icc 17.0.0 miscompiles valid C code at -Os, -O2 and -O3 on x86_64-linux-gnu

[Zhendong_Su]

Compiler version and platform: 

Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721

$ icc -O1 small.c
$ ./a.out
54
$ 
$ icc -Os small.c
$ ./a.out
55
$ 
$ cat small.c
int printf (const char *, ...);

int main ()
{
  unsigned char a = 1;
  while (a != 54)
    a += (unsigned) 3; 
  printf ("%d\n", a); 
  return 0; 
}
$ 

[Melanie_B_Intel]

Thank you for reporting this problem. I opened DPD200415454 in our internal bug tracking system. --Melanie

[Zhendong_Su]

Thank you, Melanie.