math.h File Reference

Math helper macros. More...

Detailed Description

Math helper macros.

Author

Benjamin Valentin benja.nosp@m.min..nosp@m.valen.nosp@m.tin@.nosp@m.ml-pa.nosp@m..com

Definition in file math.h.

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#define	SIGNOF(a)
	Returns the sign of a, either -1 or 1.
#define	DIV_ROUND(a, b)
	Calculates a/ b with arithmetic rounding (.5 away from zero)
#define	DIV_ROUND_UP(a, b)
	Calculates a/ b, always rounding up (towards positive infinity)
#define	DIV_ROUND_INF(a, b)
	Calculates a/ b, always rounding away from zero (towards positive and negative inf)
#define	MATH_ALIGN(num, chunk)
	Align num with the next multiple of chunk.

Macro Definition Documentation

DIV_ROUND

#define DIV_ROUND	(		a,
			b )

Value:

((SIGNOF(a) * ((SIGNOF(a) * (a)) + (SIGNOF(b) * (b)) / 2) / (b)))

Calculates a/ b with arithmetic rounding (.5 away from zero)

Definition at line 37 of file math.h.

DIV_ROUND_INF

#define DIV_ROUND_INF	(		a,
			b )

Value:

(SIGNOF(a) * (((SIGNOF(a) * (a)) + (SIGNOF(b) * (b)) - 1) / (b)))

Calculates a/ b, always rounding away from zero (towards positive and negative inf)

Definition at line 48 of file math.h.

DIV_ROUND_UP

#define DIV_ROUND_UP	(		a,
			b )

Value:

                            ((SIGNOF(a)>0 && SIGNOF(b)>0) ? (((a) + (b) - 1) / (b)):\
                            (SIGNOF(a)<0 && SIGNOF(b)<0) ? (((a) + (b) + 1) / (b)): (a) / (b))

Calculates a/ b, always rounding up (towards positive infinity)

Definition at line 42 of file math.h.

MATH_ALIGN

#define MATH_ALIGN	(		num,
			chunk )

Value:

((chunk) * DIV_ROUND_INF(num, chunk))

Align num with the next multiple of chunk.

Definition at line 53 of file math.h.

SIGNOF

#define SIGNOF

(

a

)

Value:

                              _Generic(a, unsigned char: 1,          \
                              unsigned short: 1,         \
                              unsigned int: 1,           \
                              unsigned long: 1,          \
                              unsigned long long: 1,     \
                              default: ((a) <= 0 ? ((a) == 0 ? 1L : -1L ): 1L))

Returns the sign of a, either -1 or 1.

Definition at line 28 of file math.h.