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Beginner
33 Views

Bug in icc 2015.1.148???

My code:

#include <stdio.h>

int dd, dm, dy, i;
char s[32], d[5];
FILE *file;

int main() {

  file = fopen("d.txt", "r");

  for(i=0; i<5; i++) {

    fgets(s, 30, file);

    d[0]=s[0];
    d[1]=s[1];
    d[2]=0;
    dd=atoi(d);

    d[0]=s[3];
    d[1]=s[4];
    d[2]=0;
    dm=atoi(d);

    d[0]=s[6];
    d[1]=s[7];
    d[2]=s[8];
    d[3]=s[9];
    d[4]=0;
    dy=atoi(d);

    printf("%i %i %i %s", dd, dm, dy, s);

  }

  fclose(file);

}

Compiling with O1 option:

1 9 1995 01.09.1995
4 9 1995 04.09.1995
5 9 1995 05.09.1995
6 9 1995 06.09.1995
7 9 1995 07.09.1995

Compiling with O2 or O3 option:

0 9 1995 01.09.1995
995 9 1995 04.09.1995
995 9 1995 05.09.1995
995 9 1995 06.09.1995
995 9 1995 07.09.1995

WTF?

 

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2 Replies
Highlighted
Employee
33 Views

I submitted this bug to the development team (reference number DPD200365574). You can workaround the problem by compiling with -O1 or with -O2 -unroll=0 (but this turns off loop unrolling for the entire file, you can turn of unrolling for individual loops with #nounroll see this page for info: https://software.intel.com/en-us/node/524556). Thanks for reporting this.

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Highlighted
Employee
33 Views

This issue is fixed in 15.0 Update 3.

$ icc -V test.c
Intel(R) C Intel(R) 64 Compiler XE for applications running on Intel(R) 64, Version 15.0.3.187 Build 20150407
Copyright (C) 1985-2015 Intel Corporation.  All rights reserved.

Edison Design Group C/C++ Front End, version 4.8 (Apr  8 2015 01:33:53)
Copyright 1988-2013 Edison Design Group, Inc.

GNU ld version 2.20.51.0.2-5.36.el6 20100205
$ ./a.out
1 9 1995 01.09.1995
4 9 1995 04.09.1995
5 9 1995 05.09.1995
6 9 1995 06.09.1995
7 9 1995 07.09.1995

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