ref: a3c155704117d99f4c7486f9cf48d0a281997ff1
dir: /sys/src/ape/lib/openssl/bugs/sgiccbug.c/
/* 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.
* (bug is still present in IRIX 6.3 according to
* Gage <agage@forgetmenot.Mines.EDU>
*/
/* 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;
}
}