Basic integer arithmetic implemented exclusively using the HLSL preprocessor

gistfile1.txt

//numbers are specified by the count of braces around 8
#define C0 8
#define C1 (C0)
#define C2 (C1)
#define C3 (C2)
#define C4 (C3)
#define C5 (C4)
#define C6 (C5)
#define C7 (C6)
#define C8 (C7)
#define C9 (C8)

#define NUM(x) C##x

//------------------//

#define COUNT8 -1
#define COUNT(x) (1 + C##OUNT##x)

//------------------//

#define ID8 8
#define ID(x) x

#define DEC(x) ID##x
#define INC(x) (x)

#define NOT_0 1
#define NOT_1 0
#define NOT(x) NOT_##x

#define ISZERO_8 1
#define ISZERO_(x) 0
#define ISZERO(x) ISZERO_##x

#define ISNZERO_8 0
#define ISNZERO_(x) 1
#define ISNZERO(x) ISNZERO_##x

#define CONC(x, y) x##y
#define CONC2(x, y, z) x##y##z

#define GREATER_11(x, y) 0
#define GREATER_10(x, y) 0
#define GREATER_01(x, y) 1
#define GREATER_00(x, y) GREATER(DEC(x), DEC(y))
#define GREATER(x, y) CONC2(GREATER_, ISZERO(x), ISZERO(y))(x, y)

#define SMALLER_11(x, y) 0
#define SMALLER_10(x, y) 1
#define SMALLER_01(x, y) 0
#define SMALLER_00(x, y) SMALLER(DEC(x), DEC(y))
#define SMALLER(x, y) CONC2(SMALLER_, ISZERO(x), ISZERO(y))(x, y)

#define EQUALS_11(x, y) 1
#define EQUALS_10(x, y) 0
#define EQUALS_01(x, y) 0
#define EQUALS_00(x, y) EQUALS(DEC(x), DEC(y))
#define EQUALS(x, y) CONC2(EQUALS_, ISZERO(x), ISZERO(y))(x, y)

#define ADD_1(x, y) x
#define ADD_0(x, y) ADD(INC(x), DEC(y))
#define ADD(x, y) CONC(ADD_, ISZERO(y))(x, y)

#define SUB_1(x, y) x
#define SUB_0(x, y) SUB(DEC(x), DEC(y))
#define SUB(x, y) CONC(SUB_, ISZERO(y))(x, y)

#define MUL_1(x, y, w) w
#define MUL_0(x, y, w) MUL_S(x, DEC(y), ADD(w, x))
#define MUL_S(x, y, w) CONC(MUL_, ISZERO(y))(x, y, w)
#define MUL(x, y) MUL_S(x, y, C0)

#define DIV_1(x, y, w) w
#define DIV_0_1(x, y, w) w
#define DIV_0_0(x, y, w) DIV_S(SUB(x, y), y, INC(w))
#define DIV_0(x, y, w) CONC(DIV_0_, SMALLER(x, y))(x, y, w)
#define DIV_S(x, y, w) CONC(DIV_, ISZERO(x))(x, y, w)
#define DIV_S_1(x, y) C0
#define DIV_S_0(x, y) DIV_S(x, y, C0)
#define DIV(x, y) CONC(DIV_S_, ISZERO(y))(x, y)


// examples:
return COUNT(C4);// 1+1+1+1+1-1 (4)
return EQUALS(C1, C1);// 1
return GREATER(C2, C3);// 0
return COUNT(ADD(C3, C2));// 1+1+1+1+1+1-1 (5)
return EQUALS(SUB(C5, C8), C0);// 1
return COUNT(DIV(C6, C3));// 1+1+1-1 (2)