == TABLETYPE_PRUNING) {
                 /* Only the pruning table */
                 coord_data = NULL;
-                ptable = (uint8_t *)data + INFOSIZE;
+                ptable = data + INFOSIZE;
         } else {
                 /* Coordinate has extra data */
-                coord_data = (uint8_t *)data + INFOSIZE;
-                ptable = (uint8_t *)data + info.next + INFOSIZE;
+                coord_data = data + INFOSIZE;
+                ptable = data + info.next + INFOSIZE;
         }
 
         solution_moves_reset(&solution_moves);
diff --git a/src/solvers/coord/types_macros.h b/src/solvers/coord/types_macros.h
index 84ed8eb..2767dcc 100644
--- a/src/solvers/coord/types_macros.h
+++ b/src/solvers/coord/types_macros.h
@@ -16,10 +16,10 @@
 
 typedef struct {
         const char name[255];
-        uint64_t (*coord)(cube_t, const void *);
-        cube_t (*cube)(uint64_t, const void *);
-        bool (*isnasty)(uint64_t, const void *);
-        size_t (*gendata)(void *);
+        uint64_t (*coord)(cube_t, const unsigned char *);
+        cube_t (*cube)(uint64_t, const unsigned char *);
+        bool (*isnasty)(uint64_t, const unsigned char *);
+        size_t (*gendata)(unsigned char *);
         uint64_t max;
         uint32_t moves_mask;
         uint64_t trans_mask;
diff --git a/src/solvers/h48/gendata_cocsep.h b/src/solvers/h48/gendata_cocsep.h
index f07b71a..2eac383 100644
--- a/src/solvers/h48/gendata_cocsep.h
+++ b/src/solvers/h48/gendata_cocsep.h
@@ -1,4 +1,4 @@
-STATIC size_t gendata_cocsep(char *, uint64_t *, cube_t *);
+STATIC size_t gendata_cocsep(unsigned char *, uint64_t *, cube_t *);
 STATIC uint32_t gendata_cocsep_dfs(cocsep_dfs_arg_t [static 1]);
 STATIC void getdistribution_cocsep(
     const uint32_t [static COCSEP_TABLESIZE], uint64_t [static 21]);
@@ -13,7 +13,7 @@ STATIC_INLINE int8_t get_h48_cdata(
 
 STATIC size_t
 gendata_cocsep(
-        char *buf,
+        unsigned char *buf,
         uint64_t *selfsim,
         cube_t *rep
 )
diff --git a/src/solvers/h48/gendata_eoesep.h b/src/solvers/h48/gendata_eoesep.h
index 4bf5a84..f1e3d4c 100644
--- a/src/solvers/h48/gendata_eoesep.h
+++ b/src/solvers/h48/gendata_eoesep.h
@@ -1,7 +1,7 @@
 STATIC int64_t coord_eoesep_sym(cube_t, const uint32_t [static ESEP_MAX]);
 STATIC size_t gendata_esep_classes(
     uint32_t [static ESEP_MAX], uint16_t [static ESEP_CLASSES]);
-STATIC size_t gendata_eoesep(char *, uint8_t);
+STATIC size_t gendata_eoesep(unsigned char *, uint8_t);
 STATIC uint32_t gendata_eoesep_bfs(uint8_t, uint8_t [static EOESEP_BUF],
     uint32_t [static ESEP_MAX], uint16_t [static ESEP_CLASSES]);
 STATIC uint32_t gendata_eoesep_fromnew(uint8_t, uint8_t [static EOESEP_BUF],
@@ -14,7 +14,7 @@ STATIC bool gendata_eoesep_next(cube_t, uint8_t,
     uint8_t [static EOESEP_BUF], uint32_t [static ESEP_MAX]);
 STATIC uint8_t get_eoesep_pval(
     const uint8_t [static DIV_ROUND_UP(EOESEP_TABLESIZE, 2)], int64_t);
-STATIC uint8_t get_eoesep_pval_cube(const void *, cube_t);
+STATIC uint8_t get_eoesep_pval_cube(const unsigned char *, cube_t);
 STATIC void set_eoesep_pval(
     uint8_t [static DIV_ROUND_UP(EOESEP_TABLESIZE, 2)], int64_t, uint8_t);
 
@@ -67,9 +67,10 @@ gendata_esep_classes(
 }
 
 STATIC size_t
-gendata_eoesep(char *buf, uint8_t maxdepth)
+gendata_eoesep(unsigned char *buf, uint8_t maxdepth)
 {
-        uint8_t *buf8, d;
+        uint8_t d;
+        unsigned char *buf8;
         uint16_t rep[ESEP_CLASSES];
         uint32_t *esep_classes, done, level;
         int64_t coord;
@@ -81,7 +82,7 @@ gendata_eoesep(char *buf, uint8_t maxdepth)
         LOG("Computing eoesep data\n");
         memset(buf, 0xFF, EOESEP_FULLSIZE);
         esep_classes = (uint32_t *)(buf + INFOSIZE);
-        buf8 = (uint8_t *)(buf + INFOSIZE + 4*ESEP_MAX);
+        buf8 = buf + INFOSIZE + 4*ESEP_MAX;
         gendata_esep_classes(esep_classes, rep);
 
         info = (tableinfo_t) {
@@ -258,17 +259,13 @@ get_eoesep_pval(
 }
 
 STATIC uint8_t
-get_eoesep_pval_cube(const void *data, cube_t c)
+get_eoesep_pval_cube(const unsigned char *data, cube_t c)
 {
         int64_t coord;
-        const uint8_t *table;
-        const uint32_t *esep_classes;
 
-        esep_classes = (const uint32_t *)data;
-        table = (const uint8_t *)data + 4*ESEP_MAX;
-        coord = coord_eoesep_sym(c, esep_classes);
+        coord = coord_eoesep_sym(c, (const uint32_t *)data);
 
-        return get_eoesep_pval(table, coord);
+        return get_eoesep_pval(data + 4*ESEP_MAX, coord);
 }
 
 STATIC void
diff --git a/src/solvers/h48/gendata_h48.h b/src/solvers/h48/gendata_h48.h
index 18157dc..a878978 100644
--- a/src/solvers/h48/gendata_h48.h
+++ b/src/solvers/h48/gendata_h48.h
@@ -13,20 +13,20 @@ STATIC_INLINE bool gendata_h48k2_dfs_stop(
 STATIC void gendata_h48k2_dfs(h48k2_dfs_arg_t [static 1]);
 STATIC tableinfo_t makeinfo_h48k2(gendata_h48_arg_t [static 1]);
 STATIC void *getdistribution_h48_runthread(void *);
-STATIC void getdistribution_h48(const uint8_t *,
+STATIC void getdistribution_h48(const unsigned char *,
     uint64_t [static INFO_DISTRIBUTION_LEN], uint8_t, uint8_t);
 
-STATIC const uint32_t *get_cocsepdata_constptr(const void *);
-STATIC const uint8_t *get_h48data_constptr(const void *);
+STATIC const uint32_t *get_cocsepdata_constptr(const unsigned char *);
+STATIC const unsigned char *get_h48data_constptr(const unsigned char *);
 
-STATIC_INLINE uint8_t get_h48_pval(const uint8_t *, int64_t, uint8_t);
-STATIC_INLINE void set_h48_pval(uint8_t *, int64_t, uint8_t, uint8_t);
+STATIC_INLINE uint8_t get_h48_pval(const unsigned char *, int64_t, uint8_t);
+STATIC_INLINE void set_h48_pval(unsigned char *, int64_t, uint8_t, uint8_t);
 STATIC_INLINE uint8_t get_h48_pval_atomic(
-    _Atomic const uint8_t *, int64_t, uint8_t);
+    _Atomic const unsigned char *, int64_t, uint8_t);
 STATIC_INLINE void set_h48_pval_atomic(
-    _Atomic uint8_t *, int64_t, uint8_t, uint8_t);
+    _Atomic unsigned char *, int64_t, uint8_t, uint8_t);
 
-size_t gendata_h48_derive(uint8_t, const void *, void *);
+size_t gendata_h48_derive(uint8_t, const unsigned char *, unsigned char *);
 
 STATIC uint64_t
 gendata_h48short(gendata_h48short_arg_t arg[static 1])
@@ -67,7 +67,7 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
 {
         uint64_t size, cocsepsize, h48size, fallbacksize, fallback2size, of;
         long long r;
-        void *cocsepdata_offset;
+        unsigned char *cocsepdata_offset;
         tableinfo_t cocsepinfo, h48info, fallbackinfo;
         gendata_h48_arg_t arg_h0k4;
 
@@ -95,9 +95,9 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
 
         gendata_cocsep(arg->buf, arg->selfsim, arg->crep);
 
-        cocsepdata_offset = (char *)arg->buf + INFOSIZE;
+        cocsepdata_offset = arg->buf + INFOSIZE;
         arg->cocsepdata = (uint32_t *)cocsepdata_offset;
-        arg->h48buf = (char *)arg->buf + cocsepsize;
+        arg->h48buf = (_Atomic unsigned char*)arg->buf + cocsepsize;
 
         arg->base = 99; /* TODO: set this somewhere else */
 
@@ -136,8 +136,8 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
                 arg_h0k4.base = 0;
                 arg_h0k4.maxdepth = 20;
                 arg_h0k4.buf_size = arg->buf_size - h48size;
-                arg_h0k4.buf = (char *)arg->buf + cocsepsize + h48size;
-                arg_h0k4.h48buf = (char *)arg->h48buf + h48size;
+                arg_h0k4.buf = arg->buf + cocsepsize + h48size;
+                arg_h0k4.h48buf = arg->h48buf + h48size;
 
                 gendata_h48h0k4(&arg_h0k4);
 
@@ -145,7 +145,7 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
 
         /* Add eoesep fallback table */
 
-        gendata_eoesep((char *)arg->buf + (size - fallback2size), 20);
+        gendata_eoesep(arg->buf + (size - fallback2size), 20);
 
         /* Update tableinfo with correct next values */
 
@@ -157,7 +157,7 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
         }
         h48info.next = h48size;
         r = writetableinfo(&h48info,
-             arg->buf_size - cocsepsize, (char *)arg->buf + cocsepsize);
+             arg->buf_size - cocsepsize, arg->buf + cocsepsize);
         if (r != NISSY_OK) {
                 LOG("[H48 gendata] Error: could not write info "
                     "for h48 table\n");
@@ -174,8 +174,8 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
 
                 of = cocsepsize + h48size;
                 fallbackinfo.next = fallbacksize;
-                r = writetableinfo(&fallbackinfo,
-                    arg->buf_size - of, (char *)arg->buf + of);
+                r = writetableinfo(
+                    &fallbackinfo, arg->buf_size - of, arg->buf + of);
                 if (r != NISSY_OK) {
                         LOG("[H48 gendata] Error: could not write info for "
                             "h48 fallback table\n");
@@ -189,7 +189,7 @@ gendata_h48(gendata_h48_arg_t arg[static 1])
 STATIC void
 gendata_h48h0k4(gendata_h48_arg_t arg[static 1])
 {
-        _Atomic uint8_t *table;
+        _Atomic unsigned char *table;
         uint8_t val;
         int64_t i, sc, done, d, h48max;
         uint64_t t, tt, isize, cc, bufsize;
@@ -212,7 +212,7 @@ gendata_h48h0k4(gendata_h48_arg_t arg[static 1])
                 .next = 0,
         };
 
-        table = (_Atomic uint8_t *)arg->h48buf + INFOSIZE;
+        table = arg->h48buf + INFOSIZE;
         memset(table, 0xFF, H48_TABLESIZE(0, 4));
 
         h48max = (int64_t)H48_COORDMAX(0);
@@ -261,7 +261,7 @@ gendata_h48h0k4(gendata_h48_arg_t arg[static 1])
 
         arg->info.maxvalue = d - 1;
         bufsize = arg->buf_size - COCSEP_FULLSIZE;
-        writetableinfo(&arg->info, bufsize, arg->h48buf);
+        writetableinfo(&arg->info, bufsize, (unsigned char *)arg->h48buf);
 }
 
 STATIC void *
@@ -374,7 +374,7 @@ gendata_h48k2(gendata_h48_arg_t arg[static 1])
         };
 
         uint8_t t;
-        uint8_t *table;
+        unsigned char *table;
         int64_t j;
         uint64_t i, ii, inext, count, bufsize;
         h48map_t shortcubes;
@@ -383,7 +383,7 @@ gendata_h48k2(gendata_h48_arg_t arg[static 1])
         pthread_t thread[THREADS];
         pthread_mutex_t shortcubes_mutex, table_mutex[CHUNKS];
 
-        table = (uint8_t *)arg->h48buf + INFOSIZE;
+        table = (unsigned char *)arg->h48buf + INFOSIZE;
         memset(table, 0xFF, H48_TABLESIZE(arg->h, arg->k));
 
         LOG("[H48 gendata] Computing depth <=%" PRIu8 "\n", shortdepth)
@@ -439,7 +439,7 @@ gendata_h48k2(gendata_h48_arg_t arg[static 1])
         }
 
         bufsize = arg->buf_size - COCSEP_FULLSIZE;
-        writetableinfo(&arg->info, bufsize, arg->h48buf);
+        writetableinfo(&arg->info, bufsize, (unsigned char *)arg->h48buf);
 }
 
 STATIC void *
@@ -653,7 +653,7 @@ STATIC void *
 getdistribution_h48_runthread(void *arg)
 {
         getdistribution_h48_data_t *data = (getdistribution_h48_data_t *)arg;
-        const uint8_t *table;
+        const unsigned char *table;
         uint8_t j, k, m;
         int64_t i;
 
@@ -671,7 +671,7 @@ getdistribution_h48_runthread(void *arg)
 
 STATIC void
 getdistribution_h48(
-        const uint8_t *table,
+        const unsigned char *table,
         uint64_t distr[static INFO_DISTRIBUTION_LEN],
         uint8_t h,
         uint8_t k
@@ -708,50 +708,55 @@ getdistribution_h48(
 }
 
 STATIC const uint32_t *
-get_cocsepdata_constptr(const void *data)
+get_cocsepdata_constptr(const unsigned char *data)
 {
-        return (uint32_t *)((char *)data + INFOSIZE);
+        return (uint32_t *)(data + INFOSIZE);
 }
 
-STATIC const uint8_t *
-get_h48data_constptr(const void *data)
+STATIC const unsigned char *
+get_h48data_constptr(const unsigned char *data)
 {
-        return (uint8_t *)data + COCSEP_FULLSIZE + INFOSIZE;
+        return data + COCSEP_FULLSIZE + INFOSIZE;
 }
 
 STATIC_INLINE uint8_t
-get_h48_pval(const uint8_t *table, int64_t i, uint8_t k)
+get_h48_pval(const unsigned char *table, int64_t i, uint8_t k)
 {
         return (table[H48_INDEX(i, k)] & H48_MASK(i, k)) >> H48_SHIFT(i, k);
 }
 
 STATIC_INLINE uint8_t
-get_h48_pval_atomic(_Atomic const uint8_t *table, int64_t i, uint8_t k)
+get_h48_pval_atomic(_Atomic const unsigned char *table, int64_t i, uint8_t k)
 {
         return (table[H48_INDEX(i, k)] & H48_MASK(i, k)) >> H48_SHIFT(i, k);
 }
 
 STATIC_INLINE void
-set_h48_pval(uint8_t *table, int64_t i, uint8_t k, uint8_t val)
+set_h48_pval(unsigned char *table, int64_t i, uint8_t k, uint8_t val)
 {
         table[H48_INDEX(i, k)] = (table[H48_INDEX(i, k)] & (~H48_MASK(i, k)))
             | (val << H48_SHIFT(i, k));
 }
 
 STATIC_INLINE void
-set_h48_pval_atomic(_Atomic uint8_t *table, int64_t i, uint8_t k, uint8_t val)
+set_h48_pval_atomic(
+        _Atomic unsigned char *table,
+        int64_t i,
+        uint8_t k,
+        uint8_t val
+)
 {
         table[H48_INDEX(i, k)] = (table[H48_INDEX(i, k)] & (~H48_MASK(i, k)))
             | (val << H48_SHIFT(i, k));
 }
 
 size_t
-gendata_h48_derive(uint8_t h, const void *fulltable, void *buf)
+gendata_h48_derive(uint8_t h, const unsigned char *fulltable, unsigned char *buf)
 {
         size_t cocsepsize, h48size;
         uint8_t val_full, val_derive;
-        const uint8_t *h48full;
-        uint8_t *h48derive;
+        const unsigned char *h48full;
+        unsigned char *h48derive;
         int64_t i, j, h48max;
         uint64_t bufsize;
         gendata_h48_arg_t arg;
@@ -770,14 +775,14 @@ gendata_h48_derive(uint8_t h, const void *fulltable, void *buf)
         arg.k = fulltableinfo.bits;
         arg.maxdepth = 20;
         arg.buf = buf;
-        arg.cocsepdata = (uint32_t *)((char *)buf + INFOSIZE);
+        arg.cocsepdata = (uint32_t *)(buf + INFOSIZE);
         arg.base = fulltableinfo.base;
         arg.info = makeinfo_h48k2(&arg);
 
         /* Technically this step is redundant, except that we
            need selfsim and crep */
         cocsepsize = gendata_cocsep(buf, arg.selfsim, arg.crep);
-        arg.h48buf = (_Atomic uint8_t *)buf + cocsepsize;
+        arg.h48buf = (_Atomic unsigned char *)buf + cocsepsize;
         h48size = H48_TABLESIZE(h, arg.k) + INFOSIZE;
 
         if (buf == NULL)
@@ -798,8 +803,8 @@ gendata_h48_derive(uint8_t h, const void *fulltable, void *buf)
                 goto gendata_h48_derive_error;
         }
 
-        h48full = (const uint8_t *)fulltable + cocsepsize + INFOSIZE;
-        h48derive = (uint8_t *)arg.h48buf + INFOSIZE;
+        h48full = fulltable + cocsepsize + INFOSIZE;
+        h48derive = (unsigned char *)arg.h48buf + INFOSIZE;
         memset(h48derive, 0xFF, H48_TABLESIZE(h, arg.k));
         memset(arg.info.distribution, 0,
             INFO_DISTRIBUTION_LEN * sizeof(uint64_t));
@@ -819,7 +824,8 @@ gendata_h48_derive(uint8_t h, const void *fulltable, void *buf)
         getdistribution_h48(h48derive, arg.info.distribution, h, arg.k);
 
         bufsize = arg.buf_size - COCSEP_FULLSIZE - INFOSIZE;
-        if (writetableinfo(&arg.info, bufsize, arg.h48buf) != NISSY_OK) {
+        if (writetableinfo(&arg.info, bufsize, (unsigned char *)arg.h48buf)
+            != NISSY_OK) {
                 LOG("H48 derive gendata] Error: could not write info "
                     "for table\n");
                 goto gendata_h48_derive_error;
diff --git a/src/solvers/h48/gendata_types_macros.h b/src/solvers/h48/gendata_types_macros.h
index 3f0c666..c4b1b5a 100644
--- a/src/solvers/h48/gendata_types_macros.h
+++ b/src/solvers/h48/gendata_types_macros.h
@@ -55,7 +55,7 @@ typedef struct {
         uint8_t maxdepth;
         uint16_t *n;
         uint32_t *buf32;
-        uint8_t *visited;
+        unsigned char *visited;
         uint64_t *selfsim;
         cube_t *rep;
 } cocsep_dfs_arg_t;
@@ -67,8 +67,8 @@ typedef struct {
         uint8_t maxdepth;
         tableinfo_t info;
         uint64_t buf_size;
-        void *buf;
-        void *h48buf;
+        unsigned char *buf;
+        _Atomic unsigned char *h48buf;
         uint32_t *cocsepdata;
         uint64_t selfsim[COCSEP_CLASSES];
         cube_t crep[COCSEP_CLASSES];
@@ -85,7 +85,7 @@ typedef struct {
 typedef struct {
         uint8_t depth;
         uint32_t *cocsepdata;
-        _Atomic uint8_t *table;
+        _Atomic unsigned char *table;
         uint64_t *selfsim;
         cube_t *crep;
         uint64_t start;
@@ -100,7 +100,7 @@ typedef struct {
         uint8_t base;
         uint8_t shortdepth;
         uint32_t *cocsepdata;
-        uint8_t *table;
+        unsigned char *table;
         uint64_t *selfsim;
         cube_t *crep;
         h48map_t *shortcubes;
@@ -117,8 +117,8 @@ typedef struct {
         uint8_t k;
         uint32_t *cocsepdata;
         uint64_t *selfsim;
-        uint8_t *table;
-        _Atomic uint8_t *table_atomic;
+        unsigned char *table;
+        _Atomic unsigned char *table_atomic;
         pthread_mutex_t **table_mutex;
 } gendata_h48_mark_t;
 
@@ -127,5 +127,5 @@ typedef struct {
         int64_t max;
         uint8_t k;
         uint64_t *distr;
-        const uint8_t *table;
+        const unsigned char *table;
 } getdistribution_h48_data_t;
diff --git a/src/solvers/h48/solve.h b/src/solvers/h48/solve.h
index 0fd419d..cf7095c 100644
--- a/src/solvers/h48/solve.h
+++ b/src/solvers/h48/solve.h
@@ -22,9 +22,9 @@ typedef struct {
         uint8_t k;
         uint8_t base;
         const uint32_t *cocsepdata;
-        const uint8_t *h48data;
-        const uint8_t *h48data_fallback_h0k4;
-        const void *h48data_fallback_eoesep;
+        const unsigned char *h48data;
+        const unsigned char *h48data_fallback_h0k4;
+        const unsigned char *h48data_fallback_eoesep;
         uint32_t movemask_normal;
         uint32_t movemask_inverse;
         int64_t nodes_visited;
@@ -53,7 +53,7 @@ STATIC int64_t solve_h48_maketasks(
 STATIC void *solve_h48_runthread(void *);
 STATIC int64_t solve_h48_dfs(dfsarg_solve_h48_t [static 1]);
 STATIC int64_t solve_h48(cube_t, uint8_t, uint8_t, uint8_t, uint8_t, uint8_t,
-    uint64_t, const void *, size_t n, char [n],
+    uint64_t, const unsigned char *, size_t n, char [n],
     long long [static NISSY_SIZE_SOLVE_STATS]);
 
 STATIC_INLINE bool
@@ -349,7 +349,7 @@ solve_h48(
         uint8_t optimal,
         uint8_t threads,
         uint64_t data_size,
-        const void *data,
+        const unsigned char *data,
         size_t solutions_size,
         char solutions[solutions_size],
         long long stats[static NISSY_SIZE_SOLVE_STATS]
@@ -365,8 +365,8 @@ solve_h48(
         int64_t nodes_visited, table_lookups, table_fallbacks;
         tableinfo_t info, fbinfo, fbinfo2;
         const uint32_t *cocsepdata;
-        const uint8_t *fallback, *h48data;
-        const void *fallback2;
+        const unsigned char *fallback, *h48data;
+        const unsigned char *fallback2;
         solution_moves_t solution_moves[THREADS];
         solution_settings_t settings;
         solution_list_t sollist;
@@ -379,8 +379,8 @@ solve_h48(
         if (readtableinfo_n(data_size, data, 2, &info) != NISSY_OK)
                 goto solve_h48_error_data;
 
-        cocsepdata = (uint32_t *)((char *)data + INFOSIZE);
-        h48data = (uint8_t *)data + COCSEP_FULLSIZE + INFOSIZE;
+        cocsepdata = (uint32_t *)(data + INFOSIZE);
+        h48data = data + COCSEP_FULLSIZE + INFOSIZE;
 
         /* Read fallback table(s) */
         fallback = NULL;
diff --git a/src/solvers/tables.h b/src/solvers/tables.h
index db888b5..9147972 100644
--- a/src/solvers/tables.h
+++ b/src/solvers/tables.h
@@ -1,13 +1,14 @@
-STATIC uint64_t read_unaligned_u64(const char [static sizeof(uint64_t)]);
-STATIC void write_unaligned_u64(char [static sizeof(uint64_t)], uint64_t);
-STATIC int64_t readtableinfo(size_t n, const char [n], tableinfo_t [static 1]);
+STATIC uint64_t read_unaligned_u64(const unsigned char [static sizeof(uint64_t)]);
+STATIC void write_unaligned_u64(unsigned char [static sizeof(uint64_t)], uint64_t);
+STATIC int64_t readtableinfo(
+    size_t n, const unsigned char [n], tableinfo_t [static 1]);
 STATIC int64_t readtableinfo_n(
-    size_t n, const char [n], uint8_t, tableinfo_t [static 1]);
+    size_t n, const unsigned char [n], uint8_t, tableinfo_t [static 1]);
 STATIC int64_t writetableinfo(
-    const tableinfo_t [static 1], size_t n, char [n]);
+    const tableinfo_t [static 1], size_t n, unsigned char [n]);
 
 STATIC uint64_t
-read_unaligned_u64(const char buf[static sizeof(uint64_t)])
+read_unaligned_u64(const unsigned char buf[static sizeof(uint64_t)])
 {
         uint64_t ret;
 
@@ -17,7 +18,7 @@ read_unaligned_u64(const char buf[static sizeof(uint64_t)])
 }
 
 STATIC void
-write_unaligned_u64(char buf[static sizeof(uint64_t)], uint64_t x)
+write_unaligned_u64(unsigned char buf[static sizeof(uint64_t)], uint64_t x)
 {
         memcpy(buf, &x, sizeof(uint64_t));
 }
@@ -25,7 +26,7 @@ write_unaligned_u64(char buf[static sizeof(uint64_t)], uint64_t x)
 STATIC int64_t
 readtableinfo(
         size_t buf_size,
-        const char buf[buf_size],
+        const unsigned char buf[buf_size],
         tableinfo_t info[static 1]
 )
 {
@@ -69,7 +70,7 @@ readtableinfo(
 STATIC int64_t
 readtableinfo_n(
         size_t buf_size,
-        const char buf[buf_size],
+        const unsigned char buf[buf_size],
         uint8_t n,
         tableinfo_t info[static 1]
 )
@@ -87,12 +88,12 @@ STATIC int64_t
 writetableinfo(
         const tableinfo_t info[static 1],
         size_t data_size,
-        char buf[data_size]
+        unsigned char buf[data_size]
 )
 {
         size_t i;
         bool end;
-        char *c;
+        unsigned char *c;
 
         if (data_size < info->fullsize) {
                 LOG("Error writing table: buffer size is too small "
@@ -125,10 +126,10 @@ writetableinfo(
                         *c = 0;
         }
 
-        *(uint8_t *)OFFSET(buf, INFO_OFFSET_H48H) = info->h48h;
-        *(uint8_t *)OFFSET(buf, INFO_OFFSET_BITS) = info->bits;
-        *(uint8_t *)OFFSET(buf, INFO_OFFSET_BASE) = info->base;
-        *(uint8_t *)OFFSET(buf, INFO_OFFSET_MAXVALUE) = info->maxvalue;
+        *OFFSET(buf, INFO_OFFSET_H48H) = (unsigned char)info->h48h;
+        *OFFSET(buf, INFO_OFFSET_BITS) = (unsigned char)info->bits;
+        *OFFSET(buf, INFO_OFFSET_BASE) = (unsigned char)info->base;
+        *OFFSET(buf, INFO_OFFSET_MAXVALUE) = (unsigned char)info->maxvalue;
 
         return NISSY_OK;
 }
diff --git a/src/solvers/tables_types_macros.h b/src/solvers/tables_types_macros.h
index 465bed1..3db2d25 100644
--- a/src/solvers/tables_types_macros.h
+++ b/src/solvers/tables_types_macros.h
@@ -1,4 +1,4 @@
-#define OFFSET(B, K)             (((char *)B) + K)
+#define OFFSET(B, K)             (((unsigned char *)B) + K)
 
 #define INFOSIZE                 INT64_C(512)
 #define INFO_SOLVER_STRLEN       INT64_C(100)