remove endianness argument from setup_table()

Author: ilanschnell

bitarray/_bitarray.c

@@ -4278,7 +4278,7 @@ PyInit__bitarray(void)
 
     /* setup translation table, which maps each byte to its reversed:
        reverse_trans = {0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, ..., 0xff} */
-    setup_table(reverse_trans, 0, 'r');
+    setup_table(reverse_trans, 'r');
 
     if ((m = PyModule_Create(&moduledef)) == NULL)
         return NULL;

bitarray/_util.c

@@ -295,7 +295,7 @@ sum_indices(PyObject *module, PyObject *obj)
     set_padbits(a);
 
     if (setup != a->endian) {
-        setup_table(table, IS_LE(a), 'a');
+        setup_table(table, IS_LE(a) ? 'a' : 'A');
         setup = a->endian;
     }
 
@@ -341,7 +341,7 @@ xor_indices(PyObject *module, PyObject *obj)
     set_padbits(a);
 
     if (setup != a->endian) {
-        setup_table(table, IS_LE(a), 'x');
+        setup_table(table, IS_LE(a) ? 'x' : 'X');
         setup = a->endian;
     }
 

bitarray/bitarray.h

@@ -225,20 +225,21 @@ swap_bytes(char *p, Py_ssize_t n)
     }
 }
 
-/* write 256 characters into table for given endianness, kernel operation */
+/* write 256 characters into table for given kernel operation */
 static inline void
-setup_table(char *table, int le, char kop)
+setup_table(char *table, char kop)
 {
     int j, k;
     for (k = 0; k < 256; k++) {
         table[k] = 0;
         for (j = 0; j < 8; j++) {
-            if (( le && k & 0x01 << j) ||  /* little endian */
-                (!le && k & 0x80 >> j))    /* big endian */
+            if (k & 1 << j)
                 switch (kop) {
-                case 'a': table[k] += j; break;
-                case 'x': table[k] ^= j; break;
-                case 'r': table[k] |= 1 << j; break;
+                case 'a': table[k] += j;        break;
+                case 'A': table[k] += 7 - j;    break;
+                case 'x': table[k] ^= j;        break;
+                case 'X': table[k] ^= 7 - j;    break;
+                case 'r': table[k] |= 128 >> j; break;
                 default: Py_UNREACHABLE();
                 }
         }