Sigrid Solveig Haflínudóttiruse Plan 9 naming of integer types22b11e51 year agoHistory
216 lines · 3.3 KB · C
RawDownload
#include "platform.h"#include "mp.h" static mpdigit _mptwodata[1] = { 2 };static mpint _mptwo ={	_mptwodata,	1, 1, 1,	MPstatic|MPnorm};mpint *mptwo = &_mptwo; static mpdigit _mponedata[1] = { 1 };static mpint _mpone ={	_mponedata,	1, 1, 1,	MPstatic|MPnorm};mpint *mpone = &_mpone; static mpdigit _mpzerodata[1] = { 0 };static mpint _mpzero ={	_mpzerodata,	1, 0, 1,	MPstatic|MPnorm};mpint *mpzero = &_mpzero; static int mpmindigits = 33; // set minimum digit allocationvoidmpsetminbits(int n){	if(n < 0){		fprintf(stderr, "mpsetminbits: n < 0\n");		exit(2);	}	if(n == 0)		n = 1;	mpmindigits = DIGITS(n);} // allocate an n bit 0'd numbermpint*mpnew(int n){	mpint *b; 	if(n < 0){		fprintf(stderr, "mpnew: n < 0\n");		exit(2);	} 	n = DIGITS(n);	if(n < mpmindigits)		n = mpmindigits;	b = MEM_CALLOC(1, sizeof(mpint) + n*Dbytes);	if(b == nil){		fprintf(stderr, "mpnew: no memory\n");		exit(2);	}	b->p = (mpdigit*)&b[1];	b->size = n;	b->sign = 1;	b->flags = MPnorm; 	return b;} // guarantee at least m significant bitsvoidmpbits(mpint *b, int m){	u32int n; 	n = DIGITS(m);	if(b->size >= n){		if(b->top >= n)			return;	} else {		if(b->p == (mpdigit*)&b[1]){			b->p = (mpdigit*)MEM_ALLOC(n*Dbytes);			if(b->p == nil){				fprintf(stderr, "mpbits: no memory\n");				exit(2);			}			memmove(b->p, &b[1], Dbytes*b->top);			memset(&b[1], 0, Dbytes*b->size);		} else {			b->p = (mpdigit*)MEM_REALLOC(b->p, n*Dbytes);			if(b->p == nil){				fprintf(stderr, "mpbits: no memory\n");				exit(2);			}		}		b->size = n;	}	memset(&b->p[b->top], 0, Dbytes*(n - b->top));	b->top = n;	b->flags &= ~MPnorm;} voidmpfree(mpint *b){	if(b == nil)		return;	if(b->flags & MPstatic){		fprintf(stderr, "freeing mp constant\n");		exit(2);	}	memset(b->p, 0, b->size*Dbytes);	if(b->p != (mpdigit*)&b[1])		MEM_FREE(b->p);	MEM_FREE(b);} mpint*mpnorm(mpint *b){	int i; 	if(b->flags & MPtimesafe){		assert(b->sign == 1);		b->flags &= ~MPnorm;		return b;	}	for(i = b->top-1; i >= 0; i--)		if(b->p[i] != 0)			break;	b->top = i+1;	if(b->top == 0)		b->sign = 1;	b->flags |= MPnorm;	return b;} mpint*mpcopy(mpint *old){	mpint *new; 	new = mpnew(Dbits*old->size);	new->sign = old->sign;	new->top = old->top;	new->flags = old->flags & ~(MPstatic);	memmove(new->p, old->p, Dbytes*old->top);	return new;} voidmpassign(mpint *old, mpint *new){	if(new == nil || old == new)		return;	new->top = 0;	mpbits(new, Dbits*old->top);	new->sign = old->sign;	new->top = old->top;	new->flags &= ~MPnorm;	new->flags |= old->flags & ~(MPstatic);	memmove(new->p, old->p, Dbytes*old->top);} // number of significant bits in mantissau32intmpsignif(mpint *n){	int i, j;	mpdigit d; 	if(n->top == 0)		return 0;	for(i = n->top-1; i >= 0; i--){		d = n->p[i];		for(j = Dbits-1; j >= 0; j--){			if(d & (((mpdigit)1)<<j))				return i*Dbits + j + 1;		}	}	return 0;} #if 0 // UNUSED// k, where n = 2**k * q for odd qu32intmplowbits0(mpint *n){	u32int k, bit, digit;	mpdigit d; 	assert(n->flags & MPnorm);	if(n->top==0)		return 0;	k = 0;	bit = 0;	digit = 0;	d = n->p[0];	for(;;){		if(d & (1<<bit))			break;		k++;		bit++;		if(bit==Dbits){			if(++digit >= n->top)				return 0;			d = n->p[digit];			bit = 0;		}	}	return k;}#endif

Keyboard shortcuts

General

Show keyboard shortcuts
?
Focus the current search
/

Issues and pull requests

Open filters
f

Issues, pull requests and Inbox

Select next item
j↓
Select previous item
k↑
Open selected item
Enter
Dismiss filters or clear selection
Esc

Repository code

Go to file
t