gcc/testsuite/gcc.dg/pr11864-1.c

   1 /* PR optimization/11864
   2  * Reporter: Kazumoto Kojima <kkojima@gcc.gnu.org>
   3  * Summary: [3.3/3.4 regression] miscompiles zero extension and test
   4  * Description:
   5  * gcc-3.3/3.4 -O2 for sh target may miscompile the combination of zero extension
   6  * and test if it's zero.
   7  *
   8  * Testcase tweaked by dank@kegel.com.  Not marked as xfail because it's a regression.
   9  */
  10 /* { dg-do run } */
  11 /* { dg-options "-O2" } */
  12
  13 extern void abort(void);
  14
  15 int val = 0xff00;
  16
  17 int f(void)
  18 {
  19         return val;
  20 }
  21
  22 unsigned char a[1];
  23
  24 void foo(void)
  25 {
  26         a[0] = f() & 255;
  27
  28         if (!a[0])
  29                 a[0] = f() & 255;
  30
  31         if (!a[0])
  32                 a[0] = 1 + (f() & 127);
  33 }
  34
  35 int main(int argc, char **argv)
  36 {
  37         foo();
  38         if (!a[0])
  39                 abort();
  40
  41         return 0;
  42 }