OpenSolaris_b135/lib/libbc/libc/gen/common/_Qfutility.c
/*
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*
* The contents of this file are subject to the terms of the
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* with the License.
*
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* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
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*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
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*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Copyright (c) 1988 by Sun Microsystems, Inc.
*/
/* Utility functions for Sparc FPU simulator. */
#include "_Qquad.h"
#include "_Qglobals.h"
void
fpu_normalize(pu)
unpacked *pu;
/* Normalize a number. Does not affect zeros, infs, or NaNs. */
/* The number will be normalized to 113 bit extended:
* 0x0001####,0x########,0x########,0x########.
*/
{
unsigned u,u0,u1,u2,u3,m,n,k;
u0 = pu->significand[0];
u1 = pu->significand[1];
u2 = pu->significand[2];
u3 = pu->significand[3];
if ((*pu).fpclass == fp_normal) {
if ((u0|u1|u2|u3)==0) {
(*pu).fpclass = fp_zero;
return;
}
while (u0 == 0) {
u0 = u1; u1=u2; u2=u3; u3=0;
(*pu).exponent = (*pu).exponent - 32;
}
if (u0>=0x20000) { /* u3 should be zero */
n=1; u = u0>>1;
while(u>=0x20000) {u >>= 1; n += 1;}
m = (1<<n)-1;
k = 32-n;
(*pu).exponent += n;
u3 = ((u2&m)<<k)|(u3>>n);
u2 = ((u1&m)<<k)|(u2>>n);
u1 = ((u0&m)<<k)|(u1>>n);
u0 = u;
} else if(u0<0x10000) {
n=1; u = u0<<1;
while(u<0x10000) {u <<= 1; n += 1;}
k = 32-n;
m = -(1<<k);
(*pu).exponent -= n;
u0 = (u0<<n)|((u1&m)>>k);
u1 = (u1<<n)|((u2&m)>>k);
u2 = (u2<<n)|((u3&m)>>k);
u3 = (u3<<n);
}
pu->significand[0] = u0;
pu->significand[1] = u1;
pu->significand[2] = u2;
pu->significand[3] = u3;
}
}
void
fpu_rightshift(pu, n)
unpacked *pu;
int n;
/* Right shift significand sticky by n bits. */
{
unsigned m,k,j,u0,u1,u2,u3;
if (n > 113) { /* drastic */
if (((*pu).significand[0] | (*pu).significand[1]
| (*pu).significand[2] | (*pu).significand[3]) == 0){
/* really zero */
pu->fpclass = fp_zero;
return;
} else {
pu->rounded = 0;
pu->sticky = 1;
pu->significand[3] = 0;
pu->significand[2] = 0;
pu->significand[1] = 0;
pu->significand[0] = 0;
return;
}
}
while (n >= 32) { /* big shift */
pu->sticky |= pu->rounded | (pu->significand[3]&0x7fffffff);
pu->rounded = (*pu).significand[3]>>31;
(*pu).significand[3] = (*pu).significand[2];
(*pu).significand[2] = (*pu).significand[1];
(*pu).significand[1] = (*pu).significand[0];
(*pu).significand[0] = 0;
n -= 32;
}
if (n > 0) { /* small shift */
u0 = pu->significand[0];
u1 = pu->significand[1];
u2 = pu->significand[2];
u3 = pu->significand[3];
m = (1<<n)-1;
k = 32 - n;
j = (1<<(n-1))-1;
pu->sticky |= pu->rounded | (u3&j);
pu->rounded = (u3&m)>>(n-1);
pu->significand[3] = ((u2&m)<<k)|(u3>>n);
pu->significand[2] = ((u1&m)<<k)|(u2>>n);
pu->significand[1] = ((u0&m)<<k)|(u1>>n);
pu->significand[0] = u0>>n;
}
}
void
fpu_set_exception(ex)
enum fp_exception_type ex;
/* Set the exception bit in the current exception register. */
{
_fp_current_exceptions |= 1 << (int) ex;
}
void
fpu_error_nan(pu)
unpacked *pu;
{ /* Set invalid exception and error nan in *pu */
fpu_set_exception(fp_invalid);
pu->significand[0] = 0x7fffffff|((pu->sign)<<31);
pu->significand[1] = 0xffffffff;
pu->significand[2] = 0xffffffff;
pu->significand[3] = 0xffffffff;
}
/* the following fpu_add3wc should be inlined as
* .inline _fpu_add3wc,3
* ld [%o1],%o4 ! sum = x
* addcc -1,%o3,%g0 ! restore last carry in cc reg
* addxcc %o4,%o2,%o4 ! sum = sum + y + last carry
* st %o4,[%o0] ! *z = sum
* addx %g0,%g0,%o0 ! return new carry
* .end
*/
unsigned
fpu_add3wc(z,x,y,carry)
unsigned *z,x,y,carry;
{ /* *z = x + y + carry, set carry; */
if(carry==0) {
*z = x+y;
return (*z<y);
} else {
*z = x+y+1;
return (*z<=y);
}
}
/* the following fpu_sub3wc should be inlined as
* .inline _fpu_sub3wc,3
* ld [%o1],%o4 ! sum = *x
* addcc -1,%o3,%g0 ! restore last carry in cc reg
* subxcc %o4,%o2,%o4 ! sum = sum - y - last carry
* st %o4,[%o0] ! *x = sum
* addx %g0,%g0,%o0 ! return new carry
* .end
*/
unsigned
fpu_sub3wc(z,x,y,carry)
unsigned *z,x,y,carry;
{ /* *z = x - y - carry, set carry; */
if(carry==0) {
*z = x-y;
return (*z>x);
} else {
*z = x-y-1;
return (*z>=x);
}
}
/* the following fpu_neg2wc should be inlined as
* .inline _fpu_neg2wc,2
* ld [%o1],%o3 ! tmp = *x
* addcc -1,%o2,%g0 ! restore last carry in cc reg
* subxcc %g0,%o3,%o3 ! sum = 0 - tmp - last carry
* st %o3,[%o0] ! *x = sum
* addx %g0,%g0,%o0 ! return new carry
* .end
*/
unsigned
fpu_neg2wc(z,x,carry)
unsigned *z,x,carry;
{ /* *x = 0 - *x - carry, set carry; */
if(carry==0) {
*z = -x;
return ((*z)!=0);
} else {
*z = -x-1;
return 1;
}
}
int
fpu_cmpli(x,y,n)
unsigned x[],y[]; int n;
{ /* compare two unsigned array */
int i;
i=0;
while(i<n) {
if(x[i]>y[i]) return 1;
else if(x[i]<y[i]) return -1;
i++;
}
return 0;
}
#ifdef DEBUG
void
display_unpacked(pu)
unpacked *pu;
/* Print out unpacked record. */
{
(void) printf(" unpacked ");
if (pu->sign)
(void) printf("-");
else
(void) printf("+");
switch (pu->fpclass) {
case fp_zero:
(void) printf("0 ");
break;
case fp_normal:
(void) printf("normal");
break;
case fp_infinity:
(void) printf("Inf ");
break;
case fp_quiet:
case fp_signaling:
(void) printf("nan ");
break;
}
(void) printf(" %X %X %X %X (%X,%X) exponent %X \n",
pu->significand[0], pu->significand[1],pu->significand[2],
pu->significand[3], (pu->rounded!=0),
(pu->sticky!=0),pu->exponent);
}
#endif