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From-SVN: r1504
This commit is contained in:
Torbjorn Granlund 1992-07-07 19:58:52 +00:00
parent ab49538861
commit 431b1ee0e0
1 changed files with 101 additions and 1 deletions
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102
gcc/libgcc2.c
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@ -92,7 +92,7 @@ typedef union
DItype ll;
} DIunion;
#if defined (L_udivmoddi4) || defined (L_muldi3)
#if defined (L_udivmoddi4) || defined (L_muldi3) || defined (L_udiv_using_sdiv)
#include "longlong.h"
@ -269,6 +269,106 @@ __muldi3 (u, v)
}
#endif
#ifdef L_udiv_using_sdiv
USItype
__udiv_using_sdiv (rp, a1, a0, d)
USItype *rp, a1, a0, d;
{
USItype q, r;
USItype c0, c1, b1;
if ((SItype) d >= 0)
{
if (a1 < d - a1 - (a0 >> 31))
{
/* dividend, divisor, and quotient are nonnegative */
sdiv_qrnnd (q, r, a1, a0, d);
}
else
{
/* Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d */
sub_ddmmss (c1, c0, a1, a0, d >> 1, d << 31);
/* Divide (c1*2^32 + c0) by d */
sdiv_qrnnd (q, r, c1, c0, d);
/* Add 2^31 to quotient */
q += 1 << 31;
}
}
else
{
b1 = d >> 1; /* d/2, between 2^30 and 2^31 - 1 */
c1 = a1 >> 1; /* A/2 */
c0 = (a1 << 31) + (a0 >> 1);
if (a1 < b1) /* A < 2^32*b1, so A/2 < 2^31*b1 */
{
sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */
r = 2*r + (a0 & 1); /* Remainder from A/(2*b1) */
if ((d & 1) != 0)
{
if (r >= q)
r = r - q;
else if (q - r <= d)
{
r = r - q + d;
q--;
}
else
{
r = r - q + 2*d;
q -= 2;
}
}
}
else if (c1 < b1) /* So 2^31 <= (A/2)/b1 < 2^32 */
{
c1 = (b1 - 1) - c1;
c0 = ~c0; /* logical NOT */
sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */
q = ~q; /* (A/2)/b1 */
r = (b1 - 1) - r;
r = 2*r + (a0 & 1); /* A/(2*b1) */
if ((d & 1) != 0)
{
if (r >= q)
r = r - q;
else if (q - r <= d)
{
r = r - q + d;
q--;
}
else
{
r = r - q + 2*d;
q -= 2;
}
}
}
else /* Implies c1 = b1 */
{ /* Hence a1 = d - 1 = 2*b1 - 1 */
if (a0 >= -d)
{
q = -1;
r = a0 + d;
}
else
{
q = -2;
r = a0 + 2*d;
}
}
}
*rp = r;
return q;
}
#endif
#ifdef L_udivmoddi4
static const UQItype __clz_tab[] =
{