D programming Language

intrinsic

int bsf(uint v)

Scans the bits in v starting with bit 0, looking for the first set bit.

int bsr(uint v)

Scans the bits in v from the most significant bit to the least significant bit, looking for the first set bit.

Both return the bit number of the first set bit. The return value is undefined if v is zero.

import intrinsic;

{

int x;
v = 0x21;

x = bsf(v);

printf("bsf(x%x) = %d\n", v, x);

x = bsr(v);

printf("bsr(x%x) = %d\n", v, x);

return 0;

}

bsf(x21) = 0

bsr(x21) = 5

int bt(uint *p, uint index)

Tests the bit.

int btc(uint *p, uint index)

Tests and complements the bit.

int btr(uint *p, uint index)

Tests and resets (sets to 0) the bit.

int bts(uint *p, uint index)

Tests and sets the bit.

p is a non-NULL pointer to an array of uints. index is a bit number, starting with bit 0 of p[0], and progressing. It addresses bits like the expression:

p[index / (uint.size*8)] & (1 << (index & ((uint.size*8) - 1)))

All return a non-zero value if the bit was set, and a zero if it was clear.

Example

import intrinsic;

{

array[1] = 0x100;

printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);

printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);

printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);

printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);

printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);

}
Output

btc(array, 35) = 0

array = [0]:x2, [1]:x108

btc(array, 35) = -1

array = [0]:x2, [1]:x100

bts(array, 35) = 0

array = [0]:x2, [1]:x108

btr(array, 35) = -1

array = [0]:x2, [1]:x100

bt(array, 1) = -1

array = [0]:x2, [1]:x100

ubyte inp(uint port_address)

ushort inpw(uint port_address)

uint inpl(uint port_address)

Reads I/O port at port_address.

ubyte outp(uint port_address, ubyte value)

ushort outpw(uint port_address, ushort value)

uint outpl(uint port_address, uint value)

Writes and returns value to I/O port at port_address.

real cos(real)

real fabs(real)

real rint(real)

long rndtol(real)

real sin(real)

real sqrt(real)

Intrinsic verions of the math functions of the same name.

math

const real LOG2

const real LN2

const real LOG2T

const real LOG2E

const real E

const real LOG10E

const real LN10

const real PI_2

const real PI_4

const real M_1_PI

const real M_2_PI

const real M_2_SQRTPI

const real SQRT2

const real SQRT1_2

Math constants.

real acos(real)

real asin(real)

real atan(real)

real atan2(real, real)

real cos(real x)

Compute cosine of x. x is in radians.

x	return value	invalid?
±INFINITY	NAN	yes

Compute sine of x. x is in radians.

x	return value	invalid?
±0.0	±0.0	no
±INFINITY	NAN	yes

Compute tangent of x. x is in radians.

x	return value	invalid?
±0.0	±0.0	no
±INFINITY	NAN	yes

real sinh(real)

real tanh(real)

real exp(real)

real frexp(real value, out int exp)

Calculate and return x and exp such that:

value	x	exp
+-0.0	+-0.0	0
+INFINITY	+INFINITY	int.max
-INFINITY	-INFINITY	int.min
+-NAN	+-NAN	int.min

Compute n * 2^exp

real log(real x)

Calculate the natural logarithm of x.

x	return value	divide by 0?	invalid?
±0.0	-INFINITY	yes	no
< 0.0	NAN	no	yes
+INFINITY	+INFINITY	no	no

Calculate the base-10 logarithm of x.

x	return value	divide by 0?	invalid?
±0.0	-INFINITY	yes	no
< 0.0	NAN	no	yes
+INFINITY	+INFINITY	no	no

real pow(real, real)

real sqrt(real x)

Compute square root of x.

x	return value	invalid?
-0.0	-0.0	no
<0.0	NAN	yes
+INFINITY	+INFINITY	no

real floor(real)

real log1p(real x)

Calculates the natural logarithm of 1 + x. For very small x, log1p(x) will be more accurate than log(1 + x).

x	log1p(x)	divide by 0?	invalid?
±0.0	±0.0	no	no
-1.0	-INFINITY	yes	no
<-1.0	NAN	no	yes
+INFINITY	-INFINITY	no	no

Calculates the value of the natural logarithm base (e) raised to the power of x, minus 1. For very small x, expm1(x) is more accurate than exp(x)-1.

x	ex-1
±0.0	±0.0
+INFINITY	+INFINITY
-INFINITY	-1.0

Math functions.

real hypot(real x, real y)

Calculates the length of the hypotenuse of a right-angled triangle with sides of length x and y. The hypotenuse is the value of the square root of the sums of the squares of x and y:

sqrt(x² + y²)

Note that hypot(x,y), hypot(y,x) and hypot(x,-y) are equivalent.

x	y	return value	invalid?
x	+-0.0	fabs(x)	no
+-INFINITY	y	+INFINITY	no
+-INFINITY	NAN	+INFINITY	no

Is number a nan?

int isfinite(real e)

Is number finite?

int isnormal(float f)

int isnormal(double d)

int isnormal(real e)

Is number normalized?

int issubnormal(float f)

int issubnormal(double d)

int issubnormal(real e)

Is number subnormal? (Also called "denormal".) Subnormals have a 0 exponent and a 0 most significant mantissa bit.

int isinf(real e)

Is number infinity?

int signbit(real e)

Get sign bit.

real copysign(real to, real from)

Copy sign.