1998-12-21 10:52:47 +00:00
|
|
|
/* NOCW */
|
|
|
|
|
/* sgibug.c */
|
|
|
|
|
/* bug found by Eric Young (eay@mincom.oz.au) May 95 */
|
|
|
|
|
|
|
|
|
|
#include <stdio.h>
|
|
|
|
|
|
|
|
|
|
/* This compiler bug it present on IRIX 5.3, 5.1 and 4.0.5 (these are
|
|
|
|
|
* the only versions of IRIX I have access to.
|
|
|
|
|
* defining FIXBUG removes the bug.
|
1998-12-21 11:00:56 +00:00
|
|
|
* (bug is still present in IRIX 6.3 according to
|
|
|
|
|
* Gage <agage@forgetmenot.Mines.EDU>
|
1998-12-21 10:52:47 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/* Compare the output from
|
|
|
|
|
* cc sgiccbug.c; ./a.out
|
|
|
|
|
* and
|
|
|
|
|
* cc -O sgiccbug.c; ./a.out
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
static unsigned long a[4]={0x01234567,0x89ABCDEF,0xFEDCBA98,0x76543210};
|
|
|
|
|
static unsigned long b[4]={0x89ABCDEF,0xFEDCBA98,0x76543210,0x01234567};
|
|
|
|
|
static unsigned long c[4]={0x77777778,0x8ACF1357,0x88888888,0x7530ECA9};
|
|
|
|
|
|
|
|
|
|
main()
|
|
|
|
|
{
|
|
|
|
|
unsigned long r[4];
|
|
|
|
|
sub(r,a,b);
|
|
|
|
|
fprintf(stderr,"input a= %08X %08X %08X %08X\n",a[3],a[2],a[1],a[0]);
|
|
|
|
|
fprintf(stderr,"input b= %08X %08X %08X %08X\n",b[3],b[2],b[1],b[0]);
|
|
|
|
|
fprintf(stderr,"output = %08X %08X %08X %08X\n",r[3],r[2],r[1],r[0]);
|
|
|
|
|
fprintf(stderr,"correct= %08X %08X %08X %08X\n",c[3],c[2],c[1],c[0]);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int sub(r,a,b)
|
|
|
|
|
unsigned long *r,*a,*b;
|
|
|
|
|
{
|
|
|
|
|
register unsigned long t1,t2,*ap,*bp,*rp;
|
|
|
|
|
int i,carry;
|
|
|
|
|
#ifdef FIXBUG
|
|
|
|
|
unsigned long dummy;
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
ap=a;
|
|
|
|
|
bp=b;
|
|
|
|
|
rp=r;
|
|
|
|
|
carry=0;
|
|
|
|
|
for (i=0; i<4; i++)
|
|
|
|
|
{
|
|
|
|
|
t1= *(ap++);
|
|
|
|
|
t2= *(bp++);
|
|
|
|
|
t1=(t1-t2);
|
|
|
|
|
#ifdef FIXBUG
|
|
|
|
|
dummy=t1;
|
|
|
|
|
#endif
|
|
|
|
|
*(rp++)=t1&0xffffffff;
|
|
|
|
|
}
|
|
|
|
|
}
|
