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45 lines
926 B
45 lines
926 B
/* NOCW */
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/* dggccbug.c */
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/* bug found by Eric Young (eay@cryptsoft.com) - May 1995 */
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#include <stdio.h>
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/* There is a bug in
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* gcc version 2.5.8 (88open OCS/BCS, DG-2.5.8.3, Oct 14 1994)
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* as shipped with DGUX 5.4R3.10 that can be bypassed by defining
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* DG_GCC_BUG in my code.
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* The bug manifests itself by the vaule of a pointer that is
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* used only by reference, not having it's value change when it is used
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* to check for exiting the loop. Probably caused by there being 2
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* copies of the valiable, one in a register and one being an address
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* that is passed. */
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/* compare the out put from
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* gcc dggccbug.c; ./a.out
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* and
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* gcc -O dggccbug.c; ./a.out
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* compile with -DFIXBUG to remove the bug when optimising.
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*/
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void inc(a)
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int *a;
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{
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(*a)++;
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}
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main()
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{
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int p=0;
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#ifdef FIXBUG
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int dummy;
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#endif
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while (p<3)
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{
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fprintf(stderr,"%08X\n",p);
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inc(&p);
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#ifdef FIXBUG
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dummy+=p;
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#endif
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}
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}
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