Compile-time table for find first set bit index

#define b4(x)  x, x, x, x
#define b8(x)  b4(x), b4(x)
#define b16(x) b8(x), b8(x)
#define b32(x) b16(x), b16(x)
#define b64(x) b32(x), b32(x)

#define bi2(x) 1+x, x, x
#define bi4(x) bi2(2+x), b4(1+x), b8(0+x)
#define bi8(x) bi4(4+x), b8(1+x), b16(0+x)
#define bi16(x) bi8(8+x), b16(1+x), b32(0+x)
#define bi32(x) bi16(16+x), b32(1+x), b64(0+x)

#define bim(d) {-1, bi##d(0)}


00 -1
01 1
10 0
11 0
mas2 = bim(2)

0000 -1
0001 3
0010 2
0011 2
0100 1
0101 1
0110 1
0111 1
1000 0
1001 0
1010 0
1011 0
1100 0
1101 0
1110 0
1111 0
mas4 = bim(4)

mas8 = bim(8)

mas16 = bim(16)

mas32 = bim(32)