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