diff --git a/bn_mp_complement.c b/bn_mp_complement.c
index 256ddea..9dfddc3 100644
--- a/bn_mp_complement.c
+++ b/bn_mp_complement.c
@@ -17,7 +17,7 @@
 int mp_complement(const mp_int *a, mp_int *b)
 {
    int res = mp_neg(a, b);
-   return res == MP_OKAY ? mp_sub_d(b, 1, b) : res;
+   return (res == MP_OKAY) ? mp_sub_d(b, 1uL, b) : res;
 }
 #endif
 
diff --git a/bn_mp_tc_and.c b/bn_mp_tc_and.c
index 0e28ca8..e9fe4c6 100644
--- a/bn_mp_tc_and.c
+++ b/bn_mp_tc_and.c
@@ -17,12 +17,12 @@
 int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c)
 {
    int res = MP_OKAY, bits;
-   int as = mp_isneg(a), bs = mp_isneg(b), s = 0;
-   mp_int *mx = 0, _mx, acpy, bcpy;
+   int as = mp_isneg(a), bs = mp_isneg(b);
+   mp_int *mx = NULL, _mx, acpy, bcpy;
 
-   if (as || bs) {
+   if ((as != MP_NO) || (bs != MP_NO)) {
       bits = MAX(mp_count_bits(a), mp_count_bits(b));
-      res = mp_init_set_int(&_mx, 1);
+      res = mp_init_set_int(&_mx, 1uL);
       if (res != MP_OKAY) {
          goto end;
       }
@@ -33,7 +33,7 @@ int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c)
          goto end;
       }
 
-      if (as) {
+      if (as != MP_NO) {
          res = mp_init(&acpy);
          if (res != MP_OKAY) {
             goto end;
@@ -46,7 +46,7 @@ int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c)
          }
          a = &acpy;
       }
-      if (bs) {
+      if (bs != MP_NO) {
          res = mp_init(&bcpy);
          if (res != MP_OKAY) {
             goto end;
@@ -62,9 +62,8 @@ int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c)
    }
 
    res = mp_and(a, b, c);
-   s = as & bs;
 
-   if (s && res == MP_OKAY) {
+   if ((as != MP_NO) && (bs != MP_NO) && (res == MP_OKAY)) {
       res = mp_sub(c, mx, c);
    }
 
diff --git a/bn_mp_tc_div_2d.c b/bn_mp_tc_div_2d.c
index 5ea4e38..3c617ef 100644
--- a/bn_mp_tc_div_2d.c
+++ b/bn_mp_tc_div_2d.c
@@ -17,17 +17,17 @@
 int mp_tc_div_2d(const mp_int *a, int b, mp_int *c)
 {
   int res;
-  if (!mp_isneg(a)) {
-    return mp_div_2d(a, b, c, 0);
+  if (mp_isneg(a) == MP_NO) {
+    return mp_div_2d(a, b, c, NULL);
   }
 
-  res = mp_add_d(a, 1, c);
+  res = mp_add_d(a, 1uL, c);
   if (res != MP_OKAY) {
     return res;
   }
 
-  res = mp_div_2d(c, b, c, 0);
-  return res == MP_OKAY ? mp_sub_d(c, 1, c) : res;
+  res = mp_div_2d(c, b, c, NULL);
+  return (res == MP_OKAY) ? mp_sub_d(c, 1uL, c) : res;
 }
 #endif
 
diff --git a/bn_mp_tc_or.c b/bn_mp_tc_or.c
index 1e7d583..91b6b40 100644
--- a/bn_mp_tc_or.c
+++ b/bn_mp_tc_or.c
@@ -17,12 +17,12 @@
 int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c)
 {
    int res = MP_OKAY, bits;
-   int as = mp_isneg(a), bs = mp_isneg(b), s = 0;
-   mp_int *mx = 0, _mx, acpy, bcpy;
+   int as = mp_isneg(a), bs = mp_isneg(b);
+   mp_int *mx = NULL, _mx, acpy, bcpy;
 
-   if (as || bs) {
+   if ((as != MP_NO) || (bs != MP_NO)) {
       bits = MAX(mp_count_bits(a), mp_count_bits(b));
-      res = mp_init_set_int(&_mx, 1);
+      res = mp_init_set_int(&_mx, 1uL);
       if (res != MP_OKAY) {
          goto end;
       }
@@ -33,7 +33,7 @@ int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c)
          goto end;
       }
 
-      if (as) {
+      if (as != MP_NO) {
          res = mp_init(&acpy);
          if (res != MP_OKAY) {
             goto end;
@@ -46,7 +46,7 @@ int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c)
          }
          a = &acpy;
       }
-      if (bs) {
+      if (bs != MP_NO) {
          res = mp_init(&bcpy);
          if (res != MP_OKAY) {
             goto end;
@@ -62,9 +62,8 @@ int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c)
    }
 
    res = mp_or(a, b, c);
-   s = as | bs;
 
-   if (s && res == MP_OKAY) {
+   if (((as != MP_NO) || (bs != MP_NO)) && (res == MP_OKAY)) {
       res = mp_sub(c, mx, c);
    }
 
diff --git a/bn_mp_tc_xor.c b/bn_mp_tc_xor.c
index be9b9d8..50fb12d 100644
--- a/bn_mp_tc_xor.c
+++ b/bn_mp_tc_xor.c
@@ -17,12 +17,12 @@
 int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c)
 {
    int res = MP_OKAY, bits;
-   int as = mp_isneg(a), bs = mp_isneg(b), s = 0;
-   mp_int *mx = 0, _mx, acpy, bcpy;
+   int as = mp_isneg(a), bs = mp_isneg(b);
+   mp_int *mx = NULL, _mx, acpy, bcpy;
 
-   if (as || bs) {
+   if ((as != MP_NO) || (bs != MP_NO)) {
       bits = MAX(mp_count_bits(a), mp_count_bits(b));
-      res = mp_init_set_int(&_mx, 1);
+      res = mp_init_set_int(&_mx, 1uL);
       if (res != MP_OKAY) {
          goto end;
       }
@@ -33,7 +33,7 @@ int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c)
          goto end;
       }
 
-      if (as) {
+      if (as != MP_NO) {
          res = mp_init(&acpy);
          if (res != MP_OKAY) {
             goto end;
@@ -46,7 +46,7 @@ int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c)
          }
          a = &acpy;
       }
-      if (bs) {
+      if (bs != MP_NO) {
          res = mp_init(&bcpy);
          if (res != MP_OKAY) {
             goto end;
@@ -62,9 +62,8 @@ int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c)
    }
 
    res = mp_xor(a, b, c);
-   s = as ^ bs;
 
-   if (s && res == MP_OKAY) {
+   if ((as != bs) && (res == MP_OKAY)) {
       res = mp_sub(c, mx, c);
    }