Replace #defines with C++ constants and inline functions in exor.h

Using `#define` for short/common names like `BPI` and `DIFFERENT` can break
the build when #included alongside unrelated code that uses those identifiers.

I have also removed the code that supports `int` sizes other than 32 bits.
There aren't any viable architectures where `int` is not 32 bits.

lib/abcesop/eabc/exor.h

@@ -52,41 +52,43 @@
 namespace abc::exorcism { 
 
 ////////////////////////////////////////////////////////////////////////
-///                       MACRO DEFINITIONS                          ///
+///                    CONSTANT DEFINITIONS                          ///
 ////////////////////////////////////////////////////////////////////////
 
-// the number of bits per integer (can be 16, 32, 64 - tested for 32)
-#define BPI                 32 
-#define BPIMASK             31 
-#define LOGBPI               5
+// the number of bits per integer
+constexpr int BPI = 32;
+constexpr int BPIMASK = 31;
+constexpr int LOGBPI = 5;
 
 // the maximum number of input variables
-#define MAXVARS           1000
+constexpr int MAXVARS = 1000;
 
 // the number of cubes that are allocated additionally
-#define ADDITIONAL_CUBES    33
+constexpr int ADDITIONAL_CUBES = 33;
 
 // the factor showing how many cube pairs will be allocated
-#define CUBE_PAIR_FACTOR    20
+constexpr int CUBE_PAIR_FACTOR = 20;
 // the following number of cube pairs are allocated:
 // nCubesAlloc/CUBE_PAIR_FACTOR
 
-#if BPI == 64
-#define DIFFERENT   0x5555555555555555
-#define BIT_COUNT(w)   (BitCount[(w)&0xffff] + BitCount[((w)>>16)&0xffff] + BitCount[((w)>>32)&0xffff] + BitCount[(w)>>48])
-#elif BPI == 32
-#define DIFFERENT   0x55555555
-#define BIT_COUNT(w)   (BitCount[(w)&0xffff] + BitCount[(w)>>16])
-#else
-#define DIFFERENT   0x5555
-#define BIT_COUNT(w)   (BitCount[(w)])
-#endif
+constexpr int DIFFERENT = 0x55555555;
 
+extern unsigned char BitCount[0x10000];
 
-#define VarWord(element)  ((element)>>LOGBPI)
-#define VarBit(element)   ((element)&BPIMASK)
+static inline int BIT_COUNT(int w) {
+  return BitCount[(w)&0xffff] + BitCount[(w)>>16];
+}
 
-#define TICKS_TO_SECONDS(time) ((float)(time)/(float)(CLOCKS_PER_SEC))
+static inline int VarWord(int element) {
+  return element >> LOGBPI;
+}
+static inline int VarBit(int element) {
+  return element & BPIMASK;
+}
+
+static inline int TICKS_TO_SECONDS(abctime time) {
+  return (float)(time)/(float)(CLOCKS_PER_SEC);
+}
 
 ////////////////////////////////////////////////////////////////////////
 ///                  CUBE COVER and CUBE typedefs                    ///