第七章：定点数算数. 更多...

宏定义
#define	INC_TEX_MATH
	PART 7: ARITHMETIC WITH SCALED DIMENSIONS. 更多...

#define	UNITY 65536L
	[#101] 2^{16}, rep 1.00000 更多...

#define	TWO 131072L
	[#101] 2^{17}, rep 2.00000 更多...

#define	INF_BAD 10000
	[#108]: infinitely bad value 更多...

#define	nx_plus_y(n, x, y) mult_and_add((n), (x), (y), 07777777777L)
	[105] 455, 716, 1240. 更多...

#define	mult_integers(n, x) mult_and_add((n), (x), 0, 017777777777L)
	[105] 1240. 更多...

函数
Integer	half (Integer x)
	[#100] 整除 2 更多...

Scaled	round_decimals (SmallNumber k, char digs[])
	[#102]: create a scaled integer from a given decimal fraction. 更多...

void	print_scaled (Scaled s)
	[#103]: prints scaled real, rounded to five digits 更多...

Scaled	mult_and_add (Integer n, Scaled x, Scaled y, Scaled max_ans)
	[#105]: return `nx + y` 更多...

Scaled	x_over_n (Scaled x, Integer n)
	[#106]: `x / n` 更多...

Scaled	xn_over_d (Scaled x, Integer n, Integer d)
	[#107]: `x * (n / d)` 更多...

HalfWord	badness (Scaled t, Scaled s)
	[#108]: compute the “badness” of glue. 更多...

变量
Boolean	arith_error = false
	[#104] has arithmetic overflow occurred recently? 更多...

Scaled	tex_remainder = 0
	[#104] amount subtracted to get an exact division 更多...

详细描述

第七章：定点数算数.

export:

Boolean arith_error
Scaled tex_remainder
Integer half(Integer x)
Scaled round_decimals(SmallNumber k, char digs[])
Scaled mult_and_add(Integer n, Scaled x, Scaled y, Scaled max_ans)
Scaled x_over_n(Scaled x, Integer n)
Scaled xn_over_d(Scaled x, Integer n, Integer d)
HalfWord badness(Scaled t, Scaled s)
void print_scaled(Scaled s)

宏定义说明

◆ INC_TEX_MATH

#define INC_TEX_MATH

PART 7: ARITHMETIC WITH SCALED DIMENSIONS.

◆ INF_BAD

#define INF_BAD 10000

[#108]: infinitely bad value

◆ mult_integers

#define mult_integers	(	n,
		x
	)	mult_and_add((n), (x), 0, 017777777777L)

[105] 1240.

Note: 017777777777L == 2147483647L

◆ nx_plus_y

#define nx_plus_y	(	n,
		x,
		y
	)	mult_and_add((n), (x), (y), 07777777777L)

[105] 455, 716, 1240.

Note: 07777777777L == 1073741823L

◆ TWO

#define TWO 131072L

[#101] 2^{17}, rep 2.00000

◆ UNITY

#define UNITY 65536L

[#101] 2^{16}, rep 1.00000

函数说明

◆ badness()

HalfWord badness	(	Scaled	t,
		Scaled	s
	)

[#108]: compute the “badness” of glue.

given t >= 0 when a total t is supposed to be made from amounts that sum to s.

badness = 100 * (t/s)^3
badness(t + 1,s) ≥ badness(t,s) ≥ badness(t,s + 1)

◆ half()

Integer half ( Integer x )

[#100] 整除 2

◆ mult_and_add()

Scaled mult_and_add	(	Integer	n,
		Scaled	x,
		Scaled	y,
		Scaled	max_ans
	)

[#105]: return nx + y

◆ print_scaled()

void print_scaled ( Scaled s )

[#103]: prints scaled real, rounded to five digits

◆ round_decimals()

Scaled round_decimals	(	SmallNumber	k,
		char	digs[]
	)

[#102]: create a scaled integer from a given decimal fraction.

{ dig[i], | i = k-1, 0 ≤ k ≤ 17 }

◆ x_over_n()

Scaled x_over_n	(	Scaled	x,
		Integer	n
	)

[#106]: x / n

◆ xn_over_d()

Scaled xn_over_d	(	Scaled	x,
		Integer	n,
		Integer	d
	)

[#107]: x * (n / d)

变量说明

◆ arith_error

Boolean arith_error = false

[#104] has arithmetic overflow occurred recently?

◆ tex_remainder

Scaled tex_remainder = 0

[#104] amount subtracted to get an exact division